X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/1f0299c17dc878540bf190c290392db241b425ad..fcde7208062ce955a124c1e1d074720bf646dff6:/src/png/pngwutil.c?ds=sidebyside diff --git a/src/png/pngwutil.c b/src/png/pngwutil.c index c6ae1a677e..da18e9502e 100644 --- a/src/png/pngwutil.c +++ b/src/png/pngwutil.c @@ -1,22 +1,26 @@ /* pngwutil.c - utilities to write a PNG file * - * libpng 1.0.1 - * For conditions of distribution and use, see copyright notice in png.h - * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. - * Copyright (c) 1996, 1997 Andreas Dilger - * Copyright (c) 1998, Glenn Randers-Pehrson - * March 15, 1998 + * Last changed in libpng 1.5.6 [November 3, 2011] + * Copyright (c) 1998-2011 Glenn Randers-Pehrson + * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) + * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) + * + * This code is released under the libpng license. + * For conditions of distribution and use, see the disclaimer + * and license in png.h */ -#define PNG_INTERNAL -#include "../png/png.h" +#include "pngpriv.h" + +#ifdef PNG_WRITE_SUPPORTED +#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED /* Place a 32-bit number into a buffer in PNG byte order. We work * with unsigned numbers for convenience, although one supported * ancillary chunk uses signed (two's complement) numbers. */ -void +void PNGAPI png_save_uint_32(png_bytep buf, png_uint_32 i) { buf[0] = (png_byte)((i >> 24) & 0xff); @@ -25,12 +29,14 @@ png_save_uint_32(png_bytep buf, png_uint_32 i) buf[3] = (png_byte)(i & 0xff); } -#if defined(PNG_WRITE_pCAL_SUPPORTED) +#ifdef PNG_SAVE_INT_32_SUPPORTED /* The png_save_int_32 function assumes integers are stored in two's * complement format. If this isn't the case, then this routine needs to - * be modified to write data in two's complement format. + * be modified to write data in two's complement format. Note that, + * the following works correctly even if png_int_32 has more than 32 bits + * (compare the more complex code required on read for sign extention.) */ -void +void PNGAPI png_save_int_32(png_bytep buf, png_int_32 i) { buf[0] = (png_byte)((i >> 24) & 0xff); @@ -44,107 +50,637 @@ png_save_int_32(png_bytep buf, png_int_32 i) * The parameter is declared unsigned int, not png_uint_16, * just to avoid potential problems on pre-ANSI C compilers. */ -void +void PNGAPI png_save_uint_16(png_bytep buf, unsigned int i) { buf[0] = (png_byte)((i >> 8) & 0xff); buf[1] = (png_byte)(i & 0xff); } +#endif -/* Write a PNG chunk all at once. The type is an array of ASCII characters - * representing the chunk name. The array must be at least 4 bytes in - * length, and does not need to be null terminated. To be safe, pass the - * pre-defined chunk names here, and if you need a new one, define it - * where the others are defined. The length is the length of the data. - * All the data must be present. If that is not possible, use the - * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() - * functions instead. +/* Simple function to write the signature. If we have already written + * the magic bytes of the signature, or more likely, the PNG stream is + * being embedded into another stream and doesn't need its own signature, + * we should call png_set_sig_bytes() to tell libpng how many of the + * bytes have already been written. */ -void -png_write_chunk(png_structp png_ptr, png_bytep chunk_name, - png_bytep data, png_size_t length) +void PNGAPI +png_write_sig(png_structp png_ptr) { - png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); - png_write_chunk_data(png_ptr, data, length); - png_write_chunk_end(png_ptr); + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the signature is being written */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; +#endif + + /* Write the rest of the 8 byte signature */ + png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], + (png_size_t)(8 - png_ptr->sig_bytes)); + + if (png_ptr->sig_bytes < 3) + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; } /* Write the start of a PNG chunk. The type is the chunk type. * The total_length is the sum of the lengths of all the data you will be * passing in png_write_chunk_data(). */ -void -png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name, - png_uint_32 length) +static void +png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name, + png_uint_32 length) { - png_byte buf[4]; - png_debug2(0, "Writing %s chunk (%d bytes)\n", chunk_name, length); + png_byte buf[8]; + +#if defined(PNG_DEBUG) && (PNG_DEBUG > 0) + PNG_CSTRING_FROM_CHUNK(buf, chunk_name); + png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); +#endif + + if (png_ptr == NULL) + return; - /* write the length */ +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk header is being written. + * PNG_IO_CHUNK_HDR requires a single I/O call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; +#endif + + /* Write the length and the chunk name */ png_save_uint_32(buf, length); - png_write_data(png_ptr, buf, (png_size_t)4); + png_save_uint_32(buf + 4, chunk_name); + png_write_data(png_ptr, buf, 8); + + /* Put the chunk name into png_ptr->chunk_name */ + png_ptr->chunk_name = chunk_name; - /* write the chunk name */ - png_write_data(png_ptr, chunk_name, (png_size_t)4); - /* reset the crc and run it over the chunk name */ + /* Reset the crc and run it over the chunk name */ png_reset_crc(png_ptr); - png_calculate_crc(png_ptr, chunk_name, (png_size_t)4); + + png_calculate_crc(png_ptr, buf + 4, 4); + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that chunk data will (possibly) be written. + * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; +#endif +} + +void PNGAPI +png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string, + png_uint_32 length) +{ + png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); } -/* Write the data of a PNG chunk started with png_write_chunk_start(). +/* Write the data of a PNG chunk started with png_write_chunk_header(). * Note that multiple calls to this function are allowed, and that the * sum of the lengths from these calls *must* add up to the total_length - * given to png_write_chunk_start(). + * given to png_write_chunk_header(). */ -void -png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length) +void PNGAPI +png_write_chunk_data(png_structp png_ptr, png_const_bytep data, + png_size_t length) { - /* write the data, and run the CRC over it */ + /* Write the data, and run the CRC over it */ + if (png_ptr == NULL) + return; + if (data != NULL && length > 0) { - png_calculate_crc(png_ptr, data, length); png_write_data(png_ptr, data, length); + + /* Update the CRC after writing the data, + * in case that the user I/O routine alters it. + */ + png_calculate_crc(png_ptr, data, length); } } -/* Finish a chunk started with png_write_chunk_start(). */ -void +/* Finish a chunk started with png_write_chunk_header(). */ +void PNGAPI png_write_chunk_end(png_structp png_ptr) { png_byte buf[4]; - /* write the crc */ + if (png_ptr == NULL) return; + +#ifdef PNG_IO_STATE_SUPPORTED + /* Inform the I/O callback that the chunk CRC is being written. + * PNG_IO_CHUNK_CRC requires a single I/O function call. + */ + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; +#endif + + /* Write the crc in a single operation */ png_save_uint_32(buf, png_ptr->crc); png_write_data(png_ptr, buf, (png_size_t)4); } -/* Simple function to write the signature. If we have already written - * the magic bytes of the signature, or more likely, the PNG stream is - * being embedded into another stream and doesn't need its own signature, - * we should call png_set_sig_bytes() to tell libpng how many of the - * bytes have already been written. +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. */ -void -png_write_sig(png_structp png_ptr) +static void +png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name, + png_const_bytep data, png_size_t length) +{ + if (png_ptr == NULL) + return; + + /* On 64 bit architectures 'length' may not fit in a png_uint_32. */ + if (length > PNG_UINT_32_MAX) + png_error(png_ptr, "length exceeds PNG maxima"); + + png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, length); + png_write_chunk_end(png_ptr); +} + +/* This is the API that calls the internal function above. */ +void PNGAPI +png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string, + png_const_bytep data, png_size_t length) +{ + png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, + length); +} + +/* Initialize the compressor for the appropriate type of compression. */ +static void +png_zlib_claim(png_structp png_ptr, png_uint_32 state) +{ + if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE)) + { + /* If already initialized for 'state' do not re-init. */ + if (png_ptr->zlib_state != state) + { + int ret = Z_OK; + png_const_charp who = "-"; + + /* If actually initialized for another state do a deflateEnd. */ + if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED) + { + ret = deflateEnd(&png_ptr->zstream); + who = "end"; + png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; + } + + /* zlib itself detects an incomplete state on deflateEnd */ + if (ret == Z_OK) switch (state) + { +# ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED + case PNG_ZLIB_FOR_TEXT: + ret = deflateInit2(&png_ptr->zstream, + png_ptr->zlib_text_level, png_ptr->zlib_text_method, + png_ptr->zlib_text_window_bits, + png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy); + who = "text"; + break; +# endif + + case PNG_ZLIB_FOR_IDAT: + ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, + png_ptr->zlib_method, png_ptr->zlib_window_bits, + png_ptr->zlib_mem_level, png_ptr->zlib_strategy); + who = "IDAT"; + break; + + default: + png_error(png_ptr, "invalid zlib state"); + } + + if (ret == Z_OK) + png_ptr->zlib_state = state; + + else /* an error in deflateEnd or deflateInit2 */ + { + size_t pos = 0; + char msg[64]; + + pos = png_safecat(msg, sizeof msg, pos, + "zlib failed to initialize compressor ("); + pos = png_safecat(msg, sizeof msg, pos, who); + + switch (ret) + { + case Z_VERSION_ERROR: + pos = png_safecat(msg, sizeof msg, pos, ") version error"); + break; + + case Z_STREAM_ERROR: + pos = png_safecat(msg, sizeof msg, pos, ") stream error"); + break; + + case Z_MEM_ERROR: + pos = png_safecat(msg, sizeof msg, pos, ") memory error"); + break; + + default: + pos = png_safecat(msg, sizeof msg, pos, ") unknown error"); + break; + } + + png_error(png_ptr, msg); + } + } + + /* Here on success, claim the zstream: */ + png_ptr->zlib_state |= PNG_ZLIB_IN_USE; + } + + else + png_error(png_ptr, "zstream already in use (internal error)"); +} + +/* The opposite: release the stream. It is also reset, this API will warn on + * error but will not fail. + */ +static void +png_zlib_release(png_structp png_ptr) +{ + if (png_ptr->zlib_state & PNG_ZLIB_IN_USE) + { + int ret = deflateReset(&png_ptr->zstream); + + png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE; + + if (ret != Z_OK) + { + png_const_charp err; + PNG_WARNING_PARAMETERS(p) + + switch (ret) + { + case Z_VERSION_ERROR: + err = "version"; + break; + + case Z_STREAM_ERROR: + err = "stream"; + break; + + case Z_MEM_ERROR: + err = "memory"; + break; + + default: + err = "unknown"; + break; + } + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret); + png_warning_parameter(p, 2, err); + + if (png_ptr->zstream.msg) + err = png_ptr->zstream.msg; + else + err = "[no zlib message]"; + + png_warning_parameter(p, 3, err); + + png_formatted_warning(png_ptr, p, + "zlib failed to reset compressor: @1(@2): @3"); + } + } + + else + png_warning(png_ptr, "zstream not in use (internal error)"); +} + +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +/* This pair of functions encapsulates the operation of (a) compressing a + * text string, and (b) issuing it later as a series of chunk data writes. + * The compression_state structure is shared context for these functions + * set up by the caller in order to make the whole mess thread-safe. + */ + +typedef struct +{ + png_const_bytep input; /* The uncompressed input data */ + png_size_t input_len; /* Its length */ + int num_output_ptr; /* Number of output pointers used */ + int max_output_ptr; /* Size of output_ptr */ + png_bytep *output_ptr; /* Array of pointers to output */ +} compression_state; + +/* Compress given text into storage in the png_ptr structure */ +static int /* PRIVATE */ +png_text_compress(png_structp png_ptr, + png_const_charp text, png_size_t text_len, int compression, + compression_state *comp) +{ + int ret; + + comp->num_output_ptr = 0; + comp->max_output_ptr = 0; + comp->output_ptr = NULL; + comp->input = NULL; + comp->input_len = text_len; + + /* We may just want to pass the text right through */ + if (compression == PNG_TEXT_COMPRESSION_NONE) + { + comp->input = (png_const_bytep)text; + return((int)text_len); + } + + if (compression >= PNG_TEXT_COMPRESSION_LAST) + { + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, + compression); + png_formatted_warning(png_ptr, p, "Unknown compression type @1"); + } + + /* We can't write the chunk until we find out how much data we have, + * which means we need to run the compressor first and save the + * output. This shouldn't be a problem, as the vast majority of + * comments should be reasonable, but we will set up an array of + * malloc'd pointers to be sure. + * + * If we knew the application was well behaved, we could simplify this + * greatly by assuming we can always malloc an output buffer large + * enough to hold the compressed text ((1001 * text_len / 1000) + 12) + * and malloc this directly. The only time this would be a bad idea is + * if we can't malloc more than 64K and we have 64K of random input + * data, or if the input string is incredibly large (although this + * wouldn't cause a failure, just a slowdown due to swapping). + */ + png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT); + + /* Set up the compression buffers */ + /* TODO: the following cast hides a potential overflow problem. */ + png_ptr->zstream.avail_in = (uInt)text_len; + + /* NOTE: assume zlib doesn't overwrite the input */ + png_ptr->zstream.next_in = (Bytef *)text; + png_ptr->zstream.avail_out = png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + + /* This is the same compression loop as in png_write_row() */ + do + { + /* Compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + + if (ret != Z_OK) + { + /* Error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + /* Make sure the output array has room */ + if (comp->num_output_ptr >= comp->max_output_ptr) + { + int old_max; + + old_max = comp->max_output_ptr; + comp->max_output_ptr = comp->num_output_ptr + 4; + if (comp->output_ptr != NULL) + { + png_bytepp old_ptr; + + old_ptr = comp->output_ptr; + + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t) + (comp->max_output_ptr * png_sizeof(png_charpp))); + + png_memcpy(comp->output_ptr, old_ptr, old_max + * png_sizeof(png_charp)); + + png_free(png_ptr, old_ptr); + } + else + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t) + (comp->max_output_ptr * png_sizeof(png_charp))); + } + + /* Save the data */ + comp->output_ptr[comp->num_output_ptr] = + (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)png_ptr->zbuf_size); + + png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + + comp->num_output_ptr++; + + /* and reset the buffer */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + /* Continue until we don't have any more to compress */ + } while (png_ptr->zstream.avail_in); + + /* Finish the compression */ + do + { + /* Tell zlib we are finished */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + + if (ret == Z_OK) + { + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + /* Check to make sure our output array has room */ + if (comp->num_output_ptr >= comp->max_output_ptr) + { + int old_max; + + old_max = comp->max_output_ptr; + comp->max_output_ptr = comp->num_output_ptr + 4; + if (comp->output_ptr != NULL) + { + png_bytepp old_ptr; + + old_ptr = comp->output_ptr; + + /* This could be optimized to realloc() */ + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t)(comp->max_output_ptr * + png_sizeof(png_charp))); + + png_memcpy(comp->output_ptr, old_ptr, + old_max * png_sizeof(png_charp)); + + png_free(png_ptr, old_ptr); + } + + else + comp->output_ptr = (png_bytepp)png_malloc(png_ptr, + (png_alloc_size_t)(comp->max_output_ptr * + png_sizeof(png_charp))); + } + + /* Save the data */ + comp->output_ptr[comp->num_output_ptr] = + (png_bytep)png_malloc(png_ptr, + (png_alloc_size_t)png_ptr->zbuf_size); + + png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + + comp->num_output_ptr++; + + /* and reset the buffer pointers */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + } + else if (ret != Z_STREAM_END) + { + /* We got an error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + + else + png_error(png_ptr, "zlib error"); + } + } while (ret != Z_STREAM_END); + + /* Text length is number of buffers plus last buffer */ + text_len = png_ptr->zbuf_size * comp->num_output_ptr; + + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; + + return((int)text_len); +} + +/* Ship the compressed text out via chunk writes */ +static void /* PRIVATE */ +png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) { - /* write the rest of the 8 byte signature */ - png_write_data(png_ptr, &png_sig[png_ptr->sig_bytes], - (png_size_t)8 - png_ptr->sig_bytes); + int i; + + /* Handle the no-compression case */ + if (comp->input) + { + png_write_chunk_data(png_ptr, comp->input, comp->input_len); + + return; + } + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* The zbuf_size test is because the code below doesn't work if zbuf_size is + * '1'; simply skip it to avoid memory overwrite. + */ + if (comp->input_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1) + { + unsigned int z_cmf; /* zlib compression method and flags */ + + /* Optimize the CMF field in the zlib stream. This hack of the zlib + * stream is compliant to the stream specification. + */ + + if (comp->num_output_ptr) + z_cmf = comp->output_ptr[0][0]; + else + z_cmf = png_ptr->zbuf[0]; + + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + unsigned int z_cinfo; + unsigned int half_z_window_size; + png_size_t uncompressed_text_size = comp->input_len; + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1 << (z_cinfo + 7); + + while (uncompressed_text_size <= half_z_window_size && + half_z_window_size >= 256) + { + z_cinfo--; + half_z_window_size >>= 1; + } + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + if (comp->num_output_ptr) + { + + if (comp->output_ptr[0][0] != z_cmf) + { + int tmp; + + comp->output_ptr[0][0] = (png_byte)z_cmf; + tmp = comp->output_ptr[0][1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + comp->output_ptr[0][1] = (png_byte)tmp; + } + } + else + { + int tmp; + + png_ptr->zbuf[0] = (png_byte)z_cmf; + tmp = png_ptr->zbuf[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + png_ptr->zbuf[1] = (png_byte)tmp; + } + } + + else + png_error(png_ptr, + "Invalid zlib compression method or flags in non-IDAT chunk"); + } +#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ + + /* Write saved output buffers, if any */ + for (i = 0; i < comp->num_output_ptr; i++) + { + png_write_chunk_data(png_ptr, comp->output_ptr[i], + (png_size_t)png_ptr->zbuf_size); + + png_free(png_ptr, comp->output_ptr[i]); + } + + if (comp->max_output_ptr != 0) + png_free(png_ptr, comp->output_ptr); + + /* Write anything left in zbuf */ + if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) + png_write_chunk_data(png_ptr, png_ptr->zbuf, + (png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); + + /* Reset zlib for another zTXt/iTXt or image data */ + png_zlib_release(png_ptr); } +#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ /* Write the IHDR chunk, and update the png_struct with the necessary * information. Note that the rest of this code depends upon this * information being correct. */ -void +void /* PRIVATE */ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, - int bit_depth, int color_type, int compression_type, int filter_type, - int interlace_type) + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type) { - png_byte buf[13]; /* buffer to store the IHDR info */ + png_byte buf[13]; /* Buffer to store the IHDR info */ + + png_debug(1, "in png_write_IHDR"); - png_debug(1, "in png_write_IHDR\n"); /* Check that we have valid input data from the application info */ switch (color_type) { @@ -155,35 +691,61 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, case 2: case 4: case 8: - case 16: png_ptr->channels = 1; break; - default: png_error(png_ptr,"Invalid bit depth for grayscale image"); +#ifdef PNG_WRITE_16BIT_SUPPORTED + case 16: +#endif + png_ptr->channels = 1; break; + + default: + png_error(png_ptr, + "Invalid bit depth for grayscale image"); } break; + case PNG_COLOR_TYPE_RGB: +#ifdef PNG_WRITE_16BIT_SUPPORTED if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif png_error(png_ptr, "Invalid bit depth for RGB image"); + png_ptr->channels = 3; break; + case PNG_COLOR_TYPE_PALETTE: switch (bit_depth) { case 1: case 2: case 4: - case 8: png_ptr->channels = 1; break; - default: png_error(png_ptr, "Invalid bit depth for paletted image"); + case 8: + png_ptr->channels = 1; + break; + + default: + png_error(png_ptr, "Invalid bit depth for paletted image"); } break; + case PNG_COLOR_TYPE_GRAY_ALPHA: if (bit_depth != 8 && bit_depth != 16) png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); + png_ptr->channels = 2; break; + case PNG_COLOR_TYPE_RGB_ALPHA: +#ifdef PNG_WRITE_16BIT_SUPPORTED if (bit_depth != 8 && bit_depth != 16) +#else + if (bit_depth != 8) +#endif png_error(png_ptr, "Invalid bit depth for RGBA image"); + png_ptr->channels = 4; break; + default: png_error(png_ptr, "Invalid image color type specified"); } @@ -194,7 +756,24 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, compression_type = PNG_COMPRESSION_TYPE_BASE; } - if (filter_type != PNG_FILTER_TYPE_BASE) + /* Write filter_method 64 (intrapixel differencing) only if + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and + * 2. Libpng did not write a PNG signature (this filter_method is only + * used in PNG datastreams that are embedded in MNG datastreams) and + * 3. The application called png_permit_mng_features with a mask that + * included PNG_FLAG_MNG_FILTER_64 and + * 4. The filter_method is 64 and + * 5. The color_type is RGB or RGBA + */ + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && + ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && + (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && + (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && +#endif + filter_type != PNG_FILTER_TYPE_BASE) { png_warning(png_ptr, "Invalid filter type specified"); filter_type = PNG_FILTER_TYPE_BASE; @@ -202,7 +781,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, #ifdef PNG_WRITE_INTERLACING_SUPPORTED if (interlace_type != PNG_INTERLACE_NONE && - interlace_type != PNG_INTERLACE_ADAM7) + interlace_type != PNG_INTERLACE_ADAM7) { png_warning(png_ptr, "Invalid interlace type specified"); interlace_type = PNG_INTERLACE_ADAM7; @@ -211,21 +790,25 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, interlace_type=PNG_INTERLACE_NONE; #endif - /* save off the relevent information */ + /* Save the relevent information */ png_ptr->bit_depth = (png_byte)bit_depth; png_ptr->color_type = (png_byte)color_type; png_ptr->interlaced = (png_byte)interlace_type; +#ifdef PNG_MNG_FEATURES_SUPPORTED + png_ptr->filter_type = (png_byte)filter_type; +#endif + png_ptr->compression_type = (png_byte)compression_type; png_ptr->width = width; png_ptr->height = height; png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); - png_ptr->rowbytes = ((width * (png_size_t)png_ptr->pixel_depth + 7) >> 3); - /* set the usr info, so any transformations can modify it */ + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); + /* Set the usr info, so any transformations can modify it */ png_ptr->usr_width = png_ptr->width; png_ptr->usr_bit_depth = png_ptr->bit_depth; png_ptr->usr_channels = png_ptr->channels; - /* pack the header information into the buffer */ + /* Pack the header information into the buffer */ png_save_uint_32(buf, width); png_save_uint_32(buf + 4, height); buf[8] = (png_byte)bit_depth; @@ -234,63 +817,101 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, buf[11] = (png_byte)filter_type; buf[12] = (png_byte)interlace_type; - /* write the chunk */ - png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); + /* Write the chunk */ + png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); - /* initialize zlib with PNG info */ + /* Initialize zlib with PNG info */ png_ptr->zstream.zalloc = png_zalloc; png_ptr->zstream.zfree = png_zfree; png_ptr->zstream.opaque = (voidpf)png_ptr; + if (!(png_ptr->do_filter)) { if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || - png_ptr->bit_depth < 8) + png_ptr->bit_depth < 8) png_ptr->do_filter = PNG_FILTER_NONE; + else png_ptr->do_filter = PNG_ALL_FILTERS; } + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) { if (png_ptr->do_filter != PNG_FILTER_NONE) png_ptr->zlib_strategy = Z_FILTERED; + else png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; } + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) png_ptr->zlib_mem_level = 8; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) png_ptr->zlib_window_bits = 15; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) png_ptr->zlib_method = 8; - deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, - png_ptr->zlib_method, png_ptr->zlib_window_bits, - png_ptr->zlib_mem_level, png_ptr->zlib_strategy); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->mode = PNG_HAVE_IHDR; +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY)) + png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; + + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL)) + png_ptr->zlib_text_level = png_ptr->zlib_level; + + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL)) + png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; + + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS)) + png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; + + if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD)) + png_ptr->zlib_text_method = png_ptr->zlib_method; +#else + png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; + png_ptr->zlib_text_level = png_ptr->zlib_level; + png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; + png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; + png_ptr->zlib_text_method = png_ptr->zlib_method; +#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ +#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ + + /* Record that the compressor has not yet been initialized. */ + png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; + + png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ } -/* write the palette. We are careful not to trust png_color to be in the - * correct order for PNG, so people can redefine it to any convient +/* Write the palette. We are careful not to trust png_color to be in the + * correct order for PNG, so people can redefine it to any convenient * structure. */ -void -png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal) +void /* PRIVATE */ +png_write_PLTE(png_structp png_ptr, png_const_colorp palette, + png_uint_32 num_pal) { png_uint_32 i; - png_colorp pal_ptr; + png_const_colorp pal_ptr; png_byte buf[3]; - png_debug(1, "in png_write_PLTE\n"); - if (num_pal == 0 || num_pal > 256) + png_debug(1, "in png_write_PLTE"); + + if (( +#ifdef PNG_MNG_FEATURES_SUPPORTED + !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && +#endif + num_pal == 0) || num_pal > 256) { if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) { png_error(png_ptr, "Invalid number of colors in palette"); } + else { png_warning(png_ptr, "Invalid number of colors in palette"); @@ -298,10 +919,20 @@ png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal) } } + if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) + { + png_warning(png_ptr, + "Ignoring request to write a PLTE chunk in grayscale PNG"); + + return; + } + png_ptr->num_palette = (png_uint_16)num_pal; - png_debug1(3, "num_palette = %d\n", png_ptr->num_palette); + png_debug1(3, "num_palette = %d", png_ptr->num_palette); + + png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); +#ifdef PNG_POINTER_INDEXING_SUPPORTED - png_write_chunk_start(png_ptr, png_PLTE, num_pal * 3); for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) { buf[0] = pal_ptr->red; @@ -309,87 +940,355 @@ png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal) buf[2] = pal_ptr->blue; png_write_chunk_data(png_ptr, buf, (png_size_t)3); } + +#else + /* This is a little slower but some buggy compilers need to do this + * instead + */ + pal_ptr=palette; + + for (i = 0; i < num_pal; i++) + { + buf[0] = pal_ptr[i].red; + buf[1] = pal_ptr[i].green; + buf[2] = pal_ptr[i].blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + +#endif png_write_chunk_end(png_ptr); png_ptr->mode |= PNG_HAVE_PLTE; } -/* write an IDAT chunk */ -void +/* Write an IDAT chunk */ +void /* PRIVATE */ png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) { - png_debug(1, "in png_write_IDAT\n"); - png_write_chunk(png_ptr, png_IDAT, data, length); + png_debug(1, "in png_write_IDAT"); + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if (!(png_ptr->mode & PNG_HAVE_IDAT) && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + { + /* Optimize the CMF field in the zlib stream. This hack of the zlib + * stream is compliant to the stream specification. + */ + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + /* Avoid memory underflows and multiplication overflows. + * + * The conditions below are practically always satisfied; + * however, they still must be checked. + */ + if (length >= 2 && + png_ptr->height < 16384 && png_ptr->width < 16384) + { + /* Compute the maximum possible length of the datastream */ + + /* Number of pixels, plus for each row a filter byte + * and possibly a padding byte, so increase the maximum + * size to account for these. + */ + unsigned int z_cinfo; + unsigned int half_z_window_size; + png_uint_32 uncompressed_idat_size = png_ptr->height * + ((png_ptr->width * + png_ptr->channels * png_ptr->bit_depth + 15) >> 3); + + /* If it's interlaced, each block of 8 rows is sent as up to + * 14 rows, i.e., 6 additional rows, each with a filter byte + * and possibly a padding byte + */ + if (png_ptr->interlaced) + uncompressed_idat_size += ((png_ptr->height + 7)/8) * + (png_ptr->bit_depth < 8 ? 12 : 6); + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1 << (z_cinfo + 7); + + while (uncompressed_idat_size <= half_z_window_size && + half_z_window_size >= 256) + { + z_cinfo--; + half_z_window_size >>= 1; + } + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + if (data[0] != z_cmf) + { + int tmp; + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; + } + } + } + + else + png_error(png_ptr, + "Invalid zlib compression method or flags in IDAT"); + } +#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ + + png_write_complete_chunk(png_ptr, png_IDAT, data, length); png_ptr->mode |= PNG_HAVE_IDAT; + + /* Prior to 1.5.4 this code was replicated in every caller (except at the + * end, where it isn't technically necessary). Since this function has + * flushed the data we can safely reset the zlib output buffer here. + */ + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; } -/* write an IEND chunk */ -void +/* Write an IEND chunk */ +void /* PRIVATE */ png_write_IEND(png_structp png_ptr) { - png_debug(1, "in png_write_IEND\n"); - png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); + png_debug(1, "in png_write_IEND"); + + png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); png_ptr->mode |= PNG_HAVE_IEND; } -#if defined(PNG_WRITE_gAMA_SUPPORTED) -/* write a gAMA chunk */ -void -png_write_gAMA(png_structp png_ptr, double file_gamma) +#ifdef PNG_WRITE_gAMA_SUPPORTED +/* Write a gAMA chunk */ +void /* PRIVATE */ +png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) { - png_uint_32 igamma; png_byte buf[4]; - png_debug(1, "in png_write_gAMA\n"); - /* file_gamma is saved in 1/1000000ths */ - igamma = (png_uint_32)(file_gamma * 100000.0 + 0.5); - png_save_uint_32(buf, igamma); - png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); + png_debug(1, "in png_write_gAMA"); + + /* file_gamma is saved in 1/100,000ths */ + png_save_uint_32(buf, (png_uint_32)file_gamma); + png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); } #endif -#if defined(PNG_WRITE_sRGB_SUPPORTED) -/* write a sRGB chunk */ -void +#ifdef PNG_WRITE_sRGB_SUPPORTED +/* Write a sRGB chunk */ +void /* PRIVATE */ png_write_sRGB(png_structp png_ptr, int srgb_intent) { png_byte buf[1]; - png_debug(1, "in png_write_sRGB\n"); - if(srgb_intent >= PNG_sRGB_INTENT_LAST) - png_warning(png_ptr, - "Invalid sRGB rendering intent specified"); + png_debug(1, "in png_write_sRGB"); + + if (srgb_intent >= PNG_sRGB_INTENT_LAST) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + buf[0]=(png_byte)srgb_intent; - png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); + png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); +} +#endif + +#ifdef PNG_WRITE_iCCP_SUPPORTED +/* Write an iCCP chunk */ +void /* PRIVATE */ +png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, + png_const_charp profile, int profile_len) +{ + png_size_t name_len; + png_charp new_name; + compression_state comp; + int embedded_profile_len = 0; + + png_debug(1, "in png_write_iCCP"); + + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + comp.input_len = 0; + + if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0) + return; + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + png_warning(png_ptr, "Unknown compression type in iCCP chunk"); + + if (profile == NULL) + profile_len = 0; + + if (profile_len > 3) + embedded_profile_len = + ((*( (png_const_bytep)profile ))<<24) | + ((*( (png_const_bytep)profile + 1))<<16) | + ((*( (png_const_bytep)profile + 2))<< 8) | + ((*( (png_const_bytep)profile + 3)) ); + + if (embedded_profile_len < 0) + { + png_warning(png_ptr, + "Embedded profile length in iCCP chunk is negative"); + + png_free(png_ptr, new_name); + return; + } + + if (profile_len < embedded_profile_len) + { + png_warning(png_ptr, + "Embedded profile length too large in iCCP chunk"); + + png_free(png_ptr, new_name); + return; + } + + if (profile_len > embedded_profile_len) + { + png_warning(png_ptr, + "Truncating profile to actual length in iCCP chunk"); + + profile_len = embedded_profile_len; + } + + if (profile_len) + profile_len = png_text_compress(png_ptr, profile, + (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); + + /* Make sure we include the NULL after the name and the compression type */ + png_write_chunk_header(png_ptr, png_iCCP, + (png_uint_32)(name_len + profile_len + 2)); + + new_name[name_len + 1] = 0x00; + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 2)); + + if (profile_len) + { + comp.input_len = profile_len; + png_write_compressed_data_out(png_ptr, &comp); + } + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_name); +} +#endif + +#ifdef PNG_WRITE_sPLT_SUPPORTED +/* Write a sPLT chunk */ +void /* PRIVATE */ +png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) +{ + png_size_t name_len; + png_charp new_name; + png_byte entrybuf[10]; + png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); + png_size_t palette_size = entry_size * spalette->nentries; + png_sPLT_entryp ep; +#ifndef PNG_POINTER_INDEXING_SUPPORTED + int i; +#endif + + png_debug(1, "in png_write_sPLT"); + + if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) + return; + + /* Make sure we include the NULL after the name */ + png_write_chunk_header(png_ptr, png_sPLT, + (png_uint_32)(name_len + 2 + palette_size)); + + png_write_chunk_data(png_ptr, (png_bytep)new_name, + (png_size_t)(name_len + 1)); + + png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); + + /* Loop through each palette entry, writing appropriately */ +#ifdef PNG_POINTER_INDEXING_SUPPORTED + for (ep = spalette->entries; epentries + spalette->nentries; ep++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep->red; + entrybuf[1] = (png_byte)ep->green; + entrybuf[2] = (png_byte)ep->blue; + entrybuf[3] = (png_byte)ep->alpha; + png_save_uint_16(entrybuf + 4, ep->frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep->red); + png_save_uint_16(entrybuf + 2, ep->green); + png_save_uint_16(entrybuf + 4, ep->blue); + png_save_uint_16(entrybuf + 6, ep->alpha); + png_save_uint_16(entrybuf + 8, ep->frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + } +#else + ep=spalette->entries; + for (i = 0; i>spalette->nentries; i++) + { + if (spalette->depth == 8) + { + entrybuf[0] = (png_byte)ep[i].red; + entrybuf[1] = (png_byte)ep[i].green; + entrybuf[2] = (png_byte)ep[i].blue; + entrybuf[3] = (png_byte)ep[i].alpha; + png_save_uint_16(entrybuf + 4, ep[i].frequency); + } + + else + { + png_save_uint_16(entrybuf + 0, ep[i].red); + png_save_uint_16(entrybuf + 2, ep[i].green); + png_save_uint_16(entrybuf + 4, ep[i].blue); + png_save_uint_16(entrybuf + 6, ep[i].alpha); + png_save_uint_16(entrybuf + 8, ep[i].frequency); + } + + png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + } +#endif + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_name); } #endif -#if defined(PNG_WRITE_sBIT_SUPPORTED) -/* write the sBIT chunk */ -void -png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type) +#ifdef PNG_WRITE_sBIT_SUPPORTED +/* Write the sBIT chunk */ +void /* PRIVATE */ +png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) { png_byte buf[4]; png_size_t size; - png_debug(1, "in png_write_sBIT\n"); - /* make sure we don't depend upon the order of PNG_COLOR_8 */ + png_debug(1, "in png_write_sBIT"); + + /* Make sure we don't depend upon the order of PNG_COLOR_8 */ if (color_type & PNG_COLOR_MASK_COLOR) { png_byte maxbits; - maxbits = color_type==PNG_COLOR_TYPE_PALETTE ? 8:png_ptr->usr_bit_depth; - if (sbit->red == 0 || sbit->red > maxbits || - sbit->green == 0 || sbit->green > maxbits || + maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : + png_ptr->usr_bit_depth); + + if (sbit->red == 0 || sbit->red > maxbits || + sbit->green == 0 || sbit->green > maxbits || sbit->blue == 0 || sbit->blue > maxbits) { png_warning(png_ptr, "Invalid sBIT depth specified"); return; } + buf[0] = sbit->red; buf[1] = sbit->green; buf[2] = sbit->blue; size = 3; } + else { if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) @@ -397,6 +1296,7 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type) png_warning(png_ptr, "Invalid sBIT depth specified"); return; } + buf[0] = sbit->gray; size = 1; } @@ -408,106 +1308,106 @@ png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type) png_warning(png_ptr, "Invalid sBIT depth specified"); return; } + buf[size++] = sbit->alpha; } - png_write_chunk(png_ptr, png_sBIT, buf, size); + png_write_complete_chunk(png_ptr, png_sBIT, buf, size); } #endif -#if defined(PNG_WRITE_cHRM_SUPPORTED) -/* write the cHRM chunk */ -void -png_write_cHRM(png_structp png_ptr, double white_x, double white_y, - double red_x, double red_y, double green_x, double green_y, - double blue_x, double blue_y) +#ifdef PNG_WRITE_cHRM_SUPPORTED +/* Write the cHRM chunk */ +void /* PRIVATE */ +png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, + png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, + png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, + png_fixed_point blue_y) { - png_uint_32 itemp; png_byte buf[32]; - png_debug(1, "in png_write_cHRM\n"); - /* each value is saved int 1/1000000ths */ - if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 || - white_x + white_y > 1.0) - { - png_warning(png_ptr, "Invalid cHRM white point specified"); - return; - } - itemp = (png_uint_32)(white_x * 100000.0 + 0.5); - png_save_uint_32(buf, itemp); - itemp = (png_uint_32)(white_y * 100000.0 + 0.5); - png_save_uint_32(buf + 4, itemp); + png_debug(1, "in png_write_cHRM"); - if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 || - red_x + red_y > 1.0) + /* Each value is saved in 1/100,000ths */ +#ifdef PNG_CHECK_cHRM_SUPPORTED + if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, + green_x, green_y, blue_x, blue_y)) +#endif { - png_warning(png_ptr, "Invalid cHRM red point specified"); - return; - } - itemp = (png_uint_32)(red_x * 100000.0 + 0.5); - png_save_uint_32(buf + 8, itemp); - itemp = (png_uint_32)(red_y * 100000.0 + 0.5); - png_save_uint_32(buf + 12, itemp); + png_save_uint_32(buf, (png_uint_32)white_x); + png_save_uint_32(buf + 4, (png_uint_32)white_y); - if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 || - green_x + green_y > 1.0) - { - png_warning(png_ptr, "Invalid cHRM green point specified"); - return; - } - itemp = (png_uint_32)(green_x * 100000.0 + 0.5); - png_save_uint_32(buf + 16, itemp); - itemp = (png_uint_32)(green_y * 100000.0 + 0.5); - png_save_uint_32(buf + 20, itemp); + png_save_uint_32(buf + 8, (png_uint_32)red_x); + png_save_uint_32(buf + 12, (png_uint_32)red_y); - if (blue_x < 0 || blue_x > 0.8 || blue_y < 0 || blue_y > 0.8 || - blue_x + blue_y > 1.0) - { - png_warning(png_ptr, "Invalid cHRM blue point specified"); - return; - } - itemp = (png_uint_32)(blue_x * 100000.0 + 0.5); - png_save_uint_32(buf + 24, itemp); - itemp = (png_uint_32)(blue_y * 100000.0 + 0.5); - png_save_uint_32(buf + 28, itemp); + png_save_uint_32(buf + 16, (png_uint_32)green_x); + png_save_uint_32(buf + 20, (png_uint_32)green_y); - png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); + png_save_uint_32(buf + 24, (png_uint_32)blue_x); + png_save_uint_32(buf + 28, (png_uint_32)blue_y); + + png_write_complete_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); + } } #endif -#if defined(PNG_WRITE_tRNS_SUPPORTED) -/* write the tRNS chunk */ -void -png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran, - int num_trans, int color_type) +#ifdef PNG_WRITE_tRNS_SUPPORTED +/* Write the tRNS chunk */ +void /* PRIVATE */ +png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, + png_const_color_16p tran, int num_trans, int color_type) { png_byte buf[6]; - png_debug(1, "in png_write_tRNS\n"); + png_debug(1, "in png_write_tRNS"); + if (color_type == PNG_COLOR_TYPE_PALETTE) { if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) { - png_warning(png_ptr,"Invalid number of transparent colors specified"); + png_warning(png_ptr, "Invalid number of transparent colors specified"); return; } - /* write the chunk out as it is */ - png_write_chunk(png_ptr, png_tRNS, trans, (png_size_t)num_trans); + + /* Write the chunk out as it is */ + png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, (png_size_t)num_trans); } + else if (color_type == PNG_COLOR_TYPE_GRAY) { - /* one 16 bit value */ + /* One 16 bit value */ + if (tran->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); + + return; + } + png_save_uint_16(buf, tran->gray); - png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); } + else if (color_type == PNG_COLOR_TYPE_RGB) { - /* three 16 bit values */ + /* Three 16 bit values */ png_save_uint_16(buf, tran->red); png_save_uint_16(buf + 2, tran->green); png_save_uint_16(buf + 4, tran->blue); - png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) +#else + if (buf[0] | buf[2] | buf[4]) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); + return; + } + + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); } + else { png_warning(png_ptr, "Can't write tRNS with an alpha channel"); @@ -515,67 +1415,101 @@ png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran, } #endif -#if defined(PNG_WRITE_bKGD_SUPPORTED) -/* write the background chunk */ -void -png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type) +#ifdef PNG_WRITE_bKGD_SUPPORTED +/* Write the background chunk */ +void /* PRIVATE */ +png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) { png_byte buf[6]; - png_debug(1, "in png_write_bKGD\n"); + png_debug(1, "in png_write_bKGD"); + if (color_type == PNG_COLOR_TYPE_PALETTE) { - if (back->index > png_ptr->num_palette) + if ( +#ifdef PNG_MNG_FEATURES_SUPPORTED + (png_ptr->num_palette || + (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && +#endif + back->index >= png_ptr->num_palette) { png_warning(png_ptr, "Invalid background palette index"); return; } + buf[0] = back->index; - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); } + else if (color_type & PNG_COLOR_MASK_COLOR) { png_save_uint_16(buf, back->red); png_save_uint_16(buf + 2, back->green); png_save_uint_16(buf + 4, back->blue); - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) +#else + if (buf[0] | buf[2] | buf[4]) +#endif + { + png_warning(png_ptr, + "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); + + return; + } + + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); } + else { + if (back->gray >= (1 << png_ptr->bit_depth)) + { + png_warning(png_ptr, + "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); + + return; + } + png_save_uint_16(buf, back->gray); - png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); } } #endif -#if defined(PNG_WRITE_hIST_SUPPORTED) -/* write the histogram */ -void -png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist) +#ifdef PNG_WRITE_hIST_SUPPORTED +/* Write the histogram */ +void /* PRIVATE */ +png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) { int i; png_byte buf[3]; - png_debug(1, "in png_write_hIST\n"); + png_debug(1, "in png_write_hIST"); + if (num_hist > (int)png_ptr->num_palette) { - png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist, - png_ptr->num_palette); + png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, + png_ptr->num_palette); + png_warning(png_ptr, "Invalid number of histogram entries specified"); return; } - png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + for (i = 0; i < num_hist; i++) { png_save_uint_16(buf, hist[i]); png_write_chunk_data(png_ptr, buf, (png_size_t)2); } + png_write_chunk_end(png_ptr); } #endif -#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) +#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ + defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) /* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, * and if invalid, correct the keyword rather than discarding the entire * chunk. The PNG 1.0 specification requires keywords 1-79 characters in @@ -586,44 +1520,52 @@ png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist) * by the calling routine. This avoids problems with trying to write to * static keywords without having to have duplicate copies of the strings. */ -png_size_t -png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) +png_size_t /* PRIVATE */ +png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) { png_size_t key_len; + png_const_charp ikp; png_charp kp, dp; int kflag; + int kwarn=0; + + png_debug(1, "in png_check_keyword"); - png_debug(1, "in png_check_keyword\n"); *new_key = NULL; if (key == NULL || (key_len = png_strlen(key)) == 0) { - png_chunk_warning(png_ptr, "zero length keyword"); + png_warning(png_ptr, "zero length keyword"); return ((png_size_t)0); } - png_debug1(2, "Keyword to be checked is '%s'\n", key); + png_debug1(2, "Keyword to be checked is '%s'", key); - *new_key = (png_charp)png_malloc(png_ptr, (png_uint_32)(key_len + 1)); + *new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); + + if (*new_key == NULL) + { + png_warning(png_ptr, "Out of memory while procesing keyword"); + return ((png_size_t)0); + } /* Replace non-printing characters with a blank and print a warning */ - for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++) + for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++) { - if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1)) + if ((png_byte)*ikp < 0x20 || + ((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) { -#if !defined(PNG_NO_STDIO) - char msg[40]; + PNG_WARNING_PARAMETERS(p) - sprintf(msg, "invalid keyword character 0x%02X", *kp); - png_chunk_warning(png_ptr, msg); -#else - png_chunk_warning(png_ptr, "invalid character in keyword"); -#endif + png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x, + (png_byte)*ikp); + png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1"); *dp = ' '; } + else { - *dp = *kp; + *dp = *ikp; } } *dp = '\0'; @@ -632,12 +1574,12 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) kp = *new_key + key_len - 1; if (*kp == ' ') { - png_chunk_warning(png_ptr, "trailing spaces removed from keyword"); + png_warning(png_ptr, "trailing spaces removed from keyword"); while (*kp == ' ') { - *(kp--) = '\0'; - key_len--; + *(kp--) = '\0'; + key_len--; } } @@ -645,16 +1587,16 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) kp = *new_key; if (*kp == ' ') { - png_chunk_warning(png_ptr, "leading spaces removed from keyword"); + png_warning(png_ptr, "leading spaces removed from keyword"); while (*kp == ' ') { - kp++; - key_len--; + kp++; + key_len--; } } - png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp); + png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); /* Remove multiple internal spaces. */ for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) @@ -664,10 +1606,13 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) *(dp++) = *kp; kflag = 1; } + else if (*kp == ' ') { key_len--; + kwarn = 1; } + else { *(dp++) = *kp; @@ -675,16 +1620,19 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) } } *dp = '\0'; + if (kwarn) + png_warning(png_ptr, "extra interior spaces removed from keyword"); if (key_len == 0) { - png_chunk_warning(png_ptr, "zero length keyword"); + png_free(png_ptr, *new_key); + png_warning(png_ptr, "Zero length keyword"); } if (key_len > 79) { - png_chunk_warning(png_ptr, "keyword length must be 1 - 79 characters"); - new_key[79] = '\0'; + png_warning(png_ptr, "keyword length must be 1 - 79 characters"); + (*new_key)[79] = '\0'; key_len = 79; } @@ -692,55 +1640,69 @@ png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) } #endif -#if defined(PNG_WRITE_tEXt_SUPPORTED) -/* write a tEXt chunk */ -void -png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text, - png_size_t text_len) +#ifdef PNG_WRITE_tEXt_SUPPORTED +/* Write a tEXt chunk */ +void /* PRIVATE */ +png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len) { png_size_t key_len; png_charp new_key; - png_debug(1, "in png_write_tEXt\n"); - if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0) - { - png_warning(png_ptr, "Empty keyword in tEXt chunk"); + png_debug(1, "in png_write_tEXt"); + + if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) return; - } if (text == NULL || *text == '\0') text_len = 0; - /* make sure we include the 0 after the key */ - png_write_chunk_start(png_ptr, png_tEXt, (png_uint_32)key_len+text_len+1); - png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1); + else + text_len = png_strlen(text); + + /* Make sure we include the 0 after the key */ + png_write_chunk_header(png_ptr, png_tEXt, + (png_uint_32)(key_len + text_len + 1)); + /* + * We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, + (png_size_t)(key_len + 1)); + if (text_len) - png_write_chunk_data(png_ptr, (png_bytep)text, text_len); + png_write_chunk_data(png_ptr, (png_const_bytep)text, + (png_size_t)text_len); png_write_chunk_end(png_ptr); png_free(png_ptr, new_key); } #endif -#if defined(PNG_WRITE_zTXt_SUPPORTED) -/* write a compressed text chunk */ -void -png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text, - png_size_t text_len, int compression) +#ifdef PNG_WRITE_zTXt_SUPPORTED +/* Write a compressed text chunk */ +void /* PRIVATE */ +png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, + png_size_t text_len, int compression) { png_size_t key_len; - char buf[1]; + png_byte buf; png_charp new_key; - int i, ret; - png_charpp output_ptr = NULL; /* array of pointers to output */ - int num_output_ptr = 0; /* number of output pointers used */ - int max_output_ptr = 0; /* size of output_ptr */ + compression_state comp; + + png_debug(1, "in png_write_zTXt"); - png_debug(1, "in png_write_zTXt\n"); + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + comp.input_len = 0; - if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0) + if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) { - png_warning(png_ptr, "Empty keyword in zTXt chunk"); + png_free(png_ptr, new_key); return; } @@ -751,251 +1713,202 @@ png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text, return; } + text_len = png_strlen(text); + + /* Compute the compressed data; do it now for the length */ + text_len = png_text_compress(png_ptr, text, text_len, compression, + &comp); + + /* Write start of chunk */ + png_write_chunk_header(png_ptr, png_zTXt, + (png_uint_32)(key_len+text_len + 2)); + + /* Write key */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, + (png_size_t)(key_len + 1)); + png_free(png_ptr, new_key); - if (compression >= PNG_TEXT_COMPRESSION_LAST) - { -#if !defined(PNG_NO_STDIO) - char msg[50]; - sprintf(msg, "Unknown zTXt compression type %d", compression); - png_warning(png_ptr, msg); -#else - png_warning(png_ptr, "Unknown zTXt compression type"); + buf = (png_byte)compression; + + /* Write compression */ + png_write_chunk_data(png_ptr, &buf, (png_size_t)1); + + /* Write the compressed data */ + comp.input_len = text_len; + png_write_compressed_data_out(png_ptr, &comp); + + /* Close the chunk */ + png_write_chunk_end(png_ptr); +} #endif - compression = PNG_TEXT_COMPRESSION_zTXt; - } - /* We can't write the chunk until we find out how much data we have, - * which means we need to run the compressor first, and save the - * output. This shouldn't be a problem, as the vast majority of - * comments should be reasonable, but we will set up an array of - * malloc'd pointers to be sure. - * - * If we knew the application was well behaved, we could simplify this - * greatly by assuming we can always malloc an output buffer large - * enough to hold the compressed text ((1001 * text_len / 1000) + 12) - * and malloc this directly. The only time this would be a bad idea is - * if we can't malloc more than 64K and we have 64K of random input - * data, or if the input string is incredibly large (although this - * wouldn't cause a failure, just a slowdown due to swapping). - */ +#ifdef PNG_WRITE_iTXt_SUPPORTED +/* Write an iTXt chunk */ +void /* PRIVATE */ +png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, + png_const_charp lang, png_const_charp lang_key, png_const_charp text) +{ + png_size_t lang_len, key_len, lang_key_len, text_len; + png_charp new_lang; + png_charp new_key = NULL; + png_byte cbuf[2]; + compression_state comp; - /* set up the compression buffers */ - png_ptr->zstream.avail_in = (uInt)text_len; - png_ptr->zstream.next_in = (Bytef *)text; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf; + png_debug(1, "in png_write_iTXt"); - /* this is the same compression loop as in png_write_row() */ - do + comp.num_output_ptr = 0; + comp.max_output_ptr = 0; + comp.output_ptr = NULL; + comp.input = NULL; + + if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) + return; + + if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0) { - /* compress the data */ - ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); - if (ret != Z_OK) - { - /* error */ - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); - else - png_error(png_ptr, "zlib error"); - } - /* check to see if we need more room */ - if (!png_ptr->zstream.avail_out && png_ptr->zstream.avail_in) - { - /* make sure the output array has room */ - if (num_output_ptr >= max_output_ptr) - { - int old_max; + png_warning(png_ptr, "Empty language field in iTXt chunk"); + new_lang = NULL; + lang_len = 0; + } + + if (lang_key == NULL) + lang_key_len = 0; + + else + lang_key_len = png_strlen(lang_key); - old_max = max_output_ptr; - max_output_ptr = num_output_ptr + 4; - if (output_ptr != NULL) - { - png_charpp old_ptr; + if (text == NULL) + text_len = 0; - old_ptr = output_ptr; - output_ptr = (png_charpp)png_malloc(png_ptr, - (png_uint_32)(max_output_ptr * sizeof (png_charpp))); - png_memcpy(output_ptr, old_ptr, old_max * sizeof (png_charp)); - png_free(png_ptr, old_ptr); - } - else - output_ptr = (png_charpp)png_malloc(png_ptr, - (png_uint_32)(max_output_ptr * sizeof (png_charp))); - } + else + text_len = png_strlen(text); - /* save the data */ - output_ptr[num_output_ptr] = (png_charp)png_malloc(png_ptr, - (png_uint_32)png_ptr->zbuf_size); - png_memcpy(output_ptr[num_output_ptr], png_ptr->zbuf, - png_ptr->zbuf_size); - num_output_ptr++; + /* Compute the compressed data; do it now for the length */ + text_len = png_text_compress(png_ptr, text, text_len, compression - 2, + &comp); - /* and reset the buffer */ - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->zstream.next_out = png_ptr->zbuf; - } - /* continue until we don't have anymore to compress */ - } while (png_ptr->zstream.avail_in); - /* finish the compression */ - do - { - /* tell zlib we are finished */ - ret = deflate(&png_ptr->zstream, Z_FINISH); - if (ret != Z_OK && ret != Z_STREAM_END) - { - /* we got an error */ - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); - else - png_error(png_ptr, "zlib error"); - } + /* Make sure we include the compression flag, the compression byte, + * and the NULs after the key, lang, and lang_key parts + */ - /* check to see if we need more room */ - if (!(png_ptr->zstream.avail_out) && ret == Z_OK) - { - /* check to make sure our output array has room */ - if (num_output_ptr >= max_output_ptr) - { - int old_max; + png_write_chunk_header(png_ptr, png_iTXt, (png_uint_32)( + 5 /* comp byte, comp flag, terminators for key, lang and lang_key */ + + key_len + + lang_len + + lang_key_len + + text_len)); + + /* We leave it to the application to meet PNG-1.0 requirements on the + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + */ + png_write_chunk_data(png_ptr, (png_bytep)new_key, (png_size_t)(key_len + 1)); - old_max = max_output_ptr; - max_output_ptr = num_output_ptr + 4; - if (output_ptr != NULL) - { - png_charpp old_ptr; + /* Set the compression flag */ + if (compression == PNG_ITXT_COMPRESSION_NONE || + compression == PNG_TEXT_COMPRESSION_NONE) + cbuf[0] = 0; - old_ptr = output_ptr; - /* This could be optimized to realloc() */ - output_ptr = (png_charpp)png_malloc(png_ptr, - (png_uint_32)(max_output_ptr * sizeof (png_charpp))); - png_memcpy(output_ptr, old_ptr, old_max * sizeof (png_charp)); - png_free(png_ptr, old_ptr); - } - else - output_ptr = (png_charpp)png_malloc(png_ptr, - (png_uint_32)(max_output_ptr * sizeof (png_charp))); - } + else /* compression == PNG_ITXT_COMPRESSION_zTXt */ + cbuf[0] = 1; - /* save off the data */ - output_ptr[num_output_ptr] = (png_charp)png_malloc(png_ptr, - (png_uint_32)png_ptr->zbuf_size); - png_memcpy(output_ptr[num_output_ptr], png_ptr->zbuf, - png_ptr->zbuf_size); - num_output_ptr++; + /* Set the compression method */ + cbuf[1] = 0; - /* and reset the buffer pointers */ - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - png_ptr->zstream.next_out = png_ptr->zbuf; - } - } while (ret != Z_STREAM_END); + png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); - /* text length is number of buffers plus last buffer */ - text_len = png_ptr->zbuf_size * num_output_ptr; - if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) - text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; + cbuf[0] = 0; + png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf), + (png_size_t)(lang_len + 1)); - /* write start of chunk */ - png_write_chunk_start(png_ptr, png_zTXt, (png_uint_32)(key_len+text_len+2)); - /* write key */ - png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1); - buf[0] = (png_byte)compression; - /* write compression */ - png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1); + png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), + (png_size_t)(lang_key_len + 1)); + + png_write_compressed_data_out(png_ptr, &comp); - /* write saved output buffers, if any */ - for (i = 0; i < num_output_ptr; i++) - { - png_write_chunk_data(png_ptr,(png_bytep)output_ptr[i],png_ptr->zbuf_size); - png_free(png_ptr, output_ptr[i]); - } - if (max_output_ptr != 0) - png_free(png_ptr, output_ptr); - /* write anything left in zbuf */ - if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) - png_write_chunk_data(png_ptr, png_ptr->zbuf, - png_ptr->zbuf_size - png_ptr->zstream.avail_out); - /* close the chunk */ png_write_chunk_end(png_ptr); - /* reset zlib for another zTXt or the image data */ - deflateReset(&png_ptr->zstream); + png_free(png_ptr, new_key); + png_free(png_ptr, new_lang); } #endif - -#if defined(PNG_WRITE_oFFs_SUPPORTED) -/* write the oFFs chunk */ -void -png_write_oFFs(png_structp png_ptr, png_uint_32 x_offset, - png_uint_32 y_offset, - int unit_type) +#ifdef PNG_WRITE_oFFs_SUPPORTED +/* Write the oFFs chunk */ +void /* PRIVATE */ +png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, + int unit_type) { png_byte buf[9]; - png_debug(1, "in png_write_oFFs\n"); + png_debug(1, "in png_write_oFFs"); + if (unit_type >= PNG_OFFSET_LAST) png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); - png_save_uint_32(buf, x_offset); - png_save_uint_32(buf + 4, y_offset); + png_save_int_32(buf, x_offset); + png_save_int_32(buf + 4, y_offset); buf[8] = (png_byte)unit_type; - png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); + png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); } #endif - -#if defined(PNG_WRITE_pCAL_SUPPORTED) -/* write the pCAL chunk (png-scivis-19970203) */ -void +#ifdef PNG_WRITE_pCAL_SUPPORTED +/* Write the pCAL chunk (described in the PNG extensions document) */ +void /* PRIVATE */ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, - png_int_32 X1, int type, int nparams, png_charp units, png_charpp params) + png_int_32 X1, int type, int nparams, png_const_charp units, + png_charpp params) { - png_size_t purpose_len, units_len, total_len; - png_uint_32p params_len; + png_size_t purpose_len, units_len, total_len; + png_size_tp params_len; png_byte buf[10]; png_charp new_purpose; int i; - png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams); + png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); + if (type >= PNG_EQUATION_LAST) png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; - png_debug1(3, "pCAL purpose length = %d\n", purpose_len); + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); - png_debug1(3, "pCAL units length = %d\n", units_len); + png_debug1(3, "pCAL units length = %d", (int)units_len); total_len = purpose_len + units_len + 10; - params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams - *sizeof(png_uint_32))); + params_len = (png_size_tp)png_malloc(png_ptr, + (png_alloc_size_t)(nparams * png_sizeof(png_size_t))); /* Find the length of each parameter, making sure we don't count the - null terminator for the last parameter. */ + * null terminator for the last parameter. + */ for (i = 0; i < nparams; i++) { params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); - png_debug2(3, "pCAL parameter %d length = %d\n", i, params_len[i]); - total_len += (png_size_t)params_len[i]; + png_debug2(3, "pCAL parameter %d length = %lu", i, + (unsigned long)params_len[i]); + total_len += params_len[i]; } - png_debug1(3, "pCAL total length = %d\n", total_len); - png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); - png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len); + png_debug1(3, "pCAL total length = %d", (int)total_len); + png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, purpose_len); png_save_int_32(buf, X0); png_save_int_32(buf + 4, X1); buf[8] = (png_byte)type; buf[9] = (png_byte)nparams; png_write_chunk_data(png_ptr, buf, (png_size_t)10); - png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len); + png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); png_free(png_ptr, new_purpose); for (i = 0; i < nparams; i++) { - png_write_chunk_data(png_ptr, (png_bytep)params[i], - (png_size_t)params_len[i]); + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); } png_free(png_ptr, params_len); @@ -1003,16 +1916,47 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, } #endif -#if defined(PNG_WRITE_pHYs_SUPPORTED) -/* write the pHYs chunk */ -void +#ifdef PNG_WRITE_sCAL_SUPPORTED +/* Write the sCAL chunk */ +void /* PRIVATE */ +png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, + png_const_charp height) +{ + png_byte buf[64]; + png_size_t wlen, hlen, total_len; + + png_debug(1, "in png_write_sCAL_s"); + + wlen = png_strlen(width); + hlen = png_strlen(height); + total_len = wlen + hlen + 2; + + if (total_len > 64) + { + png_warning(png_ptr, "Can't write sCAL (buffer too small)"); + return; + } + + buf[0] = (png_byte)unit; + png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ + png_memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ + + png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); + png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); +} +#endif + +#ifdef PNG_WRITE_pHYs_SUPPORTED +/* Write the pHYs chunk */ +void /* PRIVATE */ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, - png_uint_32 y_pixels_per_unit, - int unit_type) + png_uint_32 y_pixels_per_unit, + int unit_type) { png_byte buf[9]; - png_debug(1, "in png_write_pHYs\n"); + png_debug(1, "in png_write_pHYs"); + if (unit_type >= PNG_RESOLUTION_LAST) png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); @@ -1020,20 +1964,21 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, png_save_uint_32(buf + 4, y_pixels_per_unit); buf[8] = (png_byte)unit_type; - png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); + png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); } #endif -#if defined(PNG_WRITE_tIME_SUPPORTED) +#ifdef PNG_WRITE_tIME_SUPPORTED /* Write the tIME chunk. Use either png_convert_from_struct_tm() * or png_convert_from_time_t(), or fill in the structure yourself. */ -void -png_write_tIME(png_structp png_ptr, png_timep mod_time) +void /* PRIVATE */ +png_write_tIME(png_structp png_ptr, png_const_timep mod_time) { png_byte buf[7]; - png_debug(1, "in png_write_tIME\n"); + png_debug(1, "in png_write_tIME"); + if (mod_time->month > 12 || mod_time->month < 1 || mod_time->day > 31 || mod_time->day < 1 || mod_time->hour > 23 || mod_time->second > 60) @@ -1049,104 +1994,153 @@ png_write_tIME(png_structp png_ptr, png_timep mod_time) buf[5] = mod_time->minute; buf[6] = mod_time->second; - png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7); + png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); } #endif -/* initializes the row writing capability of libpng */ -void +/* Initializes the row writing capability of libpng */ +void /* PRIVATE */ png_write_start_row(png_structp png_ptr) { - png_size_t buf_size; +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - png_debug(1, "in png_write_start_row\n"); - buf_size = (png_size_t)(((png_ptr->width * png_ptr->usr_channels * - png_ptr->usr_bit_depth + 7) >> 3) + 1); + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + + png_alloc_size_t buf_size; + int usr_pixel_depth; + + png_debug(1, "in png_write_start_row"); + + usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; + buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; + + /* 1.5.6: added to allow checking in the row write code. */ + png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; + png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; + + /* Set up row buffer */ + png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size); - /* set up row buffer */ - png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size); png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; - /* set up filtering buffer, if using this filter */ +#ifdef PNG_WRITE_FILTER_SUPPORTED + /* Set up filtering buffer, if using this filter */ if (png_ptr->do_filter & PNG_FILTER_SUB) { - png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); + png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; } /* We only need to keep the previous row if we are using one of these. */ if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) { - /* set up previous row buffer */ - png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size); - png_memset(png_ptr->prev_row, 0, buf_size); + /* Set up previous row buffer */ + png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size); if (png_ptr->do_filter & PNG_FILTER_UP) { - png_ptr->up_row = (png_bytep )png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); + png_ptr->up_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; } if (png_ptr->do_filter & PNG_FILTER_AVG) { png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); + png_ptr->rowbytes + 1); + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; } if (png_ptr->do_filter & PNG_FILTER_PAETH) { - png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr, - (png_ptr->rowbytes + 1)); + png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, + png_ptr->rowbytes + 1); + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; } } +#endif /* PNG_WRITE_FILTER_SUPPORTED */ #ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* if interlaced, we need to set up width and height of pass */ + /* If interlaced, we need to set up width and height of pass */ if (png_ptr->interlaced) { if (!(png_ptr->transformations & PNG_INTERLACE)) { png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - - png_pass_ystart[0]) / png_pass_yinc[0]; + png_pass_ystart[0]) / png_pass_yinc[0]; + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - - png_pass_start[0]) / png_pass_inc[0]; + png_pass_start[0]) / png_pass_inc[0]; } + else { png_ptr->num_rows = png_ptr->height; png_ptr->usr_width = png_ptr->width; } } + else #endif { png_ptr->num_rows = png_ptr->height; png_ptr->usr_width = png_ptr->width; } + + png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT); png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; png_ptr->zstream.next_out = png_ptr->zbuf; } /* Internal use only. Called when finished processing a row of data. */ -void +void /* PRIVATE */ png_write_finish_row(png_structp png_ptr) { +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + /* Start of interlace block in the y direction */ + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; + + /* Offset to next interlace block in the y direction */ + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; +#endif + int ret; - png_debug(1, "in png_write_finish_row\n"); - /* next row */ + png_debug(1, "in png_write_finish_row"); + + /* Next row */ png_ptr->row_number++; - /* see if we are done */ + /* See if we are done */ if (png_ptr->row_number < png_ptr->num_rows) return; #ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* if interlaced, go to next pass */ + /* If interlaced, go to next pass */ if (png_ptr->interlaced) { png_ptr->row_number = 0; @@ -1154,75 +2148,88 @@ png_write_finish_row(png_structp png_ptr) { png_ptr->pass++; } + else { - /* loop until we find a non-zero width or height pass */ + /* Loop until we find a non-zero width or height pass */ do { png_ptr->pass++; + if (png_ptr->pass >= 7) break; + png_ptr->usr_width = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + png_ptr->num_rows = (png_ptr->height + - png_pass_yinc[png_ptr->pass] - 1 - - png_pass_ystart[png_ptr->pass]) / - png_pass_yinc[png_ptr->pass]; + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + if (png_ptr->transformations & PNG_INTERLACE) break; + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); } - /* reset the row above the image for the next pass */ + /* Reset the row above the image for the next pass */ if (png_ptr->pass < 7) { if (png_ptr->prev_row != NULL) - png_memset(png_ptr->prev_row, 0, - (png_size_t) (((png_uint_32)png_ptr->usr_channels * - (png_uint_32)png_ptr->usr_bit_depth * - png_ptr->width + 7) >> 3) + 1); + png_memset(png_ptr->prev_row, 0, + (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* + png_ptr->usr_bit_depth, png_ptr->width)) + 1); + return; } } #endif - /* if we get here, we've just written the last row, so we need + /* If we get here, we've just written the last row, so we need to flush the compressor */ do { - /* tell the compressor we are done */ + /* Tell the compressor we are done */ ret = deflate(&png_ptr->zstream, Z_FINISH); - /* check for an error */ - if (ret != Z_OK && ret != Z_STREAM_END) + + /* Check for an error */ + if (ret == Z_OK) + { + /* Check to see if we need more room */ + if (!(png_ptr->zstream.avail_out)) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + } + + else if (ret != Z_STREAM_END) { if (png_ptr->zstream.msg != NULL) png_error(png_ptr, png_ptr->zstream.msg); + else png_error(png_ptr, "zlib error"); } - /* check to see if we need more room */ - if (!(png_ptr->zstream.avail_out) && ret == Z_OK) - { - png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; - } } while (ret != Z_STREAM_END); - /* write any extra space */ + /* Write any extra space */ if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) { png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - - png_ptr->zstream.avail_out); + png_ptr->zstream.avail_out); } - deflateReset(&png_ptr->zstream); + png_zlib_release(png_ptr); + png_ptr->zstream.data_type = Z_BINARY; } -#if defined(PNG_WRITE_INTERLACING_SUPPORTED) +#ifdef PNG_WRITE_INTERLACING_SUPPORTED /* Pick out the correct pixels for the interlace pass. * The basic idea here is to go through the row with a source * pointer and a destination pointer (sp and dp), and copy the @@ -1230,18 +2237,23 @@ png_write_finish_row(png_structp png_ptr) * sp will always be >= dp, so we should never overwrite anything. * See the default: case for the easiest code to understand. */ -void +void /* PRIVATE */ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) { - png_debug(1, "in png_do_write_interlace\n"); - /* we don't have to do anything on the last pass (6) */ -#if defined(PNG_USELESS_TESTS_SUPPORTED) - if (row != NULL && row_info != NULL && pass < 6) -#else + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + + /* Start of interlace block */ + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; + + /* Offset to next interlace block */ + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; + + png_debug(1, "in png_do_write_interlace"); + + /* We don't have to do anything on the last pass (6) */ if (pass < 6) -#endif { - /* each pixel depth is handled seperately */ + /* Each pixel depth is handled separately */ switch (row_info->pixel_depth) { case 1: @@ -1252,15 +2264,17 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) int d; int value; png_uint_32 i; + png_uint_32 row_width = row_info->width; dp = row; d = 0; shift = 7; - for (i = png_pass_start[pass]; i < row_info->width; + + for (i = png_pass_start[pass]; i < row_width; i += png_pass_inc[pass]) { sp = row + (png_size_t)(i >> 3); - value = (int)(*sp >> (7 - (int)(i & 7))) & 0x1; + value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; d |= (value << shift); if (shift == 0) @@ -1269,14 +2283,17 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) *dp++ = (png_byte)d; d = 0; } + else shift--; } if (shift != 7) *dp = (png_byte)d; + break; } + case 2: { png_bytep sp; @@ -1285,15 +2302,17 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) int d; int value; png_uint_32 i; + png_uint_32 row_width = row_info->width; dp = row; shift = 6; d = 0; - for (i = png_pass_start[pass]; i < row_info->width; + + for (i = png_pass_start[pass]; i < row_width; i += png_pass_inc[pass]) { sp = row + (png_size_t)(i >> 2); - value = (*sp >> ((3 - (int)(i & 3)) << 1)) & 0x3; + value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; d |= (value << shift); if (shift == 0) @@ -1302,13 +2321,16 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) *dp++ = (png_byte)d; d = 0; } + else shift -= 2; } if (shift != 6) - *dp = (png_byte)d; + *dp = (png_byte)d; + break; } + case 4: { png_bytep sp; @@ -1317,15 +2339,16 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) int d; int value; png_uint_32 i; + png_uint_32 row_width = row_info->width; dp = row; shift = 4; d = 0; - for (i = png_pass_start[pass]; i < row_info->width; - i += png_pass_inc[pass]) + for (i = png_pass_start[pass]; i < row_width; + i += png_pass_inc[pass]) { sp = row + (png_size_t)(i >> 1); - value = (*sp >> ((1 - (int)(i & 1)) << 2)) & 0xf; + value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; d |= (value << shift); if (shift == 0) @@ -1334,47 +2357,55 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) *dp++ = (png_byte)d; d = 0; } + else shift -= 4; } if (shift != 4) *dp = (png_byte)d; + break; } + default: { png_bytep sp; png_bytep dp; png_uint_32 i; + png_uint_32 row_width = row_info->width; png_size_t pixel_bytes; - /* start at the beginning */ + /* Start at the beginning */ dp = row; - /* find out how many bytes each pixel takes up */ + + /* Find out how many bytes each pixel takes up */ pixel_bytes = (row_info->pixel_depth >> 3); - /* loop through the row, only looking at the pixels that - matter */ - for (i = png_pass_start[pass]; i < row_info->width; + + /* Loop through the row, only looking at the pixels that matter */ + for (i = png_pass_start[pass]; i < row_width; i += png_pass_inc[pass]) { - /* find out where the original pixel is */ + /* Find out where the original pixel is */ sp = row + (png_size_t)i * pixel_bytes; - /* move the pixel */ + + /* Move the pixel */ if (dp != sp) png_memcpy(dp, sp, pixel_bytes); - /* next pixel */ + + /* Next pixel */ dp += pixel_bytes; } break; } } - /* set new row width */ + /* Set new row width */ row_info->width = (row_info->width + - png_pass_inc[pass] - 1 - - png_pass_start[pass]) / - png_pass_inc[pass]; - row_info->rowbytes = ((row_info->width * - row_info->pixel_depth + 7) >> 3); + png_pass_inc[pass] - 1 - + png_pass_start[pass]) / + png_pass_inc[pass]; + + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, + row_info->width); } } #endif @@ -1383,69 +2414,105 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) * been specified by the application, and then writes the row out with the * chosen filter. */ -#define PNG_MAXSUM (~((png_uint_32)0) >> 1) +static void png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, + png_size_t row_bytes); + +#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) #define PNG_HISHIFT 10 #define PNG_LOMASK ((png_uint_32)0xffffL) #define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) -void +void /* PRIVATE */ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) { - png_bytep prev_row, best_row, row_buf; + png_bytep best_row; +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_bytep prev_row, row_buf; png_uint_32 mins, bpp; + png_byte filter_to_do = png_ptr->do_filter; + png_size_t row_bytes = row_info->rowbytes; +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + int num_p_filters = png_ptr->num_prev_filters; +#endif + + png_debug(1, "in png_write_find_filter"); + +#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) + { + /* These will never be selected so we need not test them. */ + filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); + } +#endif - png_debug(1, "in png_write_find_filter\n"); - /* find out how many bytes offset each pixel is */ - bpp = (row_info->pixel_depth + 7) / 8; + /* Find out how many bytes offset each pixel is */ + bpp = (row_info->pixel_depth + 7) >> 3; prev_row = png_ptr->prev_row; - best_row = row_buf = png_ptr->row_buf; +#endif + best_row = png_ptr->row_buf; +#ifdef PNG_WRITE_FILTER_SUPPORTED + row_buf = best_row; mins = PNG_MAXSUM; /* The prediction method we use is to find which method provides the * smallest value when summing the absolute values of the distances - * from zero using anything >= 128 as negative numbers. This is known + * from zero, using anything >= 128 as negative numbers. This is known * as the "minimum sum of absolute differences" heuristic. Other - * heuristics are the "weighted minumum sum of absolute differences" + * heuristics are the "weighted minimum sum of absolute differences" * (experimental and can in theory improve compression), and the "zlib - * predictive" method (not implemented in libpng 0.95), which does test - * compressions of lines using different filter methods, and then chooses - * the (series of) filter(s) which give minimum compressed data size (VERY + * predictive" method (not implemented yet), which does test compressions + * of lines using different filter methods, and then chooses the + * (series of) filter(s) that give minimum compressed data size (VERY * computationally expensive). + * + * GRR 980525: consider also + * + * (1) minimum sum of absolute differences from running average (i.e., + * keep running sum of non-absolute differences & count of bytes) + * [track dispersion, too? restart average if dispersion too large?] + * + * (1b) minimum sum of absolute differences from sliding average, probably + * with window size <= deflate window (usually 32K) + * + * (2) minimum sum of squared differences from zero or running average + * (i.e., ~ root-mean-square approach) */ + /* We don't need to test the 'no filter' case if this is the only filter * that has been chosen, as it doesn't actually do anything to the data. */ - if (png_ptr->do_filter & PNG_FILTER_NONE && - png_ptr->do_filter != PNG_FILTER_NONE) + if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE) { png_bytep rp; png_uint_32 sum = 0; - png_uint_32 i; + png_size_t i; int v; - for (i = 0, rp = row_buf + 1; i < row_info->rowbytes; i++, rp++) + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) { v = *rp; sum += (v < 128) ? v : 256 - v; } -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { png_uint_32 sumhi, sumlo; + int j; sumlo = sum & PNG_LOMASK; sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ /* Reduce the sum if we match any of the previous rows */ - for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_NONE) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) { - sumlo = (sumlo * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - sumhi = (sumhi * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } @@ -1454,12 +2521,14 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) * it has the minimum possible computational cost - none). */ sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (sumhi > PNG_HIMASK) sum = PNG_MAXSUM; + else sum = (sumhi << PNG_HISHIFT) + sumlo; } @@ -1467,43 +2536,68 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) mins = sum; } - /* sub filter */ - if (png_ptr->do_filter & PNG_FILTER_SUB) + /* Sub filter */ + if (filter_to_do == PNG_FILTER_SUB) + /* It's the only filter so no testing is needed */ + { + png_bytep rp, lp, dp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; + i++, rp++, dp++) + { + *dp = *rp; + } + + for (lp = row_buf + 1; i < row_bytes; + i++, rp++, lp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + } + + best_row = png_ptr->sub_row; + } + + else if (filter_to_do & PNG_FILTER_SUB) { png_bytep rp, dp, lp; png_uint_32 sum = 0, lmins = mins; - png_uint_32 i; + png_size_t i; int v; -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) - /* We temporarily increase the "minumum sum" by the factor we +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED + /* We temporarily increase the "minimum sum" by the factor we * would reduce the sum of this filter, so that we can do the * early exit comparison without scaling the sum each time. */ if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 lmhi, lmlo; lmlo = lmins & PNG_LOMASK; lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_SUB) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) { - lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (lmhi > PNG_HIMASK) lmins = PNG_MAXSUM; + else lmins = (lmhi << PNG_HISHIFT) + lmlo; } @@ -1516,7 +2610,8 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) sum += (v < 128) ? v : 256 - v; } - for (lp = row_buf + 1; i < row_info->rowbytes; + + for (lp = row_buf + 1; i < row_bytes; i++, rp++, lp++, dp++) { v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); @@ -1527,31 +2622,35 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) break; } -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 sumhi, sumlo; sumlo = sum & PNG_LOMASK; sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_SUB) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) { - sumlo = (sumlo * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - sumhi = (sumhi * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (sumhi > PNG_HIMASK) sum = PNG_MAXSUM; + else sum = (sumhi << PNG_HISHIFT) + sumlo; } @@ -1564,49 +2663,68 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) } } - /* up filter */ - if (png_ptr->do_filter & PNG_FILTER_UP) + /* Up filter */ + if (filter_to_do == PNG_FILTER_UP) + { + png_bytep rp, dp, pp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, + pp = prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + } + + best_row = png_ptr->up_row; + } + + else if (filter_to_do & PNG_FILTER_UP) { png_bytep rp, dp, pp; png_uint_32 sum = 0, lmins = mins; - png_uint_32 i; + png_size_t i; int v; -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 lmhi, lmlo; lmlo = lmins & PNG_LOMASK; lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_UP) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) { - lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (lmhi > PNG_HIMASK) lmins = PNG_MAXSUM; + else lmins = (lmhi << PNG_HISHIFT) + lmlo; } #endif for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, - pp = prev_row + 1; i < row_info->rowbytes; - i++, rp++, pp++, dp++) + pp = prev_row + 1; i < row_bytes; i++) { - v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); sum += (v < 128) ? v : 256 - v; @@ -1614,31 +2732,35 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) break; } -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 sumhi, sumlo; sumlo = sum & PNG_LOMASK; sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_UP) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) { - sumlo = (sumlo * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - sumhi = (sumhi * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (sumhi > PNG_HIMASK) sum = PNG_MAXSUM; + else sum = (sumhi << PNG_HISHIFT) + sumlo; } @@ -1651,55 +2773,79 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) } } - /* avg filter */ - if (png_ptr->do_filter & PNG_FILTER_AVG) + /* Avg filter */ + if (filter_to_do == PNG_FILTER_AVG) { png_bytep rp, dp, pp, lp; - png_uint_32 sum = 0, lmins = mins; png_uint_32 i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + } + + for (lp = row_buf + 1; i < row_bytes; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) + & 0xff); + } + best_row = png_ptr->avg_row; + } + + else if (filter_to_do & PNG_FILTER_AVG) + { + png_bytep rp, dp, pp, lp; + png_uint_32 sum = 0, lmins = mins; + png_size_t i; int v; -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 lmhi, lmlo; lmlo = lmins & PNG_LOMASK; lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_AVG) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) { - lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (lmhi > PNG_HIMASK) lmins = PNG_MAXSUM; + else lmins = (lmhi << PNG_HISHIFT) + lmlo; } #endif for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, - pp = prev_row + 1; i < bpp; i++, rp++, pp++, dp++) + pp = prev_row + 1; i < bpp; i++) { - v = *dp = (png_byte)(((int)*rp - ((int)*pp / 2)) & 0xff); + v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); sum += (v < 128) ? v : 256 - v; } - for (lp = row_buf + 1; i < row_info->rowbytes; - i++, rp++, pp++, lp++, dp++) + + for (lp = row_buf + 1; i < row_bytes; i++) { - v = *dp = (png_byte)(((int)*rp - (((int)*pp + (int)*lp) / 2)) & 0xff); + v = *dp++ = + (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); sum += (v < 128) ? v : 256 - v; @@ -1707,31 +2853,35 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) break; } -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 sumhi, sumlo; sumlo = sum & PNG_LOMASK; sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_NONE) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) { - sumlo = (sumlo * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - sumhi = (sumhi * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (sumhi > PNG_HIMASK) sum = PNG_MAXSUM; + else sum = (sumhi << PNG_HISHIFT) + sumlo; } @@ -1745,59 +2895,116 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) } /* Paeth filter */ - if (png_ptr->do_filter & PNG_FILTER_PAETH) + if (filter_to_do == PNG_FILTER_PAETH) + { + png_bytep rp, dp, pp, cp, lp; + png_size_t i; + + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, + pp = prev_row + 1; i < bpp; i++) + { + *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + } + + for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp++; + c = *cp++; + a = *lp++; + + p = b - c; + pc = a - c; + +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; + + *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); + } + best_row = png_ptr->paeth_row; + } + + else if (filter_to_do & PNG_FILTER_PAETH) { png_bytep rp, dp, pp, cp, lp; png_uint_32 sum = 0, lmins = mins; - png_uint_32 i; + png_size_t i; int v; -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 lmhi, lmlo; lmlo = lmins & PNG_LOMASK; lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_PAETH) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) { - lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (lmhi > PNG_HIMASK) lmins = PNG_MAXSUM; + else lmins = (lmhi << PNG_HISHIFT) + lmlo; } #endif for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, - pp = prev_row + 1; (unsigned)i < bpp; i++, rp++, pp++, dp++) + pp = prev_row + 1; i < bpp; i++) { - v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); sum += (v < 128) ? v : 256 - v; } - for (lp = row_buf + 1, cp = prev_row + 1; i < row_info->rowbytes; - i++, rp++, pp++, lp++, dp++, cp++) + + for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) { int a, b, c, pa, pb, pc, p; - b = *pp; - c = *cp; - a = *lp; - + b = *pp++; + c = *cp++; + a = *lp++; + +#ifndef PNG_SLOW_PAETH + p = b - c; + pc = a - c; +#ifdef PNG_USE_ABS + pa = abs(p); + pb = abs(pc); + pc = abs(p + pc); +#else + pa = p < 0 ? -p : p; + pb = pc < 0 ? -pc : pc; + pc = (p + pc) < 0 ? -(p + pc) : p + pc; +#endif + p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; +#else /* PNG_SLOW_PAETH */ p = a + b - c; pa = abs(p - a); pb = abs(p - b); @@ -1805,12 +3012,15 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (pa <= pb && pa <= pc) p = a; + else if (pb <= pc) p = b; + else p = c; +#endif /* PNG_SLOW_PAETH */ - v = *dp = (png_byte)(((int)*rp - p) & 0xff); + v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); sum += (v < 128) ? v : 256 - v; @@ -1818,31 +3028,35 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) break; } -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) { + int j; png_uint_32 sumhi, sumlo; sumlo = sum & PNG_LOMASK; sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - for (i = 0; i < png_ptr->num_prev_filters; i++) + for (j = 0; j < num_p_filters; j++) { - if (png_ptr->prev_filters[i] == PNG_FILTER_PAETH) + if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) { - sumlo = (sumlo * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; - sumhi = (sumhi * png_ptr->filter_weights[i]) >> - PNG_WEIGHT_SHIFT; + sumlo = (sumlo * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; + + sumhi = (sumhi * png_ptr->filter_weights[j]) >> + PNG_WEIGHT_SHIFT; } } sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; + PNG_COST_SHIFT; if (sumhi > PNG_HIMASK) sum = PNG_MAXSUM; + else sum = (sumhi << PNG_HISHIFT) + sumlo; } @@ -1853,63 +3067,94 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) best_row = png_ptr->paeth_row; } } +#endif /* PNG_WRITE_FILTER_SUPPORTED */ /* Do the actual writing of the filtered row data from the chosen filter. */ - png_write_filtered_row(png_ptr, best_row); + png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) +#ifdef PNG_WRITE_FILTER_SUPPORTED +#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED /* Save the type of filter we picked this time for future calculations */ if (png_ptr->num_prev_filters > 0) { - int i; + int j; - for (i = 1; i < (int)png_ptr->num_prev_filters; i++) + for (j = 1; j < num_p_filters; j++) { - png_ptr->prev_filters[i] = png_ptr->prev_filters[i - 1]; + png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; } - png_ptr->prev_filters[i] = best_row[0]; + + png_ptr->prev_filters[j] = best_row[0]; } #endif +#endif /* PNG_WRITE_FILTER_SUPPORTED */ } /* Do the actual writing of a previously filtered row. */ -void -png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) +static void +png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, + png_size_t avail/*includes filter byte*/) { - png_debug(1, "in png_write_filtered_row\n"); - png_debug1(2, "filter = %d\n", filtered_row[0]); - /* set up the zlib input buffer */ + png_debug(1, "in png_write_filtered_row"); + + png_debug1(2, "filter = %d", filtered_row[0]); + /* Set up the zlib input buffer */ + png_ptr->zstream.next_in = filtered_row; - png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1; - /* repeat until we have compressed all the data */ + png_ptr->zstream.avail_in = 0; + /* Repeat until we have compressed all the data */ do { - int ret; /* return of zlib */ + int ret; /* Return of zlib */ + + /* Record the number of bytes available - zlib supports at least 65535 + * bytes at one step, depending on the size of the zlib type 'uInt', the + * maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h). + * Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e. + * one more than 16 bits) and, in this case 'rowbytes+1' can overflow a + * uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called + * with smaller chunks of data. + */ + if (png_ptr->zstream.avail_in == 0) + { + if (avail > ZLIB_IO_MAX) + { + png_ptr->zstream.avail_in = ZLIB_IO_MAX; + avail -= ZLIB_IO_MAX; + } + + else + { + /* So this will fit in the available uInt space: */ + png_ptr->zstream.avail_in = (uInt)avail; + avail = 0; + } + } - /* compress the data */ + /* Compress the data */ ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); - /* check for compression errors */ + + /* Check for compression errors */ if (ret != Z_OK) { if (png_ptr->zstream.msg != NULL) png_error(png_ptr, png_ptr->zstream.msg); + else png_error(png_ptr, "zlib error"); } - /* see if it is time to write another IDAT */ + /* See if it is time to write another IDAT */ if (!(png_ptr->zstream.avail_out)) { - /* write the IDAT and reset the zlib output buffer */ + /* Write the IDAT and reset the zlib output buffer */ png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); - png_ptr->zstream.next_out = png_ptr->zbuf; - png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; } - /* repeat until all data has been compressed */ - } while (png_ptr->zstream.avail_in); + /* Repeat until all data has been compressed */ + } while (avail > 0 || png_ptr->zstream.avail_in > 0); - /* swap the current and previous rows */ + /* Swap the current and previous rows */ if (png_ptr->prev_row != NULL) { png_bytep tptr; @@ -1919,10 +3164,10 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) png_ptr->row_buf = tptr; } - /* finish row - updates counters and flushes zlib if last row */ + /* Finish row - updates counters and flushes zlib if last row */ png_write_finish_row(png_ptr); -#if defined(PNG_WRITE_FLUSH_SUPPORTED) +#ifdef PNG_WRITE_FLUSH_SUPPORTED png_ptr->flush_rows++; if (png_ptr->flush_dist > 0 && @@ -1930,5 +3175,6 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) { png_write_flush(png_ptr); } -#endif /* PNG_WRITE_FLUSH_SUPPORTED */ +#endif } +#endif /* PNG_WRITE_SUPPORTED */