X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/75b6e0a0aba793c6b739689b4414c1a2d8fcb041..b0ad146aba58fae678c885a9bc5e30d79bffb494:/src/png/pngwutil.c diff --git a/src/png/pngwutil.c b/src/png/pngwutil.c index 4736361d2e..49e6a2d213 100644 --- a/src/png/pngwutil.c +++ b/src/png/pngwutil.c @@ -1,21 +1,26 @@ /* pngwutil.c - utilities to write a PNG file * - * libpng 1.0.3 - January 14, 1999 - * 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, 1999 Glenn Randers-Pehrson + * Last changed in libpng 1.6.2 [April 25, 2013] + * Copyright (c) 1998-2013 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.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); @@ -24,126 +29,736 @@ png_save_uint_32(png_bytep buf, png_uint_32 i) buf[3] = (png_byte)(i & 0xff); } -#if defined(PNG_WRITE_pCAL_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. - */ -void -png_save_int_32(png_bytep buf, png_int_32 i) -{ - buf[0] = (png_byte)((i >> 24) & 0xff); - buf[1] = (png_byte)((i >> 16) & 0xff); - buf[2] = (png_byte)((i >> 8) & 0xff); - buf[3] = (png_byte)(i & 0xff); -} -#endif - /* Place a 16-bit number into a buffer in PNG byte order. * 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_structrp 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_structrp 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 } -/* Write the data of a PNG chunk started with png_write_chunk_start(). +void PNGAPI +png_write_chunk_start(png_structrp 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_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_structrp 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 -png_write_chunk_end(png_structp png_ptr) +/* Finish a chunk started with png_write_chunk_header(). */ +void PNGAPI +png_write_chunk_end(png_structrp 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. + */ +static void +png_write_complete_chunk(png_structrp 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_31_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_structrp 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); +} + +/* This is used below to find the size of an image to pass to png_deflate_claim, + * so it only needs to be accurate if the size is less than 16384 bytes (the + * point at which a lower LZ window size can be used.) + */ +static png_alloc_size_t +png_image_size(png_structrp png_ptr) +{ + /* Only return sizes up to the maximum of a png_uint_32, do this by limiting + * the width and height used to 15 bits. + */ + png_uint_32 h = png_ptr->height; + + if (png_ptr->rowbytes < 32768 && h < 32768) + { + if (png_ptr->interlaced) + { + /* Interlacing makes the image larger because of the replication of + * both the filter byte and the padding to a byte boundary. + */ + png_uint_32 w = png_ptr->width; + unsigned int pd = png_ptr->pixel_depth; + png_alloc_size_t cb_base; + int pass; + + for (cb_base=0, pass=0; pass<=6; ++pass) + { + png_uint_32 pw = PNG_PASS_COLS(w, pass); + + if (pw > 0) + cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass); + } + + return cb_base; + } + + else + return (png_ptr->rowbytes+1) * h; + } + + else + return 0xffffffffU; +} + +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* This is the code to hack the first two bytes of the deflate stream (the + * deflate header) to correct the windowBits value to match the actual data + * size. Note that the second argument is the *uncompressed* size but the + * first argument is the *compressed* data (and it must be deflate + * compressed.) + */ +static void +optimize_cmf(png_bytep data, png_alloc_size_t data_size) +{ + /* Optimize the CMF field in the zlib stream. The resultant zlib stream is + * still compliant to the stream specification. + */ + if (data_size <= 16384) /* else windowBits must be 15 */ + { + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + { + unsigned int z_cinfo; + unsigned int half_z_window_size; + + z_cinfo = z_cmf >> 4; + half_z_window_size = 1U << (z_cinfo + 7); + + if (data_size <= half_z_window_size) /* else no change */ + { + unsigned int tmp; + + do + { + half_z_window_size >>= 1; + --z_cinfo; + } + while (z_cinfo > 0 && data_size <= half_z_window_size); + + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; + } + } + } +} +#else +# define optimize_cmf(dp,dl) ((void)0) +#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ + +/* Initialize the compressor for the appropriate type of compression. */ +static int +png_deflate_claim(png_structrp png_ptr, png_uint_32 owner, + png_alloc_size_t data_size) +{ + if (png_ptr->zowner != 0) + { + char msg[64]; + + PNG_STRING_FROM_CHUNK(msg, owner); + msg[4] = ':'; + msg[5] = ' '; + PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner); + /* So the message that results is " using zstream"; this is an + * internal error, but is very useful for debugging. i18n requirements + * are minimal. + */ + (void)png_safecat(msg, (sizeof msg), 10, " using zstream"); +# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC + png_warning(png_ptr, msg); + + /* Attempt sane error recovery */ + if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */ + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT"); + return Z_STREAM_ERROR; + } + + png_ptr->zowner = 0; +# else + png_error(png_ptr, msg); +# endif + } + + { + int level = png_ptr->zlib_level; + int method = png_ptr->zlib_method; + int windowBits = png_ptr->zlib_window_bits; + int memLevel = png_ptr->zlib_mem_level; + int strategy; /* set below */ + int ret; /* zlib return code */ + + if (owner == png_IDAT) + { + if (png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) + strategy = png_ptr->zlib_strategy; + + else if (png_ptr->do_filter != PNG_FILTER_NONE) + strategy = PNG_Z_DEFAULT_STRATEGY; + + else + strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY; + } + + else + { +# ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED + level = png_ptr->zlib_text_level; + method = png_ptr->zlib_text_method; + windowBits = png_ptr->zlib_text_window_bits; + memLevel = png_ptr->zlib_text_mem_level; + strategy = png_ptr->zlib_text_strategy; +# else + /* If customization is not supported the values all come from the + * IDAT values except for the strategy, which is fixed to the + * default. (This is the pre-1.6.0 behavior too, although it was + * implemented in a very different way.) + */ + strategy = Z_DEFAULT_STRATEGY; +# endif + } + + /* Adjust 'windowBits' down if larger than 'data_size'; to stop this + * happening just pass 32768 as the data_size parameter. Notice that zlib + * requires an extra 262 bytes in the window in addition to the data to be + * able to see the whole of the data, so if data_size+262 takes us to the + * next windowBits size we need to fix up the value later. (Because even + * though deflate needs the extra window, inflate does not!) + */ + if (data_size <= 16384) + { + /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to + * work round a Microsoft Visual C misbehavior which, contrary to C-90, + * widens the result of the following shift to 64-bits if (and, + * apparently, only if) it is used in a test. + */ + unsigned int half_window_size = 1U << (windowBits-1); + + while (data_size + 262 <= half_window_size) + { + half_window_size >>= 1; + --windowBits; + } + } + + /* Check against the previous initialized values, if any. */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) && + (png_ptr->zlib_set_level != level || + png_ptr->zlib_set_method != method || + png_ptr->zlib_set_window_bits != windowBits || + png_ptr->zlib_set_mem_level != memLevel || + png_ptr->zlib_set_strategy != strategy)) + { + if (deflateEnd(&png_ptr->zstream) != Z_OK) + png_warning(png_ptr, "deflateEnd failed (ignored)"); + + png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED; + } + + /* For safety clear out the input and output pointers (currently zlib + * doesn't use them on Init, but it might in the future). + */ + png_ptr->zstream.next_in = NULL; + png_ptr->zstream.avail_in = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->zstream.avail_out = 0; + + /* Now initialize if required, setting the new parameters, otherwise just + * to a simple reset to the previous parameters. + */ + if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) + ret = deflateReset(&png_ptr->zstream); + + else + { + ret = deflateInit2(&png_ptr->zstream, level, method, windowBits, + memLevel, strategy); + + if (ret == Z_OK) + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; + } + + /* The return code is from either deflateReset or deflateInit2; they have + * pretty much the same set of error codes. + */ + if (ret == Z_OK) + png_ptr->zowner = owner; + + else + png_zstream_error(png_ptr, ret); + + return ret; + } +} + +/* Clean up (or trim) a linked list of compression buffers. */ +void /* PRIVATE */ +png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp) +{ + png_compression_bufferp list = *listp; + + if (list != NULL) + { + *listp = NULL; + + do + { + png_compression_bufferp next = list->next; + + png_free(png_ptr, list); + list = next; + } + while (list != NULL); + } +} + +#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 to allow access to the relevant local variables. + * + * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size + * temporary buffers. From 1.6.0 it is retained in png_struct so that it will + * be correctly freed in the event of a write error (previous implementations + * just leaked memory.) */ -void -png_write_sig(png_structp png_ptr) +typedef struct { - /* 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); + png_const_bytep input; /* The uncompressed input data */ + png_alloc_size_t input_len; /* Its length */ + png_uint_32 output_len; /* Final compressed length */ + png_byte output[1024]; /* First block of output */ +} compression_state; + +static void +png_text_compress_init(compression_state *comp, png_const_bytep input, + png_alloc_size_t input_len) +{ + comp->input = input; + comp->input_len = input_len; + comp->output_len = 0; +} + +/* Compress the data in the compression state input */ +static int +png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name, + compression_state *comp, png_uint_32 prefix_len) +{ + int ret; + + /* To find the length of the output it is necessary to first compress the + * input, the result is buffered rather than using the two-pass algorithm + * that is used on the inflate side; deflate is assumed to be slower and a + * PNG writer is assumed to have more memory available than a PNG reader. + * + * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an + * upper limit on the output size, but it is always bigger than the input + * size so it is likely to be more efficient to use this linked-list + * approach. + */ + ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len); + + if (ret != Z_OK) + return ret; + + /* Set up the compression buffers, we need a loop here to avoid overflowing a + * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited + * by the output buffer size, so there is no need to check that. Since this + * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits + * in size. + */ + { + png_compression_bufferp *end = &png_ptr->zbuffer_list; + png_alloc_size_t input_len = comp->input_len; /* may be zero! */ + png_uint_32 output_len; + + /* zlib updates these for us: */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input); + png_ptr->zstream.avail_in = 0; /* Set below */ + png_ptr->zstream.next_out = comp->output; + png_ptr->zstream.avail_out = (sizeof comp->output); + + output_len = png_ptr->zstream.avail_out; + + do + { + uInt avail_in = ZLIB_IO_MAX; + + if (avail_in > input_len) + avail_in = (uInt)input_len; + + input_len -= avail_in; + + png_ptr->zstream.avail_in = avail_in; + + if (png_ptr->zstream.avail_out == 0) + { + png_compression_buffer *next; + + /* Chunk data is limited to 2^31 bytes in length, so the prefix + * length must be counted here. + */ + if (output_len + prefix_len > PNG_UINT_31_MAX) + { + ret = Z_MEM_ERROR; + break; + } + + /* Need a new (malloc'ed) buffer, but there may be one present + * already. + */ + next = *end; + if (next == NULL) + { + next = png_voidcast(png_compression_bufferp, png_malloc_base + (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); + + if (next == NULL) + { + ret = Z_MEM_ERROR; + break; + } + + /* Link in this buffer (so that it will be freed later) */ + next->next = NULL; + *end = next; + } + + png_ptr->zstream.next_out = next->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + output_len += png_ptr->zstream.avail_out; + + /* Move 'end' to the next buffer pointer. */ + end = &next->next; + } + + /* Compress the data */ + ret = deflate(&png_ptr->zstream, + input_len > 0 ? Z_NO_FLUSH : Z_FINISH); + + /* Claw back input data that was not consumed (because avail_in is + * reset above every time round the loop). + */ + input_len += png_ptr->zstream.avail_in; + png_ptr->zstream.avail_in = 0; /* safety */ + } + while (ret == Z_OK); + + /* There may be some space left in the last output buffer, this needs to + * be subtracted from output_len. + */ + output_len -= png_ptr->zstream.avail_out; + png_ptr->zstream.avail_out = 0; /* safety */ + comp->output_len = output_len; + + /* Now double check the output length, put in a custom message if it is + * too long. Otherwise ensure the z_stream::msg pointer is set to + * something. + */ + if (output_len + prefix_len >= PNG_UINT_31_MAX) + { + png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long"); + ret = Z_MEM_ERROR; + } + + else + png_zstream_error(png_ptr, ret); + + /* Reset zlib for another zTXt/iTXt or image data */ + png_ptr->zowner = 0; + + /* The only success case is Z_STREAM_END, input_len must be 0, if not this + * is an internal error. + */ + if (ret == Z_STREAM_END && input_len == 0) + { + /* Fix up the deflate header, if required */ + optimize_cmf(comp->output, comp->input_len); + + /* But Z_OK is returned, not Z_STREAM_END; this allows the claim + * function above to return Z_STREAM_END on an error (though it never + * does in the current versions of zlib.) + */ + return Z_OK; + } + + else + return ret; + } +} + +/* Ship the compressed text out via chunk writes */ +static void +png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp) +{ + png_uint_32 output_len = comp->output_len; + png_const_bytep output = comp->output; + png_uint_32 avail = (sizeof comp->output); + png_compression_buffer *next = png_ptr->zbuffer_list; + + for (;;) + { + if (avail > output_len) + avail = output_len; + + png_write_chunk_data(png_ptr, output, avail); + + output_len -= avail; + + if (output_len == 0 || next == NULL) + break; + + avail = png_ptr->zbuffer_size; + output = next->output; + next = next->next; + } + + /* This is an internal error; 'next' must have been NULL! */ + if (output_len > 0) + png_error(png_ptr, "error writing ancillary chunked compressed data"); +} +#endif /* PNG_WRITE_COMPRESSED_TEXT_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 + * length, forbids leading or trailing whitespace, multiple internal spaces, + * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. + * + * The 'new_key' buffer must be 80 characters in size (for the keyword plus a + * trailing '\0'). If this routine returns 0 then there was no keyword, or a + * valid one could not be generated, and the caller must png_error. + */ +static png_uint_32 +png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key) +{ + png_const_charp orig_key = key; + png_uint_32 key_len = 0; + int bad_character = 0; + int space = 1; + + png_debug(1, "in png_check_keyword"); + + if (key == NULL) + { + *new_key = 0; + return 0; + } + + while (*key && key_len < 79) + { + png_byte ch = (png_byte)(0xff & *key++); + + if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/)) + *new_key++ = ch, ++key_len, space = 0; + + else if (!space) + { + /* A space or an invalid character when one wasn't seen immediately + * before; output just a space. + */ + *new_key++ = 32, ++key_len, space = 1; + + /* If the character was not a space then it is invalid. */ + if (ch != 32) + bad_character = ch; + } + + else if (!bad_character) + bad_character = ch; /* just skip it, record the first error */ + } + + if (key_len > 0 && space) /* trailing space */ + { + --key_len, --new_key; + if (!bad_character) + bad_character = 32; + } + + /* Terminate the keyword */ + *new_key = 0; + + if (key_len == 0) + return 0; + + /* Try to only output one warning per keyword: */ + if (*key) /* keyword too long */ + png_warning(png_ptr, "keyword truncated"); + + else if (bad_character) + { + PNG_WARNING_PARAMETERS(p) + + png_warning_parameter(p, 1, orig_key); + png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character); + + png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'"); + } + + return key_len; } +#endif /* 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 -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) +void /* PRIVATE */ +png_write_IHDR(png_structrp 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) { - 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) { @@ -154,35 +769,61 @@ 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"); } @@ -193,7 +834,24 @@ 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; @@ -201,7 +859,7 @@ 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; @@ -210,21 +868,25 @@ 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; @@ -233,63 +895,47 @@ 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 */ - 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; + + 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 +/* 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_structrp 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"); @@ -297,10 +943,20 @@ 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; @@ -308,75 +964,388 @@ 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 -png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) +/* This is similar to png_text_compress, above, except that it does not require + * all of the data at once and, instead of buffering the compressed result, + * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out + * because it calls the write interface. As a result it does its own error + * reporting and does not return an error code. In the event of error it will + * just call png_error. The input data length may exceed 32-bits. The 'flush' + * parameter is exactly the same as that to deflate, with the following + * meanings: + * + * Z_NO_FLUSH: normal incremental output of compressed data + * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush + * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up + * + * The routine manages the acquire and release of the png_ptr->zstream by + * checking and (at the end) clearing png_ptr->zowner, it does some sanity + * checks on the 'mode' flags while doing this. + */ +void /* PRIVATE */ +png_compress_IDAT(png_structrp png_ptr, png_const_bytep input, + png_alloc_size_t input_len, int flush) { - png_debug(1, "in png_write_IDAT\n"); - png_write_chunk(png_ptr, png_IDAT, data, length); - png_ptr->mode |= PNG_HAVE_IDAT; + if (png_ptr->zowner != png_IDAT) + { + /* First time. Ensure we have a temporary buffer for compression and + * trim the buffer list if it has more than one entry to free memory. + * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been + * created at this point, but the check here is quick and safe. + */ + if (png_ptr->zbuffer_list == NULL) + { + png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp, + png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); + png_ptr->zbuffer_list->next = NULL; + } + + else + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next); + + /* It is a terminal error if we can't claim the zstream. */ + if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + /* The output state is maintained in png_ptr->zstream, so it must be + * initialized here after the claim. + */ + png_ptr->zstream.next_out = png_ptr->zbuffer_list->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + } + + /* Now loop reading and writing until all the input is consumed or an error + * terminates the operation. The _out values are maintained across calls to + * this function, but the input must be reset each time. + */ + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); + png_ptr->zstream.avail_in = 0; /* set below */ + for (;;) + { + int ret; + + /* INPUT: from the row data */ + uInt avail = ZLIB_IO_MAX; + + if (avail > input_len) + avail = (uInt)input_len; /* safe because of the check */ + + png_ptr->zstream.avail_in = avail; + input_len -= avail; + + ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush); + + /* Include as-yet unconsumed input */ + input_len += png_ptr->zstream.avail_in; + png_ptr->zstream.avail_in = 0; + + /* OUTPUT: write complete IDAT chunks when avail_out drops to zero, note + * that these two zstream fields are preserved across the calls, therefore + * there is no need to set these up on entry to the loop. + */ + if (png_ptr->zstream.avail_out == 0) + { + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size; + + /* Write an IDAT containing the data then reset the buffer. The + * first IDAT may need deflate header optimization. + */ +# ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if (!(png_ptr->mode & PNG_HAVE_IDAT) && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +# endif + + png_write_complete_chunk(png_ptr, png_IDAT, data, size); + png_ptr->mode |= PNG_HAVE_IDAT; + + png_ptr->zstream.next_out = data; + png_ptr->zstream.avail_out = size; + + /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with + * the same flush parameter until it has finished output, for NO_FLUSH + * it doesn't matter. + */ + if (ret == Z_OK && flush != Z_NO_FLUSH) + continue; + } + + /* The order of these checks doesn't matter much; it just effect which + * possible error might be detected if multiple things go wrong at once. + */ + if (ret == Z_OK) /* most likely return code! */ + { + /* If all the input has been consumed then just return. If Z_FINISH + * was used as the flush parameter something has gone wrong if we get + * here. + */ + if (input_len == 0) + { + if (flush == Z_FINISH) + png_error(png_ptr, "Z_OK on Z_FINISH with output space"); + + return; + } + } + + else if (ret == Z_STREAM_END && flush == Z_FINISH) + { + /* This is the end of the IDAT data; any pending output must be + * flushed. For small PNG files we may still be at the beginning. + */ + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out; + +# ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if (!(png_ptr->mode & PNG_HAVE_IDAT) && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +# endif + + png_write_complete_chunk(png_ptr, png_IDAT, data, size); + png_ptr->zstream.avail_out = 0; + png_ptr->zstream.next_out = NULL; + png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT; + + png_ptr->zowner = 0; /* Release the stream */ + return; + } + + else + { + /* This is an error condition. */ + png_zstream_error(png_ptr, ret); + png_error(png_ptr, png_ptr->zstream.msg); + } + } } -/* write an IEND chunk */ -void -png_write_IEND(png_structp png_ptr) +/* Write an IEND chunk */ +void /* PRIVATE */ +png_write_IEND(png_structrp 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_structrp 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 -png_write_sRGB(png_structp png_ptr, int srgb_intent) +#ifdef PNG_WRITE_sRGB_SUPPORTED +/* Write a sRGB chunk */ +void /* PRIVATE */ +png_write_sRGB(png_structrp 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_structrp png_ptr, png_const_charp name, + png_const_bytep profile) +{ + png_uint_32 name_len; + png_uint_32 profile_len; + png_byte new_name[81]; /* 1 byte for the compression byte */ + compression_state comp; + + png_debug(1, "in png_write_iCCP"); + + /* These are all internal problems: the profile should have been checked + * before when it was stored. + */ + if (profile == NULL) + png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */ + + profile_len = png_get_uint_32(profile); + + if (profile_len < 132) + png_error(png_ptr, "ICC profile too short"); + + if (profile_len & 0x03) + png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)"); + + { + png_uint_32 embedded_profile_len = png_get_uint_32(profile); + + if (profile_len != embedded_profile_len) + png_error(png_ptr, "Profile length does not match profile"); + } + + name_len = png_check_keyword(png_ptr, name, new_name); + + if (name_len == 0) + png_error(png_ptr, "iCCP: invalid keyword"); + + new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE; + + /* Make sure we include the NULL after the name and the compression type */ + ++name_len; + + png_text_compress_init(&comp, profile, profile_len); + + /* Allow for keyword terminator and compression byte */ + if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len); + + png_write_chunk_data(png_ptr, new_name, name_len); + + png_write_compressed_data_out(png_ptr, &comp); + + png_write_chunk_end(png_ptr); } #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_sPLT_SUPPORTED +/* Write a sPLT chunk */ +void /* PRIVATE */ +png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette) +{ + png_uint_32 name_len; + png_byte new_name[80]; + 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"); + + name_len = png_check_keyword(png_ptr, spalette->name, new_name); + + if (name_len == 0) + png_error(png_ptr, "sPLT: invalid keyword"); + + /* 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, 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, entry_size); + } +#endif + + png_write_chunk_end(png_ptr); +} +#endif + +#ifdef PNG_WRITE_sBIT_SUPPORTED +/* Write the sBIT chunk */ +void /* PRIVATE */ +png_write_sBIT(png_structrp 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; + 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) @@ -384,11 +1353,13 @@ 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->red; buf[1] = sbit->green; buf[2] = sbit->blue; size = 3; } + else { if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) @@ -396,6 +1367,7 @@ 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; } @@ -407,595 +1379,472 @@ 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_structrp png_ptr, const png_xy *xy) { - 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) - { - 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); + /* Each value is saved in 1/100,000ths */ + png_save_int_32(buf, xy->whitex); + png_save_int_32(buf + 4, xy->whitey); - 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_int_32(buf + 8, xy->redx); + png_save_int_32(buf + 12, xy->redy); - 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_int_32(buf + 16, xy->greenx); + png_save_int_32(buf + 20, xy->greeny); + + png_save_int_32(buf + 24, xy->bluex); + png_save_int_32(buf + 28, xy->bluey); - png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); + png_write_complete_chunk(png_ptr, png_cHRM, buf, 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_structrp 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_app_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_app_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_app_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"); + png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); } } #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_structrp 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); - } - else - { - png_save_uint_16(buf, back->gray); - png_write_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) -{ - int i; - png_byte buf[3]; - - png_debug(1, "in png_write_hIST\n"); - 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_warning(png_ptr, "Invalid number of histogram entries specified"); - return; - } - - png_write_chunk_start(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) || \ - defined(PNG_WRITE_pCAL_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 - * length, forbids leading or trailing whitespace, multiple internal spaces, - * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. - * - * The new_key is allocated to hold the corrected keyword and must be freed - * 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 key_len; - png_charp kp, dp; - int kflag; - - 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"); - return ((png_size_t)0); - } - - png_debug1(2, "Keyword to be checked is '%s'\n", key); - - *new_key = (png_charp)png_malloc(png_ptr, (png_uint_32)(key_len + 1)); - - /* Replace non-printing characters with a blank and print a warning */ - for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++) - { - if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1)) - { -#if !defined(PNG_NO_STDIO) - char msg[40]; - - sprintf(msg, "invalid keyword character 0x%02X", *kp); - png_chunk_warning(png_ptr, msg); +#ifdef PNG_WRITE_16BIT_SUPPORTED + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) #else - png_chunk_warning(png_ptr, "invalid character in keyword"); + if (buf[0] | buf[2] | buf[4]) #endif - *dp = ' '; - } - else { - *dp = *kp; - } - } - *dp = '\0'; - - /* Remove any trailing white space. */ - kp = *new_key + key_len - 1; - if (*kp == ' ') - { - png_chunk_warning(png_ptr, "trailing spaces removed from keyword"); + png_warning(png_ptr, + "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); - while (*kp == ' ') - { - *(kp--) = '\0'; - key_len--; + return; } + + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); } - /* Remove any leading white space. */ - kp = *new_key; - if (*kp == ' ') + else { - png_chunk_warning(png_ptr, "leading spaces removed from keyword"); - - while (*kp == ' ') + if (back->gray >= (1 << png_ptr->bit_depth)) { - kp++; - key_len--; + 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_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); } +} +#endif - png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp); +#ifdef PNG_WRITE_hIST_SUPPORTED +/* Write the histogram */ +void /* PRIVATE */ +png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist) +{ + int i; + png_byte buf[3]; - /* Remove multiple internal spaces. */ - for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) - { - if (*kp == ' ' && kflag == 0) - { - *(dp++) = *kp; - kflag = 1; - } - else if (*kp == ' ') - { - key_len--; - } - else - { - *(dp++) = *kp; - kflag = 0; - } - } - *dp = '\0'; + png_debug(1, "in png_write_hIST"); - if (key_len == 0) + if (num_hist > (int)png_ptr->num_palette) { - png_chunk_warning(png_ptr, "zero length keyword"); + 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; } - if (key_len > 79) + png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + + for (i = 0; i < num_hist; i++) { - png_chunk_warning(png_ptr, "keyword length must be 1 - 79 characters"); - new_key[79] = '\0'; - key_len = 79; + png_save_uint_16(buf, hist[i]); + png_write_chunk_data(png_ptr, buf, (png_size_t)2); } - return (key_len); + png_write_chunk_end(png_ptr); } #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_structrp 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_uint_32 key_len; + png_byte new_key[80]; - 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"); - return; - } + png_debug(1, "in png_write_tEXt"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "tEXt: invalid keyword"); 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 = strlen(text); + + if (text_len > PNG_UINT_31_MAX - (key_len+1)) + png_error(png_ptr, "tEXt: text too long"); + + /* Make sure we include the 0 after the key */ + png_write_chunk_header(png_ptr, png_tEXt, + (png_uint_32)/*checked above*/(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, new_key, 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, 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_structrp 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_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 */ + png_uint_32 key_len; + png_byte new_key[81]; + compression_state comp; - png_debug(1, "in png_write_zTXt\n"); + png_debug(1, "in png_write_zTXt"); + PNG_UNUSED(text_len) /* Always use strlen */ - if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0) + if (compression == PNG_TEXT_COMPRESSION_NONE) { - png_warning(png_ptr, "Empty keyword in zTXt chunk"); + png_write_tEXt(png_ptr, key, text, 0); return; } - if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) - { - png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); - png_free(png_ptr, new_key); - return; - } + if (compression != PNG_TEXT_COMPRESSION_zTXt) + png_error(png_ptr, "zTXt: invalid compression type"); - png_free(png_ptr, new_key); + key_len = png_check_keyword(png_ptr, key, 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"); + if (key_len == 0) + png_error(png_ptr, "zTXt: invalid keyword"); + + /* Add the compression method and 1 for the keyword separator. */ + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; + ++key_len; + + /* Compute the compressed data; do it now for the length */ + png_text_compress_init(&comp, (png_const_bytep)text, + text == NULL ? 0 : strlen(text)); + + if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + + /* Write start of chunk */ + png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len); + + /* Write key */ + png_write_chunk_data(png_ptr, new_key, key_len); + + /* Write the compressed data */ + png_write_compressed_data_out(png_ptr, &comp); + + /* Close the chunk */ + png_write_chunk_end(png_ptr); +} #endif - compression = PNG_TEXT_COMPRESSION_zTXt; + +#ifdef PNG_WRITE_iTXt_SUPPORTED +/* Write an iTXt chunk */ +void /* PRIVATE */ +png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key, + png_const_charp lang, png_const_charp lang_key, png_const_charp text) +{ + png_uint_32 key_len, prefix_len; + png_size_t lang_len, lang_key_len; + png_byte new_key[82]; + compression_state comp; + + png_debug(1, "in png_write_iTXt"); + + key_len = png_check_keyword(png_ptr, key, new_key); + + if (key_len == 0) + png_error(png_ptr, "iTXt: invalid keyword"); + + /* Set the compression flag */ + switch (compression) + { + case PNG_ITXT_COMPRESSION_NONE: + case PNG_TEXT_COMPRESSION_NONE: + compression = new_key[++key_len] = 0; /* no compression */ + break; + + case PNG_TEXT_COMPRESSION_zTXt: + case PNG_ITXT_COMPRESSION_zTXt: + compression = new_key[++key_len] = 1; /* compressed */ + break; + + default: + png_error(png_ptr, "iTXt: invalid compression"); } - /* 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. + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; + ++key_len; /* for the keywod separator */ + + /* 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, however, + * specifies that the text is UTF-8 and this really doesn't require any + * checking. * - * 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). + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. + * + * TODO: validate the language tag correctly (see the spec.) */ + if (lang == NULL) lang = ""; /* empty language is valid */ + lang_len = strlen(lang)+1; + if (lang_key == NULL) lang_key = ""; /* may be empty */ + lang_key_len = strlen(lang_key)+1; + if (text == NULL) text = ""; /* may be empty */ + + prefix_len = key_len; + if (lang_len > PNG_UINT_31_MAX-prefix_len) + prefix_len = PNG_UINT_31_MAX; + else + prefix_len = (png_uint_32)(prefix_len + lang_len); - /* 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; + if (lang_key_len > PNG_UINT_31_MAX-prefix_len) + prefix_len = PNG_UINT_31_MAX; + else + prefix_len = (png_uint_32)(prefix_len + lang_key_len); + + png_text_compress_init(&comp, (png_const_bytep)text, strlen(text)); - /* this is the same compression loop as in png_write_row() */ - do + if (compression) { - /* 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; + if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + } - old_max = max_output_ptr; - max_output_ptr = num_output_ptr + 4; - if (output_ptr != NULL) - { - png_charpp old_ptr; + else + { + if (comp.input_len > PNG_UINT_31_MAX-prefix_len) + png_error(png_ptr, "iTXt: uncompressed text too long"); - 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))); - } + /* So the string will fit in a chunk: */ + comp.output_len = (png_uint_32)/*SAFE*/comp.input_len; + } - /* 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++; + png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len); - /* 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); + png_write_chunk_data(png_ptr, new_key, key_len); - /* 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"); - } + png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len); - /* 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_data(png_ptr, (png_const_bytep)lang_key, lang_key_len); - old_max = max_output_ptr; - max_output_ptr = num_output_ptr + 4; - if (output_ptr != NULL) - { - png_charpp old_ptr; - - 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))); - } + if (compression) + png_write_compressed_data_out(png_ptr, &comp); - /* 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++; - - /* 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); - - /* 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; - - /* 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); - - /* 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); + else + png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.input_len); - /* reset zlib for another zTXt or the image data */ - deflateReset(&png_ptr->zstream); + png_write_chunk_end(png_ptr); } #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_structrp 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 -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) +#ifdef PNG_WRITE_pCAL_SUPPORTED +/* Write the pCAL chunk (described in the PNG extensions document) */ +void /* PRIVATE */ +png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0, + 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_uint_32 purpose_len; + png_size_t units_len, total_len; + png_size_tp params_len; png_byte buf[10]; - png_charp new_purpose; + png_byte new_purpose[80]; 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"); + png_error(png_ptr, "Unrecognized equation type for pCAL chunk"); + + purpose_len = png_check_keyword(png_ptr, purpose, new_purpose); - purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; - png_debug1(3, "pCAL purpose length = %d\n", purpose_len); - units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); - png_debug1(3, "pCAL units length = %d\n", units_len); + if (purpose_len == 0) + png_error(png_ptr, "pCAL: invalid keyword"); + + ++purpose_len; /* terminator */ + + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); + units_len = strlen(units) + (nparams == 0 ? 0 : 1); + 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 * (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]; + params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + 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, 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_free(png_ptr, new_purpose); + png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); 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 +1852,47 @@ 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 -png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, - png_uint_32 y_pixels_per_unit, - int unit_type) +#ifdef PNG_WRITE_sCAL_SUPPORTED +/* Write the sCAL chunk */ +void /* PRIVATE */ +png_write_sCAL_s(png_structrp 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 = strlen(width); + hlen = 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; + memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ + 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_structrp png_ptr, png_uint_32 x_pixels_per_unit, + 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 +1900,21 @@ 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_structrp 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 +1930,147 @@ 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 -png_write_start_row(png_structp png_ptr) +/* Initializes the row writing capability of libpng */ +void /* PRIVATE */ +png_write_start_row(png_structrp 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}; + + /* 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_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); + 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_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 -png_write_finish_row(png_structp png_ptr) +void /* PRIVATE */ +png_write_finish_row(png_structrp png_ptr) { - int ret; +#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}; - png_debug(1, "in png_write_finish_row\n"); - /* next row */ + /* 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_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 +2078,53 @@ 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); + 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 */ - ret = deflate(&png_ptr->zstream, Z_FINISH); - /* check for an error */ - if (ret != Z_OK && 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 */ - 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); - } - - deflateReset(&png_ptr->zstream); + png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH); } -#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 +2132,23 @@ 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 separately */ + /* Each pixel depth is handled separately */ switch (row_info->pixel_depth) { case 1: @@ -1257,11 +2164,12 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) dp = row; d = 0; shift = 7; + 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) @@ -1270,14 +2178,17 @@ 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; @@ -1291,11 +2202,12 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) dp = row; shift = 6; d = 0; + 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) @@ -1304,13 +2216,16 @@ 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; @@ -1325,10 +2240,10 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) shift = 4; d = 0; for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) + 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) @@ -1337,13 +2252,16 @@ 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; @@ -1352,33 +2270,37 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) 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 */ + + /* 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 */ + memcpy(dp, sp, pixel_bytes); + + /* 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 @@ -1387,27 +2309,44 @@ 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_structrp 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 -png_write_find_filter(png_structp png_ptr, png_row_infop row_info) +void /* PRIVATE */ +png_write_find_filter(png_structrp 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_uint_32 row_bytes = row_info->rowbytes; -#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) - int num_p_filters = (int)png_ptr->num_prev_filters; + 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 @@ -1422,11 +2361,14 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) * 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) */ @@ -1435,12 +2377,11 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) /* 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 (filter_to_do & PNG_FILTER_NONE && - filter_to_do != 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_bytes; i++, rp++) @@ -1449,7 +2390,7 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) 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; @@ -1463,9 +2404,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) { sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; } } @@ -1474,12 +2416,14 @@ 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; } @@ -1487,22 +2431,25 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) mins = sum; } - /* sub filter */ + /* Sub filter */ if (filter_to_do == PNG_FILTER_SUB) - /* it's the only filter so no testing is needed */ + /* It's the only filter so no testing is needed */ { png_bytep rp, lp, dp; - png_uint_32 i; + 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; } @@ -1510,10 +2457,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) { 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) +#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. @@ -1530,19 +2477,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) { lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; } @@ -1555,7 +2505,8 @@ 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); @@ -1566,7 +2517,7 @@ 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; @@ -1579,19 +2530,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) { sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; } @@ -1604,18 +2558,19 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) } } - /* up filter */ + /* Up filter */ if (filter_to_do == PNG_FILTER_UP) { png_bytep rp, dp, pp; - png_uint_32 i; + 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++) + 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; } @@ -1623,11 +2578,11 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) { 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; @@ -1640,26 +2595,29 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) { lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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_bytes; i++) + pp = prev_row + 1; i < row_bytes; i++) { v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); @@ -1669,7 +2627,7 @@ 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; @@ -1682,19 +2640,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) { sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; } @@ -1707,16 +2668,18 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) } } - /* avg filter */ + /* Avg filter */ if (filter_to_do == PNG_FILTER_AVG) { png_bytep rp, dp, pp, lp; 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)) @@ -1729,10 +2692,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) { png_bytep rp, dp, pp, 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; @@ -1745,19 +2708,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) { lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; } @@ -1770,10 +2736,11 @@ 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_bytes; i++) { v = *dp++ = - (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); + (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); sum += (v < 128) ? v : 256 - v; @@ -1781,7 +2748,7 @@ 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; @@ -1794,19 +2761,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) { sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; } @@ -1823,9 +2793,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (filter_to_do == PNG_FILTER_PAETH) { png_bytep rp, dp, pp, cp, lp; - png_uint_32 i; + png_size_t i; + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, - pp = prev_row + 1; i < bpp; i++) + pp = prev_row + 1; i < bpp; i++) { *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); } @@ -1862,10 +2833,10 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) { 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; @@ -1878,26 +2849,29 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) { lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; i < bpp; i++) + pp = prev_row + 1; i < bpp; i++) { v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); @@ -1930,10 +2904,13 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) pa = abs(p - a); pb = abs(p - b); pc = abs(p - c); + if (pa <= pb && pa <= pc) p = a; + else if (pb <= pc) p = b; + else p = c; #endif /* PNG_SLOW_PAETH */ @@ -1946,7 +2923,7 @@ 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; @@ -1959,19 +2936,22 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) { sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; + 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; } @@ -1982,63 +2962,42 @@ 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, row_info->rowbytes+1); - png_write_filtered_row(png_ptr, best_row); - -#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 j; + for (j = 1; j < num_p_filters; j++) { png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; } + 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_structrp png_ptr, png_bytep filtered_row, + png_size_t full_row_length/*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_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 */ - do - { - int ret; /* return of zlib */ - - /* compress the data */ - ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); - /* 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"); - } + png_debug(1, "in png_write_filtered_row"); - /* see if it is time to write another IDAT */ - if (!(png_ptr->zstream.avail_out)) - { - /* 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); + png_debug1(2, "filter = %d", filtered_row[0]); - /* swap the current and previous rows */ + png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH); + + /* Swap the current and previous rows */ if (png_ptr->prev_row != NULL) { png_bytep tptr; @@ -2048,10 +3007,10 @@ 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 && @@ -2059,5 +3018,6 @@ 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 */