| 1 | /* $Header$ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1991-1997 Sam Leffler |
| 5 | * Copyright (c) 1991-1997 Silicon Graphics, Inc. |
| 6 | * |
| 7 | * Permission to use, copy, modify, distribute, and sell this software and |
| 8 | * its documentation for any purpose is hereby granted without fee, provided |
| 9 | * that (i) the above copyright notices and this permission notice appear in |
| 10 | * all copies of the software and related documentation, and (ii) the names of |
| 11 | * Sam Leffler and Silicon Graphics may not be used in any advertising or |
| 12 | * publicity relating to the software without the specific, prior written |
| 13 | * permission of Sam Leffler and Silicon Graphics. |
| 14 | * |
| 15 | * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, |
| 16 | * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY |
| 17 | * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. |
| 18 | * |
| 19 | * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR |
| 20 | * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, |
| 21 | * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, |
| 22 | * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF |
| 23 | * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE |
| 24 | * OF THIS SOFTWARE. |
| 25 | */ |
| 26 | |
| 27 | /* |
| 28 | * TIFF Library. |
| 29 | * |
| 30 | * Strip-organized Image Support Routines. |
| 31 | */ |
| 32 | #include "tiffiop.h" |
| 33 | |
| 34 | /* |
| 35 | * Compute which strip a (row,sample) value is in. |
| 36 | */ |
| 37 | tstrip_t |
| 38 | TIFFComputeStrip(TIFF* tif, uint32 row, tsample_t sample) |
| 39 | { |
| 40 | TIFFDirectory *td = &tif->tif_dir; |
| 41 | tstrip_t strip; |
| 42 | |
| 43 | strip = row / td->td_rowsperstrip; |
| 44 | if (td->td_planarconfig == PLANARCONFIG_SEPARATE) { |
| 45 | if (sample >= td->td_samplesperpixel) { |
| 46 | TIFFError(tif->tif_name, |
| 47 | "%u: Sample out of range, max %u", |
| 48 | sample, td->td_samplesperpixel); |
| 49 | return ((tstrip_t) 0); |
| 50 | } |
| 51 | strip += sample*td->td_stripsperimage; |
| 52 | } |
| 53 | return (strip); |
| 54 | } |
| 55 | |
| 56 | /* |
| 57 | * Compute how many strips are in an image. |
| 58 | */ |
| 59 | tstrip_t |
| 60 | TIFFNumberOfStrips(TIFF* tif) |
| 61 | { |
| 62 | TIFFDirectory *td = &tif->tif_dir; |
| 63 | tstrip_t nstrips; |
| 64 | |
| 65 | nstrips = (td->td_rowsperstrip == (uint32) -1 ? |
| 66 | (td->td_imagelength != 0 ? 1 : 0) : |
| 67 | TIFFhowmany(td->td_imagelength, td->td_rowsperstrip)); |
| 68 | if (td->td_planarconfig == PLANARCONFIG_SEPARATE) |
| 69 | nstrips *= td->td_samplesperpixel; |
| 70 | return (nstrips); |
| 71 | } |
| 72 | |
| 73 | /* |
| 74 | * Compute the # bytes in a variable height, row-aligned strip. |
| 75 | */ |
| 76 | tsize_t |
| 77 | TIFFVStripSize(TIFF* tif, uint32 nrows) |
| 78 | { |
| 79 | TIFFDirectory *td = &tif->tif_dir; |
| 80 | |
| 81 | if (nrows == (uint32) -1) |
| 82 | nrows = td->td_imagelength; |
| 83 | #ifdef YCBCR_SUPPORT |
| 84 | if (td->td_planarconfig == PLANARCONFIG_CONTIG && |
| 85 | td->td_photometric == PHOTOMETRIC_YCBCR && |
| 86 | !isUpSampled(tif)) { |
| 87 | /* |
| 88 | * Packed YCbCr data contain one Cb+Cr for every |
| 89 | * HorizontalSampling*VerticalSampling Y values. |
| 90 | * Must also roundup width and height when calculating |
| 91 | * since images that are not a multiple of the |
| 92 | * horizontal/vertical subsampling area include |
| 93 | * YCbCr data for the extended image. |
| 94 | */ |
| 95 | tsize_t w = |
| 96 | TIFFroundup(td->td_imagewidth, td->td_ycbcrsubsampling[0]); |
| 97 | tsize_t scanline = TIFFhowmany(w*td->td_bitspersample, 8); |
| 98 | tsize_t samplingarea = |
| 99 | td->td_ycbcrsubsampling[0]*td->td_ycbcrsubsampling[1]; |
| 100 | nrows = TIFFroundup(nrows, td->td_ycbcrsubsampling[1]); |
| 101 | /* NB: don't need TIFFhowmany here 'cuz everything is rounded */ |
| 102 | return ((tsize_t) |
| 103 | (nrows*scanline + 2*(nrows*scanline / samplingarea))); |
| 104 | } else |
| 105 | #endif |
| 106 | return ((tsize_t)(nrows * TIFFScanlineSize(tif))); |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * Compute the # bytes in a (row-aligned) strip. |
| 111 | * |
| 112 | * Note that if RowsPerStrip is larger than the |
| 113 | * recorded ImageLength, then the strip size is |
| 114 | * truncated to reflect the actual space required |
| 115 | * to hold the strip. |
| 116 | */ |
| 117 | tsize_t |
| 118 | TIFFStripSize(TIFF* tif) |
| 119 | { |
| 120 | TIFFDirectory* td = &tif->tif_dir; |
| 121 | uint32 rps = td->td_rowsperstrip; |
| 122 | if (rps > td->td_imagelength) |
| 123 | rps = td->td_imagelength; |
| 124 | return (TIFFVStripSize(tif, rps)); |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * Compute a default strip size based on the image |
| 129 | * characteristics and a requested value. If the |
| 130 | * request is <1 then we choose a strip size according |
| 131 | * to certain heuristics. |
| 132 | */ |
| 133 | uint32 |
| 134 | TIFFDefaultStripSize(TIFF* tif, uint32 request) |
| 135 | { |
| 136 | return (*tif->tif_defstripsize)(tif, request); |
| 137 | } |
| 138 | |
| 139 | uint32 |
| 140 | _TIFFDefaultStripSize(TIFF* tif, uint32 s) |
| 141 | { |
| 142 | if ((int32) s < 1) { |
| 143 | /* |
| 144 | * If RowsPerStrip is unspecified, try to break the |
| 145 | * image up into strips that are approximately 8Kbytes. |
| 146 | */ |
| 147 | tsize_t scanline = TIFFScanlineSize(tif); |
| 148 | s = (uint32)(8*1024) / (scanline == 0 ? 1 : scanline); |
| 149 | if (s == 0) /* very wide images */ |
| 150 | s = 1; |
| 151 | } |
| 152 | return (s); |
| 153 | } |
| 154 | |
| 155 | /* |
| 156 | * Return the number of bytes to read/write in a call to |
| 157 | * one of the scanline-oriented i/o routines. Note that |
| 158 | * this number may be 1/samples-per-pixel if data is |
| 159 | * stored as separate planes. |
| 160 | */ |
| 161 | tsize_t |
| 162 | TIFFScanlineSize(TIFF* tif) |
| 163 | { |
| 164 | TIFFDirectory *td = &tif->tif_dir; |
| 165 | tsize_t scanline; |
| 166 | |
| 167 | scanline = td->td_bitspersample * td->td_imagewidth; |
| 168 | if (td->td_planarconfig == PLANARCONFIG_CONTIG) |
| 169 | scanline *= td->td_samplesperpixel; |
| 170 | return ((tsize_t) TIFFhowmany(scanline, 8)); |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * Return the number of bytes required to store a complete |
| 175 | * decoded and packed raster scanline (as opposed to the |
| 176 | * I/O size returned by TIFFScanlineSize which may be less |
| 177 | * if data is store as separate planes). |
| 178 | */ |
| 179 | tsize_t |
| 180 | TIFFRasterScanlineSize(TIFF* tif) |
| 181 | { |
| 182 | TIFFDirectory *td = &tif->tif_dir; |
| 183 | tsize_t scanline; |
| 184 | |
| 185 | scanline = td->td_bitspersample * td->td_imagewidth; |
| 186 | if (td->td_planarconfig == PLANARCONFIG_CONTIG) { |
| 187 | scanline *= td->td_samplesperpixel; |
| 188 | return ((tsize_t) TIFFhowmany(scanline, 8)); |
| 189 | } else |
| 190 | return ((tsize_t) |
| 191 | TIFFhowmany(scanline, 8)*td->td_samplesperpixel); |
| 192 | } |