libavcodec/8bps.c

   1 /*
   2  * Quicktime Planar RGB (8BPS) Video Decoder
   3  * Copyright (C) 2003 Roberto Togni
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file libavcodec/8bps.c
  24  * QT 8BPS Video Decoder by Roberto Togni
  25  * For more information about the 8BPS format, visit:
  26  *   http://www.pcisys.net/~melanson/codecs/
  27  *
  28  * Supports: PAL8 (RGB 8bpp, paletted)
  29  *         : BGR24 (RGB 24bpp) (can also output it as RGB32)
  30  *         : RGB32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)
  31  *
  32  */
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36
  37 #include "libavutil/intreadwrite.h"
  38 #include "avcodec.h"
  39
  40
  41 static const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGB32, PIX_FMT_NONE};
  42
  43 /*
  44  * Decoder context
  45  */
  46 typedef struct EightBpsContext {
  47
  48         AVCodecContext *avctx;
  49         AVFrame pic;
  50
  51         unsigned char planes;
  52         unsigned char planemap[4];
  53 } EightBpsContext;
  54
  55
  56 /*
  57  *
  58  * Decode a frame
  59  *
  60  */
  61 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
  62 {
  63         EightBpsContext * const c = avctx->priv_data;
  64         const unsigned char *encoded = buf;
  65         unsigned char *pixptr, *pixptr_end;
  66         unsigned int height = avctx->height; // Real image height
  67         unsigned int dlen, p, row;
  68         const unsigned char *lp, *dp;
  69         unsigned char count;
  70         unsigned int px_inc;
  71         unsigned int planes = c->planes;
  72         unsigned char *planemap = c->planemap;
  73
  74         if(c->pic.data[0])
  75                 avctx->release_buffer(avctx, &c->pic);
  76
  77         c->pic.reference = 0;
  78         c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
  79         if(avctx->get_buffer(avctx, &c->pic) < 0){
  80                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  81                 return -1;
  82         }
  83
  84         /* Set data pointer after line lengths */
  85         dp = encoded + planes * (height << 1);
  86
  87         /* Ignore alpha plane, don't know what to do with it */
  88         if (planes == 4)
  89                 planes--;
  90
  91         px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);
  92
  93         for (p = 0; p < planes; p++) {
  94                 /* Lines length pointer for this plane */
  95                 lp = encoded + p * (height << 1);
  96
  97                 /* Decode a plane */
  98                 for(row = 0; row < height; row++) {
  99                         pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
 100                         pixptr_end = pixptr + c->pic.linesize[0];
 101                         dlen = be2me_16(*(const unsigned short *)(lp+row*2));
 102                         /* Decode a row of this plane */
 103                         while(dlen > 0) {
 104                                 if(dp + 1 >= buf+buf_size) return -1;
 105                                 if ((count = *dp++) <= 127) {
 106                                         count++;
 107                                         dlen -= count + 1;
 108                                         if (pixptr + count * px_inc > pixptr_end)
 109                                             break;
 110                                         if(dp + count > buf+buf_size) return -1;
 111                                         while(count--) {
 112                                                 *pixptr = *dp++;
 113                                                 pixptr += px_inc;
 114                                         }
 115                                 } else {
 116                                         count = 257 - count;
 117                                         if (pixptr + count * px_inc > pixptr_end)
 118                                             break;
 119                                         while(count--) {
 120                                                 *pixptr = *dp;
 121                                                 pixptr += px_inc;
 122                                         }
 123                                         dp++;
 124                                         dlen -= 2;
 125                                 }
 126                         }
 127                 }
 128         }
 129
 130         if (avctx->palctrl) {
 131                 memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
 132                 if (avctx->palctrl->palette_changed) {
 133                         c->pic.palette_has_changed = 1;
 134                         avctx->palctrl->palette_changed = 0;
 135                 } else
 136                         c->pic.palette_has_changed = 0;
 137         }
 138
 139         *data_size = sizeof(AVFrame);
 140         *(AVFrame*)data = c->pic;
 141
 142         /* always report that the buffer was completely consumed */
 143         return buf_size;
 144 }
 145
 146
 147 /*
 148  *
 149  * Init 8BPS decoder
 150  *
 151  */
 152 static av_cold int decode_init(AVCodecContext *avctx)
 153 {
 154         EightBpsContext * const c = avctx->priv_data;
 155
 156         c->avctx = avctx;
 157
 158         c->pic.data[0] = NULL;
 159
 160     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
 161         return 1;
 162     }
 163
 164         switch (avctx->bits_per_coded_sample) {
 165                 case 8:
 166                         avctx->pix_fmt = PIX_FMT_PAL8;
 167                         c->planes = 1;
 168                         c->planemap[0] = 0; // 1st plane is palette indexes
 169                         if (avctx->palctrl == NULL) {
 170                                 av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
 171                                 return -1;
 172                         }
 173                         break;
 174                 case 24:
 175                         avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
 176                         c->planes = 3;
 177                         c->planemap[0] = 2; // 1st plane is red
 178                         c->planemap[1] = 1; // 2nd plane is green
 179                         c->planemap[2] = 0; // 3rd plane is blue
 180                         break;
 181                 case 32:
 182                         avctx->pix_fmt = PIX_FMT_RGB32;
 183                         c->planes = 4;
 184 #ifdef WORDS_BIGENDIAN
 185                         c->planemap[0] = 1; // 1st plane is red
 186                         c->planemap[1] = 2; // 2nd plane is green
 187                         c->planemap[2] = 3; // 3rd plane is blue
 188                         c->planemap[3] = 0; // 4th plane is alpha???
 189 #else
 190                         c->planemap[0] = 2; // 1st plane is red
 191                         c->planemap[1] = 1; // 2nd plane is green
 192                         c->planemap[2] = 0; // 3rd plane is blue
 193                         c->planemap[3] = 3; // 4th plane is alpha???
 194 #endif
 195                         break;
 196                 default:
 197                         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_coded_sample);
 198                         return -1;
 199         }
 200
 201   return 0;
 202 }
 203
 204
 205
 206
 207 /*
 208  *
 209  * Uninit 8BPS decoder
 210  *
 211  */
 212 static av_cold int decode_end(AVCodecContext *avctx)
 213 {
 214         EightBpsContext * const c = avctx->priv_data;
 215
 216         if (c->pic.data[0])
 217                 avctx->release_buffer(avctx, &c->pic);
 218
 219         return 0;
 220 }
 221
 222
 223
 224 AVCodec eightbps_decoder = {
 225         "8bps",
 226         CODEC_TYPE_VIDEO,
 227         CODEC_ID_8BPS,
 228         sizeof(EightBpsContext),
 229         decode_init,
 230         NULL,
 231         decode_end,
 232         decode_frame,
 233         CODEC_CAP_DR1,
 234         .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
 235 };