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 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 "avcodec.h"
  38
  39
  40 static const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGB32, PIX_FMT_NONE};
  41
  42 /*
  43  * Decoder context
  44  */
  45 typedef struct EightBpsContext {
  46
  47         AVCodecContext *avctx;
  48         AVFrame pic;
  49
  50         unsigned char planes;
  51         unsigned char planemap[4];
  52 } EightBpsContext;
  53
  54
  55 /*
  56  *
  57  * Decode a frame
  58  *
  59  */
  60 static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
  61 {
  62         EightBpsContext * const c = avctx->priv_data;
  63         const unsigned char *encoded = buf;
  64         unsigned char *pixptr, *pixptr_end;
  65         unsigned int height = avctx->height; // Real image height
  66         unsigned int dlen, p, row;
  67         const unsigned char *lp, *dp;
  68         unsigned char count;
  69         unsigned int px_inc;
  70         unsigned int planes = c->planes;
  71         unsigned char *planemap = c->planemap;
  72
  73         if(c->pic.data[0])
  74                 avctx->release_buffer(avctx, &c->pic);
  75
  76         c->pic.reference = 0;
  77         c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
  78         if(avctx->get_buffer(avctx, &c->pic) < 0){
  79                 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
  80                 return -1;
  81         }
  82
  83         /* Set data pointer after line lengths */
  84         dp = encoded + planes * (height << 1);
  85
  86         /* Ignore alpha plane, don't know what to do with it */
  87         if (planes == 4)
  88                 planes--;
  89
  90         px_inc = planes + (avctx->pix_fmt == PIX_FMT_RGB32);
  91
  92         for (p = 0; p < planes; p++) {
  93                 /* Lines length pointer for this plane */
  94                 lp = encoded + p * (height << 1);
  95
  96                 /* Decode a plane */
  97                 for(row = 0; row < height; row++) {
  98                         pixptr = c->pic.data[0] + row * c->pic.linesize[0] + planemap[p];
  99                         pixptr_end = pixptr + c->pic.linesize[0];
 100                         dlen = be2me_16(*(const unsigned short *)(lp+row*2));
 101                         /* Decode a row of this plane */
 102                         while(dlen > 0) {
 103                                 if(dp + 1 >= buf+buf_size) return -1;
 104                                 if ((count = *dp++) <= 127) {
 105                                         count++;
 106                                         dlen -= count + 1;
 107                                         if (pixptr + count * px_inc > pixptr_end)
 108                                             break;
 109                                         if(dp + count > buf+buf_size) return -1;
 110                                         while(count--) {
 111                                                 *pixptr = *dp++;
 112                                                 pixptr += px_inc;
 113                                         }
 114                                 } else {
 115                                         count = 257 - count;
 116                                         if (pixptr + count * px_inc > pixptr_end)
 117                                             break;
 118                                         while(count--) {
 119                                                 *pixptr = *dp;
 120                                                 pixptr += px_inc;
 121                                         }
 122                                         dp++;
 123                                         dlen -= 2;
 124                                 }
 125                         }
 126                 }
 127         }
 128
 129         if (avctx->palctrl) {
 130                 memcpy (c->pic.data[1], avctx->palctrl->palette, AVPALETTE_SIZE);
 131                 if (avctx->palctrl->palette_changed) {
 132                         c->pic.palette_has_changed = 1;
 133                         avctx->palctrl->palette_changed = 0;
 134                 } else
 135                         c->pic.palette_has_changed = 0;
 136         }
 137
 138         *data_size = sizeof(AVFrame);
 139         *(AVFrame*)data = c->pic;
 140
 141         /* always report that the buffer was completely consumed */
 142         return buf_size;
 143 }
 144
 145
 146 /*
 147  *
 148  * Init 8BPS decoder
 149  *
 150  */
 151 static av_cold int decode_init(AVCodecContext *avctx)
 152 {
 153         EightBpsContext * const c = avctx->priv_data;
 154
 155         c->avctx = avctx;
 156
 157         c->pic.data[0] = NULL;
 158
 159     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
 160         return 1;
 161     }
 162
 163         switch (avctx->bits_per_sample) {
 164                 case 8:
 165                         avctx->pix_fmt = PIX_FMT_PAL8;
 166                         c->planes = 1;
 167                         c->planemap[0] = 0; // 1st plane is palette indexes
 168                         if (avctx->palctrl == NULL) {
 169                                 av_log(avctx, AV_LOG_ERROR, "Error: PAL8 format but no palette from demuxer.\n");
 170                                 return -1;
 171                         }
 172                         break;
 173                 case 24:
 174                         avctx->pix_fmt = avctx->get_format(avctx, pixfmt_rgb24);
 175                         c->planes = 3;
 176                         c->planemap[0] = 2; // 1st plane is red
 177                         c->planemap[1] = 1; // 2nd plane is green
 178                         c->planemap[2] = 0; // 3rd plane is blue
 179                         break;
 180                 case 32:
 181                         avctx->pix_fmt = PIX_FMT_RGB32;
 182                         c->planes = 4;
 183 #ifdef WORDS_BIGENDIAN
 184                         c->planemap[0] = 1; // 1st plane is red
 185                         c->planemap[1] = 2; // 2nd plane is green
 186                         c->planemap[2] = 3; // 3rd plane is blue
 187                         c->planemap[3] = 0; // 4th plane is alpha???
 188 #else
 189                         c->planemap[0] = 2; // 1st plane is red
 190                         c->planemap[1] = 1; // 2nd plane is green
 191                         c->planemap[2] = 0; // 3rd plane is blue
 192                         c->planemap[3] = 3; // 4th plane is alpha???
 193 #endif
 194                         break;
 195                 default:
 196                         av_log(avctx, AV_LOG_ERROR, "Error: Unsupported color depth: %u.\n", avctx->bits_per_sample);
 197                         return -1;
 198         }
 199
 200   return 0;
 201 }
 202
 203
 204
 205
 206 /*
 207  *
 208  * Uninit 8BPS decoder
 209  *
 210  */
 211 static av_cold int decode_end(AVCodecContext *avctx)
 212 {
 213         EightBpsContext * const c = avctx->priv_data;
 214
 215         if (c->pic.data[0])
 216                 avctx->release_buffer(avctx, &c->pic);
 217
 218         return 0;
 219 }
 220
 221
 222
 223 AVCodec eightbps_decoder = {
 224         "8bps",
 225         CODEC_TYPE_VIDEO,
 226         CODEC_ID_8BPS,
 227         sizeof(EightBpsContext),
 228         decode_init,
 229         NULL,
 230         decode_end,
 231         decode_frame,
 232         CODEC_CAP_DR1,
 233         .long_name = NULL_IF_CONFIG_SMALL("QuickTime 8BPS video"),
 234 };