quicktime/ffmpeg/libavcodec/8bps.c

   1 /*
   2  * Quicktime Planar RGB (8BPS) Video Decoder
   3  * Copyright (C) 2003 Roberto Togni
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  */
  20
  21 /**
  22  * @file 8bps.c
  23  * QT 8BPS Video Decoder by Roberto Togni <rtogni at bresciaonline dot it>
  24  * For more information about the 8BPS format, visit:
  25  *   http://www.pcisys.net/~melanson/codecs/
  26  *
  27  * Supports: PAL8 (RGB 8bpp, paletted)
  28  *         : BGR24 (RGB 24bpp) (can also output it as RGBA32)
  29  *         : RGBA32 (RGB 32bpp, 4th plane is probably alpha and it's ignored)
  30  *
  31  */
  32
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35
  36 #include "common.h"
  37 #include "avcodec.h"
  38
  39
  40 const enum PixelFormat pixfmt_rgb24[] = {PIX_FMT_BGR24, PIX_FMT_RGBA32, -1};
  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, uint8_t *buf, int buf_size)
  61 {
  62         EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
  63         unsigned char *encoded = (unsigned char *)buf;
  64         unsigned char *pixptr, *pixptr_end;
  65         unsigned int height = avctx->height; // Real image height
  66         unsigned int dlen, p, row;
  67         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_RGBA32);
  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(*(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 int decode_init(AVCodecContext *avctx)
 152 {
 153         EightBpsContext * const c = (EightBpsContext *)avctx->priv_data;
 154
 155         c->avctx = avctx;
 156         avctx->has_b_frames = 0;
 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_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_RGBA32;
 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_sample);
 198                         return -1;
 199         }
 200
 201   return 0;
 202 }
 203
 204
 205
 206
 207 /*
 208  *
 209  * Uninit 8BPS decoder
 210  *
 211  */
 212 static int decode_end(AVCodecContext *avctx)
 213 {
 214         EightBpsContext * const c = (EightBpsContext *)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 };