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Member "quicktime4linux-2.3/thirdparty/ffmpeg.053108/libavcodec/8bps.c" (8 Aug 2008, 7834 Bytes) of package /linux/privat/old/quicktime4linux-2.3-src.tar.gz:


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    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 <rtogni at bresciaonline dot it>
   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 = "QuickTime 8BPS video",
  234 };