Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * DNxHD/VC-3 parser
  3.  * Copyright (c) 2008 Baptiste Coudurier <baptiste.coudurier@free.fr>
  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
  24.  * DNxHD/VC-3 parser
  25.  */
  26.  
  27. #include "parser.h"
  28.  
  29. #define DNXHD_HEADER_PREFIX 0x000002800100
  30.  
  31. typedef struct {
  32.     ParseContext pc;
  33.     int interlaced;
  34.     int cur_field; /* first field is 0, second is 1 */
  35. } DNXHDParserContext;
  36.  
  37. static int dnxhd_find_frame_end(DNXHDParserContext *dctx,
  38.                                 const uint8_t *buf, int buf_size)
  39. {
  40.     ParseContext *pc = &dctx->pc;
  41.     uint64_t state = pc->state64;
  42.     int pic_found = pc->frame_start_found;
  43.     int i = 0;
  44.     int interlaced = dctx->interlaced;
  45.     int cur_field = dctx->cur_field;
  46.  
  47.     if (!pic_found) {
  48.         for (i = 0; i < buf_size; i++) {
  49.             state = (state<<8) | buf[i];
  50.             if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
  51.                 i++;
  52.                 pic_found = 1;
  53.                 interlaced = (state&2)>>1; /* byte following the 5-byte header prefix */
  54.                 cur_field = state&1;
  55.                 break;
  56.             }
  57.         }
  58.     }
  59.  
  60.     if (pic_found) {
  61.         if (!buf_size) /* EOF considered as end of frame */
  62.             return 0;
  63.         for (; i < buf_size; i++) {
  64.             state = (state<<8) | buf[i];
  65.             if ((state & 0xffffffffff00LL) == DNXHD_HEADER_PREFIX) {
  66.                 if (!interlaced || dctx->cur_field) {
  67.                     pc->frame_start_found = 0;
  68.                     pc->state64 = -1;
  69.                     dctx->interlaced = interlaced;
  70.                     dctx->cur_field = 0;
  71.                     return i-5;
  72.                 } else {
  73.                     /* continue, to get the second field */
  74.                     dctx->interlaced = interlaced = (state&2)>>1;
  75.                     dctx->cur_field = cur_field = state&1;
  76.                 }
  77.             }
  78.         }
  79.     }
  80.     pc->frame_start_found = pic_found;
  81.     pc->state64 = state;
  82.     dctx->interlaced = interlaced;
  83.     dctx->cur_field = cur_field;
  84.     return END_NOT_FOUND;
  85. }
  86.  
  87. static int dnxhd_parse(AVCodecParserContext *s,
  88.                        AVCodecContext *avctx,
  89.                        const uint8_t **poutbuf, int *poutbuf_size,
  90.                        const uint8_t *buf, int buf_size)
  91. {
  92.     DNXHDParserContext *dctx = s->priv_data;
  93.     ParseContext *pc = &dctx->pc;
  94.     int next;
  95.  
  96.     if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
  97.         next = buf_size;
  98.     } else {
  99.         next = dnxhd_find_frame_end(dctx, buf, buf_size);
  100.         if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
  101.             *poutbuf = NULL;
  102.             *poutbuf_size = 0;
  103.             return buf_size;
  104.         }
  105.     }
  106.     *poutbuf = buf;
  107.     *poutbuf_size = buf_size;
  108.     return next;
  109. }
  110.  
  111. AVCodecParser ff_dnxhd_parser = {
  112.     .codec_ids      = { AV_CODEC_ID_DNXHD },
  113.     .priv_data_size = sizeof(DNXHDParserContext),
  114.     .parser_parse   = dnxhd_parse,
  115.     .parser_close   = ff_parse_close,
  116. };
  117.