libavcodec/rv34_parser.c

   1 /*
   2  * RV30/40 parser
   3  * Copyright (c) 2011 Konstantin Shishkov
   4  *
   5  * This file is part of Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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  * RV30/40 parser
  25  */
  26
  27 #include "parser.h"
  28 #include "libavutil/intreadwrite.h"
  29
  30 typedef struct {
  31     ParseContext pc;
  32     int64_t key_dts;
  33     int key_pts;
  34 } RV34ParseContext;
  35
  36 static const int rv_to_av_frame_type[4] = {
  37     AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_I, AV_PICTURE_TYPE_P, AV_PICTURE_TYPE_B,
  38 };
  39
  40 static int rv34_parse(AVCodecParserContext *s,
  41                       AVCodecContext *avctx,
  42                       const uint8_t **poutbuf, int *poutbuf_size,
  43                       const uint8_t *buf, int buf_size)
  44 {
  45     RV34ParseContext *pc = s->priv_data;
  46     int type, pts, hdr;
  47
  48     if (buf_size < 13 + *buf * 8) {
  49         *poutbuf = buf;
  50         *poutbuf_size = buf_size;
  51         return buf_size;
  52     }
  53
  54     hdr = AV_RB32(buf + 9 + *buf * 8);
  55     if (avctx->codec_id == AV_CODEC_ID_RV30) {
  56         type = (hdr >> 27) & 3;
  57         pts  = (hdr >>  7) & 0x1FFF;
  58     } else {
  59         type = (hdr >> 29) & 3;
  60         pts  = (hdr >>  6) & 0x1FFF;
  61     }
  62
  63     if (type != 3 && s->pts != AV_NOPTS_VALUE) {
  64         pc->key_dts = s->pts;
  65         pc->key_pts = pts;
  66     } else {
  67         if (type != 3)
  68             s->pts = pc->key_dts + ((pts - pc->key_pts) & 0x1FFF);
  69         else
  70             s->pts = pc->key_dts - ((pc->key_pts - pts) & 0x1FFF);
  71     }
  72     s->pict_type = rv_to_av_frame_type[type];
  73
  74     *poutbuf = buf;
  75     *poutbuf_size = buf_size;
  76     return buf_size;
  77 }
  78
  79 #if CONFIG_RV30_PARSER
  80 AVCodecParser ff_rv30_parser = {
  81     .codec_ids      = { AV_CODEC_ID_RV30 },
  82     .priv_data_size = sizeof(RV34ParseContext),
  83     .parser_parse   = rv34_parse,
  84 };
  85 #endif
  86
  87 #if CONFIG_RV40_PARSER
  88 AVCodecParser ff_rv40_parser = {
  89     .codec_ids      = { AV_CODEC_ID_RV40 },
  90     .priv_data_size = sizeof(RV34ParseContext),
  91     .parser_parse   = rv34_parse,
  92 };
  93 #endif