FFmpeg
rv34_parser.c
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1 /*
2  * RV30/40 parser
3  * Copyright (c) 2011 Konstantin Shishkov
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  * RV30/40 parser
25  */
26 
27 #include "avcodec.h"
28 #include "libavutil/intreadwrite.h"
29 
30 typedef struct RV34ParseContext {
31  int64_t key_dts;
32  int key_pts;
34 
35 static const int rv_to_av_frame_type[4] = {
37 };
38 
40  AVCodecContext *avctx,
41  const uint8_t **poutbuf, int *poutbuf_size,
42  const uint8_t *buf, int buf_size)
43 {
44  RV34ParseContext *pc = s->priv_data;
45  int type, pts, hdr;
46 
47  if (buf_size < 13 + *buf * 8) {
48  *poutbuf = buf;
49  *poutbuf_size = buf_size;
50  return buf_size;
51  }
52 
53  hdr = AV_RB32(buf + 9 + *buf * 8);
54  if (avctx->codec_id == AV_CODEC_ID_RV30) {
55  type = (hdr >> 27) & 3;
56  pts = (hdr >> 7) & 0x1FFF;
57  } else {
58  type = (hdr >> 29) & 3;
59  pts = (hdr >> 6) & 0x1FFF;
60  }
61 
62  if (type != 3 && s->pts != AV_NOPTS_VALUE) {
63  pc->key_dts = s->pts;
64  pc->key_pts = pts;
65  } else {
66  if (type != 3)
67  s->pts = pc->key_dts + ((pts - pc->key_pts) & 0x1FFF);
68  else
69  s->pts = pc->key_dts - ((pc->key_pts - pts) & 0x1FFF);
70  }
71  s->pict_type = rv_to_av_frame_type[type];
72 
73  *poutbuf = buf;
74  *poutbuf_size = buf_size;
75  return buf_size;
76 }
77 
80  .priv_data_size = sizeof(RV34ParseContext),
81  .parser_parse = rv34_parse,
82 };
rv34_parse
static int rv34_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition: rv34_parser.c:39
rv_to_av_frame_type
static const int rv_to_av_frame_type[4]
Definition: rv34_parser.c:35
RV34ParseContext::key_pts
int key_pts
Definition: rv34_parser.c:32
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
pts
static int64_t pts
Definition: transcode_aac.c:644
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:455
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:279
AVCodecParser::codec_ids
int codec_ids[7]
Definition: avcodec.h:2868
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
AV_CODEC_ID_RV30
@ AV_CODEC_ID_RV30
Definition: codec_id.h:120
AV_CODEC_ID_RV40
@ AV_CODEC_ID_RV40
Definition: codec_id.h:121
RV34ParseContext::key_dts
int64_t key_dts
Definition: rv34_parser.c:31
ff_rv34_parser
const AVCodecParser ff_rv34_parser
Definition: rv34_parser.c:78
avcodec.h
AVCodecParserContext
Definition: avcodec.h:2708
AVCodecContext
main external API structure.
Definition: avcodec.h:445
AV_PICTURE_TYPE_B
@ AV_PICTURE_TYPE_B
Bi-dir predicted.
Definition: avutil.h:281
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:280
AVCodecParser
Definition: avcodec.h:2867
RV34ParseContext
Definition: rv34_parser.c:30