vc1test.c
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1 /*
2  * VC1 Test Bitstreams Format Demuxer
3  * Copyright (c) 2006, 2008 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 
29 #include "libavutil/intreadwrite.h"
30 #include "avformat.h"
31 #include "internal.h"
32 
33 #define VC1_EXTRADATA_SIZE 4
34 
35 static int vc1t_probe(AVProbeData *p)
36 {
37  if (p->buf_size < 24)
38  return 0;
39  if (p->buf[3] != 0xC5 || AV_RL32(&p->buf[4]) != 4 || AV_RL32(&p->buf[20]) != 0xC)
40  return 0;
41 
42  return AVPROBE_SCORE_MAX/2;
43 }
44 
47 {
48  AVIOContext *pb = s->pb;
49  AVStream *st;
50  int frames;
51  uint32_t fps;
52 
53  frames = avio_rl24(pb);
54  if(avio_r8(pb) != 0xC5 || avio_rl32(pb) != 4)
55  return -1;
56 
57  /* init video codec */
58  st = avformat_new_stream(s, NULL);
59  if (!st)
60  return -1;
61 
64 
68  st->codec->height = avio_rl32(pb);
69  st->codec->width = avio_rl32(pb);
70  if(avio_rl32(pb) != 0xC)
71  return -1;
72  avio_skip(pb, 8);
73  fps = avio_rl32(pb);
74  if(fps == 0xFFFFFFFF)
75  avpriv_set_pts_info(st, 32, 1, 1000);
76  else{
77  if (!fps) {
78  av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");
79  fps = 1;
80  }
81  avpriv_set_pts_info(st, 24, 1, fps);
82  st->duration = frames;
83  }
84 
85  return 0;
86 }
87 
89  AVPacket *pkt)
90 {
91  AVIOContext *pb = s->pb;
92  int frame_size;
93  int keyframe = 0;
94  uint32_t pts;
95 
96  if(pb->eof_reached)
97  return AVERROR(EIO);
98 
99  frame_size = avio_rl24(pb);
100  if(avio_r8(pb) & 0x80)
101  keyframe = 1;
102  pts = avio_rl32(pb);
103  if(av_get_packet(pb, pkt, frame_size) < 0)
104  return AVERROR(EIO);
105  if(s->streams[0]->time_base.den == 1000)
106  pkt->pts = pts;
107  pkt->flags |= keyframe ? AV_PKT_FLAG_KEY : 0;
108  pkt->pos -= 8;
109 
110  return pkt->size;
111 }
112 
114  .name = "vc1test",
115  .long_name = NULL_IF_CONFIG_SMALL("VC-1 test bitstream format"),
116  .read_probe = vc1t_probe,
117  .read_header = vc1t_read_header,
118  .read_packet = vc1t_read_packet,
119  .flags = AVFMT_GENERIC_INDEX,
120 };
Bytestream IO Context.
Definition: avio.h:68
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:933
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the pts for a given stream.
Definition: utils.c:3828
int size
Definition: avcodec.h:909
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:954
Format I/O context.
Definition: avformat.h:863
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1387
AVStream ** streams
Definition: avformat.h:908
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:269
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:652
static int vc1t_probe(AVProbeData *p)
Definition: vc1test.c:35
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:738
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
AV_RL32
Definition: bytestream.h:89
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2776
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:914
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:632
AVCodecContext * codec
codec context
Definition: avformat.h:623
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:342
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:341
int width
picture width / height.
Definition: avcodec.h:1408
AVInputFormat ff_vc1t_demuxer
Definition: vc1test.c:113
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: avio.h:483
#define VC1_EXTRADATA_SIZE
Definition: vc1test.c:33
Stream structure.
Definition: avformat.h:620
NULL
Definition: eval.c:50
enum AVMediaType codec_type
Definition: avcodec.h:1574
AVIOContext * pb
Definition: avformat.h:896
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
int extradata_size
Definition: avcodec.h:1388
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:64
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:376
This structure contains the data a format has to probe a file.
Definition: avformat.h:339
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:684
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:345
Main libavformat public API header.
int den
denominator
Definition: rational.h:45
int eof_reached
true if eof reached
Definition: avio.h:98
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:460
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:730
static int vc1t_read_header(AVFormatContext *s, AVFormatParameters *ap)
Definition: vc1test.c:45
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:652
static int vc1t_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: vc1test.c:88
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:901
enum CodecID codec_id
Definition: avcodec.h:1575