FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vc1test.c
Go to the documentation of this file.
1 /*
2  * VC1 Test Bitstreams Format Demuxer
3  * Copyright (c) 2006, 2008 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  * VC1 test bitstream file demuxer
25  * by Konstantin Shishkov
26  * Format specified in SMPTE standard 421 Annex L
27  */
28 
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 
46 {
47  AVIOContext *pb = s->pb;
48  AVStream *st;
49  int frames;
50  uint32_t fps;
51 
52  frames = avio_rl24(pb);
53  if(avio_r8(pb) != 0xC5 || avio_rl32(pb) != 4)
54  return -1;
55 
56  /* init video codec */
57  st = avformat_new_stream(s, NULL);
58  if (!st)
59  return -1;
60 
63 
67  st->codec->height = avio_rl32(pb);
68  st->codec->width = avio_rl32(pb);
69  if(avio_rl32(pb) != 0xC)
70  return -1;
71  avio_skip(pb, 8);
72  fps = avio_rl32(pb);
73  if(fps == 0xFFFFFFFF)
74  avpriv_set_pts_info(st, 32, 1, 1000);
75  else{
76  if (!fps) {
77  av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");
78  fps = 1;
79  }
80  avpriv_set_pts_info(st, 24, 1, fps);
81  st->duration = frames;
82  }
83 
84  return 0;
85 }
86 
88  AVPacket *pkt)
89 {
90  AVIOContext *pb = s->pb;
91  int frame_size;
92  int keyframe = 0;
93  uint32_t pts;
94 
95  if(url_feof(pb))
96  return AVERROR(EIO);
97 
98  frame_size = avio_rl24(pb);
99  if(avio_r8(pb) & 0x80)
100  keyframe = 1;
101  pts = avio_rl32(pb);
102  if(av_get_packet(pb, pkt, frame_size) < 0)
103  return AVERROR(EIO);
104  if(s->streams[0]->time_base.den == 1000)
105  pkt->pts = pts;
106  pkt->flags |= keyframe ? AV_PKT_FLAG_KEY : 0;
107  pkt->pos -= 8;
108 
109  return pkt->size;
110 }
111 
113  .name = "vc1test",
114  .long_name = NULL_IF_CONFIG_SMALL("VC-1 test bitstream"),
115  .read_probe = vc1t_probe,
116  .read_header = vc1t_read_header,
117  .read_packet = vc1t_read_packet,
118  .flags = AVFMT_GENERIC_INDEX,
119 };