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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 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 
vc1t_probe(const AVProbeData * p)35 static int vc1t_probe(const AVProbeData *p)
36 {
37     uint32_t size;
38 
39     if (p->buf_size < 24)
40         return 0;
41 
42     size = AV_RL32(&p->buf[4]);
43     if (p->buf[3] != 0xC5 || size < 4 || size > p->buf_size - 20 ||
44         AV_RL32(&p->buf[size+16]) != 0xC)
45         return 0;
46 
47     return AVPROBE_SCORE_EXTENSION;
48 }
49 
vc1t_read_header(AVFormatContext * s)50 static int vc1t_read_header(AVFormatContext *s)
51 {
52     AVIOContext *pb = s->pb;
53     AVStream *st;
54     int frames, ret;
55     uint32_t fps;
56     uint32_t size;
57 
58     frames = avio_rl24(pb);
59     if (avio_r8(pb) != 0xC5 || ((size = avio_rl32(pb)) < 4))
60         return AVERROR_INVALIDDATA;
61 
62     /* init video codec */
63     st = avformat_new_stream(s, NULL);
64     if (!st)
65         return AVERROR(ENOMEM);
66 
67     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
68     st->codecpar->codec_id = AV_CODEC_ID_WMV3;
69 
70     if ((ret = ff_get_extradata(s, st->codecpar, pb, VC1_EXTRADATA_SIZE)) < 0)
71         return ret;
72 
73     avio_skip(pb, size - 4);
74     st->codecpar->height = avio_rl32(pb);
75     st->codecpar->width = avio_rl32(pb);
76     if(avio_rl32(pb) != 0xC)
77         return AVERROR_INVALIDDATA;
78     avio_skip(pb, 8);
79     fps = avio_rl32(pb);
80     if(fps == 0xFFFFFFFF)
81         avpriv_set_pts_info(st, 32, 1, 1000);
82     else{
83         if (!fps) {
84             av_log(s, AV_LOG_ERROR, "Zero FPS specified, defaulting to 1 FPS\n");
85             fps = 1;
86         }
87         avpriv_set_pts_info(st, 24, 1, fps);
88         st->duration = frames;
89     }
90 
91     return 0;
92 }
93 
vc1t_read_packet(AVFormatContext * s,AVPacket * pkt)94 static int vc1t_read_packet(AVFormatContext *s,
95                            AVPacket *pkt)
96 {
97     AVIOContext *pb = s->pb;
98     int frame_size;
99     int keyframe = 0;
100     uint32_t pts;
101 
102     if(avio_feof(pb))
103         return AVERROR(EIO);
104 
105     frame_size = avio_rl24(pb);
106     if(avio_r8(pb) & 0x80)
107         keyframe = 1;
108     pts = avio_rl32(pb);
109     if(av_get_packet(pb, pkt, frame_size) < 0)
110         return AVERROR(EIO);
111     if(s->streams[0]->time_base.den == 1000)
112         pkt->pts = pts;
113     pkt->flags |= keyframe ? AV_PKT_FLAG_KEY : 0;
114     pkt->pos -= 8;
115 
116     return pkt->size;
117 }
118 
119 AVInputFormat ff_vc1t_demuxer = {
120     .name           = "vc1test",
121     .long_name      = NULL_IF_CONFIG_SMALL("VC-1 test bitstream"),
122     .read_probe     = vc1t_probe,
123     .read_header    = vc1t_read_header,
124     .read_packet    = vc1t_read_packet,
125     .extensions     = "rcv",
126     .flags          = AVFMT_GENERIC_INDEX,
127 };
128