FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
mvi.c
Go to the documentation of this file.
1 /*
2  * Motion Pixels MVI Demuxer
3  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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 
23 #include "avformat.h"
24 #include "internal.h"
25 
26 #define MVI_FRAC_BITS 10
27 
28 #define MVI_AUDIO_STREAM_INDEX 0
29 #define MVI_VIDEO_STREAM_INDEX 1
30 
31 typedef struct MviDemuxContext {
32  unsigned int (*get_int)(AVIOContext *);
33  uint32_t audio_data_size;
35  uint64_t audio_frame_size;
39 
41 {
42  MviDemuxContext *mvi = s->priv_data;
43  AVIOContext *pb = s->pb;
44  AVStream *ast, *vst;
45  unsigned int version, frames_count, msecs_per_frame, player_version;
46 
47  ast = avformat_new_stream(s, NULL);
48  if (!ast)
49  return AVERROR(ENOMEM);
50 
51  vst = avformat_new_stream(s, NULL);
52  if (!vst)
53  return AVERROR(ENOMEM);
54 
55  vst->codec->extradata_size = 2;
57  if (!vst->codec->extradata)
58  return AVERROR(ENOMEM);
59 
60  version = avio_r8(pb);
61  vst->codec->extradata[0] = avio_r8(pb);
62  vst->codec->extradata[1] = avio_r8(pb);
63  frames_count = avio_rl32(pb);
64  msecs_per_frame = avio_rl32(pb);
65  vst->codec->width = avio_rl16(pb);
66  vst->codec->height = avio_rl16(pb);
67  avio_r8(pb);
68  ast->codec->sample_rate = avio_rl16(pb);
69  mvi->audio_data_size = avio_rl32(pb);
70  avio_r8(pb);
71  player_version = avio_rl32(pb);
72  avio_rl16(pb);
73  avio_r8(pb);
74 
75  if (frames_count == 0 || mvi->audio_data_size == 0)
76  return AVERROR_INVALIDDATA;
77 
78  if (version != 7 || player_version > 213) {
79  av_log(s, AV_LOG_ERROR, "unhandled version (%d,%d)\n", version, player_version);
80  return AVERROR_INVALIDDATA;
81  }
82 
83  avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
86  ast->codec->channels = 1;
88  ast->codec->bits_per_coded_sample = 8;
89  ast->codec->bit_rate = ast->codec->sample_rate * 8;
90 
91  avpriv_set_pts_info(vst, 64, msecs_per_frame, 1000000);
92  vst->avg_frame_rate = av_inv_q(vst->time_base);
95 
96  mvi->get_int = (vst->codec->width * vst->codec->height < (1 << 16)) ? avio_rl16 : avio_rl24;
97 
98  mvi->audio_frame_size = ((uint64_t)mvi->audio_data_size << MVI_FRAC_BITS) / frames_count;
99  if (!mvi->audio_frame_size) {
100  av_log(s, AV_LOG_ERROR, "audio_frame_size is 0\n");
101  return AVERROR_INVALIDDATA;
102  }
103  mvi->audio_size_counter = (ast->codec->sample_rate * 830 / mvi->audio_frame_size - 1) * mvi->audio_frame_size;
104  mvi->audio_size_left = mvi->audio_data_size;
105 
106  return 0;
107 }
108 
110 {
111  int ret, count;
112  MviDemuxContext *mvi = s->priv_data;
113  AVIOContext *pb = s->pb;
114 
115  if (mvi->video_frame_size == 0) {
116  mvi->video_frame_size = (mvi->get_int)(pb);
117  if (mvi->audio_size_left == 0)
118  return AVERROR(EIO);
119  count = (mvi->audio_size_counter + mvi->audio_frame_size + 512) >> MVI_FRAC_BITS;
120  if (count > mvi->audio_size_left)
121  count = mvi->audio_size_left;
122  if ((ret = av_get_packet(pb, pkt, count)) < 0)
123  return ret;
125  mvi->audio_size_left -= count;
126  mvi->audio_size_counter += mvi->audio_frame_size - (count << MVI_FRAC_BITS);
127  } else {
128  if ((ret = av_get_packet(pb, pkt, mvi->video_frame_size)) < 0)
129  return ret;
131  mvi->video_frame_size = 0;
132  }
133  return 0;
134 }
135 
137  .name = "mvi",
138  .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels MVI"),
139  .priv_data_size = sizeof(MviDemuxContext),
142  .extensions = "mvi",
143 };