mvi.c
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1 /*
2  * Motion Pixels MVI Demuxer
3  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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 
22 #include "libavutil/channel_layout.h"
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;
34  uint64_t audio_size_counter;
35  uint64_t audio_frame_size;
36  int audio_size_left;
37  int video_frame_size;
38 } MviDemuxContext;
39 
40 static int read_header(AVFormatContext *s)
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;
56  vst->codec->extradata = av_mallocz(2 + FF_INPUT_BUFFER_PADDING_SIZE);
57 
58  version = avio_r8(pb);
59  vst->codec->extradata[0] = avio_r8(pb);
60  vst->codec->extradata[1] = avio_r8(pb);
61  frames_count = avio_rl32(pb);
62  msecs_per_frame = avio_rl32(pb);
63  vst->codec->width = avio_rl16(pb);
64  vst->codec->height = avio_rl16(pb);
65  avio_r8(pb);
66  ast->codec->sample_rate = avio_rl16(pb);
67  mvi->audio_data_size = avio_rl32(pb);
68  avio_r8(pb);
69  player_version = avio_rl32(pb);
70  avio_rl16(pb);
71  avio_r8(pb);
72 
73  if (frames_count == 0 || mvi->audio_data_size == 0)
74  return AVERROR_INVALIDDATA;
75 
76  if (version != 7 || player_version > 213) {
77  av_log(s, AV_LOG_ERROR, "unhandled version (%d,%d)\n", version, player_version);
78  return AVERROR_INVALIDDATA;
79  }
80 
81  avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
82  ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;
83  ast->codec->codec_id = AV_CODEC_ID_PCM_U8;
84  ast->codec->channels = 1;
85  ast->codec->channel_layout = AV_CH_LAYOUT_MONO;
86  ast->codec->bits_per_coded_sample = 8;
87  ast->codec->bit_rate = ast->codec->sample_rate * 8;
88 
89  avpriv_set_pts_info(vst, 64, msecs_per_frame, 1000000);
90  vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
91  vst->codec->codec_id = AV_CODEC_ID_MOTIONPIXELS;
92 
93  mvi->get_int = (vst->codec->width * vst->codec->height < (1 << 16)) ? avio_rl16 : avio_rl24;
94 
95  mvi->audio_frame_size = ((uint64_t)mvi->audio_data_size << MVI_FRAC_BITS) / frames_count;
96  mvi->audio_size_counter = (ast->codec->sample_rate * 830 / mvi->audio_frame_size - 1) * mvi->audio_frame_size;
97  mvi->audio_size_left = mvi->audio_data_size;
98 
99  return 0;
100 }
101 
102 static int read_packet(AVFormatContext *s, AVPacket *pkt)
103 {
104  int ret, count;
105  MviDemuxContext *mvi = s->priv_data;
106  AVIOContext *pb = s->pb;
107 
108  if (mvi->video_frame_size == 0) {
109  mvi->video_frame_size = (mvi->get_int)(pb);
110  if (mvi->audio_size_left == 0)
111  return AVERROR(EIO);
112  count = (mvi->audio_size_counter + mvi->audio_frame_size + 512) >> MVI_FRAC_BITS;
113  if (count > mvi->audio_size_left)
114  count = mvi->audio_size_left;
115  if ((ret = av_get_packet(pb, pkt, count)) < 0)
116  return ret;
117  pkt->stream_index = MVI_AUDIO_STREAM_INDEX;
118  mvi->audio_size_left -= count;
119  mvi->audio_size_counter += mvi->audio_frame_size - (count << MVI_FRAC_BITS);
120  } else {
121  if ((ret = av_get_packet(pb, pkt, mvi->video_frame_size)) < 0)
122  return ret;
123  pkt->stream_index = MVI_VIDEO_STREAM_INDEX;
124  mvi->video_frame_size = 0;
125  }
126  return 0;
127 }
128 
129 AVInputFormat ff_mvi_demuxer = {
130  .name = "mvi",
131  .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels MVI"),
132  .priv_data_size = sizeof(MviDemuxContext),
133  .read_header = read_header,
134  .read_packet = read_packet,
135  .extensions = "mvi",
136 };