Libav
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 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 
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 
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);
84  ast->codec->channels = 1;
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->avg_frame_rate = av_inv_q(vst->time_base);
93 
94  mvi->get_int = (vst->codec->width * vst->codec->height < (1 << 16)) ? avio_rl16 : avio_rl24;
95 
96  mvi->audio_frame_size = ((uint64_t)mvi->audio_data_size << MVI_FRAC_BITS) / frames_count;
97  if (mvi->audio_frame_size <= 1 << MVI_FRAC_BITS - 1) {
98  av_log(s, AV_LOG_ERROR, "Invalid audio_data_size (%d) or frames_count (%d)\n",
99  mvi->audio_data_size, frames_count);
100  return AVERROR_INVALIDDATA;
101  }
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 };
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
AVInputFormat ff_mvi_demuxer
Definition: mvi.c:136
#define MVI_AUDIO_STREAM_INDEX
Definition: mvi.c:28
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:3208
Format I/O context.
Definition: avformat.h:871
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1162
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:118
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2481
unsigned int(* get_int)(AVIOContext *)
Definition: mvi.c:32
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:558
#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:142
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:148
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2662
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:754
int audio_size_left
Definition: mvi.c:36
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1840
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:437
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:702
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:509
int bit_rate
the average bitrate
Definition: avcodec.h:1112
audio channel layout utility functions
uint64_t audio_size_counter
Definition: mvi.c:34
int width
picture width / height.
Definition: avcodec.h:1217
#define MVI_VIDEO_STREAM_INDEX
Definition: mvi.c:29
Stream structure.
Definition: avformat.h:683
uint64_t audio_frame_size
Definition: mvi.c:35
NULL
Definition: eval.c:55
enum AVMediaType codec_type
Definition: avcodec.h:1062
version
Definition: ffv1enc.c:1080
enum AVCodecID codec_id
Definition: avcodec.h:1065
int sample_rate
samples per second
Definition: avcodec.h:1779
AVIOContext * pb
I/O context.
Definition: avformat.h:913
int extradata_size
Definition: avcodec.h:1163
static av_always_inline AVRational av_inv_q(AVRational q)
Invert a rational.
Definition: rational.h:122
uint32_t audio_data_size
Definition: mvi.c:33
int video_frame_size
Definition: mvi.c:37
static int read_header(AVFormatContext *s)
Definition: mvi.c:40
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:542
Main libavformat public API header.
#define MVI_FRAC_BITS
Definition: mvi.c:26
int channels
number of audio channels
Definition: avcodec.h:1780
void * priv_data
Format private data.
Definition: avformat.h:899
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:516
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:550
int stream_index
Definition: avcodec.h:975
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:719
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:950
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:205
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mvi.c:109