FFmpeg
moflex.c
Go to the documentation of this file.
1 /*
2  * MOFLEX demuxer
3  * Copyright (c) 2015-2016 Florian Nouwt
4  * Copyright (c) 2017 Adib Surani
5  * Copyright (c) 2020 Paul B Mahol
6  *
7  * This file is part of FFmpeg.
8  *
9  * FFmpeg is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU Lesser General Public
11  * License as published by the Free Software Foundation; either
12  * version 2.1 of the License, or (at your option) any later version.
13  *
14  * FFmpeg is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17  * Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public
20  * License along with FFmpeg; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22  */
23 
24 #include "libavcodec/bytestream.h"
25 
26 #include "avformat.h"
27 #include "internal.h"
28 
29 typedef struct BitReader {
30  unsigned last;
31  unsigned pos;
32 } BitReader;
33 
34 typedef struct MOFLEXDemuxContext {
35  unsigned size;
36  int64_t pos;
37  int64_t ts;
38  int flags;
39  int in_block;
40 
43 
44 static int pop(BitReader *br, AVIOContext *pb)
45 {
46  if (avio_feof(pb))
47  return AVERROR_EOF;
48 
49  if ((br->pos & 7) == 0)
50  br->last = (unsigned)avio_r8(pb) << 24U;
51  else
52  br->last <<= 1;
53 
54  br->pos++;
55  return !!(br->last & 0x80000000);
56 }
57 
58 static int pop_int(BitReader *br, AVIOContext *pb, int n)
59 {
60  int value = 0;
61 
62  for (int i = 0; i < n; i++) {
63  int ret = pop(br, pb);
64 
65  if (ret < 0)
66  return ret;
67  if (ret > INT_MAX - value - value)
68  return AVERROR_INVALIDDATA;
69  value = 2 * value + ret;
70  }
71 
72  return value;
73 }
74 
75 static int pop_length(BitReader *br, AVIOContext *pb)
76 {
77  int ret, n = 1;
78 
79  while ((ret = pop(br, pb)) == 0)
80  n++;
81 
82  if (ret < 0)
83  return ret;
84  return n;
85 }
86 
87 static int read_var_byte(AVFormatContext *s, unsigned *out)
88 {
89  AVIOContext *pb = s->pb;
90  unsigned value = 0, data;
91 
92  data = avio_r8(pb);
93  if (!(data & 0x80)) {
94  *out = data;
95  return 0;
96  }
97 
98  value = (data & 0x7F) << 7;
99  data = avio_r8(pb);
100  if (!(data & 0x80)) {
101  value |= data;
102  *out = value;
103  return 0;
104  }
105 
106  value = ((data & 0x7F) | value) << 7;
107  data = avio_r8(pb);
108  if (!(data & 0x80)) {
109  value |= data;
110  *out = value;
111  return 0;
112  }
113 
114  value = (((data & 0x7F) | value) << 7) | avio_r8(pb);
115  *out = value;
116 
117  return 0;
118 }
119 
120 static int moflex_probe(const AVProbeData *p)
121 {
122  GetByteContext gb;
123  int score = 0;
124 
125  bytestream2_init(&gb, p->buf, p->buf_size);
126 
127  if (bytestream2_get_be16(&gb) != 0x4C32)
128  return 0;
129  score += 10;
130 
131  bytestream2_skip(&gb, 10);
132  if (bytestream2_get_be16(&gb) == 0)
133  return 0;
134  score += 5;
135 
136  while (bytestream2_get_bytes_left(&gb) > 0) {
137  int type = bytestream2_get_byte(&gb);
138  int size = bytestream2_get_byte(&gb);
139 
140  if (type == 0) {
141  score += 5 * (size == 0);
142  break;
143  }
144  if ((type == 1 && size == 12) ||
145  (type == 2 && size == 6) ||
146  (type == 3 && size == 13) ||
147  (type == 4 && size == 2))
148  score += 20;
149  bytestream2_skip(&gb, size);
150  }
151 
152  return FFMIN(AVPROBE_SCORE_MAX, score);
153 }
154 
156 {
157  MOFLEXDemuxContext *m = s->priv_data;
158  AVIOContext *pb = s->pb;
159 
160  if (avio_rb16(pb) != 0x4C32) {
161  if (avio_feof(pb))
162  return AVERROR_EOF;
163  avio_seek(pb, -2, SEEK_CUR);
164  return 1;
165  }
166 
167  avio_skip(pb, 2);
168  m->ts = avio_rb64(pb);
169  m->size = avio_rb16(pb) + 1;
170 
171  while (!avio_feof(pb)) {
172  unsigned type, ssize, codec_id = 0;
173  unsigned codec_type, width = 0, height = 0, sample_rate = 0, channels = 0;
174  int stream_index = -1;
175  int format;
176  AVRational fps;
177 
178  read_var_byte(s, &type);
179  read_var_byte(s, &ssize);
180 
181  switch (type) {
182  case 0:
183  if (ssize > 0)
184  avio_skip(pb, ssize);
185  return 0;
186  case 2:
188  stream_index = avio_r8(pb);
189  codec_id = avio_r8(pb);
190  switch (codec_id) {
191  case 0: codec_id = AV_CODEC_ID_FASTAUDIO; break;
192  case 1: codec_id = AV_CODEC_ID_ADPCM_IMA_MOFLEX; break;
193  case 2: codec_id = AV_CODEC_ID_PCM_S16LE; break;
194  default:
195  av_log(s, AV_LOG_ERROR, "Unsupported audio codec: %d\n", codec_id);
196  return AVERROR_PATCHWELCOME;
197  }
198  sample_rate = avio_rb24(pb) + 1;
199  channels = avio_r8(pb) + 1;
200  break;
201  case 1:
202  case 3:
204  stream_index = avio_r8(pb);
205  codec_id = avio_r8(pb);
206  switch (codec_id) {
207  case 0: codec_id = AV_CODEC_ID_MOBICLIP; break;
208  default:
209  av_log(s, AV_LOG_ERROR, "Unsupported video codec: %d\n", codec_id);
210  return AVERROR_PATCHWELCOME;
211  }
212  fps.num = avio_rb16(pb);
213  fps.den = avio_rb16(pb);
214  width = avio_rb16(pb);
215  height = avio_rb16(pb);
217  avio_skip(pb, type == 3 ? 3 : 2);
218  break;
219  case 4:
221  stream_index = avio_r8(pb);
222  avio_skip(pb, 1);
223  break;
224  }
225 
226  if (stream_index == s->nb_streams) {
228 
229  if (!st)
230  return AVERROR(ENOMEM);
231 
233  st->codecpar->codec_id = codec_id;
234  st->codecpar->width = width;
235  st->codecpar->height = height;
237  st->codecpar->channels = channels;
238  st->codecpar->format = format;
239  st->priv_data = av_packet_alloc();
240  if (!st->priv_data)
241  return AVERROR(ENOMEM);
242 
243  if (sample_rate)
244  avpriv_set_pts_info(st, 63, 1, sample_rate);
245  else
246  avpriv_set_pts_info(st, 63, fps.den, fps.num);
247  }
248  }
249 
250  return 0;
251 }
252 
254 {
255  int ret;
256 
258  if (ret < 0)
259  return ret;
260 
261  s->ctx_flags |= AVFMTCTX_NOHEADER;
262  avio_seek(s->pb, 0, SEEK_SET);
263 
264  return 0;
265 }
266 
268 {
269  MOFLEXDemuxContext *m = s->priv_data;
270  AVIOContext *pb = s->pb;
271  BitReader *br = &m->br;
272  int ret;
273 
274  while (!avio_feof(pb)) {
275  if (!m->in_block) {
276  m->pos = avio_tell(pb);
277 
279  if (ret < 0)
280  return ret;
281 
282  m->flags = avio_r8(pb);
283  if (m->flags & 2)
284  avio_skip(pb, 2);
285  }
286 
287  while ((avio_tell(pb) < m->pos + m->size) && !avio_feof(pb) && avio_r8(pb)) {
288  int stream_index, bits, pkt_size, endframe;
289  AVPacket *packet;
290 
291  m->in_block = 1;
292 
293  avio_seek(pb, -1, SEEK_CUR);
294  br->pos = br->last = 0;
295 
296  bits = pop_length(br, pb);
297  if (bits < 0)
298  return bits;
299  stream_index = pop_int(br, pb, bits);
300  if (stream_index < 0)
301  return stream_index;
302  if (stream_index >= s->nb_streams)
303  return AVERROR_INVALIDDATA;
304 
305  endframe = pop(br, pb);
306  if (endframe < 0)
307  return endframe;
308  if (endframe) {
309  bits = pop_length(br, pb);
310  if (bits < 0)
311  return bits;
312  pop_int(br, pb, bits);
313  pop(br, pb);
314  bits = pop_length(br, pb);
315  if (bits < 0)
316  return bits;
317  pop_int(br, pb, bits * 2 + 26);
318  }
319 
320  pkt_size = pop_int(br, pb, 13) + 1;
321  if (pkt_size > m->size)
322  return AVERROR_INVALIDDATA;
323  packet = s->streams[stream_index]->priv_data;
324  if (!packet) {
325  avio_skip(pb, pkt_size);
326  continue;
327  }
328 
329  ret = av_append_packet(pb, packet, pkt_size);
330  if (ret < 0)
331  return ret;
332  if (endframe && packet->size > 0) {
333  av_packet_move_ref(pkt, packet);
334  pkt->pos = m->pos;
335  pkt->stream_index = stream_index;
336  if (s->streams[stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
337  pkt->duration = 1;
338  if (pkt->data[0] & 0x80)
340  } else {
342  }
343  return ret;
344  }
345  }
346 
347  m->in_block = 0;
348 
349  if (m->flags % 2 == 0) {
350  if (m->size <= 0)
351  return AVERROR_INVALIDDATA;
352  avio_seek(pb, m->pos + m->size, SEEK_SET);
353  }
354  }
355 
356  return AVERROR_EOF;
357 }
358 
359 static int moflex_read_seek(AVFormatContext *s, int stream_index,
360  int64_t pts, int flags)
361 {
362  MOFLEXDemuxContext *m = s->priv_data;
363 
364  m->in_block = 0;
365 
366  return -1;
367 }
368 
370 {
371  for (int i = 0; i < s->nb_streams; i++) {
372  av_packet_free((AVPacket **)&s->streams[i]->priv_data);
373  }
374 
375  return 0;
376 }
377 
379  .name = "moflex",
380  .long_name = NULL_IF_CONFIG_SMALL("MobiClip MOFLEX"),
381  .priv_data_size = sizeof(MOFLEXDemuxContext),
387  .extensions = "moflex",
389 };
AV_CODEC_ID_PCM_S16LE
@ AV_CODEC_ID_PCM_S16LE
Definition: codec_id.h:313
pop_length
static int pop_length(BitReader *br, AVIOContext *pb)
Definition: moflex.c:75
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4547
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
BitReader
Definition: moflex.c:29
out
FILE * out
Definition: movenc.c:54
GetByteContext
Definition: bytestream.h:33
AVStream::priv_data
void * priv_data
Definition: avformat.h:888
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
AV_CODEC_ID_MOBICLIP
@ AV_CODEC_ID_MOBICLIP
Definition: codec_id.h:303
AV_CODEC_ID_FASTAUDIO
@ AV_CODEC_ID_FASTAUDIO
Definition: codec_id.h:519
AVPacket::data
uint8_t * data
Definition: packet.h:369
moflex_probe
static int moflex_probe(const AVProbeData *p)
Definition: moflex.c:120
data
const char data[16]
Definition: mxf.c:142
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:387
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
codec_type
enum AVMediaType codec_type
Definition: rtp.c:37
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:410
sample_rate
sample_rate
Definition: ffmpeg_filter.c:158
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:75
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
U
#define U(x)
Definition: vp56_arith.h:37
read_seek
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
MOFLEXDemuxContext
Definition: moflex.c:34
read_close
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
MOFLEXDemuxContext::ts
int64_t ts
Definition: moflex.c:37
pop
static int pop(BitReader *br, AVIOContext *pb)
Definition: moflex.c:44
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
pts
static int64_t pts
Definition: transcode_aac.c:652
AVRational::num
int num
Numerator.
Definition: rational.h:59
MOFLEXDemuxContext::flags
int flags
Definition: moflex.c:38
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
AVInputFormat
Definition: avformat.h:640
width
#define width
s
#define s(width, name)
Definition: cbs_vp9.c:257
MOFLEXDemuxContext::br
BitReader br
Definition: moflex.c:41
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:126
bits
uint8_t bits
Definition: vp3data.h:141
channels
channels
Definition: aptx.h:33
codec_id
enum AVCodecID codec_id
Definition: vaapi_decode.c:369
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
AVMEDIA_TYPE_DATA
@ AVMEDIA_TYPE_DATA
Opaque data information usually continuous.
Definition: avutil.h:203
AVFormatContext
Format I/O context.
Definition: avformat.h:1231
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:527
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
read_probe
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
AVFMTCTX_NOHEADER
#define AVFMTCTX_NOHEADER
signal that no header is present (streams are added dynamically)
Definition: avformat.h:1176
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
MOFLEXDemuxContext::size
unsigned size
Definition: moflex.c:35
avio_rb64
uint64_t avio_rb64(AVIOContext *s)
Definition: aviobuf.c:902
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
av_packet_move_ref
void av_packet_move_ref(AVPacket *dst, AVPacket *src)
Move every field in src to dst and reset src.
Definition: avpacket.c:690
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
moflex_read_close
static int moflex_read_close(AVFormatContext *s)
Definition: moflex.c:369
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
avio_rb24
unsigned int avio_rb24(AVIOContext *s)
Definition: aviobuf.c:774
AVPacket::size
int size
Definition: packet.h:370
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
avpriv_set_pts_info
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:4993
size
int size
Definition: twinvq_data.h:10344
pop_int
static int pop_int(BitReader *br, AVIOContext *pb, int n)
Definition: moflex.c:58
moflex_read_seek
static int moflex_read_seek(AVFormatContext *s, int stream_index, int64_t pts, int flags)
Definition: moflex.c:359
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:624
height
#define height
FFMIN
#define FFMIN(a, b)
Definition: common.h:105
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
av_packet_alloc
AVPacket * av_packet_alloc(void)
Allocate an AVPacket and set its fields to default values.
Definition: avpacket.c:64
moflex_read_sync
static int moflex_read_sync(AVFormatContext *s)
Definition: moflex.c:155
i
int i
Definition: input.c:407
BitReader::last
unsigned last
Definition: moflex.c:30
AVCodecParameters::height
int height
Definition: codec_par.h:127
read_var_byte
static int read_var_byte(AVFormatContext *s, unsigned *out)
Definition: moflex.c:87
value
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default value
Definition: writing_filters.txt:86
ret
ret
Definition: filter_design.txt:187
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVStream
Stream structure.
Definition: avformat.h:873
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:253
avio_rb16
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:766
av_append_packet
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:326
avformat.h
AVRational::den
int den
Denominator.
Definition: rational.h:60
moflex_read_packet
static int moflex_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: moflex.c:267
AVPacket::stream_index
int stream_index
Definition: packet.h:371
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVCodecParameters::format
int format
Definition: codec_par.h:84
moflex_read_header
static int moflex_read_header(AVFormatContext *s)
Definition: moflex.c:253
ff_moflex_demuxer
AVInputFormat ff_moflex_demuxer
Definition: moflex.c:378
AV_CODEC_ID_ADPCM_IMA_MOFLEX
@ AV_CODEC_ID_ADPCM_IMA_MOFLEX
Definition: codec_id.h:403
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:346
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:389
format
fg outputs[0] format
Definition: ffmpeg_filter.c:177
bytestream.h
MOFLEXDemuxContext::in_block
int in_block
Definition: moflex.c:39
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
BitReader::pos
unsigned pos
Definition: moflex.c:31
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
MOFLEXDemuxContext::pos
int64_t pos
Definition: moflex.c:36
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:364