FFmpeg
mmf.c
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1 /*
2  * Yamaha SMAF format
3  * Copyright (c) 2005 Vidar Madsen
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 #include "config_components.h"
23 
25 #include "avformat.h"
26 #include "avio_internal.h"
27 #include "internal.h"
28 #include "mux.h"
29 #include "pcm.h"
30 #include "rawenc.h"
31 #include "riff.h"
32 #include "version.h"
33 
34 typedef struct MMFContext {
35  int64_t atrpos, atsqpos, awapos;
36  int64_t data_end;
37  int stereo;
38 } MMFContext;
39 
40 static const int mmf_rates[] = { 4000, 8000, 11025, 22050, 44100 };
41 
42 static int mmf_rate(int code)
43 {
44  if ((code < 0) || (code > 4))
45  return -1;
46  return mmf_rates[code];
47 }
48 
49 #if CONFIG_MMF_MUXER
50 static int mmf_rate_code(int rate)
51 {
52  int i;
53  for (i = 0; i < 5; i++)
54  if (mmf_rates[i] == rate)
55  return i;
56  return -1;
57 }
58 
59 /* Copy of end_tag() from avienc.c, but for big-endian chunk size */
60 static void end_tag_be(AVIOContext *pb, int64_t start)
61 {
62  int64_t pos;
63 
64  pos = avio_tell(pb);
65  avio_seek(pb, start - 4, SEEK_SET);
66  avio_wb32(pb, (uint32_t)(pos - start));
67  avio_seek(pb, pos, SEEK_SET);
68 }
69 
70 static int mmf_write_header(AVFormatContext *s)
71 {
72  MMFContext *mmf = s->priv_data;
73  AVIOContext *pb = s->pb;
74  int64_t pos;
75  int rate;
76  const char *version = s->flags & AVFMT_FLAG_BITEXACT ?
77  "VN:Lavf," :
78  "VN:"LIBAVFORMAT_IDENT",";
79 
80  rate = mmf_rate_code(s->streams[0]->codecpar->sample_rate);
81  if (rate < 0) {
82  av_log(s, AV_LOG_ERROR, "Unsupported sample rate %d, supported are 4000, 8000, 11025, 22050 and 44100\n",
83  s->streams[0]->codecpar->sample_rate);
84  return AVERROR(EINVAL);
85  }
86 
87  mmf->stereo = s->streams[0]->codecpar->ch_layout.nb_channels > 1;
88  if (mmf->stereo &&
89  s->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
90  av_log(s, AV_LOG_ERROR, "Yamaha SMAF stereo is experimental, "
91  "add '-strict %d' if you want to use it.\n",
93  return AVERROR(EINVAL);
94  }
95 
96  ffio_wfourcc(pb, "MMMD");
97  avio_wb32(pb, 0);
98  pos = ff_start_tag(pb, "CNTI");
99  avio_w8(pb, 0); /* class */
100  avio_w8(pb, 1); /* type */
101  avio_w8(pb, 1); /* code type */
102  avio_w8(pb, 0); /* status */
103  avio_w8(pb, 0); /* counts */
104  end_tag_be(pb, pos);
105 
106  pos = ff_start_tag(pb, "OPDA");
107  avio_write(pb, version, strlen(version)); /* metadata ("ST:songtitle,VN:version,...") */
108  end_tag_be(pb, pos);
109 
110  avio_write(pb, "ATR\x00", 4);
111  avio_wb32(pb, 0);
112  mmf->atrpos = avio_tell(pb);
113  avio_w8(pb, 0); /* format type */
114  avio_w8(pb, 0); /* sequence type */
115  avio_w8(pb, (mmf->stereo << 7) | (1 << 4) | rate); /* (channel << 7) | (format << 4) | rate */
116  avio_w8(pb, 0); /* wave base bit */
117  avio_w8(pb, 2); /* time base d */
118  avio_w8(pb, 2); /* time base g */
119 
120  ffio_wfourcc(pb, "Atsq");
121  avio_wb32(pb, 16);
122  mmf->atsqpos = avio_tell(pb);
123  /* Will be filled on close */
124  avio_write(pb, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16);
125 
126  mmf->awapos = ff_start_tag(pb, "Awa\x01");
127 
128  avpriv_set_pts_info(s->streams[0], 64, 1, s->streams[0]->codecpar->sample_rate);
129 
130  return 0;
131 }
132 
133 /* Write a variable-length symbol */
134 static void put_varlength(AVIOContext *pb, int val)
135 {
136  if (val < 128)
137  avio_w8(pb, val);
138  else {
139  val -= 128;
140  avio_w8(pb, 0x80 | val >> 7);
141  avio_w8(pb, 0x7f & val);
142  }
143 }
144 
145 static int mmf_write_trailer(AVFormatContext *s)
146 {
147  AVIOContext *pb = s->pb;
148  MMFContext *mmf = s->priv_data;
149  int64_t pos, size;
150  int gatetime;
151 
152  if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
153  /* Fill in length fields */
154  end_tag_be(pb, mmf->awapos);
155  end_tag_be(pb, mmf->atrpos);
156  end_tag_be(pb, 8);
157 
158  pos = avio_tell(pb);
159  size = pos - mmf->awapos;
160 
161  /* Fill Atsq chunk */
162  avio_seek(pb, mmf->atsqpos, SEEK_SET);
163 
164  /* "play wav" */
165  avio_w8(pb, 0); /* start time */
166  avio_w8(pb, (mmf->stereo << 6) | 1); /* (channel << 6) | wavenum */
167  gatetime = size * 500 / s->streams[0]->codecpar->sample_rate;
168  put_varlength(pb, gatetime); /* duration */
169 
170  /* "nop" */
171  put_varlength(pb, gatetime); /* start time */
172  avio_write(pb, "\xff\x00", 2); /* nop */
173 
174  /* "end of sequence" */
175  avio_write(pb, "\x00\x00\x00\x00", 4);
176 
177  avio_seek(pb, pos, SEEK_SET);
178  }
179  return 0;
180 }
181 #endif /* CONFIG_MMF_MUXER */
182 
183 static int mmf_probe(const AVProbeData *p)
184 {
185  /* check file header */
186  if (p->buf[0] == 'M' && p->buf[1] == 'M' &&
187  p->buf[2] == 'M' && p->buf[3] == 'D' &&
188  p->buf[8] == 'C' && p->buf[9] == 'N' &&
189  p->buf[10] == 'T' && p->buf[11] == 'I')
190  return AVPROBE_SCORE_MAX;
191  else
192  return 0;
193 }
194 
195 /* mmf input */
197 {
198  MMFContext *mmf = s->priv_data;
199  unsigned int tag;
200  AVIOContext *pb = s->pb;
201  AVStream *st;
202  int64_t size;
203  int rate, params;
204 
205  tag = avio_rl32(pb);
206  if (tag != MKTAG('M', 'M', 'M', 'D'))
207  return AVERROR_INVALIDDATA;
208  avio_skip(pb, 4); /* file_size */
209 
210  /* Skip some unused chunks that may or may not be present */
211  for (;; avio_skip(pb, size)) {
212  tag = avio_rl32(pb);
213  size = avio_rb32(pb);
214  if (tag == MKTAG('C', 'N', 'T', 'I'))
215  continue;
216  if (tag == MKTAG('O', 'P', 'D', 'A'))
217  continue;
218  break;
219  }
220 
221  /* Tag = "ATRx", where "x" = track number */
222  if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
223  av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
224  return AVERROR_PATCHWELCOME;
225  }
226  if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
227  av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
228  return AVERROR_PATCHWELCOME;
229  }
230 
231  avio_r8(pb); /* format type */
232  avio_r8(pb); /* sequence type */
233  params = avio_r8(pb); /* (channel << 7) | (format << 4) | rate */
234  rate = mmf_rate(params & 0x0f);
235  if (rate < 0) {
236  av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
237  return AVERROR_INVALIDDATA;
238  }
239  avio_r8(pb); /* wave base bit */
240  avio_r8(pb); /* time base d */
241  avio_r8(pb); /* time base g */
242 
243  /* Skip some unused chunks that may or may not be present */
244  for (;; avio_skip(pb, size)) {
245  tag = avio_rl32(pb);
246  size = avio_rb32(pb);
247  if (tag == MKTAG('A', 't', 's', 'q'))
248  continue;
249  if (tag == MKTAG('A', 's', 'p', 'I'))
250  continue;
251  break;
252  }
253 
254  /* Make sure it's followed by an Awa chunk, aka wave data */
255  if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
256  av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
257  return AVERROR_INVALIDDATA;
258  }
259  mmf->data_end = avio_tell(pb) + size;
260 
261  st = avformat_new_stream(s, NULL);
262  if (!st)
263  return AVERROR(ENOMEM);
264 
267  st->codecpar->sample_rate = rate;
268  av_channel_layout_default(&st->codecpar->ch_layout, (params >> 7) + 1);
270  st->codecpar->bit_rate = st->codecpar->sample_rate *
272 
273  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
274 
275  return 0;
276 }
277 
278 #define MAX_SIZE 4096
279 
281 {
282  MMFContext *mmf = s->priv_data;
283  int64_t left, size;
284  int ret;
285 
286  left = mmf->data_end - avio_tell(s->pb);
287  size = FFMIN(left, MAX_SIZE);
288  if (avio_feof(s->pb) || size <= 0)
289  return AVERROR_EOF;
290 
291  ret = av_get_packet(s->pb, pkt, size);
292  if (ret < 0)
293  return ret;
294 
295  pkt->stream_index = 0;
296 
297  return ret;
298 }
299 
300 #if CONFIG_MMF_DEMUXER
302  .name = "mmf",
303  .long_name = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
304  .priv_data_size = sizeof(MMFContext),
309 };
310 #endif
311 
312 #if CONFIG_MMF_MUXER
314  .p.name = "mmf",
315  .p.long_name = NULL_IF_CONFIG_SMALL("Yamaha SMAF"),
316  .p.mime_type = "application/vnd.smaf",
317  .p.extensions = "mmf",
318  .priv_data_size = sizeof(MMFContext),
319  .p.audio_codec = AV_CODEC_ID_ADPCM_YAMAHA,
320  .p.video_codec = AV_CODEC_ID_NONE,
321  .write_header = mmf_write_header,
322  .write_packet = ff_raw_write_packet,
323  .write_trailer = mmf_write_trailer,
324 };
325 #endif
LIBAVFORMAT_IDENT
#define LIBAVFORMAT_IDENT
Definition: version.h:45
AVOutputFormat::name
const char * name
Definition: avformat.h:511
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
pcm.h
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
ffio_wfourcc
static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
Definition: avio_internal.h:128
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
MMFContext::stereo
int stereo
Definition: mmf.c:37
MMFContext::atrpos
int64_t atrpos
Definition: mmf.c:35
MMFContext::awapos
int64_t awapos
Definition: mmf.c:35
FF_COMPLIANCE_EXPERIMENTAL
#define FF_COMPLIANCE_EXPERIMENTAL
Allow nonstandardized experimental things.
Definition: defs.h:62
MAX_SIZE
#define MAX_SIZE
Definition: mmf.c:278
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:36
mmf_probe
static int mmf_probe(const AVProbeData *p)
Definition: mmf.c:183
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:464
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:843
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:513
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:481
val
static double val(void *priv, double ch)
Definition: aeval.c:78
MMFContext
Definition: mmf.c:34
ff_start_tag
int64_t ff_start_tag(AVIOContext *pb, const char *tag)
Definition: riffenc.c:31
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:808
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:180
AVInputFormat
Definition: avformat.h:549
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:41
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:554
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:454
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
MMFContext::data_end
int64_t data_end
Definition: mmf.c:36
ff_raw_write_packet
int ff_raw_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawenc.c:31
ff_mmf_muxer
const FFOutputFormat ff_mmf_muxer
AVFormatContext
Format I/O context.
Definition: avformat.h:1363
mmf_rates
static const int mmf_rates[]
Definition: mmf.c:40
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:864
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
AV_CODEC_ID_ADPCM_YAMAHA
@ AV_CODEC_ID_ADPCM_YAMAHA
Definition: codec_id.h:384
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:452
FFOutputFormat
Definition: mux.h:32
avio_w8
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:226
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:206
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:171
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:777
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
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:106
mmf_rate
static int mmf_rate(int code)
Definition: mmf.c:42
size
int size
Definition: twinvq_data.h:10344
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:248
avio_wb32
void avio_wb32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:412
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:650
version
version
Definition: libkvazaar.c:321
rawenc.h
av_channel_layout_default
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
Get the default channel layout for a given number of channels.
Definition: channel_layout.c:1033
mmf_read_header
static int mmf_read_header(AVFormatContext *s)
Definition: mmf.c:196
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
MMFContext::atsqpos
int64_t atsqpos
Definition: mmf.c:35
code
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
Definition: filter_design.txt:178
avio_internal.h
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
av_get_packet
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:103
version.h
tag
uint32_t tag
Definition: movenc.c:1786
ret
ret
Definition: filter_design.txt:187
AVFMT_FLAG_BITEXACT
#define AVFMT_FLAG_BITEXACT
When muxing, try to avoid writing any random/volatile data to the output.
Definition: avformat.h:1498
AVStream
Stream structure.
Definition: avformat.h:841
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:278
pos
unsigned int pos
Definition: spdifenc.c:413
avformat.h
left
Tag MUST be and< 10hcoeff half pel interpolation filter coefficients, hcoeff[0] are the 2 middle coefficients[1] are the next outer ones and so on, resulting in a filter like:...eff[2], hcoeff[1], hcoeff[0], hcoeff[0], hcoeff[1], hcoeff[2] ... the sign of the coefficients is not explicitly stored but alternates after each coeff and coeff[0] is positive, so ...,+,-,+,-,+,+,-,+,-,+,... hcoeff[0] is not explicitly stored but found by subtracting the sum of all stored coefficients with signs from 32 hcoeff[0]=32 - hcoeff[1] - hcoeff[2] - ... a good choice for hcoeff and htaps is htaps=6 hcoeff={40,-10, 2} an alternative which requires more computations at both encoder and decoder side and may or may not be better is htaps=8 hcoeff={42,-14, 6,-2}ref_frames minimum of the number of available reference frames and max_ref_frames for example the first frame after a key frame always has ref_frames=1spatial_decomposition_type wavelet type 0 is a 9/7 symmetric compact integer wavelet 1 is a 5/3 symmetric compact integer wavelet others are reserved stored as delta from last, last is reset to 0 if always_reset||keyframeqlog quality(logarithmic quantizer scale) stored as delta from last, last is reset to 0 if always_reset||keyframemv_scale stored as delta from last, last is reset to 0 if always_reset||keyframe FIXME check that everything works fine if this changes between framesqbias dequantization bias stored as delta from last, last is reset to 0 if always_reset||keyframeblock_max_depth maximum depth of the block tree stored as delta from last, last is reset to 0 if always_reset||keyframequant_table quantization tableHighlevel bitstream structure:==============================--------------------------------------------|Header|--------------------------------------------|------------------------------------|||Block0||||split?||||yes no||||......... intra?||||:Block01 :yes no||||:Block02 :....... ..........||||:Block03 ::y DC ::ref index:||||:Block04 ::cb DC ::motion x :||||......... :cr DC ::motion y :||||....... ..........|||------------------------------------||------------------------------------|||Block1|||...|--------------------------------------------|------------ ------------ ------------|||Y subbands||Cb subbands||Cr subbands||||--- ---||--- ---||--- ---|||||LL0||HL0||||LL0||HL0||||LL0||HL0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||LH0||HH0||||LH0||HH0||||LH0||HH0|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HL1||LH1||||HL1||LH1||||HL1||LH1|||||--- ---||--- ---||--- ---||||--- ---||--- ---||--- ---|||||HH1||HL2||||HH1||HL2||||HH1||HL2|||||...||...||...|||------------ ------------ ------------|--------------------------------------------Decoding process:=================------------|||Subbands|------------||||------------|Intra DC||||LL0 subband prediction ------------|\ Dequantization ------------------- \||Reference frames|\ IDWT|------- -------|Motion \|||Frame 0||Frame 1||Compensation . OBMC v -------|------- -------|--------------. \------> Frame n output Frame Frame<----------------------------------/|...|------------------- Range Coder:============Binary Range Coder:------------------- The implemented range coder is an adapted version based upon "Range encoding: an algorithm for removing redundancy from a digitised message." by G. N. N. Martin. The symbols encoded by the Snow range coder are bits(0|1). The associated probabilities are not fix but change depending on the symbol mix seen so far. bit seen|new state ---------+----------------------------------------------- 0|256 - state_transition_table[256 - old_state];1|state_transition_table[old_state];state_transition_table={ 0, 0, 0, 0, 0, 0, 0, 0, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 190, 191, 192, 194, 194, 195, 196, 197, 198, 199, 200, 201, 202, 202, 204, 205, 206, 207, 208, 209, 209, 210, 211, 212, 213, 215, 215, 216, 217, 218, 219, 220, 220, 222, 223, 224, 225, 226, 227, 227, 229, 229, 230, 231, 232, 234, 234, 235, 236, 237, 238, 239, 240, 241, 242, 243, 244, 245, 246, 247, 248, 248, 0, 0, 0, 0, 0, 0, 0};FIXME Range Coding of integers:------------------------- FIXME Neighboring Blocks:===================left and top are set to the respective blocks unless they are outside of the image in which case they are set to the Null block top-left is set to the top left block unless it is outside of the image in which case it is set to the left block if this block has no larger parent block or it is at the left side of its parent block and the top right block is not outside of the image then the top right block is used for top-right else the top-left block is used Null block y, cb, cr are 128 level, ref, mx and my are 0 Motion Vector Prediction:=========================1. the motion vectors of all the neighboring blocks are scaled to compensate for the difference of reference frames scaled_mv=(mv *(256 *(current_reference+1)/(mv.reference+1))+128)> the median of the scaled left
Definition: snow.txt:386
channel_layout.h
AVIO_SEEKABLE_NORMAL
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:41
AVPacket::stream_index
int stream_index
Definition: packet.h:524
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:365
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:29
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:97
mmf_read_packet
static int mmf_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mmf.c:280
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:499
riff.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
AVCodecParameters::bit_rate
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:84
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
ff_mmf_demuxer
const AVInputFormat ff_mmf_demuxer
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:393
mux.h