FFmpeg
4xm.c
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1 /*
2  * 4X Technologies .4xm File Demuxer (no muxer)
3  * Copyright (c) 2003 The FFmpeg project
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 /**
23  * @file
24  * 4X Technologies file demuxer
25  * by Mike Melanson (melanson@pcisys.net)
26  * for more information on the .4xm file format, visit:
27  * http://www.pcisys.net/~melanson/codecs/
28  */
29 
30 #include "libavutil/intreadwrite.h"
31 #include "libavutil/intfloat.h"
32 #include "libavcodec/internal.h"
33 #include "avformat.h"
34 #include "internal.h"
35 
36 #define RIFF_TAG MKTAG('R', 'I', 'F', 'F')
37 #define FOURXMV_TAG MKTAG('4', 'X', 'M', 'V')
38 #define LIST_TAG MKTAG('L', 'I', 'S', 'T')
39 #define HEAD_TAG MKTAG('H', 'E', 'A', 'D')
40 #define TRK__TAG MKTAG('T', 'R', 'K', '_')
41 #define MOVI_TAG MKTAG('M', 'O', 'V', 'I')
42 #define VTRK_TAG MKTAG('V', 'T', 'R', 'K')
43 #define STRK_TAG MKTAG('S', 'T', 'R', 'K')
44 #define std__TAG MKTAG('s', 't', 'd', '_')
45 #define name_TAG MKTAG('n', 'a', 'm', 'e')
46 #define vtrk_TAG MKTAG('v', 't', 'r', 'k')
47 #define strk_TAG MKTAG('s', 't', 'r', 'k')
48 #define ifrm_TAG MKTAG('i', 'f', 'r', 'm')
49 #define pfrm_TAG MKTAG('p', 'f', 'r', 'm')
50 #define cfrm_TAG MKTAG('c', 'f', 'r', 'm')
51 #define ifr2_TAG MKTAG('i', 'f', 'r', '2')
52 #define pfr2_TAG MKTAG('p', 'f', 'r', '2')
53 #define cfr2_TAG MKTAG('c', 'f', 'r', '2')
54 #define snd__TAG MKTAG('s', 'n', 'd', '_')
55 
56 #define vtrk_SIZE 0x44
57 #define strk_SIZE 0x28
58 
59 #define GET_LIST_HEADER() \
60  fourcc_tag = avio_rl32(pb); \
61  size = avio_rl32(pb); \
62  if (fourcc_tag != LIST_TAG) \
63  return AVERROR_INVALIDDATA; \
64  fourcc_tag = avio_rl32(pb);
65 
66 typedef struct AudioTrack {
68  int bits;
69  int channels;
71  int adpcm;
72  int64_t audio_pts;
73 } AudioTrack;
74 
75 typedef struct FourxmDemuxContext {
79 
80  int64_t video_pts;
83 
84 static int fourxm_probe(const AVProbeData *p)
85 {
86  if ((AV_RL32(&p->buf[0]) != RIFF_TAG) ||
87  (AV_RL32(&p->buf[8]) != FOURXMV_TAG))
88  return 0;
89 
90  return AVPROBE_SCORE_MAX;
91 }
92 
94  FourxmDemuxContext *fourxm, uint8_t *buf, int size,
95  int left)
96 {
97  AVStream *st;
98  /* check that there is enough data */
99  if (size != vtrk_SIZE || left < size + 8) {
100  return AVERROR_INVALIDDATA;
101  }
102 
103  /* allocate a new AVStream */
104  st = avformat_new_stream(s, NULL);
105  if (!st)
106  return AVERROR(ENOMEM);
107 
108  avpriv_set_pts_info(st, 60, fourxm->fps.den, fourxm->fps.num);
109 
110  fourxm->video_stream_index = st->index;
111 
114 
116  if (!st->codecpar->extradata)
117  return AVERROR(ENOMEM);
118  st->codecpar->extradata_size = 4;
119  AV_WL32(st->codecpar->extradata, AV_RL32(buf + 16));
120  st->codecpar->width = AV_RL32(buf + 36);
121  st->codecpar->height = AV_RL32(buf + 40);
122 
123  return 0;
124 }
125 
126 
128  FourxmDemuxContext *fourxm, uint8_t *buf, int size,
129  int left)
130 {
131  AVStream *st;
132  int track;
133  /* check that there is enough data */
134  if (size != strk_SIZE || left < size + 8)
135  return AVERROR_INVALIDDATA;
136 
137  track = AV_RL32(buf + 8);
138  if ((unsigned)track >= UINT_MAX / sizeof(AudioTrack) - 1) {
139  av_log(s, AV_LOG_ERROR, "current_track too large\n");
140  return AVERROR_INVALIDDATA;
141  }
142 
143  if (track + 1 > fourxm->track_count) {
144  if (av_reallocp_array(&fourxm->tracks, track + 1, sizeof(AudioTrack)))
145  return AVERROR(ENOMEM);
146  memset(&fourxm->tracks[fourxm->track_count], 0,
147  sizeof(AudioTrack) * (track + 1 - fourxm->track_count));
148  fourxm->track_count = track + 1;
149  }
150  fourxm->tracks[track].adpcm = AV_RL32(buf + 12);
151  fourxm->tracks[track].channels = AV_RL32(buf + 36);
152  fourxm->tracks[track].sample_rate = AV_RL32(buf + 40);
153  fourxm->tracks[track].bits = AV_RL32(buf + 44);
154  fourxm->tracks[track].audio_pts = 0;
155 
156  if (fourxm->tracks[track].channels <= 0 ||
157  fourxm->tracks[track].channels > FF_SANE_NB_CHANNELS ||
158  fourxm->tracks[track].sample_rate <= 0 ||
159  fourxm->tracks[track].bits <= 0 ||
160  fourxm->tracks[track].bits > INT_MAX / FF_SANE_NB_CHANNELS) {
161  av_log(s, AV_LOG_ERROR, "audio header invalid\n");
162  return AVERROR_INVALIDDATA;
163  }
164  if (!fourxm->tracks[track].adpcm && fourxm->tracks[track].bits<8) {
165  av_log(s, AV_LOG_ERROR, "bits unspecified for non ADPCM\n");
166  return AVERROR_INVALIDDATA;
167  }
168 
169  if (fourxm->tracks[track].sample_rate > INT64_MAX / fourxm->tracks[track].bits / fourxm->tracks[track].channels) {
170  av_log(s, AV_LOG_ERROR, "Overflow during bit rate calculation %d * %d * %d\n",
171  fourxm->tracks[track].sample_rate, fourxm->tracks[track].bits, fourxm->tracks[track].channels);
172  return AVERROR_INVALIDDATA;
173  }
174 
175  /* allocate a new AVStream */
176  st = avformat_new_stream(s, NULL);
177  if (!st)
178  return AVERROR(ENOMEM);
179 
180  st->id = track;
181  avpriv_set_pts_info(st, 60, 1, fourxm->tracks[track].sample_rate);
182 
183  fourxm->tracks[track].stream_index = st->index;
184 
186  st->codecpar->codec_tag = 0;
187  st->codecpar->channels = fourxm->tracks[track].channels;
188  st->codecpar->sample_rate = fourxm->tracks[track].sample_rate;
189  st->codecpar->bits_per_coded_sample = fourxm->tracks[track].bits;
190  st->codecpar->bit_rate = (int64_t)st->codecpar->channels *
191  st->codecpar->sample_rate *
193  st->codecpar->block_align = st->codecpar->channels *
195 
196  if (fourxm->tracks[track].adpcm){
198  } else if (st->codecpar->bits_per_coded_sample == 8) {
200  } else
202 
203  return 0;
204 }
205 
207 {
208  AVIOContext *pb = s->pb;
209  unsigned int fourcc_tag;
210  unsigned int size;
211  int header_size;
212  FourxmDemuxContext *fourxm = s->priv_data;
213  unsigned char *header;
214  int i, ret;
215 
216  fourxm->track_count = 0;
217  fourxm->tracks = NULL;
218  fourxm->fps = (AVRational){1,1};
219 
220  /* skip the first 3 32-bit numbers */
221  avio_skip(pb, 12);
222 
223  /* check for LIST-HEAD */
224  GET_LIST_HEADER();
225  header_size = size - 4;
226  if (fourcc_tag != HEAD_TAG || header_size < 0)
227  return AVERROR_INVALIDDATA;
228 
229  /* allocate space for the header and load the whole thing */
230  header = av_malloc(header_size);
231  if (!header)
232  return AVERROR(ENOMEM);
233  if (avio_read(pb, header, header_size) != header_size) {
234  av_free(header);
235  return AVERROR(EIO);
236  }
237 
238  /* take the lazy approach and search for any and all vtrk and strk chunks */
239  for (i = 0; i < header_size - 8; i++) {
240  fourcc_tag = AV_RL32(&header[i]);
241  size = AV_RL32(&header[i + 4]);
242  if (size > header_size - i - 8 && (fourcc_tag == vtrk_TAG || fourcc_tag == strk_TAG)) {
243  av_log(s, AV_LOG_ERROR, "chunk larger than array %d>%d\n", size, header_size - i - 8);
244  ret = AVERROR_INVALIDDATA;
245  goto fail;
246  }
247 
248  if (fourcc_tag == std__TAG) {
249  if (header_size - i < 16) {
250  av_log(s, AV_LOG_ERROR, "std TAG truncated\n");
251  ret = AVERROR_INVALIDDATA;
252  goto fail;
253  }
254  fourxm->fps = av_d2q(av_int2float(AV_RL32(&header[i + 12])), 10000);
255  } else if (fourcc_tag == vtrk_TAG) {
256  if ((ret = parse_vtrk(s, fourxm, header + i, size,
257  header_size - i)) < 0)
258  goto fail;
259 
260  i += 8 + size;
261  } else if (fourcc_tag == strk_TAG) {
262  if ((ret = parse_strk(s, fourxm, header + i, size,
263  header_size - i)) < 0)
264  goto fail;
265 
266  i += 8 + size;
267  }
268  }
269 
270  /* skip over the LIST-MOVI chunk (which is where the stream should be */
271  GET_LIST_HEADER();
272  if (fourcc_tag != MOVI_TAG) {
273  ret = AVERROR_INVALIDDATA;
274  goto fail;
275  }
276 
277  av_free(header);
278  /* initialize context members */
279  fourxm->video_pts = -1; /* first frame will push to 0 */
280 
281  return 0;
282 fail:
283  av_freep(&fourxm->tracks);
284  av_free(header);
285  return ret;
286 }
287 
289  AVPacket *pkt)
290 {
291  FourxmDemuxContext *fourxm = s->priv_data;
292  AVIOContext *pb = s->pb;
293  unsigned int fourcc_tag;
294  unsigned int size;
295  int ret = 0;
296  unsigned int track_number;
297  int packet_read = 0;
298  unsigned char header[8];
299  int audio_frame_count;
300 
301  while (!packet_read) {
302  if ((ret = avio_read(s->pb, header, 8)) < 0)
303  return ret;
304  fourcc_tag = AV_RL32(&header[0]);
305  size = AV_RL32(&header[4]);
306  if (avio_feof(pb))
307  return AVERROR(EIO);
308  switch (fourcc_tag) {
309  case LIST_TAG:
310  /* this is a good time to bump the video pts */
311  fourxm->video_pts++;
312 
313  /* skip the LIST-* tag and move on to the next fourcc */
314  avio_rl32(pb);
315  break;
316 
317  case ifrm_TAG:
318  case pfrm_TAG:
319  case cfrm_TAG:
320  case ifr2_TAG:
321  case pfr2_TAG:
322  case cfr2_TAG:
323  /* allocate 8 more bytes than 'size' to account for fourcc
324  * and size */
325  if (size + 8 < size || av_new_packet(pkt, size + 8))
326  return AVERROR(EIO);
327  pkt->stream_index = fourxm->video_stream_index;
328  pkt->pts = fourxm->video_pts;
329  pkt->pos = avio_tell(s->pb);
330  memcpy(pkt->data, header, 8);
331  ret = avio_read(s->pb, &pkt->data[8], size);
332 
333  if (ret < 0) {
334  av_packet_unref(pkt);
335  } else {
336  packet_read = 1;
337  av_shrink_packet(pkt, ret + 8);
338  }
339  break;
340 
341  case snd__TAG:
342  track_number = avio_rl32(pb);
343  avio_skip(pb, 4);
344  size -= 8;
345 
346  if (track_number < fourxm->track_count &&
347  fourxm->tracks[track_number].channels > 0) {
348  ret = av_get_packet(s->pb, pkt, size);
349  if (ret < 0)
350  return AVERROR(EIO);
351  pkt->stream_index =
352  fourxm->tracks[track_number].stream_index;
353  pkt->pts = fourxm->tracks[track_number].audio_pts;
354  packet_read = 1;
355 
356  /* pts accounting */
357  audio_frame_count = size;
358  if (fourxm->tracks[track_number].adpcm)
359  audio_frame_count -= 2 * (fourxm->tracks[track_number].channels);
360  audio_frame_count /= fourxm->tracks[track_number].channels;
361  if (fourxm->tracks[track_number].adpcm) {
362  audio_frame_count *= 2;
363  } else
364  audio_frame_count /=
365  (fourxm->tracks[track_number].bits / 8);
366  fourxm->tracks[track_number].audio_pts += audio_frame_count;
367  } else {
368  avio_skip(pb, size);
369  }
370  break;
371 
372  default:
373  avio_skip(pb, size);
374  break;
375  }
376  }
377  return ret;
378 }
379 
381 {
382  FourxmDemuxContext *fourxm = s->priv_data;
383 
384  av_freep(&fourxm->tracks);
385 
386  return 0;
387 }
388 
390  .name = "4xm",
391  .long_name = NULL_IF_CONFIG_SMALL("4X Technologies"),
392  .priv_data_size = sizeof(FourxmDemuxContext),
397 };
#define FF_SANE_NB_CHANNELS
Definition: internal.h:86
#define NULL
Definition: coverity.c:32
int sample_rate
Definition: 4xm.c:67
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t audio_pts
Definition: 4xm.c:72
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1500
void av_shrink_packet(AVPacket *pkt, int size)
Reduce packet size, correctly zeroing padding.
Definition: avpacket.c:101
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:4929
#define ifr2_TAG
Definition: 4xm.c:51
static av_always_inline float av_int2float(uint32_t i)
Reinterpret a 32-bit integer as a float.
Definition: intfloat.h:40
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
int num
Numerator.
Definition: rational.h:59
int index
stream index in AVFormatContext
Definition: avformat.h:882
static int audio_frame_count
#define strk_SIZE
Definition: 4xm.c:57
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
static int parse_vtrk(AVFormatContext *s, FourxmDemuxContext *fourxm, uint8_t *buf, int size, int left)
Definition: 4xm.c:93
int channels
Definition: 4xm.c:69
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
static AVPacket pkt
AVRational fps
Definition: 4xm.c:81
static int fourxm_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: 4xm.c:288
int adpcm
Definition: 4xm.c:71
Format I/O context.
Definition: avformat.h:1358
#define cfrm_TAG
Definition: 4xm.c:50
uint8_t
#define av_malloc(s)
int width
Video only.
Definition: avcodec.h:4034
#define FOURXMV_TAG
Definition: 4xm.c:37
int id
Format-specific stream ID.
Definition: avformat.h:888
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4502
static int fourxm_probe(const AVProbeData *p)
Definition: 4xm.c:84
#define vtrk_SIZE
Definition: 4xm.c:56
#define strk_TAG
Definition: 4xm.c:47
uint8_t * data
Definition: avcodec.h:1480
Definition: 4xm.c:66
static av_cold int read_close(AVFormatContext *ctx)
Definition: libcdio.c:145
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:310
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
static const uint8_t header[24]
Definition: sdr2.c:67
AVInputFormat ff_fourxm_demuxer
Definition: 4xm.c:389
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:650
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3997
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:772
#define RIFF_TAG
Definition: 4xm.c:36
int video_stream_index
Definition: 4xm.c:76
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
#define fail()
Definition: checkasm.h:122
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:3986
int av_reallocp_array(void *ptr, size_t nmemb, size_t size)
Allocate, reallocate, or free an array through a pointer to a pointer.
Definition: mem.c:205
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
int block_align
Audio only.
Definition: avcodec.h:4085
static int fourxm_read_close(AVFormatContext *s)
Definition: 4xm.c:380
static int parse_strk(AVFormatContext *s, FourxmDemuxContext *fourxm, uint8_t *buf, int size, int left)
Definition: 4xm.c:127
int stream_index
Definition: 4xm.c:70
int64_t video_pts
Definition: 4xm.c:80
int track_count
Definition: 4xm.c:77
#define pfrm_TAG
Definition: 4xm.c:49
#define s(width, name)
Definition: cbs_vp9.c:257
AudioTrack * tracks
Definition: 4xm.c:78
#define MOVI_TAG
Definition: 4xm.c:41
static int fourxm_read_header(AVFormatContext *s)
Definition: 4xm.c:206
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
if(ret)
Stream structure.
Definition: avformat.h:881
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
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:206
void * buf
Definition: avisynth_c.h:766
#define LIST_TAG
Definition: 4xm.c:38
#define std__TAG
Definition: 4xm.c:44
Rational number (pair of numerator and denominator).
Definition: rational.h:58
#define ifrm_TAG
Definition: 4xm.c:48
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
#define snd__TAG
Definition: 4xm.c:54
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
AVRational av_d2q(double d, int max)
Convert a double precision floating point number to a rational.
Definition: rational.c:106
int sample_rate
Audio only.
Definition: avcodec.h:4078
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
common internal api header.
#define vtrk_TAG
Definition: 4xm.c:46
int bits
Definition: 4xm.c:68
int den
Denominator.
Definition: rational.h:60
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:793
#define GET_LIST_HEADER()
Definition: 4xm.c:59
#define av_free(p)
void * priv_data
Format private data.
Definition: avformat.h:1386
#define cfr2_TAG
Definition: 4xm.c:53
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4010
uint8_t * extradata
Extra binary data needed for initializing the decoder, codec-dependent.
Definition: avcodec.h:3982
#define pfr2_TAG
Definition: 4xm.c:52
int channels
Audio only.
Definition: avcodec.h:4074
#define av_freep(p)
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3972
int stream_index
Definition: avcodec.h:1482
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
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1457
#define HEAD_TAG
Definition: 4xm.c:39
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1473
#define AV_WL32(p, v)
Definition: intreadwrite.h:426