nsvdec.c
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1 /*
2  * NSV demuxer
3  * Copyright (c) 2004 The Libav Project
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/mathematics.h"
23 #include "avformat.h"
24 #include "internal.h"
25 #include "riff.h"
26 #include "libavutil/dict.h"
27 
28 //#define DEBUG_DUMP_INDEX // XXX dumbdriving-271.nsv breaks with it commented!!
29 #define CHECK_SUBSEQUENT_NSVS
30 //#define DISABLE_AUDIO
31 
32 /* max bytes to crawl for trying to resync
33  * stupid streaming servers don't start at chunk boundaries...
34  */
35 #define NSV_MAX_RESYNC (500*1024)
36 #define NSV_MAX_RESYNC_TRIES 300
37 
38 /*
39  * First version by Francois Revol - revol@free.fr
40  * References:
41  * (1) http://www.multimedia.cx/nsv-format.txt
42  * seems someone came to the same conclusions as me, and updated it:
43  * (2) http://www.stud.ktu.lt/~vitslav/nsv/nsv-format.txt
44  * http://www.stud.ktu.lt/~vitslav/nsv/
45  * official docs
46  * (3) http://ultravox.aol.com/NSVFormat.rtf
47  * Sample files:
48  * (S1) http://www.nullsoft.com/nsv/samples/
49  * http://www.nullsoft.com/nsv/samples/faster.nsv
50  * http://streamripper.sourceforge.net/openbb/read.php?TID=492&page=4
51  */
52 
53 /*
54  * notes on the header (Francois Revol):
55  *
56  * It is followed by strings, then a table, but nothing tells
57  * where the table begins according to (1). After checking faster.nsv,
58  * I believe NVSf[16-19] gives the size of the strings data
59  * (that is the offset of the data table after the header).
60  * After checking all samples from (S1) all confirms this.
61  *
62  * Then, about NSVf[12-15], faster.nsf has 179700. When veiwing it in VLC,
63  * I noticed there was about 1 NVSs chunk/s, so I ran
64  * strings faster.nsv | grep NSVs | wc -l
65  * which gave me 180. That leads me to think that NSVf[12-15] might be the
66  * file length in milliseconds.
67  * Let's try that:
68  * for f in *.nsv; do HTIME="$(od -t x4 "$f" | head -1 | sed 's/.* //')"; echo "'$f' $((0x$HTIME))s = $((0x$HTIME/1000/60)):$((0x$HTIME/1000%60))"; done
69  * except for nstrailer (which doesn't have an NSVf header), it repports correct time.
70  *
71  * nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
72  * so the header seems to not be mandatory. (for streaming).
73  *
74  * index slice duration check (excepts nsvtrailer.nsv):
75  * for f in [^n]*.nsv; do
76  * DUR="$(avconv -i "$f" 2> /dev/null | grep 'NSVf duration' | cut -d ' ' -f 4)"
77  * IC="$(avconv -i "$f" 2> /dev/null | grep 'INDEX ENTRIES' | cut -d ' ' -f 2)"
78  * echo "duration $DUR, slite time $(($DUR/$IC))"
79  * done
80  */
81 
82 /*
83  * TODO:
84  * - handle timestamps !!!
85  * - use index
86  * - mime-type in probe()
87  * - seek
88  */
89 
90 #if 0
91 struct NSVf_header {
92  uint32_t chunk_tag; /* 'NSVf' */
93  uint32_t chunk_size;
94  uint32_t file_size; /* max 4GB ??? no one learns anything it seems :^) */
95  uint32_t file_length; //unknown1; /* what about MSB of file_size ? */
96  uint32_t info_strings_size; /* size of the info strings */ //unknown2;
97  uint32_t table_entries;
98  uint32_t table_entries_used; /* the left ones should be -1 */
99 };
100 
101 struct NSVs_header {
102  uint32_t chunk_tag; /* 'NSVs' */
103  uint32_t v4cc; /* or 'NONE' */
104  uint32_t a4cc; /* or 'NONE' */
105  uint16_t vwidth; /* assert(vwidth%16==0) */
106  uint16_t vheight; /* assert(vheight%16==0) */
107  uint8_t framerate; /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
108  uint16_t unknown;
109 };
110 
111 struct nsv_avchunk_header {
112  uint8_t vchunk_size_lsb;
113  uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
114  uint16_t achunk_size;
115 };
116 
117 struct nsv_pcm_header {
118  uint8_t bits_per_sample;
119  uint8_t channel_count;
120  uint16_t sample_rate;
121 };
122 #endif
123 
124 /* variation from avi.h */
125 /*typedef struct CodecTag {
126  int id;
127  unsigned int tag;
128 } CodecTag;*/
129 
130 /* tags */
131 
132 #define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
133 #define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
134 #define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
135 #define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
136 #define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
137 #define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
138 #define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
139 
140 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
141 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
142 
143 /* hardcoded stream indexes */
144 #define NSV_ST_VIDEO 0
145 #define NSV_ST_AUDIO 1
146 #define NSV_ST_SUBT 2
147 
148 enum NSVStatus {
157 };
158 
159 typedef struct NSVStream {
160  int frame_offset; /* current frame (video) or byte (audio) counter
161  (used to compute the pts) */
162  int scale;
163  int rate;
164  int sample_size; /* audio only data */
165  int start;
166 
167  int new_frame_offset; /* temporary storage (used during seek) */
168  int cum_len; /* temporary storage (used during seek) */
169 } NSVStream;
170 
171 typedef struct {
173  int NSVf_end;
174  uint32_t *nsvs_file_offset;
177  AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
178  /* cached */
179  int64_t duration;
180  uint32_t vtag, atag;
181  uint16_t vwidth, vheight;
182  int16_t avsync;
184  uint32_t *nsvs_timestamps;
185  //DVDemuxContext* dv_demux;
186 } NSVContext;
187 
189  { CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
190  { CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
191  { CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
192  { CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
193  { CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
194  { CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
195  { CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
196  { CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
197  { CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
198 /*
199  { CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
200  { CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
201 */
202  { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
203  { CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
204  { CODEC_ID_NONE, 0 },
205 };
206 
208  { CODEC_ID_MP3, MKTAG('M', 'P', '3', ' ') },
209  { CODEC_ID_AAC, MKTAG('A', 'A', 'C', ' ') },
210  { CODEC_ID_AAC, MKTAG('A', 'A', 'C', 'P') },
211  { CODEC_ID_SPEEX, MKTAG('S', 'P', 'X', ' ') },
212  { CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
213  { CODEC_ID_NONE, 0 },
214 };
215 
216 //static int nsv_load_index(AVFormatContext *s);
217 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
218 
219 #define print_tag(str, tag, size) \
220  av_dlog(NULL, "%s: tag=%c%c%c%c\n", \
221  str, tag & 0xff, \
222  (tag >> 8) & 0xff, \
223  (tag >> 16) & 0xff, \
224  (tag >> 24) & 0xff);
225 
226 /* try to find something we recognize, and set the state accordingly */
228 {
229  NSVContext *nsv = s->priv_data;
230  AVIOContext *pb = s->pb;
231  uint32_t v = 0;
232  int i;
233 
234  av_dlog(s, "%s(), offset = %"PRId64", state = %d\n", __FUNCTION__, avio_tell(pb), nsv->state);
235 
236  //nsv->state = NSV_UNSYNC;
237 
238  for (i = 0; i < NSV_MAX_RESYNC; i++) {
239  if (pb->eof_reached) {
240  av_dlog(s, "NSV EOF\n");
241  nsv->state = NSV_UNSYNC;
242  return -1;
243  }
244  v <<= 8;
245  v |= avio_r8(pb);
246  if (i < 8) {
247  av_dlog(s, "NSV resync: [%d] = %02x\n", i, v & 0x0FF);
248  }
249 
250  if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
251  av_dlog(s, "NSV resynced on BEEF after %d bytes\n", i+1);
252  nsv->state = NSV_FOUND_BEEF;
253  return 0;
254  }
255  /* we read as big endian, thus the MK*BE* */
256  if (v == TB_NSVF) { /* NSVf */
257  av_dlog(s, "NSV resynced on NSVf after %d bytes\n", i+1);
258  nsv->state = NSV_FOUND_NSVF;
259  return 0;
260  }
261  if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
262  av_dlog(s, "NSV resynced on NSVs after %d bytes\n", i+1);
263  nsv->state = NSV_FOUND_NSVS;
264  return 0;
265  }
266 
267  }
268  av_dlog(s, "NSV sync lost\n");
269  return -1;
270 }
271 
273 {
274  NSVContext *nsv = s->priv_data;
275  AVIOContext *pb = s->pb;
276  unsigned int av_unused file_size;
277  unsigned int size;
278  int64_t duration;
279  int strings_size;
280  int table_entries;
281  int table_entries_used;
282 
283  av_dlog(s, "%s()\n", __FUNCTION__);
284 
285  nsv->state = NSV_UNSYNC; /* in case we fail */
286 
287  size = avio_rl32(pb);
288  if (size < 28)
289  return -1;
290  nsv->NSVf_end = size;
291 
292  //s->file_size = (uint32_t)avio_rl32(pb);
293  file_size = (uint32_t)avio_rl32(pb);
294  av_dlog(s, "NSV NSVf chunk_size %u\n", size);
295  av_dlog(s, "NSV NSVf file_size %u\n", file_size);
296 
297  nsv->duration = duration = avio_rl32(pb); /* in ms */
298  av_dlog(s, "NSV NSVf duration %"PRId64" ms\n", duration);
299  // XXX: store it in AVStreams
300 
301  strings_size = avio_rl32(pb);
302  table_entries = avio_rl32(pb);
303  table_entries_used = avio_rl32(pb);
304  av_dlog(s, "NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
305  strings_size, table_entries, table_entries_used);
306  if (pb->eof_reached)
307  return -1;
308 
309  av_dlog(s, "NSV got header; filepos %"PRId64"\n", avio_tell(pb));
310 
311  if (strings_size > 0) {
312  char *strings; /* last byte will be '\0' to play safe with str*() */
313  char *p, *endp;
314  char *token, *value;
315  char quote;
316 
317  p = strings = av_mallocz((size_t)strings_size + 1);
318  if (!p)
319  return AVERROR(ENOMEM);
320  endp = strings + strings_size;
321  avio_read(pb, strings, strings_size);
322  while (p < endp) {
323  while (*p == ' ')
324  p++; /* strip out spaces */
325  if (p >= endp-2)
326  break;
327  token = p;
328  p = strchr(p, '=');
329  if (!p || p >= endp-2)
330  break;
331  *p++ = '\0';
332  quote = *p++;
333  value = p;
334  p = strchr(p, quote);
335  if (!p || p >= endp)
336  break;
337  *p++ = '\0';
338  av_dlog(s, "NSV NSVf INFO: %s='%s'\n", token, value);
339  av_dict_set(&s->metadata, token, value, 0);
340  }
341  av_free(strings);
342  }
343  if (pb->eof_reached)
344  return -1;
345 
346  av_dlog(s, "NSV got infos; filepos %"PRId64"\n", avio_tell(pb));
347 
348  if (table_entries_used > 0) {
349  int i;
350  nsv->index_entries = table_entries_used;
351  if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
352  return -1;
353  nsv->nsvs_file_offset = av_malloc((unsigned)table_entries_used * sizeof(uint32_t));
354  if (!nsv->nsvs_file_offset)
355  return AVERROR(ENOMEM);
356 
357  for(i=0;i<table_entries_used;i++)
358  nsv->nsvs_file_offset[i] = avio_rl32(pb) + size;
359 
360  if(table_entries > table_entries_used &&
361  avio_rl32(pb) == MKTAG('T','O','C','2')) {
362  nsv->nsvs_timestamps = av_malloc((unsigned)table_entries_used*sizeof(uint32_t));
363  if (!nsv->nsvs_timestamps)
364  return AVERROR(ENOMEM);
365  for(i=0;i<table_entries_used;i++) {
366  nsv->nsvs_timestamps[i] = avio_rl32(pb);
367  }
368  }
369  }
370 
371  av_dlog(s, "NSV got index; filepos %"PRId64"\n", avio_tell(pb));
372 
373 #ifdef DEBUG_DUMP_INDEX
374 #define V(v) ((v<0x20 || v > 127)?'.':v)
375  /* dump index */
376  av_dlog(s, "NSV %d INDEX ENTRIES:\n", table_entries);
377  av_dlog(s, "NSV [dataoffset][fileoffset]\n", table_entries);
378  for (i = 0; i < table_entries; i++) {
379  unsigned char b[8];
380  avio_seek(pb, size + nsv->nsvs_file_offset[i], SEEK_SET);
381  avio_read(pb, b, 8);
382  av_dlog(s, "NSV [0x%08lx][0x%08lx]: %02x %02x %02x %02x %02x %02x %02x %02x"
383  "%c%c%c%c%c%c%c%c\n",
384  nsv->nsvs_file_offset[i], size + nsv->nsvs_file_offset[i],
385  b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
386  V(b[0]), V(b[1]), V(b[2]), V(b[3]), V(b[4]), V(b[5]), V(b[6]), V(b[7]) );
387  }
388  //avio_seek(pb, size, SEEK_SET); /* go back to end of header */
389 #undef V
390 #endif
391 
392  avio_seek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
393 
394  if (pb->eof_reached)
395  return -1;
396  nsv->state = NSV_HAS_READ_NSVF;
397  return 0;
398 }
399 
401 {
402  NSVContext *nsv = s->priv_data;
403  AVIOContext *pb = s->pb;
404  uint32_t vtag, atag;
405  uint16_t vwidth, vheight;
406  AVRational framerate;
407  int i;
408  AVStream *st;
409  NSVStream *nst;
410  av_dlog(s, "%s()\n", __FUNCTION__);
411 
412  vtag = avio_rl32(pb);
413  atag = avio_rl32(pb);
414  vwidth = avio_rl16(pb);
415  vheight = avio_rl16(pb);
416  i = avio_r8(pb);
417 
418  av_dlog(s, "NSV NSVs framerate code %2x\n", i);
419  if(i&0x80) { /* odd way of giving native framerates from docs */
420  int t=(i & 0x7F)>>2;
421  if(t<16) framerate = (AVRational){1, t+1};
422  else framerate = (AVRational){t-15, 1};
423 
424  if(i&1){
425  framerate.num *= 1000;
426  framerate.den *= 1001;
427  }
428 
429  if((i&3)==3) framerate.num *= 24;
430  else if((i&3)==2) framerate.num *= 25;
431  else framerate.num *= 30;
432  }
433  else
434  framerate= (AVRational){i, 1};
435 
436  nsv->avsync = avio_rl16(pb);
437  nsv->framerate = framerate;
438 
439  print_tag("NSV NSVs vtag", vtag, 0);
440  print_tag("NSV NSVs atag", atag, 0);
441  av_dlog(s, "NSV NSVs vsize %dx%d\n", vwidth, vheight);
442 
443  /* XXX change to ap != NULL ? */
444  if (s->nb_streams == 0) { /* streams not yet published, let's do that */
445  nsv->vtag = vtag;
446  nsv->atag = atag;
447  nsv->vwidth = vwidth;
448  nsv->vheight = vwidth;
449  if (vtag != T_NONE) {
450  int i;
451  st = avformat_new_stream(s, NULL);
452  if (!st)
453  goto fail;
454 
455  st->id = NSV_ST_VIDEO;
456  nst = av_mallocz(sizeof(NSVStream));
457  if (!nst)
458  goto fail;
459  st->priv_data = nst;
461  st->codec->codec_tag = vtag;
462  st->codec->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
463  st->codec->width = vwidth;
464  st->codec->height = vheight;
465  st->codec->bits_per_coded_sample = 24; /* depth XXX */
466 
467  avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
468  st->start_time = 0;
469  st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
470 
471  for(i=0;i<nsv->index_entries;i++) {
472  if(nsv->nsvs_timestamps) {
474  0, 0, AVINDEX_KEYFRAME);
475  } else {
476  int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
477  av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
478  }
479  }
480  }
481  if (atag != T_NONE) {
482 #ifndef DISABLE_AUDIO
483  st = avformat_new_stream(s, NULL);
484  if (!st)
485  goto fail;
486 
487  st->id = NSV_ST_AUDIO;
488  nst = av_mallocz(sizeof(NSVStream));
489  if (!nst)
490  goto fail;
491  st->priv_data = nst;
493  st->codec->codec_tag = atag;
494  st->codec->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
495 
496  st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
497 
498  /* set timebase to common denominator of ms and framerate */
499  avpriv_set_pts_info(st, 64, 1, framerate.num*1000);
500  st->start_time = 0;
501  st->duration = (int64_t)nsv->duration * framerate.num;
502 #endif
503  }
504 #ifdef CHECK_SUBSEQUENT_NSVS
505  } else {
506  if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
507  av_dlog(s, "NSV NSVs header values differ from the first one!!!\n");
508  //return -1;
509  }
510 #endif /* CHECK_SUBSEQUENT_NSVS */
511  }
512 
513  nsv->state = NSV_HAS_READ_NSVS;
514  return 0;
515 fail:
516  /* XXX */
517  nsv->state = NSV_UNSYNC;
518  return -1;
519 }
520 
522 {
523  NSVContext *nsv = s->priv_data;
524  int i, err;
525 
526  av_dlog(s, "%s()\n", __FUNCTION__);
527  av_dlog(s, "filename '%s'\n", s->filename);
528 
529  nsv->state = NSV_UNSYNC;
530  nsv->ahead[0].data = nsv->ahead[1].data = NULL;
531 
532  for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
533  if (nsv_resync(s) < 0)
534  return -1;
535  if (nsv->state == NSV_FOUND_NSVF) {
536  err = nsv_parse_NSVf_header(s, ap);
537  if (err < 0)
538  return err;
539  }
540  /* we need the first NSVs also... */
541  if (nsv->state == NSV_FOUND_NSVS) {
542  err = nsv_parse_NSVs_header(s, ap);
543  if (err < 0)
544  return err;
545  break; /* we just want the first one */
546  }
547  }
548  if (s->nb_streams < 1) /* no luck so far */
549  return -1;
550  /* now read the first chunk, so we can attempt to decode more info */
551  err = nsv_read_chunk(s, 1);
552 
553  av_dlog(s, "parsed header\n");
554  return err;
555 }
556 
557 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
558 {
559  NSVContext *nsv = s->priv_data;
560  AVIOContext *pb = s->pb;
561  AVStream *st[2] = {NULL, NULL};
562  NSVStream *nst;
563  AVPacket *pkt;
564  int i, err = 0;
565  uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
566  uint32_t vsize;
567  uint16_t asize;
568  uint16_t auxsize;
569  uint32_t av_unused auxtag;
570 
571  av_dlog(s, "%s(%d)\n", __FUNCTION__, fill_header);
572 
573  if (nsv->ahead[0].data || nsv->ahead[1].data)
574  return 0; //-1; /* hey! eat what you've in your plate first! */
575 
576 null_chunk_retry:
577  if (pb->eof_reached)
578  return -1;
579 
580  for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
581  err = nsv_resync(s);
582  if (err < 0)
583  return err;
584  if (nsv->state == NSV_FOUND_NSVS)
585  err = nsv_parse_NSVs_header(s, NULL);
586  if (err < 0)
587  return err;
588  if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
589  return -1;
590 
591  auxcount = avio_r8(pb);
592  vsize = avio_rl16(pb);
593  asize = avio_rl16(pb);
594  vsize = (vsize << 4) | (auxcount >> 4);
595  auxcount &= 0x0f;
596  av_dlog(s, "NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize);
597  /* skip aux stuff */
598  for (i = 0; i < auxcount; i++) {
599  auxsize = avio_rl16(pb);
600  auxtag = avio_rl32(pb);
601  av_dlog(s, "NSV aux data: '%c%c%c%c', %d bytes\n",
602  (auxtag & 0x0ff),
603  ((auxtag >> 8) & 0x0ff),
604  ((auxtag >> 16) & 0x0ff),
605  ((auxtag >> 24) & 0x0ff),
606  auxsize);
607  avio_skip(pb, auxsize);
608  vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
609  }
610 
611  if (pb->eof_reached)
612  return -1;
613  if (!vsize && !asize) {
614  nsv->state = NSV_UNSYNC;
615  goto null_chunk_retry;
616  }
617 
618  /* map back streams to v,a */
619  if (s->nb_streams > 0)
620  st[s->streams[0]->id] = s->streams[0];
621  if (s->nb_streams > 1)
622  st[s->streams[1]->id] = s->streams[1];
623 
624  if (vsize && st[NSV_ST_VIDEO]) {
625  nst = st[NSV_ST_VIDEO]->priv_data;
626  pkt = &nsv->ahead[NSV_ST_VIDEO];
627  av_get_packet(pb, pkt, vsize);
628  pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
629  pkt->dts = nst->frame_offset;
630  pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
631  for (i = 0; i < FFMIN(8, vsize); i++)
632  av_dlog(s, "NSV video: [%d] = %02x\n", i, pkt->data[i]);
633  }
634  if(st[NSV_ST_VIDEO])
635  ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
636 
637  if (asize && st[NSV_ST_AUDIO]) {
638  nst = st[NSV_ST_AUDIO]->priv_data;
639  pkt = &nsv->ahead[NSV_ST_AUDIO];
640  /* read raw audio specific header on the first audio chunk... */
641  /* on ALL audio chunks ?? seems so! */
642  if (asize && st[NSV_ST_AUDIO]->codec->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
643  uint8_t bps;
644  uint8_t channels;
645  uint16_t samplerate;
646  bps = avio_r8(pb);
647  channels = avio_r8(pb);
648  samplerate = avio_rl16(pb);
649  asize-=4;
650  av_dlog(s, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
651  if (fill_header) {
652  st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
653  if (bps != 16) {
654  av_dlog(s, "NSV AUDIO bit/sample != 16 (%d)!!!\n", bps);
655  }
656  bps /= channels; // ???
657  if (bps == 8)
659  samplerate /= 4;/* UGH ??? XXX */
660  channels = 1;
661  st[NSV_ST_AUDIO]->codec->channels = channels;
662  st[NSV_ST_AUDIO]->codec->sample_rate = samplerate;
663  av_dlog(s, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
664  }
665  }
666  av_get_packet(pb, pkt, asize);
667  pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
668  pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
669  if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
670  /* on a nsvs frame we have new information on a/v sync */
671  pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
672  pkt->dts *= (int64_t)1000 * nsv->framerate.den;
673  pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
674  av_dlog(s, "NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts);
675  }
676  nst->frame_offset++;
677  }
678 
679  nsv->state = NSV_UNSYNC;
680  return 0;
681 }
682 
683 
685 {
686  NSVContext *nsv = s->priv_data;
687  int i, err = 0;
688 
689  av_dlog(s, "%s()\n", __FUNCTION__);
690 
691  /* in case we don't already have something to eat ... */
692  if (nsv->ahead[0].data == NULL && nsv->ahead[1].data == NULL)
693  err = nsv_read_chunk(s, 0);
694  if (err < 0)
695  return err;
696 
697  /* now pick one of the plates */
698  for (i = 0; i < 2; i++) {
699  if (nsv->ahead[i].data) {
700  av_dlog(s, "%s: using cached packet[%d]\n", __FUNCTION__, i);
701  /* avoid the cost of new_packet + memcpy(->data) */
702  memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
703  nsv->ahead[i].data = NULL; /* we ate that one */
704  return pkt->size;
705  }
706  }
707 
708  /* this restaurant is not approvisionned :^] */
709  return -1;
710 }
711 
712 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
713 {
714  NSVContext *nsv = s->priv_data;
715  AVStream *st = s->streams[stream_index];
716  NSVStream *nst = st->priv_data;
717  int index;
718 
719  index = av_index_search_timestamp(st, timestamp, flags);
720  if(index < 0)
721  return -1;
722 
723  avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET);
725  nsv->state = NSV_UNSYNC;
726  return 0;
727 }
728 
730 {
731 /* int i; */
732  NSVContext *nsv = s->priv_data;
733 
734  av_freep(&nsv->nsvs_file_offset);
735  av_freep(&nsv->nsvs_timestamps);
736  if (nsv->ahead[0].data)
737  av_free_packet(&nsv->ahead[0]);
738  if (nsv->ahead[1].data)
739  av_free_packet(&nsv->ahead[1]);
740 
741 #if 0
742 
743  for(i=0;i<s->nb_streams;i++) {
744  AVStream *st = s->streams[i];
745  NSVStream *ast = st->priv_data;
746  if(ast){
747  av_free(ast->index_entries);
748  av_free(ast);
749  }
750  av_free(st->codec->palctrl);
751  }
752 
753 #endif
754  return 0;
755 }
756 
757 static int nsv_probe(AVProbeData *p)
758 {
759  int i;
760  int score;
761  int vsize, asize, auxcount;
762  score = 0;
763  av_dlog(NULL, "nsv_probe(), buf_size %d\n", p->buf_size);
764  /* check file header */
765  /* streamed files might not have any header */
766  if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
767  p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
768  return AVPROBE_SCORE_MAX;
769  /* XXX: do streamed files always start at chunk boundary ?? */
770  /* or do we need to search NSVs in the byte stream ? */
771  /* seems the servers don't bother starting clean chunks... */
772  /* sometimes even the first header is at 9KB or something :^) */
773  for (i = 1; i < p->buf_size - 3; i++) {
774  if (p->buf[i+0] == 'N' && p->buf[i+1] == 'S' &&
775  p->buf[i+2] == 'V' && p->buf[i+3] == 's') {
776  score = AVPROBE_SCORE_MAX/5;
777  /* Get the chunk size and check if at the end we are getting 0xBEEF */
778  auxcount = p->buf[i+19];
779  vsize = p->buf[i+20] | p->buf[i+21] << 8;
780  asize = p->buf[i+22] | p->buf[i+23] << 8;
781  vsize = (vsize << 4) | (auxcount >> 4);
782  if ((asize + vsize + i + 23) < p->buf_size - 2) {
783  if (p->buf[i+23+asize+vsize+1] == 0xEF &&
784  p->buf[i+23+asize+vsize+2] == 0xBE)
785  return AVPROBE_SCORE_MAX-20;
786  }
787  }
788  }
789  /* so we'll have more luck on extension... */
790  if (av_match_ext(p->filename, "nsv"))
791  return AVPROBE_SCORE_MAX/2;
792  /* FIXME: add mime-type check */
793  return score;
794 }
795 
797  .name = "nsv",
798  .long_name = NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
799  .priv_data_size = sizeof(NSVContext),
805 };