3 * Copyright (c) 2004 The FFmpeg Project
5 * first version by Francois Revol <revol@free.fr>
7 * This file is part of FFmpeg.
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.
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.
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
24 #include "libavutil/attributes.h"
25 #include "libavutil/mathematics.h"
28 #include "libavutil/dict.h"
29 #include "libavutil/intreadwrite.h"
31 /* max bytes to crawl for trying to resync
32 * stupid streaming servers don't start at chunk boundaries...
34 #define NSV_MAX_RESYNC (500*1024)
35 #define NSV_MAX_RESYNC_TRIES 300
39 * (1) http://www.multimedia.cx/nsv-format.txt
40 * seems someone came to the same conclusions as me, and updated it:
41 * (2) http://www.stud.ktu.lt/~vitslav/nsv/nsv-format.txt
42 * http://www.stud.ktu.lt/~vitslav/nsv/
44 * (3) http://ultravox.aol.com/NSVFormat.rtf
46 * (S1) http://www.nullsoft.com/nsv/samples/
47 * http://www.nullsoft.com/nsv/samples/faster.nsv
48 * http://streamripper.sourceforge.net/openbb/read.php?TID=492&page=4
52 * notes on the header (Francois Revol):
54 * It is followed by strings, then a table, but nothing tells
55 * where the table begins according to (1). After checking faster.nsv,
56 * I believe NVSf[16-19] gives the size of the strings data
57 * (that is the offset of the data table after the header).
58 * After checking all samples from (S1) all confirms this.
60 * Then, about NSVf[12-15], faster.nsf has 179700. When veiwing it in VLC,
61 * I noticed there was about 1 NVSs chunk/s, so I ran
62 * strings faster.nsv | grep NSVs | wc -l
63 * which gave me 180. That leads me to think that NSVf[12-15] might be the
64 * file length in milliseconds.
66 * 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
67 * except for nstrailer (which doesn't have an NSVf header), it repports correct time.
69 * nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
70 * so the header seems to not be mandatory. (for streaming).
72 * index slice duration check (excepts nsvtrailer.nsv):
73 * for f in [^n]*.nsv; do DUR="$(ffmpeg -i "$f" 2>/dev/null | grep 'NSVf duration' | cut -d ' ' -f 4)"; IC="$(ffmpeg -i "$f" 2>/dev/null | grep 'INDEX ENTRIES' | cut -d ' ' -f 2)"; echo "duration $DUR, slite time $(($DUR/$IC))"; done
78 * - handle timestamps !!!
80 * - mime-type in probe()
86 uint32_t chunk_tag; /* 'NSVf' */
88 uint32_t file_size; /* max 4GB ??? no one learns anything it seems :^) */
89 uint32_t file_length; //unknown1; /* what about MSB of file_size ? */
90 uint32_t info_strings_size; /* size of the info strings */ //unknown2;
91 uint32_t table_entries;
92 uint32_t table_entries_used; /* the left ones should be -1 */
96 uint32_t chunk_tag; /* 'NSVs' */
97 uint32_t v4cc; /* or 'NONE' */
98 uint32_t a4cc; /* or 'NONE' */
99 uint16_t vwidth; /* av_assert0(vwidth%16==0) */
100 uint16_t vheight; /* av_assert0(vheight%16==0) */
101 uint8_t framerate; /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
105 struct nsv_avchunk_header {
106 uint8_t vchunk_size_lsb;
107 uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
108 uint16_t achunk_size;
111 struct nsv_pcm_header {
112 uint8_t bits_per_sample;
113 uint8_t channel_count;
114 uint16_t sample_rate;
118 /* variation from avi.h */
119 /*typedef struct CodecTag {
126 #define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
127 #define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
128 #define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
129 #define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
130 #define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
131 #define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
132 #define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
134 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
135 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
137 /* hardcoded stream indexes */
138 #define NSV_ST_VIDEO 0
139 #define NSV_ST_AUDIO 1
140 #define NSV_ST_SUBT 2
153 typedef struct NSVStream {
154 int frame_offset; /* current frame (video) or byte (audio) counter
155 (used to compute the pts) */
158 int sample_size; /* audio only data */
161 int new_frame_offset; /* temporary storage (used during seek) */
162 int cum_len; /* temporary storage (used during seek) */
168 uint32_t *nsvs_file_offset;
170 enum NSVStatus state;
171 AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
175 uint16_t vwidth, vheight;
177 AVRational framerate;
178 uint32_t *nsvs_timestamps;
179 //DVDemuxContext* dv_demux;
182 static const AVCodecTag nsv_codec_video_tags[] = {
183 { AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
184 { AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
185 { AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
186 { AV_CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
187 { AV_CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
188 { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
189 { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
190 { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
191 { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
192 { AV_CODEC_ID_VP8, MKTAG('V', 'P', '8', '0') },
194 { AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
195 { AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
197 { AV_CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
198 { AV_CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
199 { AV_CODEC_ID_NONE, 0 },
202 static const AVCodecTag nsv_codec_audio_tags[] = {
203 { AV_CODEC_ID_MP3, MKTAG('M', 'P', '3', ' ') },
204 { AV_CODEC_ID_AAC, MKTAG('A', 'A', 'C', ' ') },
205 { AV_CODEC_ID_AAC, MKTAG('A', 'A', 'C', 'P') },
206 { AV_CODEC_ID_AAC, MKTAG('V', 'L', 'B', ' ') },
207 { AV_CODEC_ID_SPEEX, MKTAG('S', 'P', 'X', ' ') },
208 { AV_CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
209 { AV_CODEC_ID_NONE, 0 },
212 //static int nsv_load_index(AVFormatContext *s);
213 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
215 #define print_tag(str, tag, size) \
216 av_dlog(NULL, "%s: tag=%c%c%c%c\n", \
219 (tag >> 16) & 0xff, \
222 /* try to find something we recognize, and set the state accordingly */
223 static int nsv_resync(AVFormatContext *s)
225 NSVContext *nsv = s->priv_data;
226 AVIOContext *pb = s->pb;
230 av_dlog(s, "%s(), offset = %"PRId64", state = %d\n", __FUNCTION__, avio_tell(pb), nsv->state);
232 //nsv->state = NSV_UNSYNC;
234 for (i = 0; i < NSV_MAX_RESYNC; i++) {
236 av_dlog(s, "NSV EOF\n");
237 nsv->state = NSV_UNSYNC;
243 av_dlog(s, "NSV resync: [%d] = %02x\n", i, v & 0x0FF);
246 if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
247 av_dlog(s, "NSV resynced on BEEF after %d bytes\n", i+1);
248 nsv->state = NSV_FOUND_BEEF;
251 /* we read as big-endian, thus the MK*BE* */
252 if (v == TB_NSVF) { /* NSVf */
253 av_dlog(s, "NSV resynced on NSVf after %d bytes\n", i+1);
254 nsv->state = NSV_FOUND_NSVF;
257 if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
258 av_dlog(s, "NSV resynced on NSVs after %d bytes\n", i+1);
259 nsv->state = NSV_FOUND_NSVS;
264 av_dlog(s, "NSV sync lost\n");
268 static int nsv_parse_NSVf_header(AVFormatContext *s)
270 NSVContext *nsv = s->priv_data;
271 AVIOContext *pb = s->pb;
272 unsigned int av_unused file_size;
277 int table_entries_used;
279 av_dlog(s, "%s()\n", __FUNCTION__);
281 nsv->state = NSV_UNSYNC; /* in case we fail */
283 size = avio_rl32(pb);
286 nsv->NSVf_end = size;
288 //s->file_size = (uint32_t)avio_rl32(pb);
289 file_size = (uint32_t)avio_rl32(pb);
290 av_dlog(s, "NSV NSVf chunk_size %u\n", size);
291 av_dlog(s, "NSV NSVf file_size %u\n", file_size);
293 nsv->duration = duration = avio_rl32(pb); /* in ms */
294 av_dlog(s, "NSV NSVf duration %"PRId64" ms\n", duration);
295 // XXX: store it in AVStreams
297 strings_size = avio_rl32(pb);
298 table_entries = avio_rl32(pb);
299 table_entries_used = avio_rl32(pb);
300 av_dlog(s, "NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
301 strings_size, table_entries, table_entries_used);
305 av_dlog(s, "NSV got header; filepos %"PRId64"\n", avio_tell(pb));
307 if (strings_size > 0) {
308 char *strings; /* last byte will be '\0' to play safe with str*() */
313 p = strings = av_mallocz((size_t)strings_size + 1);
315 return AVERROR(ENOMEM);
316 endp = strings + strings_size;
317 avio_read(pb, strings, strings_size);
320 p++; /* strip out spaces */
325 if (!p || p >= endp-2)
330 p = strchr(p, quote);
334 av_dlog(s, "NSV NSVf INFO: %s='%s'\n", token, value);
335 av_dict_set(&s->metadata, token, value, 0);
342 av_dlog(s, "NSV got infos; filepos %"PRId64"\n", avio_tell(pb));
344 if (table_entries_used > 0) {
346 nsv->index_entries = table_entries_used;
347 if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
349 nsv->nsvs_file_offset = av_malloc((unsigned)table_entries_used * sizeof(uint32_t));
350 if (!nsv->nsvs_file_offset)
351 return AVERROR(ENOMEM);
353 for(i=0;i<table_entries_used;i++)
354 nsv->nsvs_file_offset[i] = avio_rl32(pb) + size;
356 if(table_entries > table_entries_used &&
357 avio_rl32(pb) == MKTAG('T','O','C','2')) {
358 nsv->nsvs_timestamps = av_malloc((unsigned)table_entries_used*sizeof(uint32_t));
359 if (!nsv->nsvs_timestamps)
360 return AVERROR(ENOMEM);
361 for(i=0;i<table_entries_used;i++) {
362 nsv->nsvs_timestamps[i] = avio_rl32(pb);
367 av_dlog(s, "NSV got index; filepos %"PRId64"\n", avio_tell(pb));
369 avio_seek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
373 nsv->state = NSV_HAS_READ_NSVF;
377 static int nsv_parse_NSVs_header(AVFormatContext *s)
379 NSVContext *nsv = s->priv_data;
380 AVIOContext *pb = s->pb;
382 uint16_t vwidth, vheight;
383 AVRational framerate;
387 av_dlog(s, "%s()\n", __FUNCTION__);
389 vtag = avio_rl32(pb);
390 atag = avio_rl32(pb);
391 vwidth = avio_rl16(pb);
392 vheight = avio_rl16(pb);
395 av_dlog(s, "NSV NSVs framerate code %2x\n", i);
396 if(i&0x80) { /* odd way of giving native framerates from docs */
398 if(t<16) framerate = (AVRational){1, t+1};
399 else framerate = (AVRational){t-15, 1};
402 framerate.num *= 1000;
403 framerate.den *= 1001;
406 if((i&3)==3) framerate.num *= 24;
407 else if((i&3)==2) framerate.num *= 25;
408 else framerate.num *= 30;
411 framerate= (AVRational){i, 1};
413 nsv->avsync = avio_rl16(pb);
414 nsv->framerate = framerate;
416 print_tag("NSV NSVs vtag", vtag, 0);
417 print_tag("NSV NSVs atag", atag, 0);
418 av_dlog(s, "NSV NSVs vsize %dx%d\n", vwidth, vheight);
420 /* XXX change to ap != NULL ? */
421 if (s->nb_streams == 0) { /* streams not yet published, let's do that */
424 nsv->vwidth = vwidth;
425 nsv->vheight = vwidth;
426 if (vtag != T_NONE) {
428 st = avformat_new_stream(s, NULL);
432 st->id = NSV_ST_VIDEO;
433 nst = av_mallocz(sizeof(NSVStream));
437 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
438 st->codec->codec_tag = vtag;
439 st->codec->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
440 st->codec->width = vwidth;
441 st->codec->height = vheight;
442 st->codec->bits_per_coded_sample = 24; /* depth XXX */
444 avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
446 st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
448 for(i=0;i<nsv->index_entries;i++) {
449 if(nsv->nsvs_timestamps) {
450 av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
451 0, 0, AVINDEX_KEYFRAME);
453 int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
454 av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
458 if (atag != T_NONE) {
459 st = avformat_new_stream(s, NULL);
463 st->id = NSV_ST_AUDIO;
464 nst = av_mallocz(sizeof(NSVStream));
468 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
469 st->codec->codec_tag = atag;
470 st->codec->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
472 st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
474 /* set timebase to common denominator of ms and framerate */
475 avpriv_set_pts_info(st, 64, 1, framerate.num*1000);
477 st->duration = (int64_t)nsv->duration * framerate.num;
480 if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
481 av_dlog(s, "NSV NSVs header values differ from the first one!!!\n");
486 nsv->state = NSV_HAS_READ_NSVS;
490 nsv->state = NSV_UNSYNC;
494 static int nsv_read_header(AVFormatContext *s)
496 NSVContext *nsv = s->priv_data;
499 av_dlog(s, "%s()\n", __FUNCTION__);
500 av_dlog(s, "filename '%s'\n", s->filename);
502 nsv->state = NSV_UNSYNC;
503 nsv->ahead[0].data = nsv->ahead[1].data = NULL;
505 for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
506 if (nsv_resync(s) < 0)
508 if (nsv->state == NSV_FOUND_NSVF) {
509 err = nsv_parse_NSVf_header(s);
513 /* we need the first NSVs also... */
514 if (nsv->state == NSV_FOUND_NSVS) {
515 err = nsv_parse_NSVs_header(s);
518 break; /* we just want the first one */
521 if (s->nb_streams < 1) /* no luck so far */
523 /* now read the first chunk, so we can attempt to decode more info */
524 err = nsv_read_chunk(s, 1);
526 av_dlog(s, "parsed header\n");
530 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
532 NSVContext *nsv = s->priv_data;
533 AVIOContext *pb = s->pb;
534 AVStream *st[2] = {NULL, NULL};
538 uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
544 av_dlog(s, "%s(%d)\n", __FUNCTION__, fill_header);
546 if (nsv->ahead[0].data || nsv->ahead[1].data)
547 return 0; //-1; /* hey! eat what you've in your plate first! */
553 for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
557 if (nsv->state == NSV_FOUND_NSVS)
558 err = nsv_parse_NSVs_header(s);
561 if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
564 auxcount = avio_r8(pb);
565 vsize = avio_rl16(pb);
566 asize = avio_rl16(pb);
567 vsize = (vsize << 4) | (auxcount >> 4);
569 av_dlog(s, "NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize);
571 for (i = 0; i < auxcount; i++) {
572 uint32_t av_unused auxtag;
573 auxsize = avio_rl16(pb);
574 auxtag = avio_rl32(pb);
575 av_dlog(s, "NSV aux data: '%c%c%c%c', %d bytes\n",
577 ((auxtag >> 8) & 0x0ff),
578 ((auxtag >> 16) & 0x0ff),
579 ((auxtag >> 24) & 0x0ff),
581 avio_skip(pb, auxsize);
582 vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
587 if (!vsize && !asize) {
588 nsv->state = NSV_UNSYNC;
589 goto null_chunk_retry;
592 /* map back streams to v,a */
593 if (s->nb_streams > 0)
594 st[s->streams[0]->id] = s->streams[0];
595 if (s->nb_streams > 1)
596 st[s->streams[1]->id] = s->streams[1];
598 if (vsize && st[NSV_ST_VIDEO]) {
599 nst = st[NSV_ST_VIDEO]->priv_data;
600 pkt = &nsv->ahead[NSV_ST_VIDEO];
601 if ((ret = av_get_packet(pb, pkt, vsize)) < 0)
603 pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
604 pkt->dts = nst->frame_offset;
605 pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
606 for (i = 0; i < FFMIN(8, vsize); i++)
607 av_dlog(s, "NSV video: [%d] = %02x\n", i, pkt->data[i]);
610 ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
612 if (asize && st[NSV_ST_AUDIO]) {
613 nst = st[NSV_ST_AUDIO]->priv_data;
614 pkt = &nsv->ahead[NSV_ST_AUDIO];
615 /* read raw audio specific header on the first audio chunk... */
616 /* on ALL audio chunks ?? seems so! */
617 if (asize && st[NSV_ST_AUDIO]->codec->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
622 channels = avio_r8(pb);
623 samplerate = avio_rl16(pb);
624 if (!channels || !samplerate)
625 return AVERROR_INVALIDDATA;
627 av_dlog(s, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
629 st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
631 av_dlog(s, "NSV AUDIO bit/sample != 16 (%d)!!!\n", bps);
634 bps /= channels; // ???
636 av_log(s, AV_LOG_WARNING, "Channels is 0\n");
638 st[NSV_ST_AUDIO]->codec->codec_id = AV_CODEC_ID_PCM_U8;
639 samplerate /= 4;/* UGH ??? XXX */
641 st[NSV_ST_AUDIO]->codec->channels = channels;
642 st[NSV_ST_AUDIO]->codec->sample_rate = samplerate;
643 av_dlog(s, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
646 if ((ret = av_get_packet(pb, pkt, asize)) < 0)
648 pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
649 pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
650 if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
651 /* on a nsvs frame we have new information on a/v sync */
652 pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
653 pkt->dts *= (int64_t)1000 * nsv->framerate.den;
654 pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
655 av_dlog(s, "NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts);
660 nsv->state = NSV_UNSYNC;
665 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
667 NSVContext *nsv = s->priv_data;
670 av_dlog(s, "%s()\n", __FUNCTION__);
672 /* in case we don't already have something to eat ... */
673 if (!nsv->ahead[0].data && !nsv->ahead[1].data)
674 err = nsv_read_chunk(s, 0);
678 /* now pick one of the plates */
679 for (i = 0; i < 2; i++) {
680 if (nsv->ahead[i].data) {
681 av_dlog(s, "%s: using cached packet[%d]\n", __FUNCTION__, i);
682 /* avoid the cost of new_packet + memcpy(->data) */
683 memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
684 nsv->ahead[i].data = NULL; /* we ate that one */
689 /* this restaurant is not approvisionned :^] */
693 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
695 NSVContext *nsv = s->priv_data;
696 AVStream *st = s->streams[stream_index];
697 NSVStream *nst = st->priv_data;
700 index = av_index_search_timestamp(st, timestamp, flags);
704 if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
707 nst->frame_offset = st->index_entries[index].timestamp;
708 nsv->state = NSV_UNSYNC;
712 static int nsv_read_close(AVFormatContext *s)
714 NSVContext *nsv = s->priv_data;
716 av_freep(&nsv->nsvs_file_offset);
717 av_freep(&nsv->nsvs_timestamps);
718 if (nsv->ahead[0].data)
719 av_free_packet(&nsv->ahead[0]);
720 if (nsv->ahead[1].data)
721 av_free_packet(&nsv->ahead[1]);
725 static int nsv_probe(AVProbeData *p)
729 av_dlog(NULL, "nsv_probe(), buf_size %d\n", p->buf_size);
730 /* check file header */
731 /* streamed files might not have any header */
732 if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
733 p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
734 return AVPROBE_SCORE_MAX;
735 /* XXX: do streamed files always start at chunk boundary ?? */
736 /* or do we need to search NSVs in the byte stream ? */
737 /* seems the servers don't bother starting clean chunks... */
738 /* sometimes even the first header is at 9KB or something :^) */
739 for (i = 1; i < p->buf_size - 3; i++) {
740 if (AV_RL32(p->buf + i) == AV_RL32("NSVs")) {
741 /* Get the chunk size and check if at the end we are getting 0xBEEF */
742 int vsize = AV_RL24(p->buf+i+19) >> 4;
743 int asize = AV_RL16(p->buf+i+22);
744 int offset = i + 23 + asize + vsize + 1;
745 if (offset <= p->buf_size - 2 && AV_RL16(p->buf + offset) == 0xBEEF)
746 return 4*AVPROBE_SCORE_MAX/5;
747 score = AVPROBE_SCORE_MAX/5;
750 /* so we'll have more luck on extension... */
751 if (av_match_ext(p->filename, "nsv"))
752 return AVPROBE_SCORE_EXTENSION;
753 /* FIXME: add mime-type check */
757 AVInputFormat ff_nsv_demuxer = {
759 .long_name = NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
760 .priv_data_size = sizeof(NSVContext),
761 .read_probe = nsv_probe,
762 .read_header = nsv_read_header,
763 .read_packet = nsv_read_packet,
764 .read_close = nsv_read_close,
765 .read_seek = nsv_read_seek,