3 * Copyright (c) 2004 The FFmpeg Project.
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 //#define DEBUG_DUMP_INDEX // XXX dumbdriving-271.nsv breaks with it commented!!
25 #define CHECK_SUBSEQUENT_NSVS
26 //#define DISABLE_AUDIO
28 /* max bytes to crawl for trying to resync
29 * stupid streaming servers don't start at chunk boundaries...
31 #define NSV_MAX_RESYNC (500*1024)
32 #define NSV_MAX_RESYNC_TRIES 300
35 * First version by Francois Revol - revol@free.fr
37 * (1) http://www.multimedia.cx/nsv-format.txt
38 * seems someone came to the same conclusions as me, and updated it:
39 * (2) http://www.stud.ktu.lt/~vitslav/nsv/nsv-format.txt
40 * http://www.stud.ktu.lt/~vitslav/nsv/
42 * (S1) http://www.nullsoft.com/nsv/samples/
43 * http://www.nullsoft.com/nsv/samples/faster.nsv
44 * http://streamripper.sourceforge.net/openbb/read.php?TID=492&page=4
48 * notes on the header (Francois Revol):
50 * It is followed by strings, then a table, but nothing tells
51 * where the table begins according to (1). After checking faster.nsv,
52 * I believe NVSf[16-19] gives the size of the strings data
53 * (that is the offset of the data table after the header).
54 * After checking all samples from (S1) all confirms this.
56 * Then, about NSVf[12-15], faster.nsf has 179700. When veiwing it in VLC,
57 * I noticed there was about 1 NVSs chunk/s, so I ran
58 * strings faster.nsv | grep NSVs | wc -l
59 * which gave me 180. That leads me to think that NSVf[12-15] might be the
60 * file length in milliseconds.
62 * 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
63 * except for nstrailer (which doesn't have an NSVf header), it repports correct time.
65 * nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
66 * so the header seems to not be mandatory. (for streaming).
68 * index slice duration check (excepts nsvtrailer.nsv):
69 * 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
74 * - handle timestamps !!!
76 * - mime-type in probe()
81 #define PRINT(_v) printf _v
88 uint32_t chunk_tag; /* 'NSVf' */
90 uint32_t file_size; /* max 4GB ??? noone learns anything it seems :^) */
91 uint32_t file_length; //unknown1; /* what about MSB of file_size ? */
92 uint32_t info_strings_size; /* size of the info strings */ //unknown2;
93 uint32_t table_entries;
94 uint32_t table_entries_used; /* the left ones should be -1 */
98 uint32_t chunk_tag; /* 'NSVs' */
99 uint32_t v4cc; /* or 'NONE' */
100 uint32_t a4cc; /* or 'NONE' */
101 uint16_t vwidth; /* assert(vwidth%16==0) */
102 uint16_t vheight; /* assert(vheight%16==0) */
103 uint8_t framerate; /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
107 struct nsv_avchunk_header {
108 uint8_t vchunk_size_lsb;
109 uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
110 uint16_t achunk_size;
113 struct nsv_pcm_header {
114 uint8_t bits_per_sample;
115 uint8_t channel_count;
116 uint16_t sample_rate;
120 /* variation from avi.h */
121 /*typedef struct CodecTag {
128 #define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
129 #define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
130 #define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
131 #define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
132 #define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
133 #define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
134 #define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
136 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
137 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
139 /* hardcoded stream indices */
140 #define NSV_ST_VIDEO 0
141 #define NSV_ST_AUDIO 1
142 #define NSV_ST_SUBT 2
155 typedef struct NSVStream {
156 int frame_offset; /* current frame (video) or byte (audio) counter
157 (used to compute the pts) */
160 int sample_size; /* audio only data */
163 int new_frame_offset; /* temporary storage (used during seek) */
164 int cum_len; /* temporary storage (used during seek) */
170 uint32_t *nsvf_index_data;
172 enum NSVStatus state;
173 AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
177 uint16_t vwidth, vheight;
178 //DVDemuxContext* dv_demux;
181 static const CodecTag nsv_codec_video_tags[] = {
182 { CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
183 { CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
184 { CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
186 { CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
187 { CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
188 { CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
189 { CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
190 { CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
191 { CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
192 { CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
193 { CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
195 { CODEC_ID_XVID, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
196 { CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
200 static const CodecTag nsv_codec_audio_tags[] = {
201 { CODEC_ID_MP3, MKTAG('M', 'P', '3', ' ') },
202 { CODEC_ID_AAC, MKTAG('A', 'A', 'C', ' ') },
203 { CODEC_ID_AAC, MKTAG('A', 'A', 'C', 'P') }, /* _CUTTED__MUXED_2 Heads - Out Of The City.nsv */
204 { CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
208 static const uint64_t nsv_framerate_table[] = {
209 ((uint64_t)AV_TIME_BASE * 30),
210 ((uint64_t)AV_TIME_BASE * 30000 / 1001), /* 29.97 */
211 ((uint64_t)AV_TIME_BASE * 25),
212 ((uint64_t)AV_TIME_BASE * 24000 / 1001), /* 23.98 */
213 ((uint64_t)AV_TIME_BASE * 30), /* ?? */
214 ((uint64_t)AV_TIME_BASE * 15000 / 1001), /* 14.98 */
217 //static int nsv_load_index(AVFormatContext *s);
218 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
221 static void print_tag(const char *str, unsigned int tag, int size)
223 printf("%s: tag=%c%c%c%c\n",
231 /* try to find something we recognize, and set the state accordingly */
232 static int nsv_resync(AVFormatContext *s)
234 NSVContext *nsv = s->priv_data;
235 ByteIOContext *pb = &s->pb;
239 PRINT(("%s(), offset = %Ld, state = %d\n", __FUNCTION__, url_ftell(pb), nsv->state));
241 //nsv->state = NSV_UNSYNC;
243 for (i = 0; i < NSV_MAX_RESYNC; i++) {
245 PRINT(("NSV EOF\n"));
246 nsv->state = NSV_UNSYNC;
253 PRINT(("NSV resync: [%d] = %02x\n", i, v & 0x0FF));
257 if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
258 PRINT(("NSV resynced on BEEF after %d bytes\n", i+1));
259 nsv->state = NSV_FOUND_BEEF;
262 /* we read as big endian, thus the MK*BE* */
263 if (v == TB_NSVF) { /* NSVf */
264 PRINT(("NSV resynced on NSVf after %d bytes\n", i+1));
265 nsv->state = NSV_FOUND_NSVF;
268 if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
269 PRINT(("NSV resynced on NSVs after %d bytes\n", i+1));
270 nsv->state = NSV_FOUND_NSVS;
275 PRINT(("NSV sync lost\n"));
279 static int nsv_parse_NSVf_header(AVFormatContext *s, AVFormatParameters *ap)
281 NSVContext *nsv = s->priv_data;
282 ByteIOContext *pb = &s->pb;
283 uint32_t tag, tag1, handler;
284 int codec_type, stream_index, frame_period, bit_rate, scale, rate;
285 unsigned int file_size, size, nb_frames;
289 int table_entries_used;
294 PRINT(("%s()\n", __FUNCTION__));
296 nsv->state = NSV_UNSYNC; /* in case we fail */
301 nsv->NSVf_end = size;
303 //s->file_size = (uint32_t)get_le32(pb);
304 file_size = (uint32_t)get_le32(pb);
305 PRINT(("NSV NSVf chunk_size %ld\n", size));
306 PRINT(("NSV NSVf file_size %Ld\n", file_size));
308 duration = get_le32(pb); /* in ms */
309 nsv->duration = duration * AV_TIME_BASE / 1000; /* convert */
310 PRINT(("NSV NSVf duration %Ld ms\n", duration));
311 // XXX: store it in AVStreams
313 strings_size = get_le32(pb);
314 table_entries = get_le32(pb);
315 table_entries_used = get_le32(pb);
316 PRINT(("NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
317 strings_size, table_entries, table_entries_used));
321 PRINT(("NSV got header; filepos %Ld\n", url_ftell(pb)));
323 if (strings_size > 0) {
324 char *strings; /* last byte will be '\0' to play safe with str*() */
329 p = strings = av_mallocz(strings_size + 1);
330 endp = strings + strings_size;
331 get_buffer(pb, strings, strings_size);
334 p++; /* strip out spaces */
339 if (!p || p >= endp-2)
344 p = strchr(p, quote);
348 PRINT(("NSV NSVf INFO: %s='%s'\n", token, value));
349 if (!strcmp(token, "ASPECT")) {
351 } else if (!strcmp(token, "CREATOR") || !strcmp(token, "Author")) {
352 strncpy(s->author, value, 512-1);
353 } else if (!strcmp(token, "Copyright")) {
354 strncpy(s->copyright, value, 512-1);
355 } else if (!strcmp(token, "TITLE") || !strcmp(token, "Title")) {
356 strncpy(s->title, value, 512-1);
364 PRINT(("NSV got infos; filepos %Ld\n", url_ftell(pb)));
366 if (table_entries_used > 0) {
367 nsv->index_entries = table_entries_used;
368 nsv->nsvf_index_data = av_malloc(table_entries * sizeof(uint32_t));
369 get_buffer(pb, nsv->nsvf_index_data, table_entries * sizeof(uint32_t));
372 PRINT(("NSV got index; filepos %Ld\n", url_ftell(pb)));
374 #ifdef DEBUG_DUMP_INDEX
375 #define V(v) ((v<0x20 || v > 127)?'.':v)
377 PRINT(("NSV %d INDEX ENTRIES:\n", table_entries));
378 PRINT(("NSV [dataoffset][fileoffset]\n", table_entries));
379 for (i = 0; i < table_entries; i++) {
381 url_fseek(pb, size + nsv->nsvf_index_data[i], SEEK_SET);
382 get_buffer(pb, b, 8);
383 PRINT(("NSV [0x%08lx][0x%08lx]: %02x %02x %02x %02x %02x %02x %02x %02x"
384 "%c%c%c%c%c%c%c%c\n",
385 nsv->nsvf_index_data[i], size + nsv->nsvf_index_data[i],
386 b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
387 V(b[0]), V(b[1]), V(b[2]), V(b[3]), V(b[4]), V(b[5]), V(b[6]), V(b[7]) ));
389 //url_fseek(pb, size, SEEK_SET); /* go back to end of header */
393 url_fseek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
397 nsv->state = NSV_HAS_READ_NSVF;
401 static int nsv_parse_NSVs_header(AVFormatContext *s, AVFormatParameters *ap)
403 NSVContext *nsv = s->priv_data;
404 ByteIOContext *pb = &s->pb;
406 uint16_t vwidth, vheight;
411 PRINT(("%s()\n", __FUNCTION__));
415 vwidth = get_le16(pb);
416 vheight = get_le16(pb);
417 framerate = (uint8_t)get_byte(pb);
418 /* XXX how big must the table be ? */
419 /* seems there is more to that... */
420 PRINT(("NSV NSVs framerate code %2x\n", framerate));
421 framerate = (framerate & 0x80)?(nsv_framerate_table[framerate & 0x7F]):(framerate*AV_TIME_BASE);
422 unknown = get_le16(pb);
424 print_tag("NSV NSVs vtag", vtag, 0);
425 print_tag("NSV NSVs atag", atag, 0);
426 PRINT(("NSV NSVs vsize %dx%d\n", vwidth, vheight));
427 PRINT(("NSV NSVs framerate %2x\n", framerate));
430 /* XXX change to ap != NULL ? */
431 if (s->nb_streams == 0) { /* streams not yet published, let's do that */
434 nsv->vwidth = vwidth;
435 nsv->vheight = vwidth;
436 if (vtag != T_NONE) {
437 st = av_new_stream(s, NSV_ST_VIDEO);
441 nst = av_mallocz(sizeof(NSVStream));
445 st->codec.codec_type = CODEC_TYPE_VIDEO;
446 st->codec.codec_tag = vtag;
447 st->codec.codec_id = codec_get_id(nsv_codec_video_tags, vtag);
448 st->codec.width = vwidth;
449 st->codec.height = vheight;
450 st->codec.bits_per_sample = 24; /* depth XXX */
452 st->codec.frame_rate = framerate;
453 st->codec.frame_rate_base = AV_TIME_BASE;
454 av_set_pts_info(st, 64, AV_TIME_BASE, framerate);
456 st->duration = nsv->duration;
458 if (atag != T_NONE) {
459 #ifndef DISABLE_AUDIO
460 st = av_new_stream(s, NSV_ST_AUDIO);
464 nst = av_mallocz(sizeof(NSVStream));
468 st->codec.codec_type = CODEC_TYPE_AUDIO;
469 st->codec.codec_tag = atag;
470 st->codec.codec_id = codec_get_id(nsv_codec_audio_tags, atag);
472 st->duration = nsv->duration;
474 st->need_parsing = 1; /* for PCM we will read a chunk later and put correct info */
476 //st->codec.channels = 2; //XXX:channels;
477 //st->codec.sample_rate = 1000;
478 //av_set_pts_info(st, 64, 1, st->codec.sample_rate);
482 #ifdef CHECK_SUBSEQUENT_NSVS
484 if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
485 PRINT(("NSV NSVs header values differ from the first one!!!\n"));
488 #endif /* CHECK_SUBSEQUENT_NSVS */
491 nsv->state = NSV_HAS_READ_NSVS;
495 nsv->state = NSV_UNSYNC;
499 static int nsv_read_header(AVFormatContext *s, AVFormatParameters *ap)
501 NSVContext *nsv = s->priv_data;
502 ByteIOContext *pb = &s->pb;
503 uint32_t tag, tag1, handler;
504 int codec_type, stream_index, frame_period, bit_rate, scale, rate;
505 unsigned int size, nb_frames;
511 PRINT(("%s()\n", __FUNCTION__));
512 PRINT(("filename '%s'\n", s->filename));
514 nsv->state = NSV_UNSYNC;
515 nsv->ahead[0].data = nsv->ahead[1].data = NULL;
517 for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
518 if (nsv_resync(s) < 0)
520 if (nsv->state == NSV_FOUND_NSVF)
521 err = nsv_parse_NSVf_header(s, ap);
522 /* we need the first NSVs also... */
523 if (nsv->state == NSV_FOUND_NSVS) {
524 err = nsv_parse_NSVs_header(s, ap);
525 break; /* we just want the first one */
528 if (s->nb_streams < 1) /* no luck so far */
530 /* now read the first chunk, so we can attempt to decode more info */
531 err = nsv_read_chunk(s, 1);
533 PRINT(("parsed header\n"));
537 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
539 NSVContext *nsv = s->priv_data;
540 ByteIOContext *pb = &s->pb;
541 AVStream *st[2] = {NULL, NULL};
546 uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
552 PRINT(("%s(%d)\n", __FUNCTION__, fill_header));
554 if (nsv->ahead[0].data || nsv->ahead[1].data)
555 return 0; //-1; /* hey! eat what you've in your plate first! */
561 for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
565 if (nsv->state == NSV_FOUND_NSVS)
566 err = nsv_parse_NSVs_header(s, NULL);
569 if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
572 auxcount = get_byte(pb);
573 vsize = get_le16(pb);
574 asize = get_le16(pb);
575 vsize = (vsize << 4) | (auxcount >> 4);
577 PRINT(("NSV CHUNK %d aux, %ld bytes video, %d bytes audio\n", auxcount, vsize, asize));
579 for (i = 0; i < auxcount; i++) {
580 auxsize = get_le16(pb);
581 auxtag = get_le32(pb);
582 PRINT(("NSV aux data: '%c%c%c%c', %d bytes\n",
584 ((auxtag >> 8) & 0x0ff),
585 ((auxtag >> 16) & 0x0ff),
586 ((auxtag >> 24) & 0x0ff),
588 url_fskip(pb, auxsize);
589 vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
594 if (!vsize && !asize) {
595 nsv->state = NSV_UNSYNC;
596 goto null_chunk_retry;
599 /* map back streams to v,a */
601 st[s->streams[0]->id] = s->streams[0];
603 st[s->streams[1]->id] = s->streams[1];
605 if (vsize/* && st[NSV_ST_VIDEO]*/) {
606 nst = st[NSV_ST_VIDEO]->priv_data;
607 pkt = &nsv->ahead[NSV_ST_VIDEO];
608 av_new_packet(pkt, vsize);
609 get_buffer(pb, pkt->data, vsize);
610 pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
611 pkt->dts = nst->frame_offset++;
612 pkt->flags |= PKT_FLAG_KEY; /* stupid format has no way to tell XXX: try the index */
614 for (i = 0; i < MIN(8, vsize); i++)
615 PRINT(("NSV video: [%d] = %02x\n", i, pkt->data[i]));
618 if (asize/*st[NSV_ST_AUDIO]*/) {
619 nst = st[NSV_ST_AUDIO]->priv_data;
620 pkt = &nsv->ahead[NSV_ST_AUDIO];
621 /* read raw audio specific header on the first audio chunk... */
622 /* on ALL audio chunks ?? seems so! */
623 if (asize && st[NSV_ST_AUDIO]->codec.codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
628 channels = get_byte(pb);
629 samplerate = get_le16(pb);
631 PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %ld\n", bps, channels, samplerate));
633 st[NSV_ST_AUDIO]->need_parsing = 0; /* we know everything */
635 PRINT(("NSV AUDIO bit/sample != 16 (%d)!!!\n", bps));
637 bps /= channels; // ???
639 st[NSV_ST_AUDIO]->codec.codec_id = CODEC_ID_PCM_U8;
640 samplerate /= 4;/* UGH ??? XXX */
642 st[NSV_ST_AUDIO]->codec.channels = channels;
643 st[NSV_ST_AUDIO]->codec.sample_rate = samplerate;
644 av_set_pts_info(st[NSV_ST_AUDIO], 64, 1,
645 st[NSV_ST_AUDIO]->codec.sample_rate);
646 PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %ld\n", bps, channels, samplerate));
649 av_new_packet(pkt, asize);
651 get_buffer(pb, pkt->data, asize);
652 pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
653 //pkt->dts = nst->frame_offset;
654 //if (nst->sample_size)
655 // pkt->dts /= nst->sample_size;
656 nst->frame_offset += asize; // XXX: that's valid only for PCM !?
659 //pkt->flags |= PKT_FLAG_KEY;
660 nsv->state = NSV_UNSYNC;
665 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
667 NSVContext *nsv = s->priv_data;
668 ByteIOContext *pb = &s->pb;
671 PRINT(("%s()\n", __FUNCTION__));
673 /* in case we don't already have something to eat ... */
674 if (nsv->ahead[0].data == NULL && nsv->ahead[1].data == NULL)
675 err = nsv_read_chunk(s, 0);
679 /* now pick one of the plates */
680 for (i = 0; i < 2; i++) {
681 if (nsv->ahead[i].data) {
682 PRINT(("%s: using cached packet[%d]\n", __FUNCTION__, i));
683 /* avoid the cost of new_packet + memcpy(->data) */
684 memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
685 nsv->ahead[i].data = NULL; /* we ate that one */
690 /* this restaurant is not approvisionned :^] */
694 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
696 NSVContext *avi = s->priv_data;
705 static int nsv_read_close(AVFormatContext *s)
708 NSVContext *nsv = s->priv_data;
710 if (nsv->index_entries)
711 av_free(nsv->nsvf_index_data);
715 for(i=0;i<s->nb_streams;i++) {
716 AVStream *st = s->streams[i];
717 NSVStream *ast = st->priv_data;
719 av_free(ast->index_entries);
722 av_free(st->codec.extradata);
723 av_free(st->codec.palctrl);
730 static int nsv_probe(AVProbeData *p)
733 PRINT(("nsv_probe(), buf_size %d\n", p->buf_size));
734 /* check file header */
735 if (p->buf_size <= 32)
737 if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
738 p->buf[2] == 'V' && p->buf[3] == 'f')
739 return AVPROBE_SCORE_MAX;
740 /* streamed files might not have any header */
741 if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
742 p->buf[2] == 'V' && p->buf[3] == 's')
743 return AVPROBE_SCORE_MAX;
744 /* XXX: do streamed files always start at chunk boundary ?? */
745 /* or do we need to search NSVs in the byte stream ? */
746 /* seems the servers don't bother starting clean chunks... */
747 /* sometimes even the first header is at 9KB or something :^) */
748 for (i = 1; i < p->buf_size - 3; i++) {
749 if (p->buf[i+0] == 'N' && p->buf[i+1] == 'S' &&
750 p->buf[i+2] == 'V' && p->buf[i+3] == 's')
751 return AVPROBE_SCORE_MAX-20;
753 /* so we'll have more luck on extension... */
754 if (match_ext(p->filename, "nsv"))
755 return AVPROBE_SCORE_MAX-20;
756 /* FIXME: add mime-type check */
760 static AVInputFormat nsv_iformat = {
762 "NullSoft Video format",
771 int nsvdec_init(void)
773 av_register_input_format(&nsv_iformat);