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 AVRational nsv_framerate_table[] = {
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 unsigned int file_size, size;
287 int table_entries_used;
289 PRINT(("%s()\n", __FUNCTION__));
291 nsv->state = NSV_UNSYNC; /* in case we fail */
296 nsv->NSVf_end = size;
298 //s->file_size = (uint32_t)get_le32(pb);
299 file_size = (uint32_t)get_le32(pb);
300 PRINT(("NSV NSVf chunk_size %u\n", size));
301 PRINT(("NSV NSVf file_size %u\n", file_size));
303 nsv->duration = duration = get_le32(pb); /* in ms */
304 PRINT(("NSV NSVf duration %Ld ms\n", duration));
305 // XXX: store it in AVStreams
307 strings_size = get_le32(pb);
308 table_entries = get_le32(pb);
309 table_entries_used = get_le32(pb);
310 PRINT(("NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
311 strings_size, table_entries, table_entries_used));
315 PRINT(("NSV got header; filepos %Ld\n", url_ftell(pb)));
317 if (strings_size > 0) {
318 char *strings; /* last byte will be '\0' to play safe with str*() */
323 p = strings = av_mallocz(strings_size + 1);
324 endp = strings + strings_size;
325 get_buffer(pb, strings, strings_size);
328 p++; /* strip out spaces */
333 if (!p || p >= endp-2)
338 p = strchr(p, quote);
342 PRINT(("NSV NSVf INFO: %s='%s'\n", token, value));
343 if (!strcmp(token, "ASPECT")) {
345 } else if (!strcmp(token, "CREATOR") || !strcmp(token, "Author")) {
346 strncpy(s->author, value, 512-1);
347 } else if (!strcmp(token, "Copyright")) {
348 strncpy(s->copyright, value, 512-1);
349 } else if (!strcmp(token, "TITLE") || !strcmp(token, "Title")) {
350 strncpy(s->title, value, 512-1);
358 PRINT(("NSV got infos; filepos %Ld\n", url_ftell(pb)));
360 if (table_entries_used > 0) {
361 nsv->index_entries = table_entries_used;
362 if((unsigned)table_entries >= UINT_MAX / sizeof(uint32_t))
364 nsv->nsvf_index_data = av_malloc(table_entries * sizeof(uint32_t));
365 get_buffer(pb, nsv->nsvf_index_data, table_entries * sizeof(uint32_t));
368 PRINT(("NSV got index; filepos %Ld\n", url_ftell(pb)));
370 #ifdef DEBUG_DUMP_INDEX
371 #define V(v) ((v<0x20 || v > 127)?'.':v)
373 PRINT(("NSV %d INDEX ENTRIES:\n", table_entries));
374 PRINT(("NSV [dataoffset][fileoffset]\n", table_entries));
375 for (i = 0; i < table_entries; i++) {
377 url_fseek(pb, size + nsv->nsvf_index_data[i], SEEK_SET);
378 get_buffer(pb, b, 8);
379 PRINT(("NSV [0x%08lx][0x%08lx]: %02x %02x %02x %02x %02x %02x %02x %02x"
380 "%c%c%c%c%c%c%c%c\n",
381 nsv->nsvf_index_data[i], size + nsv->nsvf_index_data[i],
382 b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
383 V(b[0]), V(b[1]), V(b[2]), V(b[3]), V(b[4]), V(b[5]), V(b[6]), V(b[7]) ));
385 //url_fseek(pb, size, SEEK_SET); /* go back to end of header */
389 url_fseek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
393 nsv->state = NSV_HAS_READ_NSVF;
397 static int nsv_parse_NSVs_header(AVFormatContext *s, AVFormatParameters *ap)
399 NSVContext *nsv = s->priv_data;
400 ByteIOContext *pb = &s->pb;
402 uint16_t vwidth, vheight;
403 AVRational framerate;
408 PRINT(("%s()\n", __FUNCTION__));
412 vwidth = get_le16(pb);
413 vheight = get_le16(pb);
415 /* XXX how big must the table be ? */
416 /* seems there is more to that... */
417 PRINT(("NSV NSVs framerate code %2x\n", i));
418 if(i&0x80) framerate= nsv_framerate_table[i & 0x7F];
419 else framerate= (AVRational){i, 1};
420 unknown = get_le16(pb);
422 print_tag("NSV NSVs vtag", vtag, 0);
423 print_tag("NSV NSVs atag", atag, 0);
424 PRINT(("NSV NSVs vsize %dx%d\n", vwidth, vheight));
427 /* XXX change to ap != NULL ? */
428 if (s->nb_streams == 0) { /* streams not yet published, let's do that */
431 nsv->vwidth = vwidth;
432 nsv->vheight = vwidth;
433 if (vtag != T_NONE) {
434 st = av_new_stream(s, NSV_ST_VIDEO);
438 nst = av_mallocz(sizeof(NSVStream));
442 st->codec->codec_type = CODEC_TYPE_VIDEO;
443 st->codec->codec_tag = vtag;
444 st->codec->codec_id = codec_get_id(nsv_codec_video_tags, vtag);
445 st->codec->width = vwidth;
446 st->codec->height = vheight;
447 st->codec->bits_per_sample = 24; /* depth XXX */
449 av_set_pts_info(st, 64, framerate.den, framerate.num);
451 st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
453 if (atag != T_NONE) {
454 #ifndef DISABLE_AUDIO
455 st = av_new_stream(s, NSV_ST_AUDIO);
459 nst = av_mallocz(sizeof(NSVStream));
463 st->codec->codec_type = CODEC_TYPE_AUDIO;
464 st->codec->codec_tag = atag;
465 st->codec->codec_id = codec_get_id(nsv_codec_audio_tags, atag);
467 // st->duration = nsv->duration; //FIXME
469 st->need_parsing = 1; /* for PCM we will read a chunk later and put correct info */
471 //st->codec->channels = 2; //XXX:channels;
472 //st->codec->sample_rate = 1000;
473 //av_set_pts_info(st, 64, 1, st->codec->sample_rate);
477 #ifdef CHECK_SUBSEQUENT_NSVS
479 if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
480 PRINT(("NSV NSVs header values differ from the first one!!!\n"));
483 #endif /* CHECK_SUBSEQUENT_NSVS */
486 nsv->state = NSV_HAS_READ_NSVS;
490 nsv->state = NSV_UNSYNC;
494 static int nsv_read_header(AVFormatContext *s, AVFormatParameters *ap)
496 NSVContext *nsv = s->priv_data;
499 PRINT(("%s()\n", __FUNCTION__));
500 PRINT(("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, ap);
510 /* we need the first NSVs also... */
511 if (nsv->state == NSV_FOUND_NSVS) {
512 err = nsv_parse_NSVs_header(s, ap);
513 break; /* we just want the first one */
516 if (s->nb_streams < 1) /* no luck so far */
518 /* now read the first chunk, so we can attempt to decode more info */
519 err = nsv_read_chunk(s, 1);
521 PRINT(("parsed header\n"));
525 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
527 NSVContext *nsv = s->priv_data;
528 ByteIOContext *pb = &s->pb;
529 AVStream *st[2] = {NULL, NULL};
533 uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
539 PRINT(("%s(%d)\n", __FUNCTION__, fill_header));
541 if (nsv->ahead[0].data || nsv->ahead[1].data)
542 return 0; //-1; /* hey! eat what you've in your plate first! */
548 for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
552 if (nsv->state == NSV_FOUND_NSVS)
553 err = nsv_parse_NSVs_header(s, NULL);
556 if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
559 auxcount = get_byte(pb);
560 vsize = get_le16(pb);
561 asize = get_le16(pb);
562 vsize = (vsize << 4) | (auxcount >> 4);
564 PRINT(("NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize));
566 for (i = 0; i < auxcount; i++) {
567 auxsize = get_le16(pb);
568 auxtag = get_le32(pb);
569 PRINT(("NSV aux data: '%c%c%c%c', %d bytes\n",
571 ((auxtag >> 8) & 0x0ff),
572 ((auxtag >> 16) & 0x0ff),
573 ((auxtag >> 24) & 0x0ff),
575 url_fskip(pb, auxsize);
576 vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
581 if (!vsize && !asize) {
582 nsv->state = NSV_UNSYNC;
583 goto null_chunk_retry;
586 /* map back streams to v,a */
588 st[s->streams[0]->id] = s->streams[0];
590 st[s->streams[1]->id] = s->streams[1];
592 if (vsize/* && st[NSV_ST_VIDEO]*/) {
593 nst = st[NSV_ST_VIDEO]->priv_data;
594 pkt = &nsv->ahead[NSV_ST_VIDEO];
595 av_get_packet(pb, pkt, vsize);
596 pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
597 pkt->dts = nst->frame_offset++;
598 pkt->flags |= PKT_FLAG_KEY; /* stupid format has no way to tell XXX: try the index */
600 for (i = 0; i < MIN(8, vsize); i++)
601 PRINT(("NSV video: [%d] = %02x\n", i, pkt->data[i]));
604 if (asize/*st[NSV_ST_AUDIO]*/) {
605 nst = st[NSV_ST_AUDIO]->priv_data;
606 pkt = &nsv->ahead[NSV_ST_AUDIO];
607 /* read raw audio specific header on the first audio chunk... */
608 /* on ALL audio chunks ?? seems so! */
609 if (asize && st[NSV_ST_AUDIO]->codec->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
614 channels = get_byte(pb);
615 samplerate = get_le16(pb);
617 PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate));
619 st[NSV_ST_AUDIO]->need_parsing = 0; /* we know everything */
621 PRINT(("NSV AUDIO bit/sample != 16 (%d)!!!\n", bps));
623 bps /= channels; // ???
625 st[NSV_ST_AUDIO]->codec->codec_id = CODEC_ID_PCM_U8;
626 samplerate /= 4;/* UGH ??? XXX */
628 st[NSV_ST_AUDIO]->codec->channels = channels;
629 st[NSV_ST_AUDIO]->codec->sample_rate = samplerate;
630 av_set_pts_info(st[NSV_ST_AUDIO], 64, 1,
631 st[NSV_ST_AUDIO]->codec->sample_rate);
632 PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate));
635 av_get_packet(pb, pkt, asize);
636 pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
637 //pkt->dts = nst->frame_offset;
638 //if (nst->sample_size)
639 // pkt->dts /= nst->sample_size;
640 nst->frame_offset += asize; // XXX: that's valid only for PCM !?
643 //pkt->flags |= PKT_FLAG_KEY;
644 nsv->state = NSV_UNSYNC;
649 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
651 NSVContext *nsv = s->priv_data;
654 PRINT(("%s()\n", __FUNCTION__));
656 /* in case we don't already have something to eat ... */
657 if (nsv->ahead[0].data == NULL && nsv->ahead[1].data == NULL)
658 err = nsv_read_chunk(s, 0);
662 /* now pick one of the plates */
663 for (i = 0; i < 2; i++) {
664 if (nsv->ahead[i].data) {
665 PRINT(("%s: using cached packet[%d]\n", __FUNCTION__, i));
666 /* avoid the cost of new_packet + memcpy(->data) */
667 memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
668 nsv->ahead[i].data = NULL; /* we ate that one */
673 /* this restaurant is not approvisionned :^] */
677 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
680 NSVContext *avi = s->priv_data;
690 static int nsv_read_close(AVFormatContext *s)
693 NSVContext *nsv = s->priv_data;
695 if (nsv->index_entries)
696 av_free(nsv->nsvf_index_data);
700 for(i=0;i<s->nb_streams;i++) {
701 AVStream *st = s->streams[i];
702 NSVStream *ast = st->priv_data;
704 av_free(ast->index_entries);
707 av_free(st->codec->extradata);
708 av_free(st->codec->palctrl);
715 static int nsv_probe(AVProbeData *p)
718 // PRINT(("nsv_probe(), buf_size %d\n", p->buf_size));
719 /* check file header */
720 if (p->buf_size <= 32)
722 if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
723 p->buf[2] == 'V' && p->buf[3] == 'f')
724 return AVPROBE_SCORE_MAX;
725 /* streamed files might not have any header */
726 if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
727 p->buf[2] == 'V' && p->buf[3] == 's')
728 return AVPROBE_SCORE_MAX;
729 /* XXX: do streamed files always start at chunk boundary ?? */
730 /* or do we need to search NSVs in the byte stream ? */
731 /* seems the servers don't bother starting clean chunks... */
732 /* sometimes even the first header is at 9KB or something :^) */
733 for (i = 1; i < p->buf_size - 3; i++) {
734 if (p->buf[i+0] == 'N' && p->buf[i+1] == 'S' &&
735 p->buf[i+2] == 'V' && p->buf[i+3] == 's')
736 return AVPROBE_SCORE_MAX-20;
738 /* so we'll have more luck on extension... */
739 if (match_ext(p->filename, "nsv"))
740 return AVPROBE_SCORE_MAX-20;
741 /* FIXME: add mime-type check */
745 static AVInputFormat nsv_iformat = {
747 "NullSoft Video format",
756 int nsvdec_init(void)
758 av_register_input_format(&nsv_iformat);