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/libavformat/nsvdec.c

http://github.com/FFmpeg/FFmpeg
C | 746 lines | 551 code | 86 blank | 109 comment | 141 complexity | 455caae6bd442e4ea6782fffae61328b MD5 | raw file
  1/*
  2 * NSV demuxer
  3 * Copyright (c) 2004 The FFmpeg Project
  4 *
  5 * first version by Francois Revol <revol@free.fr>
  6 *
  7 * This file is part of FFmpeg.
  8 *
  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.
 13 *
 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.
 18 *
 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
 22 */
 23
 24#include "libavutil/attributes.h"
 25#include "libavutil/mathematics.h"
 26#include "avformat.h"
 27#include "internal.h"
 28#include "libavutil/dict.h"
 29#include "libavutil/intreadwrite.h"
 30
 31/* max bytes to crawl for trying to resync
 32 * stupid streaming servers don't start at chunk boundaries...
 33 */
 34#define NSV_MAX_RESYNC (500*1024)
 35#define NSV_MAX_RESYNC_TRIES 300
 36
 37/*
 38 * References:
 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/
 43 * official docs
 44 * (3) http://ultravox.aol.com/NSVFormat.rtf
 45 * Sample files:
 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
 49 */
 50
 51/*
 52 * notes on the header (Francois Revol):
 53 *
 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.
 59 *
 60 * Then, about NSVf[12-15], faster.nsf has 179700. When viewing 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.
 65 * Let's try that:
 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 nsvtrailer (which doesn't have an NSVf header), it reports correct time.
 68 *
 69 * nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
 70 * so the header seems to not be mandatory. (for streaming).
 71 *
 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
 74 */
 75
 76/*
 77 * TODO:
 78 * - handle timestamps !!!
 79 * - use index
 80 * - mime-type in probe()
 81 * - seek
 82 */
 83
 84#if 0
 85struct NSVf_header {
 86    uint32_t chunk_tag; /* 'NSVf' */
 87    uint32_t chunk_size;
 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 */
 93};
 94
 95struct NSVs_header {
 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 */
102    uint16_t unknown;
103};
104
105struct 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;
109};
110
111struct nsv_pcm_header {
112    uint8_t bits_per_sample;
113    uint8_t channel_count;
114    uint16_t sample_rate;
115};
116#endif
117
118/* variation from avi.h */
119/*typedef struct CodecTag {
120    int id;
121    unsigned int tag;
122} CodecTag;*/
123
124/* tags */
125
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) */
133
134#define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
135#define TB_NSVS MKBETAG('N', 'S', 'V', 's')
136
137/* hardcoded stream indexes */
138#define NSV_ST_VIDEO 0
139#define NSV_ST_AUDIO 1
140#define NSV_ST_SUBT 2
141
142enum NSVStatus {
143    NSV_UNSYNC,
144    NSV_FOUND_NSVF,
145    NSV_HAS_READ_NSVF,
146    NSV_FOUND_NSVS,
147    NSV_HAS_READ_NSVS,
148    NSV_FOUND_BEEF,
149    NSV_GOT_VIDEO,
150    NSV_GOT_AUDIO,
151};
152
153typedef struct NSVStream {
154    int frame_offset; /* current frame (video) or byte (audio) counter
155                         (used to compute the pts) */
156    int scale;
157    int rate;
158    int sample_size; /* audio only data */
159    int start;
160
161    int new_frame_offset; /* temporary storage (used during seek) */
162    int cum_len; /* temporary storage (used during seek) */
163} NSVStream;
164
165typedef struct NSVContext {
166    int  base_offset;
167    int  NSVf_end;
168    uint32_t *nsvs_file_offset;
169    int index_entries;
170    enum NSVStatus state;
171    AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
172    /* cached */
173    int64_t duration;
174    uint32_t vtag, atag;
175    uint16_t vwidth, vheight;
176    int16_t avsync;
177    AVRational framerate;
178    uint32_t *nsvs_timestamps;
179    int nsvf;
180} NSVContext;
181
182static 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') },
193/*
194    { AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
195    { AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
196*/
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 },
200};
201
202static 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 },
210};
211
212//static int nsv_load_index(AVFormatContext *s);
213static int nsv_read_chunk(AVFormatContext *s, int fill_header);
214static int nsv_read_close(AVFormatContext *s);
215
216/* try to find something we recognize, and set the state accordingly */
217static int nsv_resync(AVFormatContext *s)
218{
219    NSVContext *nsv = s->priv_data;
220    AVIOContext *pb = s->pb;
221    uint32_t v = 0;
222    int i;
223
224    for (i = 0; i < NSV_MAX_RESYNC; i++) {
225        if (avio_feof(pb)) {
226            av_log(s, AV_LOG_TRACE, "NSV EOF\n");
227            nsv->state = NSV_UNSYNC;
228            return -1;
229        }
230        v <<= 8;
231        v |= avio_r8(pb);
232        if (i < 8) {
233            av_log(s, AV_LOG_TRACE, "NSV resync: [%d] = %02"PRIx32"\n", i, v & 0x0FF);
234        }
235
236        if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
237            av_log(s, AV_LOG_TRACE, "NSV resynced on BEEF after %d bytes\n", i+1);
238            nsv->state = NSV_FOUND_BEEF;
239            return 0;
240        }
241        /* we read as big-endian, thus the MK*BE* */
242        if (v == TB_NSVF) { /* NSVf */
243            av_log(s, AV_LOG_TRACE, "NSV resynced on NSVf after %d bytes\n", i+1);
244            nsv->state = NSV_FOUND_NSVF;
245            return 0;
246        }
247        if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
248            av_log(s, AV_LOG_TRACE, "NSV resynced on NSVs after %d bytes\n", i+1);
249            nsv->state = NSV_FOUND_NSVS;
250            return 0;
251        }
252
253    }
254    av_log(s, AV_LOG_TRACE, "NSV sync lost\n");
255    return -1;
256}
257
258static int nsv_parse_NSVf_header(AVFormatContext *s)
259{
260    NSVContext *nsv = s->priv_data;
261    AVIOContext *pb = s->pb;
262    unsigned int av_unused file_size;
263    unsigned int size;
264    int64_t duration;
265    int strings_size;
266    int table_entries;
267    int table_entries_used;
268
269    nsv->state = NSV_UNSYNC; /* in case we fail */
270
271    if (nsv->nsvf) {
272        av_log(s, AV_LOG_TRACE, "Multiple NSVf\n");
273        return 0;
274    }
275    nsv->nsvf = 1;
276
277    size = avio_rl32(pb);
278    if (size < 28)
279        return -1;
280    nsv->NSVf_end = size;
281
282    file_size = (uint32_t)avio_rl32(pb);
283    av_log(s, AV_LOG_TRACE, "NSV NSVf chunk_size %u\n", size);
284    av_log(s, AV_LOG_TRACE, "NSV NSVf file_size %u\n", file_size);
285
286    nsv->duration = duration = avio_rl32(pb); /* in ms */
287    av_log(s, AV_LOG_TRACE, "NSV NSVf duration %"PRId64" ms\n", duration);
288    // XXX: store it in AVStreams
289
290    strings_size = avio_rl32(pb);
291    table_entries = avio_rl32(pb);
292    table_entries_used = avio_rl32(pb);
293    av_log(s, AV_LOG_TRACE, "NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
294            strings_size, table_entries, table_entries_used);
295    if (avio_feof(pb))
296        return -1;
297
298    av_log(s, AV_LOG_TRACE, "NSV got header; filepos %"PRId64"\n", avio_tell(pb));
299
300    if (strings_size > 0) {
301        char *strings; /* last byte will be '\0' to play safe with str*() */
302        char *p, *endp;
303        char *token, *value;
304        char quote;
305
306        p = strings = av_mallocz((size_t)strings_size + 1);
307        if (!p)
308            return AVERROR(ENOMEM);
309        endp = strings + strings_size;
310        avio_read(pb, strings, strings_size);
311        while (p < endp) {
312            while (*p == ' ')
313                p++; /* strip out spaces */
314            if (p >= endp-2)
315                break;
316            token = p;
317            p = strchr(p, '=');
318            if (!p || p >= endp-2)
319                break;
320            *p++ = '\0';
321            quote = *p++;
322            value = p;
323            p = strchr(p, quote);
324            if (!p || p >= endp)
325                break;
326            *p++ = '\0';
327            av_log(s, AV_LOG_TRACE, "NSV NSVf INFO: %s='%s'\n", token, value);
328            av_dict_set(&s->metadata, token, value, 0);
329        }
330        av_free(strings);
331    }
332    if (avio_feof(pb))
333        return -1;
334
335    av_log(s, AV_LOG_TRACE, "NSV got infos; filepos %"PRId64"\n", avio_tell(pb));
336
337    if (table_entries_used > 0) {
338        int i;
339        nsv->index_entries = table_entries_used;
340        if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
341            return -1;
342        nsv->nsvs_file_offset = av_malloc_array((unsigned)table_entries_used, sizeof(uint32_t));
343        if (!nsv->nsvs_file_offset)
344            return AVERROR(ENOMEM);
345
346        for(i=0;i<table_entries_used;i++) {
347            if (avio_feof(pb))
348                return AVERROR_INVALIDDATA;
349            nsv->nsvs_file_offset[i] = avio_rl32(pb) + size;
350        }
351
352        if(table_entries > table_entries_used &&
353           avio_rl32(pb) == MKTAG('T','O','C','2')) {
354            nsv->nsvs_timestamps = av_malloc_array((unsigned)table_entries_used, sizeof(uint32_t));
355            if (!nsv->nsvs_timestamps)
356                return AVERROR(ENOMEM);
357            for(i=0;i<table_entries_used;i++) {
358                nsv->nsvs_timestamps[i] = avio_rl32(pb);
359            }
360        }
361    }
362
363    av_log(s, AV_LOG_TRACE, "NSV got index; filepos %"PRId64"\n", avio_tell(pb));
364
365    avio_seek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
366
367    if (avio_feof(pb))
368        return -1;
369    nsv->state = NSV_HAS_READ_NSVF;
370    return 0;
371}
372
373static int nsv_parse_NSVs_header(AVFormatContext *s)
374{
375    NSVContext *nsv = s->priv_data;
376    AVIOContext *pb = s->pb;
377    uint32_t vtag, atag;
378    uint16_t vwidth, vheight;
379    AVRational framerate;
380    int i;
381    AVStream *st;
382    NSVStream *nst;
383
384    vtag = avio_rl32(pb);
385    atag = avio_rl32(pb);
386    vwidth = avio_rl16(pb);
387    vheight = avio_rl16(pb);
388    i = avio_r8(pb);
389
390    av_log(s, AV_LOG_TRACE, "NSV NSVs framerate code %2x\n", i);
391    if(i&0x80) { /* odd way of giving native framerates from docs */
392        int t=(i & 0x7F)>>2;
393        if(t<16) framerate = (AVRational){1, t+1};
394        else     framerate = (AVRational){t-15, 1};
395
396        if(i&1){
397            framerate.num *= 1000;
398            framerate.den *= 1001;
399        }
400
401        if((i&3)==3)      framerate.num *= 24;
402        else if((i&3)==2) framerate.num *= 25;
403        else              framerate.num *= 30;
404    }
405    else
406        framerate= (AVRational){i, 1};
407
408    nsv->avsync = avio_rl16(pb);
409    nsv->framerate = framerate;
410
411    av_log(s, AV_LOG_TRACE, "NSV NSVs vsize %dx%d\n", vwidth, vheight);
412
413    /* XXX change to ap != NULL ? */
414    if (s->nb_streams == 0) { /* streams not yet published, let's do that */
415        nsv->vtag = vtag;
416        nsv->atag = atag;
417        nsv->vwidth = vwidth;
418        nsv->vheight = vwidth;
419        if (vtag != T_NONE) {
420            int i;
421            st = avformat_new_stream(s, NULL);
422            if (!st)
423                goto fail;
424
425            st->id = NSV_ST_VIDEO;
426            nst = av_mallocz(sizeof(NSVStream));
427            if (!nst)
428                goto fail;
429            st->priv_data = nst;
430            st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
431            st->codecpar->codec_tag = vtag;
432            st->codecpar->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
433            st->codecpar->width = vwidth;
434            st->codecpar->height = vheight;
435            st->codecpar->bits_per_coded_sample = 24; /* depth XXX */
436
437            avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
438            st->start_time = 0;
439            st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
440
441            for(i=0;i<nsv->index_entries;i++) {
442                if(nsv->nsvs_timestamps) {
443                    av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
444                                       0, 0, AVINDEX_KEYFRAME);
445                } else {
446                    int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
447                    av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
448                }
449            }
450        }
451        if (atag != T_NONE) {
452            st = avformat_new_stream(s, NULL);
453            if (!st)
454                goto fail;
455
456            st->id = NSV_ST_AUDIO;
457            nst = av_mallocz(sizeof(NSVStream));
458            if (!nst)
459                goto fail;
460            st->priv_data = nst;
461            st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
462            st->codecpar->codec_tag = atag;
463            st->codecpar->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
464
465            st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
466
467            /* set timebase to common denominator of ms and framerate */
468            avpriv_set_pts_info(st, 64, 1, framerate.num*1000);
469            st->start_time = 0;
470            st->duration = (int64_t)nsv->duration * framerate.num;
471        }
472    } else {
473        if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
474            av_log(s, AV_LOG_TRACE, "NSV NSVs header values differ from the first one!!!\n");
475            //return -1;
476        }
477    }
478
479    nsv->state = NSV_HAS_READ_NSVS;
480    return 0;
481fail:
482    /* XXX */
483    nsv->state = NSV_UNSYNC;
484    return -1;
485}
486
487static int nsv_read_header(AVFormatContext *s)
488{
489    NSVContext *nsv = s->priv_data;
490    int i, err;
491
492    nsv->state = NSV_UNSYNC;
493    nsv->ahead[0].data = nsv->ahead[1].data = NULL;
494
495    for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
496        err = nsv_resync(s);
497        if (err < 0)
498            goto fail;
499        if (nsv->state == NSV_FOUND_NSVF) {
500            err = nsv_parse_NSVf_header(s);
501            if (err < 0)
502                goto fail;
503        }
504            /* we need the first NSVs also... */
505        if (nsv->state == NSV_FOUND_NSVS) {
506            err = nsv_parse_NSVs_header(s);
507            if (err < 0)
508                goto fail;
509            break; /* we just want the first one */
510        }
511    }
512    if (s->nb_streams < 1) { /* no luck so far */
513        err = AVERROR_INVALIDDATA;
514        goto fail;
515    }
516
517    /* now read the first chunk, so we can attempt to decode more info */
518    err = nsv_read_chunk(s, 1);
519fail:
520    if (err < 0)
521        nsv_read_close(s);
522
523    av_log(s, AV_LOG_TRACE, "parsed header\n");
524    return err;
525}
526
527static int nsv_read_chunk(AVFormatContext *s, int fill_header)
528{
529    NSVContext *nsv = s->priv_data;
530    AVIOContext *pb = s->pb;
531    AVStream *st[2] = {NULL, NULL};
532    NSVStream *nst;
533    AVPacket *pkt;
534    int i, err = 0;
535    uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
536    uint32_t vsize;
537    uint16_t asize;
538    uint16_t auxsize;
539    int ret;
540
541    if (nsv->ahead[0].data || nsv->ahead[1].data)
542        return 0; //-1; /* hey! eat what you've in your plate first! */
543
544null_chunk_retry:
545    if (avio_feof(pb))
546        return -1;
547
548    for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
549        err = nsv_resync(s);
550    if (err < 0)
551        return err;
552    if (nsv->state == NSV_FOUND_NSVS)
553        err = nsv_parse_NSVs_header(s);
554    if (err < 0)
555        return err;
556    if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
557        return -1;
558
559    auxcount = avio_r8(pb);
560    vsize = avio_rl16(pb);
561    asize = avio_rl16(pb);
562    vsize = (vsize << 4) | (auxcount >> 4);
563    auxcount &= 0x0f;
564    av_log(s, AV_LOG_TRACE, "NSV CHUNK %d aux, %"PRIu32" bytes video, %d bytes audio\n", auxcount, vsize, asize);
565    /* skip aux stuff */
566    for (i = 0; i < auxcount; i++) {
567        uint32_t av_unused auxtag;
568        auxsize = avio_rl16(pb);
569        auxtag = avio_rl32(pb);
570        avio_skip(pb, auxsize);
571        vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming brain-dead */
572    }
573
574    if (avio_feof(pb))
575        return -1;
576    if (!vsize && !asize) {
577        nsv->state = NSV_UNSYNC;
578        goto null_chunk_retry;
579    }
580
581    /* map back streams to v,a */
582    if (s->nb_streams > 0)
583        st[s->streams[0]->id] = s->streams[0];
584    if (s->nb_streams > 1)
585        st[s->streams[1]->id] = s->streams[1];
586
587    if (vsize && st[NSV_ST_VIDEO]) {
588        nst = st[NSV_ST_VIDEO]->priv_data;
589        pkt = &nsv->ahead[NSV_ST_VIDEO];
590        if ((ret = av_get_packet(pb, pkt, vsize)) < 0)
591            return ret;
592        pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
593        pkt->dts = nst->frame_offset;
594        pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
595        for (i = 0; i < FFMIN(8, vsize); i++)
596            av_log(s, AV_LOG_TRACE, "NSV video: [%d] = %02x\n", i, pkt->data[i]);
597    }
598    if(st[NSV_ST_VIDEO])
599        ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
600
601    if (asize && st[NSV_ST_AUDIO]) {
602        nst = st[NSV_ST_AUDIO]->priv_data;
603        pkt = &nsv->ahead[NSV_ST_AUDIO];
604        /* read raw audio specific header on the first audio chunk... */
605        /* on ALL audio chunks ?? seems so! */
606        if (asize && st[NSV_ST_AUDIO]->codecpar->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
607            uint8_t bps;
608            uint8_t channels;
609            uint16_t samplerate;
610            bps = avio_r8(pb);
611            channels = avio_r8(pb);
612            samplerate = avio_rl16(pb);
613            if (!channels || !samplerate)
614                return AVERROR_INVALIDDATA;
615            asize-=4;
616            av_log(s, AV_LOG_TRACE, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
617            if (fill_header) {
618                st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
619                if (bps != 16) {
620                    av_log(s, AV_LOG_TRACE, "NSV AUDIO bit/sample != 16 (%d)!!!\n", bps);
621                }
622                bps /= channels; // ???
623                if (bps == 8)
624                    st[NSV_ST_AUDIO]->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
625                samplerate /= 4;/* UGH ??? XXX */
626                channels = 1;
627                st[NSV_ST_AUDIO]->codecpar->channels = channels;
628                st[NSV_ST_AUDIO]->codecpar->sample_rate = samplerate;
629                av_log(s, AV_LOG_TRACE, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
630            }
631        }
632        if ((ret = av_get_packet(pb, pkt, asize)) < 0)
633            return ret;
634        pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
635        pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
636        if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
637            /* on a nsvs frame we have new information on a/v sync */
638            pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
639            pkt->dts *= (int64_t)1000        * nsv->framerate.den;
640            pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
641            av_log(s, AV_LOG_TRACE, "NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts);
642        }
643        nst->frame_offset++;
644    }
645
646    nsv->state = NSV_UNSYNC;
647    return 0;
648}
649
650
651static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
652{
653    NSVContext *nsv = s->priv_data;
654    int i, err = 0;
655
656    /* in case we don't already have something to eat ... */
657    if (!nsv->ahead[0].data && !nsv->ahead[1].data)
658        err = nsv_read_chunk(s, 0);
659    if (err < 0)
660        return err;
661
662    /* now pick one of the plates */
663    for (i = 0; i < 2; i++) {
664        if (nsv->ahead[i].data) {
665            av_packet_move_ref(pkt, &nsv->ahead[i]);
666            return 0;
667        }
668    }
669
670    /* this restaurant is not provisioned :^] */
671    return -1;
672}
673
674static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
675{
676    NSVContext *nsv = s->priv_data;
677    AVStream *st = s->streams[stream_index];
678    NSVStream *nst = st->priv_data;
679    int index;
680
681    index = av_index_search_timestamp(st, timestamp, flags);
682    if(index < 0)
683        return -1;
684
685    if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
686        return -1;
687
688    nst->frame_offset = st->index_entries[index].timestamp;
689    nsv->state = NSV_UNSYNC;
690    return 0;
691}
692
693static int nsv_read_close(AVFormatContext *s)
694{
695    NSVContext *nsv = s->priv_data;
696
697    av_freep(&nsv->nsvs_file_offset);
698    av_freep(&nsv->nsvs_timestamps);
699    if (nsv->ahead[0].data)
700        av_packet_unref(&nsv->ahead[0]);
701    if (nsv->ahead[1].data)
702        av_packet_unref(&nsv->ahead[1]);
703    return 0;
704}
705
706static int nsv_probe(const AVProbeData *p)
707{
708    int i, score = 0;
709
710    /* check file header */
711    /* streamed files might not have any header */
712    if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
713        p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
714        return AVPROBE_SCORE_MAX;
715    /* XXX: do streamed files always start at chunk boundary ?? */
716    /* or do we need to search NSVs in the byte stream ? */
717    /* seems the servers don't bother starting clean chunks... */
718    /* sometimes even the first header is at 9KB or something :^) */
719    for (i = 1; i < p->buf_size - 3; i++) {
720        if (AV_RL32(p->buf + i) == AV_RL32("NSVs")) {
721            /* Get the chunk size and check if at the end we are getting 0xBEEF */
722            int vsize = AV_RL24(p->buf+i+19) >> 4;
723            int asize = AV_RL16(p->buf+i+22);
724            int offset = i + 23 + asize + vsize + 1;
725            if (offset <= p->buf_size - 2 && AV_RL16(p->buf + offset) == 0xBEEF)
726                return 4*AVPROBE_SCORE_MAX/5;
727            score = AVPROBE_SCORE_MAX/5;
728        }
729    }
730    /* so we'll have more luck on extension... */
731    if (av_match_ext(p->filename, "nsv"))
732        return AVPROBE_SCORE_EXTENSION;
733    /* FIXME: add mime-type check */
734    return score;
735}
736
737AVInputFormat ff_nsv_demuxer = {
738    .name           = "nsv",
739    .long_name      = NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
740    .priv_data_size = sizeof(NSVContext),
741    .read_probe     = nsv_probe,
742    .read_header    = nsv_read_header,
743    .read_packet    = nsv_read_packet,
744    .read_close     = nsv_read_close,
745    .read_seek      = nsv_read_seek,
746};