libavformat/nsvdec.c

   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 "libavutil/mem.h"
  27 #include "avformat.h"
  28 #include "demux.h"
  29 #include "internal.h"
  30 #include "libavutil/dict.h"
  31 #include "libavutil/intreadwrite.h"
  32
  33 /* max bytes to crawl for trying to resync
  34  * stupid streaming servers don't start at chunk boundaries...
  35  */
  36 #define NSV_MAX_RESYNC (500*1024)
  37 #define NSV_MAX_RESYNC_TRIES 300
  38
  39 /*
  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 viewing 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 nsvtrailer (which doesn't have an NSVf header), it reports 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 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
  76  */
  77
  78 /*
  79  * TODO:
  80  * - handle timestamps !!!
  81  * - use index
  82  * - mime-type in probe()
  83  * - seek
  84  */
  85
  86 #if 0
  87 struct NSVf_header {
  88     uint32_t chunk_tag; /* 'NSVf' */
  89     uint32_t chunk_size;
  90     uint32_t file_size; /* max 4GB ??? no one 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 */
  95 };
  96
  97 struct NSVs_header {
  98     uint32_t chunk_tag; /* 'NSVs' */
  99     uint32_t v4cc;      /* or 'NONE' */
 100     uint32_t a4cc;      /* or 'NONE' */
 101     uint16_t vwidth;    /* av_assert0(vwidth%16==0) */
 102     uint16_t vheight;   /* av_assert0(vheight%16==0) */
 103     uint8_t framerate;  /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
 104     uint16_t unknown;
 105 };
 106
 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;
 111 };
 112
 113 struct nsv_pcm_header {
 114     uint8_t bits_per_sample;
 115     uint8_t channel_count;
 116     uint16_t sample_rate;
 117 };
 118 #endif
 119
 120 /* variation from avi.h */
 121 /*typedef struct CodecTag {
 122     int id;
 123     unsigned int tag;
 124 } CodecTag;*/
 125
 126 /* tags */
 127
 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) */
 135
 136 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
 137 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
 138
 139 /* hardcoded stream indexes */
 140 #define NSV_ST_VIDEO 0
 141 #define NSV_ST_AUDIO 1
 142 #define NSV_ST_SUBT 2
 143
 144 enum NSVStatus {
 145     NSV_UNSYNC,
 146     NSV_FOUND_NSVF,
 147     NSV_HAS_READ_NSVF,
 148     NSV_FOUND_NSVS,
 149     NSV_HAS_READ_NSVS,
 150     NSV_FOUND_BEEF,
 151     NSV_GOT_VIDEO,
 152     NSV_GOT_AUDIO,
 153 };
 154
 155 typedef struct NSVStream {
 156     int frame_offset; /* current frame (video) or byte (audio) counter
 157                          (used to compute the pts) */
 158     int scale;
 159     int rate;
 160     int sample_size; /* audio only data */
 161     int start;
 162
 163     int new_frame_offset; /* temporary storage (used during seek) */
 164     int cum_len; /* temporary storage (used during seek) */
 165 } NSVStream;
 166
 167 typedef struct NSVContext {
 168     int  base_offset;
 169     int  NSVf_end;
 170     uint32_t *nsvs_file_offset;
 171     int index_entries;
 172     enum NSVStatus state;
 173     AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
 174     /* cached */
 175     int64_t duration;
 176     uint32_t vtag, atag;
 177     uint16_t vwidth, vheight;
 178     int16_t avsync;
 179     AVRational framerate;
 180     uint32_t *nsvs_timestamps;
 181     int nsvf;
 182 } NSVContext;
 183
 184 static const AVCodecTag nsv_codec_video_tags[] = {
 185     { AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
 186     { AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
 187     { AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
 188     { AV_CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
 189     { AV_CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
 190     { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
 191     { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
 192     { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
 193     { AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
 194     { AV_CODEC_ID_VP8, MKTAG('V', 'P', '8', '0') },
 195 /*
 196     { AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
 197     { AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
 198 */
 199     { AV_CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
 200     { AV_CODEC_ID_H264,  MKTAG('H', '2', '6', '4') },
 201     { AV_CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
 202     { AV_CODEC_ID_NONE, 0 },
 203 };
 204
 205 static const AVCodecTag nsv_codec_audio_tags[] = {
 206     { AV_CODEC_ID_MP3,       MKTAG('M', 'P', '3', ' ') },
 207     { AV_CODEC_ID_AAC,       MKTAG('A', 'A', 'C', ' ') },
 208     { AV_CODEC_ID_AAC,       MKTAG('A', 'A', 'C', 'P') },
 209     { AV_CODEC_ID_AAC,       MKTAG('A', 'A', 'V', ' ') },
 210     { AV_CODEC_ID_AAC,       MKTAG('V', 'L', 'B', ' ') },
 211     { AV_CODEC_ID_SPEEX,     MKTAG('S', 'P', 'X', ' ') },
 212     { AV_CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
 213     { AV_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 /* try to find something we recognize, and set the state accordingly */
 220 static int nsv_resync(AVFormatContext *s)
 221 {
 222     NSVContext *nsv = s->priv_data;
 223     AVIOContext *pb = s->pb;
 224     uint32_t v = 0;
 225     int i;
 226
 227     for (i = 0; i < NSV_MAX_RESYNC; i++) {
 228         if (avio_feof(pb)) {
 229             av_log(s, AV_LOG_TRACE, "NSV EOF\n");
 230             nsv->state = NSV_UNSYNC;
 231             return -1;
 232         }
 233         v <<= 8;
 234         v |= avio_r8(pb);
 235         if (i < 8) {
 236             av_log(s, AV_LOG_TRACE, "NSV resync: [%d] = %02"PRIx32"\n", i, v & 0x0FF);
 237         }
 238
 239         if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
 240             av_log(s, AV_LOG_TRACE, "NSV resynced on BEEF after %d bytes\n", i+1);
 241             nsv->state = NSV_FOUND_BEEF;
 242             return 0;
 243         }
 244         /* we read as big-endian, thus the MK*BE* */
 245         if (v == TB_NSVF) { /* NSVf */
 246             av_log(s, AV_LOG_TRACE, "NSV resynced on NSVf after %d bytes\n", i+1);
 247             nsv->state = NSV_FOUND_NSVF;
 248             return 0;
 249         }
 250         if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
 251             av_log(s, AV_LOG_TRACE, "NSV resynced on NSVs after %d bytes\n", i+1);
 252             nsv->state = NSV_FOUND_NSVS;
 253             return 0;
 254         }
 255
 256     }
 257     av_log(s, AV_LOG_TRACE, "NSV sync lost\n");
 258     return -1;
 259 }
 260
 261 static int nsv_parse_NSVf_header(AVFormatContext *s)
 262 {
 263     NSVContext *nsv = s->priv_data;
 264     AVIOContext *pb = s->pb;
 265     unsigned int av_unused file_size;
 266     unsigned int size;
 267     int64_t duration;
 268     int strings_size;
 269     int table_entries;
 270     int table_entries_used;
 271
 272     nsv->state = NSV_UNSYNC; /* in case we fail */
 273
 274     if (nsv->nsvf) {
 275         av_log(s, AV_LOG_TRACE, "Multiple NSVf\n");
 276         return 0;
 277     }
 278     nsv->nsvf = 1;
 279
 280     size = avio_rl32(pb);
 281     if (size < 28)
 282         return -1;
 283     nsv->NSVf_end = size;
 284
 285     file_size = (uint32_t)avio_rl32(pb);
 286     av_log(s, AV_LOG_TRACE, "NSV NSVf chunk_size %u\n", size);
 287     av_log(s, AV_LOG_TRACE, "NSV NSVf file_size %u\n", file_size);
 288
 289     nsv->duration = duration = avio_rl32(pb); /* in ms */
 290     av_log(s, AV_LOG_TRACE, "NSV NSVf duration %"PRId64" ms\n", duration);
 291     // XXX: store it in AVStreams
 292
 293     strings_size = avio_rl32(pb);
 294     table_entries = avio_rl32(pb);
 295     table_entries_used = avio_rl32(pb);
 296     av_log(s, AV_LOG_TRACE, "NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
 297             strings_size, table_entries, table_entries_used);
 298     if (avio_feof(pb))
 299         return -1;
 300
 301     av_log(s, AV_LOG_TRACE, "NSV got header; filepos %"PRId64"\n", avio_tell(pb));
 302
 303     if (strings_size > 0) {
 304         char *strings; /* last byte will be '\0' to play safe with str*() */
 305         char *p, *endp;
 306         char *token, *value;
 307         char quote;
 308
 309         p = strings = av_mallocz((size_t)strings_size + 1);
 310         if (!p)
 311             return AVERROR(ENOMEM);
 312         endp = strings + strings_size;
 313         avio_read(pb, strings, strings_size);
 314         while (p < endp) {
 315             while (*p == ' ')
 316                 p++; /* strip out spaces */
 317             if (p >= endp-2)
 318                 break;
 319             token = p;
 320             p = strchr(p, '=');
 321             if (!p || p >= endp-2)
 322                 break;
 323             *p++ = '\0';
 324             quote = *p++;
 325             value = p;
 326             p = strchr(p, quote);
 327             if (!p || p >= endp)
 328                 break;
 329             *p++ = '\0';
 330             av_log(s, AV_LOG_TRACE, "NSV NSVf INFO: %s='%s'\n", token, value);
 331             av_dict_set(&s->metadata, token, value, 0);
 332         }
 333         av_free(strings);
 334     }
 335     if (avio_feof(pb))
 336         return -1;
 337
 338     av_log(s, AV_LOG_TRACE, "NSV got infos; filepos %"PRId64"\n", avio_tell(pb));
 339
 340     if (table_entries_used > 0) {
 341         int i;
 342         nsv->index_entries = table_entries_used;
 343         if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
 344             return -1;
 345         nsv->nsvs_file_offset = av_malloc_array((unsigned)table_entries_used, sizeof(uint32_t));
 346         if (!nsv->nsvs_file_offset)
 347             return AVERROR(ENOMEM);
 348
 349         for(i=0;i<table_entries_used;i++) {
 350             if (avio_feof(pb))
 351                 return AVERROR_INVALIDDATA;
 352             nsv->nsvs_file_offset[i] = avio_rl32(pb) + size;
 353         }
 354
 355         if(table_entries > table_entries_used &&
 356            avio_rl32(pb) == MKTAG('T','O','C','2')) {
 357             nsv->nsvs_timestamps = av_malloc_array((unsigned)table_entries_used, sizeof(uint32_t));
 358             if (!nsv->nsvs_timestamps)
 359                 return AVERROR(ENOMEM);
 360             for(i=0;i<table_entries_used;i++) {
 361                 nsv->nsvs_timestamps[i] = avio_rl32(pb);
 362             }
 363         }
 364     }
 365
 366     av_log(s, AV_LOG_TRACE, "NSV got index; filepos %"PRId64"\n", avio_tell(pb));
 367
 368     avio_seek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
 369
 370     if (avio_feof(pb))
 371         return -1;
 372     nsv->state = NSV_HAS_READ_NSVF;
 373     return 0;
 374 }
 375
 376 static int nsv_parse_NSVs_header(AVFormatContext *s)
 377 {
 378     NSVContext *nsv = s->priv_data;
 379     AVIOContext *pb = s->pb;
 380     uint32_t vtag, atag;
 381     uint16_t vwidth, vheight;
 382     AVRational framerate;
 383     int i;
 384     AVStream *st;
 385     NSVStream *nst;
 386
 387     vtag = avio_rl32(pb);
 388     atag = avio_rl32(pb);
 389     vwidth = avio_rl16(pb);
 390     vheight = avio_rl16(pb);
 391     i = avio_r8(pb);
 392
 393     av_log(s, AV_LOG_TRACE, "NSV NSVs framerate code %2x\n", i);
 394     if(i&0x80) { /* odd way of giving native framerates from docs */
 395         int t=(i & 0x7F)>>2;
 396         if(t<16) framerate = (AVRational){1, t+1};
 397         else     framerate = (AVRational){t-15, 1};
 398
 399         if(i&1){
 400             framerate.num *= 1000;
 401             framerate.den *= 1001;
 402         }
 403
 404         if((i&3)==3)      framerate.num *= 24;
 405         else if((i&3)==2) framerate.num *= 25;
 406         else              framerate.num *= 30;
 407     }
 408     else
 409         framerate= (AVRational){i, 1};
 410
 411     nsv->avsync = avio_rl16(pb);
 412     nsv->framerate = framerate;
 413
 414     av_log(s, AV_LOG_TRACE, "NSV NSVs vsize %dx%d\n", vwidth, vheight);
 415
 416     /* XXX change to ap != NULL ? */
 417     if (s->nb_streams == 0) { /* streams not yet published, let's do that */
 418         nsv->vtag = vtag;
 419         nsv->atag = atag;
 420         nsv->vwidth = vwidth;
 421         nsv->vheight = vwidth;
 422         if (vtag != T_NONE) {
 423             int i;
 424             st = avformat_new_stream(s, NULL);
 425             if (!st)
 426                 goto fail;
 427
 428             st->id = NSV_ST_VIDEO;
 429             nst = av_mallocz(sizeof(NSVStream));
 430             if (!nst)
 431                 goto fail;
 432             st->priv_data = nst;
 433             st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
 434             st->codecpar->codec_tag = vtag;
 435             st->codecpar->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
 436             st->codecpar->width = vwidth;
 437             st->codecpar->height = vheight;
 438             st->codecpar->bits_per_coded_sample = 24; /* depth XXX */
 439
 440             avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
 441             st->start_time = 0;
 442             st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
 443
 444             for(i=0;i<nsv->index_entries;i++) {
 445                 if(nsv->nsvs_timestamps) {
 446                     av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
 447                                        0, 0, AVINDEX_KEYFRAME);
 448                 } else {
 449                     int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
 450                     av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
 451                 }
 452             }
 453         }
 454         if (atag != T_NONE) {
 455             st = avformat_new_stream(s, NULL);
 456             if (!st)
 457                 goto fail;
 458
 459             st->id = NSV_ST_AUDIO;
 460             nst = av_mallocz(sizeof(NSVStream));
 461             if (!nst)
 462                 goto fail;
 463             st->priv_data = nst;
 464             st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
 465             st->codecpar->codec_tag = atag;
 466             st->codecpar->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
 467
 468             if (atag == MKTAG('A', 'A', 'V', ' ')) {
 469                 static const uint8_t aav_pce[] = {
 470                     0x12, 0x00, 0x05, 0x08, 0x48, 0x00,
 471                     0x20, 0x00, 0xC6, 0x40, 0x04, 0x4C,
 472                     0x61, 0x76, 0x63, 0x56, 0xE5, 0x00,
 473                     0x00, 0x00,
 474                 };
 475                 int ret;
 476
 477                 if ((ret = ff_alloc_extradata(st->codecpar, sizeof(aav_pce))) < 0)
 478                     return ret;
 479
 480                 st->codecpar->sample_rate = 44100;
 481                 memcpy(st->codecpar->extradata, aav_pce, sizeof(aav_pce));
 482             }
 483
 484             ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
 485
 486             /* set timebase to common denominator of ms and framerate */
 487             avpriv_set_pts_info(st, 64, 1, framerate.num*1000);
 488             st->start_time = 0;
 489             st->duration = (int64_t)nsv->duration * framerate.num;
 490         }
 491     } else {
 492         if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
 493             av_log(s, AV_LOG_TRACE, "NSV NSVs header values differ from the first one!!!\n");
 494             //return -1;
 495         }
 496     }
 497
 498     nsv->state = NSV_HAS_READ_NSVS;
 499     return 0;
 500 fail:
 501     /* XXX */
 502     nsv->state = NSV_UNSYNC;
 503     return -1;
 504 }
 505
 506 static int nsv_read_header(AVFormatContext *s)
 507 {
 508     NSVContext *nsv = s->priv_data;
 509     int i, err;
 510
 511     nsv->state = NSV_UNSYNC;
 512     nsv->ahead[0].data = nsv->ahead[1].data = NULL;
 513
 514     for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
 515         err = nsv_resync(s);
 516         if (err < 0)
 517             return err;
 518         if (nsv->state == NSV_FOUND_NSVF) {
 519             err = nsv_parse_NSVf_header(s);
 520             if (err < 0)
 521                 return err;
 522         }
 523             /* we need the first NSVs also... */
 524         if (nsv->state == NSV_FOUND_NSVS) {
 525             err = nsv_parse_NSVs_header(s);
 526             if (err < 0)
 527                 return err;
 528             break; /* we just want the first one */
 529         }
 530     }
 531     if (s->nb_streams < 1) /* no luck so far */
 532         return AVERROR_INVALIDDATA;
 533
 534     /* now read the first chunk, so we can attempt to decode more info */
 535     err = nsv_read_chunk(s, 1);
 536
 537     av_log(s, AV_LOG_TRACE, "parsed header\n");
 538     return err;
 539 }
 540
 541 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
 542 {
 543     NSVContext *nsv = s->priv_data;
 544     AVIOContext *pb = s->pb;
 545     AVStream *st[2] = {NULL, NULL};
 546     NSVStream *nst;
 547     AVPacket *pkt;
 548     int i, err = 0;
 549     uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
 550     uint32_t vsize;
 551     uint16_t asize;
 552     uint16_t auxsize;
 553     int ret;
 554
 555     if (nsv->ahead[0].data || nsv->ahead[1].data)
 556         return 0; //-1; /* hey! eat what you've in your plate first! */
 557
 558 null_chunk_retry:
 559     if (avio_feof(pb))
 560         return -1;
 561
 562     for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
 563         err = nsv_resync(s);
 564     if (err < 0)
 565         return err;
 566     if (nsv->state == NSV_FOUND_NSVS)
 567         err = nsv_parse_NSVs_header(s);
 568     if (err < 0)
 569         return err;
 570     if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
 571         return -1;
 572
 573     auxcount = avio_r8(pb);
 574     vsize = avio_rl16(pb);
 575     asize = avio_rl16(pb);
 576     vsize = (vsize << 4) | (auxcount >> 4);
 577     auxcount &= 0x0f;
 578     av_log(s, AV_LOG_TRACE, "NSV CHUNK %d aux, %"PRIu32" bytes video, %d bytes audio\n", auxcount, vsize, asize);
 579     /* skip aux stuff */
 580     for (i = 0; i < auxcount; i++) {
 581         uint32_t av_unused auxtag;
 582         auxsize = avio_rl16(pb);
 583         auxtag = avio_rl32(pb);
 584         avio_skip(pb, auxsize);
 585         vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming brain-dead */
 586     }
 587
 588     if (avio_feof(pb))
 589         return -1;
 590     if (!vsize && !asize) {
 591         nsv->state = NSV_UNSYNC;
 592         goto null_chunk_retry;
 593     }
 594
 595     /* map back streams to v,a */
 596     if (s->nb_streams > 0)
 597         st[s->streams[0]->id] = s->streams[0];
 598     if (s->nb_streams > 1)
 599         st[s->streams[1]->id] = s->streams[1];
 600
 601     if (vsize && st[NSV_ST_VIDEO]) {
 602         nst = st[NSV_ST_VIDEO]->priv_data;
 603         pkt = &nsv->ahead[NSV_ST_VIDEO];
 604         if ((ret = av_get_packet(pb, pkt, vsize)) < 0)
 605             return ret;
 606         pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
 607         pkt->dts = nst->frame_offset;
 608         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
 609         for (i = 0; i < FFMIN(8, vsize); i++)
 610             av_log(s, AV_LOG_TRACE, "NSV video: [%d] = %02x\n", i, pkt->data[i]);
 611     }
 612     if(st[NSV_ST_VIDEO])
 613         ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
 614
 615     if (asize && st[NSV_ST_AUDIO]) {
 616         nst = st[NSV_ST_AUDIO]->priv_data;
 617         pkt = &nsv->ahead[NSV_ST_AUDIO];
 618         /* read raw audio specific header on the first audio chunk... */
 619         /* on ALL audio chunks ?? seems so! */
 620         if (asize >= 4 && st[NSV_ST_AUDIO]->codecpar->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
 621             uint8_t bps;
 622             uint8_t channels;
 623             uint16_t samplerate;
 624             bps = avio_r8(pb);
 625             channels = avio_r8(pb);
 626             samplerate = avio_rl16(pb);
 627             if (!channels || !samplerate)
 628                 return AVERROR_INVALIDDATA;
 629             asize-=4;
 630             av_log(s, AV_LOG_TRACE, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
 631             if (fill_header) {
 632                 ffstream(st[NSV_ST_AUDIO])->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
 633                 if (bps != 16) {
 634                     av_log(s, AV_LOG_TRACE, "NSV AUDIO bit/sample != 16 (%d)!!!\n", bps);
 635                 }
 636                 bps /= channels; // ???
 637                 if (bps == 8)
 638                     st[NSV_ST_AUDIO]->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
 639                 samplerate /= 4;/* UGH ??? XXX */
 640                 channels = 1;
 641                 st[NSV_ST_AUDIO]->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
 642                 st[NSV_ST_AUDIO]->codecpar->sample_rate = samplerate;
 643                 av_log(s, AV_LOG_TRACE, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
 644             }
 645         }
 646         if ((ret = av_get_packet(pb, pkt, asize)) < 0)
 647             return ret;
 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_log(s, AV_LOG_TRACE, "NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts);
 656         }
 657         nst->frame_offset++;
 658     }
 659
 660     nsv->state = NSV_UNSYNC;
 661     return 0;
 662 }
 663
 664
 665 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
 666 {
 667     NSVContext *nsv = s->priv_data;
 668     int i, err = 0;
 669
 670     /* in case we don't already have something to eat ... */
 671     if (!nsv->ahead[0].data && !nsv->ahead[1].data)
 672         err = nsv_read_chunk(s, 0);
 673     if (err < 0)
 674         return err;
 675
 676     /* now pick one of the plates */
 677     for (i = 0; i < 2; i++) {
 678         if (nsv->ahead[i].data) {
 679             av_packet_move_ref(pkt, &nsv->ahead[i]);
 680             return 0;
 681         }
 682     }
 683
 684     /* this restaurant is not provisioned :^] */
 685     return -1;
 686 }
 687
 688 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 689 {
 690     NSVContext *nsv = s->priv_data;
 691     AVStream *st = s->streams[stream_index];
 692     FFStream *const sti = ffstream(st);
 693     NSVStream *nst = st->priv_data;
 694     int index;
 695
 696     index = av_index_search_timestamp(st, timestamp, flags);
 697     if(index < 0)
 698         return -1;
 699
 700     if (avio_seek(s->pb, sti->index_entries[index].pos, SEEK_SET) < 0)
 701         return -1;
 702
 703     nst->frame_offset = sti->index_entries[index].timestamp;
 704     nsv->state = NSV_UNSYNC;
 705     return 0;
 706 }
 707
 708 static int nsv_read_close(AVFormatContext *s)
 709 {
 710     NSVContext *nsv = s->priv_data;
 711
 712     av_freep(&nsv->nsvs_file_offset);
 713     av_freep(&nsv->nsvs_timestamps);
 714     if (nsv->ahead[0].data)
 715         av_packet_unref(&nsv->ahead[0]);
 716     if (nsv->ahead[1].data)
 717         av_packet_unref(&nsv->ahead[1]);
 718     return 0;
 719 }
 720
 721 static int nsv_probe(const AVProbeData *p)
 722 {
 723     int i, score = 0;
 724
 725     /* check file header */
 726     /* streamed files might not have any header */
 727     if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
 728         p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
 729         return AVPROBE_SCORE_MAX;
 730     /* XXX: do streamed files always start at chunk boundary ?? */
 731     /* or do we need to search NSVs in the byte stream ? */
 732     /* seems the servers don't bother starting clean chunks... */
 733     /* sometimes even the first header is at 9KB or something :^) */
 734     for (i = 1; i < p->buf_size - 3; i++) {
 735         if (AV_RL32(p->buf + i) == AV_RL32("NSVs")) {
 736             /* Get the chunk size and check if at the end we are getting 0xBEEF */
 737             int vsize = AV_RL24(p->buf+i+19) >> 4;
 738             int asize = AV_RL16(p->buf+i+22);
 739             int offset = i + 23 + asize + vsize + 1;
 740             if (offset <= p->buf_size - 2 && AV_RL16(p->buf + offset) == 0xBEEF)
 741                 return 4*AVPROBE_SCORE_MAX/5;
 742             score = AVPROBE_SCORE_MAX/5;
 743         }
 744     }
 745     /* so we'll have more luck on extension... */
 746     if (av_match_ext(p->filename, "nsv"))
 747         return AVPROBE_SCORE_EXTENSION;
 748     /* FIXME: add mime-type check */
 749     return score;
 750 }
 751
 752 const FFInputFormat ff_nsv_demuxer = {
 753     .p.name         = "nsv",
 754     .p.long_name    = NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
 755     .priv_data_size = sizeof(NSVContext),
 756     .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,
 757     .read_probe     = nsv_probe,
 758     .read_header    = nsv_read_header,
 759     .read_packet    = nsv_read_packet,
 760     .read_close     = nsv_read_close,
 761     .read_seek      = nsv_read_seek,
 762 };