libavformat/nsvdec.c

   1 /*
   2  * NSV demuxer
   3  * Copyright (c) 2004 The FFmpeg Project
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21 #include "avformat.h"
  22 #include "riff.h"
  23
  24 //#define DEBUG
  25 //#define DEBUG_DUMP_INDEX // XXX dumbdriving-271.nsv breaks with it commented!!
  26 //#define DEBUG_SEEK
  27 #define CHECK_SUBSEQUENT_NSVS
  28 //#define DISABLE_AUDIO
  29
  30 /* max bytes to crawl for trying to resync
  31  * stupid streaming servers don't start at chunk boundaries...
  32  */
  33 #define NSV_MAX_RESYNC (500*1024)
  34 #define NSV_MAX_RESYNC_TRIES 300
  35
  36 /*
  37  * First version by Francois Revol - revol@free.fr
  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 veiwing it in VLC,
  61  * I noticed there was about 1 NVSs chunk/s, so I ran
  62  * strings faster.nsv | grep NSVs | wc -l
  63  * which gave me 180. That leads me to think that NSVf[12-15] might be the
  64  * file length in milliseconds.
  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 nstrailer (which doesn't have an NSVf header), it repports 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 #ifdef DEBUG
  85 #define PRINT(_v) printf _v
  86 #else
  87 #define PRINT(_v)
  88 #endif
  89
  90 #if 0
  91 struct NSVf_header {
  92     uint32_t chunk_tag; /* 'NSVf' */
  93     uint32_t chunk_size;
  94     uint32_t file_size; /* max 4GB ??? no one learns anything it seems :^) */
  95     uint32_t file_length; //unknown1;  /* what about MSB of file_size ? */
  96     uint32_t info_strings_size; /* size of the info strings */ //unknown2;
  97     uint32_t table_entries;
  98     uint32_t table_entries_used; /* the left ones should be -1 */
  99 };
 100
 101 struct NSVs_header {
 102     uint32_t chunk_tag; /* 'NSVs' */
 103     uint32_t v4cc;      /* or 'NONE' */
 104     uint32_t a4cc;      /* or 'NONE' */
 105     uint16_t vwidth;    /* assert(vwidth%16==0) */
 106     uint16_t vheight;   /* assert(vheight%16==0) */
 107     uint8_t framerate;  /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
 108     uint16_t unknown;
 109 };
 110
 111 struct nsv_avchunk_header {
 112     uint8_t vchunk_size_lsb;
 113     uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
 114     uint16_t achunk_size;
 115 };
 116
 117 struct nsv_pcm_header {
 118     uint8_t bits_per_sample;
 119     uint8_t channel_count;
 120     uint16_t sample_rate;
 121 };
 122 #endif
 123
 124 /* variation from avi.h */
 125 /*typedef struct CodecTag {
 126     int id;
 127     unsigned int tag;
 128 } CodecTag;*/
 129
 130 /* tags */
 131
 132 #define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
 133 #define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
 134 #define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
 135 #define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
 136 #define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
 137 #define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
 138 #define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
 139
 140 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
 141 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
 142
 143 /* hardcoded stream indexes */
 144 #define NSV_ST_VIDEO 0
 145 #define NSV_ST_AUDIO 1
 146 #define NSV_ST_SUBT 2
 147
 148 enum NSVStatus {
 149     NSV_UNSYNC,
 150     NSV_FOUND_NSVF,
 151     NSV_HAS_READ_NSVF,
 152     NSV_FOUND_NSVS,
 153     NSV_HAS_READ_NSVS,
 154     NSV_FOUND_BEEF,
 155     NSV_GOT_VIDEO,
 156     NSV_GOT_AUDIO,
 157 };
 158
 159 typedef struct NSVStream {
 160     int frame_offset; /* current frame (video) or byte (audio) counter
 161                          (used to compute the pts) */
 162     int scale;
 163     int rate;
 164     int sample_size; /* audio only data */
 165     int start;
 166
 167     int new_frame_offset; /* temporary storage (used during seek) */
 168     int cum_len; /* temporary storage (used during seek) */
 169 } NSVStream;
 170
 171 typedef struct {
 172     int  base_offset;
 173     int  NSVf_end;
 174     uint32_t *nsvs_file_offset;
 175     int index_entries;
 176     enum NSVStatus state;
 177     AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
 178     /* cached */
 179     int64_t duration;
 180     uint32_t vtag, atag;
 181     uint16_t vwidth, vheight;
 182     int16_t avsync;
 183     AVRational framerate;
 184     uint32_t *nsvs_timestamps;
 185     //DVDemuxContext* dv_demux;
 186 } NSVContext;
 187
 188 static const AVCodecTag nsv_codec_video_tags[] = {
 189     { CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
 190     { CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
 191     { CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
 192     { CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
 193     { CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
 194     { CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
 195     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
 196     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
 197     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
 198 /*
 199     { CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
 200     { CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
 201 */
 202     { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
 203     { CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
 204     { 0, 0 },
 205 };
 206
 207 static const AVCodecTag nsv_codec_audio_tags[] = {
 208     { CODEC_ID_MP3,       MKTAG('M', 'P', '3', ' ') },
 209     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', ' ') },
 210     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', 'P') },
 211     { CODEC_ID_SPEEX,     MKTAG('S', 'P', 'X', ' ') },
 212     { CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
 213     { 0, 0 },
 214 };
 215
 216 //static int nsv_load_index(AVFormatContext *s);
 217 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
 218
 219 #ifdef DEBUG
 220 static void print_tag(const char *str, unsigned int tag, int size)
 221 {
 222     printf("%s: tag=%c%c%c%c\n",
 223            str, tag & 0xff,
 224            (tag >> 8) & 0xff,
 225            (tag >> 16) & 0xff,
 226            (tag >> 24) & 0xff);
 227 }
 228 #endif
 229
 230 /* try to find something we recognize, and set the state accordingly */
 231 static int nsv_resync(AVFormatContext *s)
 232 {
 233     NSVContext *nsv = s->priv_data;
 234     ByteIOContext *pb = s->pb;
 235     uint32_t v = 0;
 236     int i;
 237
 238     PRINT(("%s(), offset = %"PRId64", state = %d\n", __FUNCTION__, url_ftell(pb), nsv->state));
 239
 240     //nsv->state = NSV_UNSYNC;
 241
 242     for (i = 0; i < NSV_MAX_RESYNC; i++) {
 243         if (url_feof(pb)) {
 244             PRINT(("NSV EOF\n"));
 245             nsv->state = NSV_UNSYNC;
 246             return -1;
 247         }
 248         v <<= 8;
 249         v |= get_byte(pb);
 250 /*
 251         if (i < 8) {
 252             PRINT(("NSV resync: [%d] = %02x\n", i, v & 0x0FF));
 253         }
 254 */
 255
 256         if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
 257             PRINT(("NSV resynced on BEEF after %d bytes\n", i+1));
 258             nsv->state = NSV_FOUND_BEEF;
 259             return 0;
 260         }
 261         /* we read as big endian, thus the MK*BE* */
 262         if (v == TB_NSVF) { /* NSVf */
 263             PRINT(("NSV resynced on NSVf after %d bytes\n", i+1));
 264             nsv->state = NSV_FOUND_NSVF;
 265             return 0;
 266         }
 267         if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
 268             PRINT(("NSV resynced on NSVs after %d bytes\n", i+1));
 269             nsv->state = NSV_FOUND_NSVS;
 270             return 0;
 271         }
 272
 273     }
 274     PRINT(("NSV sync lost\n"));
 275     return -1;
 276 }
 277
 278 static int nsv_parse_NSVf_header(AVFormatContext *s, AVFormatParameters *ap)
 279 {
 280     NSVContext *nsv = s->priv_data;
 281     ByteIOContext *pb = s->pb;
 282     unsigned int file_size, size;
 283     int64_t duration;
 284     int strings_size;
 285     int table_entries;
 286     int table_entries_used;
 287
 288     PRINT(("%s()\n", __FUNCTION__));
 289
 290     nsv->state = NSV_UNSYNC; /* in case we fail */
 291
 292     size = get_le32(pb);
 293     if (size < 28)
 294         return -1;
 295     nsv->NSVf_end = size;
 296
 297     //s->file_size = (uint32_t)get_le32(pb);
 298     file_size = (uint32_t)get_le32(pb);
 299     PRINT(("NSV NSVf chunk_size %u\n", size));
 300     PRINT(("NSV NSVf file_size %u\n", file_size));
 301
 302     nsv->duration = duration = get_le32(pb); /* in ms */
 303     PRINT(("NSV NSVf duration %"PRId64" ms\n", duration));
 304     // XXX: store it in AVStreams
 305
 306     strings_size = get_le32(pb);
 307     table_entries = get_le32(pb);
 308     table_entries_used = get_le32(pb);
 309     PRINT(("NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
 310             strings_size, table_entries, table_entries_used));
 311     if (url_feof(pb))
 312         return -1;
 313
 314     PRINT(("NSV got header; filepos %"PRId64"\n", url_ftell(pb)));
 315
 316     if (strings_size > 0) {
 317         char *strings; /* last byte will be '\0' to play safe with str*() */
 318         char *p, *endp;
 319         char *token, *value;
 320         char quote;
 321
 322         p = strings = av_mallocz(strings_size + 1);
 323         endp = strings + strings_size;
 324         get_buffer(pb, strings, strings_size);
 325         while (p < endp) {
 326             while (*p == ' ')
 327                 p++; /* strip out spaces */
 328             if (p >= endp-2)
 329                 break;
 330             token = p;
 331             p = strchr(p, '=');
 332             if (!p || p >= endp-2)
 333                 break;
 334             *p++ = '\0';
 335             quote = *p++;
 336             value = p;
 337             p = strchr(p, quote);
 338             if (!p || p >= endp)
 339                 break;
 340             *p++ = '\0';
 341             PRINT(("NSV NSVf INFO: %s='%s'\n", token, value));
 342             av_metadata_set(&s->metadata, token, value);
 343         }
 344         av_free(strings);
 345     }
 346     if (url_feof(pb))
 347         return -1;
 348
 349     PRINT(("NSV got infos; filepos %"PRId64"\n", url_ftell(pb)));
 350
 351     if (table_entries_used > 0) {
 352         int i;
 353         nsv->index_entries = table_entries_used;
 354         if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
 355             return -1;
 356         nsv->nsvs_file_offset = av_malloc((unsigned)table_entries_used * sizeof(uint32_t));
 357
 358         for(i=0;i<table_entries_used;i++)
 359             nsv->nsvs_file_offset[i] = get_le32(pb) + size;
 360
 361         if(table_entries > table_entries_used &&
 362            get_le32(pb) == MKTAG('T','O','C','2')) {
 363             nsv->nsvs_timestamps = av_malloc((unsigned)table_entries_used*sizeof(uint32_t));
 364             for(i=0;i<table_entries_used;i++) {
 365                 nsv->nsvs_timestamps[i] = get_le32(pb);
 366             }
 367         }
 368     }
 369
 370     PRINT(("NSV got index; filepos %"PRId64"\n", url_ftell(pb)));
 371
 372 #ifdef DEBUG_DUMP_INDEX
 373 #define V(v) ((v<0x20 || v > 127)?'.':v)
 374     /* dump index */
 375     PRINT(("NSV %d INDEX ENTRIES:\n", table_entries));
 376     PRINT(("NSV [dataoffset][fileoffset]\n", table_entries));
 377     for (i = 0; i < table_entries; i++) {
 378         unsigned char b[8];
 379         url_fseek(pb, size + nsv->nsvs_file_offset[i], SEEK_SET);
 380         get_buffer(pb, b, 8);
 381         PRINT(("NSV [0x%08lx][0x%08lx]: %02x %02x %02x %02x %02x %02x %02x %02x"
 382            "%c%c%c%c%c%c%c%c\n",
 383            nsv->nsvs_file_offset[i], size + nsv->nsvs_file_offset[i],
 384            b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
 385            V(b[0]), V(b[1]), V(b[2]), V(b[3]), V(b[4]), V(b[5]), V(b[6]), V(b[7]) ));
 386     }
 387     //url_fseek(pb, size, SEEK_SET); /* go back to end of header */
 388 #undef V
 389 #endif
 390
 391     url_fseek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
 392
 393     if (url_feof(pb))
 394         return -1;
 395     nsv->state = NSV_HAS_READ_NSVF;
 396     return 0;
 397 }
 398
 399 static int nsv_parse_NSVs_header(AVFormatContext *s, AVFormatParameters *ap)
 400 {
 401     NSVContext *nsv = s->priv_data;
 402     ByteIOContext *pb = s->pb;
 403     uint32_t vtag, atag;
 404     uint16_t vwidth, vheight;
 405     AVRational framerate;
 406     int i;
 407     AVStream *st;
 408     NSVStream *nst;
 409     PRINT(("%s()\n", __FUNCTION__));
 410
 411     vtag = get_le32(pb);
 412     atag = get_le32(pb);
 413     vwidth = get_le16(pb);
 414     vheight = get_le16(pb);
 415     i = get_byte(pb);
 416
 417     PRINT(("NSV NSVs framerate code %2x\n", i));
 418     if(i&0x80) { /* odd way of giving native framerates from docs */
 419         int t=(i & 0x7F)>>2;
 420         if(t<16) framerate = (AVRational){1, t+1};
 421         else     framerate = (AVRational){t-15, 1};
 422
 423         if(i&1){
 424             framerate.num *= 1000;
 425             framerate.den *= 1001;
 426         }
 427
 428         if((i&3)==3)      framerate.num *= 24;
 429         else if((i&3)==2) framerate.num *= 25;
 430         else              framerate.num *= 30;
 431     }
 432     else
 433         framerate= (AVRational){i, 1};
 434
 435     nsv->avsync = get_le16(pb);
 436     nsv->framerate = framerate;
 437 #ifdef DEBUG
 438     print_tag("NSV NSVs vtag", vtag, 0);
 439     print_tag("NSV NSVs atag", atag, 0);
 440     PRINT(("NSV NSVs vsize %dx%d\n", vwidth, vheight));
 441 #endif
 442
 443     /* XXX change to ap != NULL ? */
 444     if (s->nb_streams == 0) { /* streams not yet published, let's do that */
 445         nsv->vtag = vtag;
 446         nsv->atag = atag;
 447         nsv->vwidth = vwidth;
 448         nsv->vheight = vwidth;
 449         if (vtag != T_NONE) {
 450             int i;
 451             st = av_new_stream(s, NSV_ST_VIDEO);
 452             if (!st)
 453                 goto fail;
 454
 455             nst = av_mallocz(sizeof(NSVStream));
 456             if (!nst)
 457                 goto fail;
 458             st->priv_data = nst;
 459             st->codec->codec_type = CODEC_TYPE_VIDEO;
 460             st->codec->codec_tag = vtag;
 461             st->codec->codec_id = codec_get_id(nsv_codec_video_tags, vtag);
 462             st->codec->width = vwidth;
 463             st->codec->height = vheight;
 464             st->codec->bits_per_coded_sample = 24; /* depth XXX */
 465
 466             av_set_pts_info(st, 64, framerate.den, framerate.num);
 467             st->start_time = 0;
 468             st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
 469
 470             for(i=0;i<nsv->index_entries;i++) {
 471                 if(nsv->nsvs_timestamps) {
 472                     av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
 473                                        0, 0, AVINDEX_KEYFRAME);
 474                 } else {
 475                     int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
 476                     av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
 477                 }
 478             }
 479         }
 480         if (atag != T_NONE) {
 481 #ifndef DISABLE_AUDIO
 482             st = av_new_stream(s, NSV_ST_AUDIO);
 483             if (!st)
 484                 goto fail;
 485
 486             nst = av_mallocz(sizeof(NSVStream));
 487             if (!nst)
 488                 goto fail;
 489             st->priv_data = nst;
 490             st->codec->codec_type = CODEC_TYPE_AUDIO;
 491             st->codec->codec_tag = atag;
 492             st->codec->codec_id = codec_get_id(nsv_codec_audio_tags, atag);
 493
 494             st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
 495
 496             /* set timebase to common denominator of ms and framerate */
 497             av_set_pts_info(st, 64, 1, framerate.num*1000);
 498             st->start_time = 0;
 499             st->duration = (int64_t)nsv->duration * framerate.num;
 500 #endif
 501         }
 502 #ifdef CHECK_SUBSEQUENT_NSVS
 503     } else {
 504         if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
 505             PRINT(("NSV NSVs header values differ from the first one!!!\n"));
 506             //return -1;
 507         }
 508 #endif /* CHECK_SUBSEQUENT_NSVS */
 509     }
 510
 511     nsv->state = NSV_HAS_READ_NSVS;
 512     return 0;
 513 fail:
 514     /* XXX */
 515     nsv->state = NSV_UNSYNC;
 516     return -1;
 517 }
 518
 519 static int nsv_read_header(AVFormatContext *s, AVFormatParameters *ap)
 520 {
 521     NSVContext *nsv = s->priv_data;
 522     int i, err;
 523
 524     PRINT(("%s()\n", __FUNCTION__));
 525     PRINT(("filename '%s'\n", s->filename));
 526
 527     nsv->state = NSV_UNSYNC;
 528     nsv->ahead[0].data = nsv->ahead[1].data = NULL;
 529
 530     for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
 531         if (nsv_resync(s) < 0)
 532             return -1;
 533         if (nsv->state == NSV_FOUND_NSVF)
 534             err = nsv_parse_NSVf_header(s, ap);
 535             /* we need the first NSVs also... */
 536         if (nsv->state == NSV_FOUND_NSVS) {
 537             err = nsv_parse_NSVs_header(s, ap);
 538             break; /* we just want the first one */
 539         }
 540     }
 541     if (s->nb_streams < 1) /* no luck so far */
 542         return -1;
 543     /* now read the first chunk, so we can attempt to decode more info */
 544     err = nsv_read_chunk(s, 1);
 545
 546     PRINT(("parsed header\n"));
 547     return 0;
 548 }
 549
 550 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
 551 {
 552     NSVContext *nsv = s->priv_data;
 553     ByteIOContext *pb = s->pb;
 554     AVStream *st[2] = {NULL, NULL};
 555     NSVStream *nst;
 556     AVPacket *pkt;
 557     int i, err = 0;
 558     uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
 559     uint32_t vsize;
 560     uint16_t asize;
 561     uint16_t auxsize;
 562     uint32_t auxtag;
 563
 564     PRINT(("%s(%d)\n", __FUNCTION__, fill_header));
 565
 566     if (nsv->ahead[0].data || nsv->ahead[1].data)
 567         return 0; //-1; /* hey! eat what you've in your plate first! */
 568
 569 null_chunk_retry:
 570     if (url_feof(pb))
 571         return -1;
 572
 573     for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
 574         err = nsv_resync(s);
 575     if (err < 0)
 576         return err;
 577     if (nsv->state == NSV_FOUND_NSVS)
 578         err = nsv_parse_NSVs_header(s, NULL);
 579     if (err < 0)
 580         return err;
 581     if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
 582         return -1;
 583
 584     auxcount = get_byte(pb);
 585     vsize = get_le16(pb);
 586     asize = get_le16(pb);
 587     vsize = (vsize << 4) | (auxcount >> 4);
 588     auxcount &= 0x0f;
 589     PRINT(("NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize));
 590     /* skip aux stuff */
 591     for (i = 0; i < auxcount; i++) {
 592         auxsize = get_le16(pb);
 593         auxtag = get_le32(pb);
 594         PRINT(("NSV aux data: '%c%c%c%c', %d bytes\n",
 595               (auxtag & 0x0ff),
 596               ((auxtag >> 8) & 0x0ff),
 597               ((auxtag >> 16) & 0x0ff),
 598               ((auxtag >> 24) & 0x0ff),
 599               auxsize));
 600         url_fskip(pb, auxsize);
 601         vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
 602     }
 603
 604     if (url_feof(pb))
 605         return -1;
 606     if (!vsize && !asize) {
 607         nsv->state = NSV_UNSYNC;
 608         goto null_chunk_retry;
 609     }
 610
 611     /* map back streams to v,a */
 612     if (s->streams[0])
 613         st[s->streams[0]->id] = s->streams[0];
 614     if (s->streams[1])
 615         st[s->streams[1]->id] = s->streams[1];
 616
 617     if (vsize/* && st[NSV_ST_VIDEO]*/) {
 618         nst = st[NSV_ST_VIDEO]->priv_data;
 619         pkt = &nsv->ahead[NSV_ST_VIDEO];
 620         av_get_packet(pb, pkt, vsize);
 621         pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
 622         pkt->dts = nst->frame_offset;
 623         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
 624 /*
 625         for (i = 0; i < MIN(8, vsize); i++)
 626             PRINT(("NSV video: [%d] = %02x\n", i, pkt->data[i]));
 627 */
 628     }
 629     if(st[NSV_ST_VIDEO])
 630         ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
 631
 632     if (asize/*st[NSV_ST_AUDIO]*/) {
 633         nst = st[NSV_ST_AUDIO]->priv_data;
 634         pkt = &nsv->ahead[NSV_ST_AUDIO];
 635         /* read raw audio specific header on the first audio chunk... */
 636         /* on ALL audio chunks ?? seems so! */
 637         if (asize && st[NSV_ST_AUDIO]->codec->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
 638             uint8_t bps;
 639             uint8_t channels;
 640             uint16_t samplerate;
 641             bps = get_byte(pb);
 642             channels = get_byte(pb);
 643             samplerate = get_le16(pb);
 644             asize-=4;
 645             PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate));
 646             if (fill_header) {
 647                 st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
 648                 if (bps != 16) {
 649                     PRINT(("NSV AUDIO bit/sample != 16 (%d)!!!\n", bps));
 650                 }
 651                 bps /= channels; // ???
 652                 if (bps == 8)
 653                     st[NSV_ST_AUDIO]->codec->codec_id = CODEC_ID_PCM_U8;
 654                 samplerate /= 4;/* UGH ??? XXX */
 655                 channels = 1;
 656                 st[NSV_ST_AUDIO]->codec->channels = channels;
 657                 st[NSV_ST_AUDIO]->codec->sample_rate = samplerate;
 658                 PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate));
 659             }
 660         }
 661         av_get_packet(pb, pkt, asize);
 662         pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
 663         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
 664         if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
 665             /* on a nsvs frame we have new information on a/v sync */
 666             pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
 667             pkt->dts *= (int64_t)1000        * nsv->framerate.den;
 668             pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
 669             PRINT(("NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts));
 670         }
 671         nst->frame_offset++;
 672     }
 673
 674     nsv->state = NSV_UNSYNC;
 675     return 0;
 676 }
 677
 678
 679 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
 680 {
 681     NSVContext *nsv = s->priv_data;
 682     int i, err = 0;
 683
 684     PRINT(("%s()\n", __FUNCTION__));
 685
 686     /* in case we don't already have something to eat ... */
 687     if (nsv->ahead[0].data == NULL && nsv->ahead[1].data == NULL)
 688         err = nsv_read_chunk(s, 0);
 689     if (err < 0)
 690         return err;
 691
 692     /* now pick one of the plates */
 693     for (i = 0; i < 2; i++) {
 694         if (nsv->ahead[i].data) {
 695                 PRINT(("%s: using cached packet[%d]\n", __FUNCTION__, i));
 696             /* avoid the cost of new_packet + memcpy(->data) */
 697             memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
 698             nsv->ahead[i].data = NULL; /* we ate that one */
 699             return pkt->size;
 700         }
 701     }
 702
 703     /* this restaurant is not approvisionned :^] */
 704     return -1;
 705 }
 706
 707 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
 708 {
 709     NSVContext *nsv = s->priv_data;
 710     AVStream *st = s->streams[stream_index];
 711     NSVStream *nst = st->priv_data;
 712     int index;
 713
 714     index = av_index_search_timestamp(st, timestamp, flags);
 715     if(index < 0)
 716         return -1;
 717
 718     url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
 719     nst->frame_offset = st->index_entries[index].timestamp;
 720     nsv->state = NSV_UNSYNC;
 721     return 0;
 722 }
 723
 724 static int nsv_read_close(AVFormatContext *s)
 725 {
 726 /*     int i; */
 727     NSVContext *nsv = s->priv_data;
 728
 729     av_freep(&nsv->nsvs_file_offset);
 730     av_freep(&nsv->nsvs_timestamps);
 731
 732 #if 0
 733
 734     for(i=0;i<s->nb_streams;i++) {
 735         AVStream *st = s->streams[i];
 736         NSVStream *ast = st->priv_data;
 737         if(ast){
 738             av_free(ast->index_entries);
 739             av_free(ast);
 740         }
 741         av_free(st->codec->palctrl);
 742     }
 743
 744 #endif
 745     return 0;
 746 }
 747
 748 static int nsv_probe(AVProbeData *p)
 749 {
 750     int i;
 751 //    PRINT(("nsv_probe(), buf_size %d\n", p->buf_size));
 752     /* check file header */
 753     /* streamed files might not have any header */
 754     if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
 755         p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
 756         return AVPROBE_SCORE_MAX;
 757     /* XXX: do streamed files always start at chunk boundary ?? */
 758     /* or do we need to search NSVs in the byte stream ? */
 759     /* seems the servers don't bother starting clean chunks... */
 760     /* sometimes even the first header is at 9KB or something :^) */
 761     for (i = 1; i < p->buf_size - 3; i++) {
 762         if (p->buf[i+0] == 'N' && p->buf[i+1] == 'S' &&
 763             p->buf[i+2] == 'V' && p->buf[i+3] == 's')
 764             return AVPROBE_SCORE_MAX-20;
 765     }
 766     /* so we'll have more luck on extension... */
 767     if (match_ext(p->filename, "nsv"))
 768         return AVPROBE_SCORE_MAX/2;
 769     /* FIXME: add mime-type check */
 770     return 0;
 771 }
 772
 773 AVInputFormat nsv_demuxer = {
 774     "nsv",
 775     NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
 776     sizeof(NSVContext),
 777     nsv_probe,
 778     nsv_read_header,
 779     nsv_read_packet,
 780     nsv_read_close,
 781     nsv_read_seek,
 782 };