FFmpeg: libavformat/nsvdec.c Source File

00001 /*
00002  * NSV demuxer
00003  * Copyright (c) 2004 The FFmpeg Project
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavutil/mathematics.h"
00023 #include "avformat.h"
00024 #include "internal.h"
00025 #include "riff.h"
00026 #include "libavutil/dict.h"
00027 #include "libavutil/intreadwrite.h"
00028 
00029 //#define DEBUG_DUMP_INDEX // XXX dumbdriving-271.nsv breaks with it commented!!
00030 #define CHECK_SUBSEQUENT_NSVS
00031 //#define DISABLE_AUDIO
00032 
00033 /* max bytes to crawl for trying to resync
00034  * stupid streaming servers don't start at chunk boundaries...
00035  */
00036 #define NSV_MAX_RESYNC (500*1024)
00037 #define NSV_MAX_RESYNC_TRIES 300
00038 
00039 /*
00040  * First version by Francois Revol - revol@free.fr
00041  * References:
00042  * (1) http://www.multimedia.cx/nsv-format.txt
00043  * seems someone came to the same conclusions as me, and updated it:
00044  * (2) http://www.stud.ktu.lt/~vitslav/nsv/nsv-format.txt
00045  *     http://www.stud.ktu.lt/~vitslav/nsv/
00046  * official docs
00047  * (3) http://ultravox.aol.com/NSVFormat.rtf
00048  * Sample files:
00049  * (S1) http://www.nullsoft.com/nsv/samples/
00050  * http://www.nullsoft.com/nsv/samples/faster.nsv
00051  * http://streamripper.sourceforge.net/openbb/read.php?TID=492&page=4
00052  */
00053 
00054 /*
00055  * notes on the header (Francois Revol):
00056  *
00057  * It is followed by strings, then a table, but nothing tells
00058  * where the table begins according to (1). After checking faster.nsv,
00059  * I believe NVSf[16-19] gives the size of the strings data
00060  * (that is the offset of the data table after the header).
00061  * After checking all samples from (S1) all confirms this.
00062  *
00063  * Then, about NSVf[12-15], faster.nsf has 179700. When veiwing it in VLC,
00064  * I noticed there was about 1 NVSs chunk/s, so I ran
00065  * strings faster.nsv | grep NSVs | wc -l
00066  * which gave me 180. That leads me to think that NSVf[12-15] might be the
00067  * file length in milliseconds.
00068  * Let's try that:
00069  * 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
00070  * except for nstrailer (which doesn't have an NSVf header), it repports correct time.
00071  *
00072  * nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
00073  * so the header seems to not be mandatory. (for streaming).
00074  *
00075  * index slice duration check (excepts nsvtrailer.nsv):
00076  * 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
00077  */
00078 
00079 /*
00080  * TODO:
00081  * - handle timestamps !!!
00082  * - use index
00083  * - mime-type in probe()
00084  * - seek
00085  */
00086 
00087 #if 0
00088 struct NSVf_header {
00089     uint32_t chunk_tag; /* 'NSVf' */
00090     uint32_t chunk_size;
00091     uint32_t file_size; /* max 4GB ??? no one learns anything it seems :^) */
00092     uint32_t file_length; //unknown1;  /* what about MSB of file_size ? */
00093     uint32_t info_strings_size; /* size of the info strings */ //unknown2;
00094     uint32_t table_entries;
00095     uint32_t table_entries_used; /* the left ones should be -1 */
00096 };
00097 
00098 struct NSVs_header {
00099     uint32_t chunk_tag; /* 'NSVs' */
00100     uint32_t v4cc;      /* or 'NONE' */
00101     uint32_t a4cc;      /* or 'NONE' */
00102     uint16_t vwidth;    /* assert(vwidth%16==0) */
00103     uint16_t vheight;   /* assert(vheight%16==0) */
00104     uint8_t framerate;  /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
00105     uint16_t unknown;
00106 };
00107 
00108 struct nsv_avchunk_header {
00109     uint8_t vchunk_size_lsb;
00110     uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
00111     uint16_t achunk_size;
00112 };
00113 
00114 struct nsv_pcm_header {
00115     uint8_t bits_per_sample;
00116     uint8_t channel_count;
00117     uint16_t sample_rate;
00118 };
00119 #endif
00120 
00121 /* variation from avi.h */
00122 /*typedef struct CodecTag {
00123     int id;
00124     unsigned int tag;
00125 } CodecTag;*/
00126 
00127 /* tags */
00128 
00129 #define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
00130 #define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
00131 #define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
00132 #define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
00133 #define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
00134 #define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
00135 #define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
00136 
00137 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
00138 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
00139 
00140 /* hardcoded stream indexes */
00141 #define NSV_ST_VIDEO 0
00142 #define NSV_ST_AUDIO 1
00143 #define NSV_ST_SUBT 2
00144 
00145 enum NSVStatus {
00146     NSV_UNSYNC,
00147     NSV_FOUND_NSVF,
00148     NSV_HAS_READ_NSVF,
00149     NSV_FOUND_NSVS,
00150     NSV_HAS_READ_NSVS,
00151     NSV_FOUND_BEEF,
00152     NSV_GOT_VIDEO,
00153     NSV_GOT_AUDIO,
00154 };
00155 
00156 typedef struct NSVStream {
00157     int frame_offset; /* current frame (video) or byte (audio) counter
00158                          (used to compute the pts) */
00159     int scale;
00160     int rate;
00161     int sample_size; /* audio only data */
00162     int start;
00163 
00164     int new_frame_offset; /* temporary storage (used during seek) */
00165     int cum_len; /* temporary storage (used during seek) */
00166 } NSVStream;
00167 
00168 typedef struct {
00169     int  base_offset;
00170     int  NSVf_end;
00171     uint32_t *nsvs_file_offset;
00172     int index_entries;
00173     enum NSVStatus state;
00174     AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
00175     /* cached */
00176     int64_t duration;
00177     uint32_t vtag, atag;
00178     uint16_t vwidth, vheight;
00179     int16_t avsync;
00180     AVRational framerate;
00181     uint32_t *nsvs_timestamps;
00182     //DVDemuxContext* dv_demux;
00183 } NSVContext;
00184 
00185 static const AVCodecTag nsv_codec_video_tags[] = {
00186     { CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
00187     { CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
00188     { CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
00189     { CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
00190     { CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
00191     { CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
00192     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
00193     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
00194     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
00195     { CODEC_ID_VP8, MKTAG('V', 'P', '8', '0') },
00196 /*
00197     { CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
00198     { CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
00199 */
00200     { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
00201     { CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
00202     { CODEC_ID_NONE, 0 },
00203 };
00204 
00205 static const AVCodecTag nsv_codec_audio_tags[] = {
00206     { CODEC_ID_MP3,       MKTAG('M', 'P', '3', ' ') },
00207     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', ' ') },
00208     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', 'P') },
00209     { CODEC_ID_AAC,       MKTAG('V', 'L', 'B', ' ') },
00210     { CODEC_ID_SPEEX,     MKTAG('S', 'P', 'X', ' ') },
00211     { CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
00212     { CODEC_ID_NONE,      0 },
00213 };
00214 
00215 //static int nsv_load_index(AVFormatContext *s);
00216 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
00217 
00218 #define print_tag(str, tag, size)       \
00219     av_dlog(NULL, "%s: tag=%c%c%c%c\n", \
00220             str, tag & 0xff,            \
00221             (tag >> 8) & 0xff,          \
00222             (tag >> 16) & 0xff,         \
00223             (tag >> 24) & 0xff);
00224 
00225 /* try to find something we recognize, and set the state accordingly */
00226 static int nsv_resync(AVFormatContext *s)
00227 {
00228     NSVContext *nsv = s->priv_data;
00229     AVIOContext *pb = s->pb;
00230     uint32_t v = 0;
00231     int i;
00232 
00233     av_dlog(s, "%s(), offset = %"PRId64", state = %d\n", __FUNCTION__, avio_tell(pb), nsv->state);
00234 
00235     //nsv->state = NSV_UNSYNC;
00236 
00237     for (i = 0; i < NSV_MAX_RESYNC; i++) {
00238         if (url_feof(pb)) {
00239             av_dlog(s, "NSV EOF\n");
00240             nsv->state = NSV_UNSYNC;
00241             return -1;
00242         }
00243         v <<= 8;
00244         v |= avio_r8(pb);
00245         if (i < 8) {
00246             av_dlog(s, "NSV resync: [%d] = %02x\n", i, v & 0x0FF);
00247         }
00248 
00249         if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
00250             av_dlog(s, "NSV resynced on BEEF after %d bytes\n", i+1);
00251             nsv->state = NSV_FOUND_BEEF;
00252             return 0;
00253         }
00254         /* we read as big endian, thus the MK*BE* */
00255         if (v == TB_NSVF) { /* NSVf */
00256             av_dlog(s, "NSV resynced on NSVf after %d bytes\n", i+1);
00257             nsv->state = NSV_FOUND_NSVF;
00258             return 0;
00259         }
00260         if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
00261             av_dlog(s, "NSV resynced on NSVs after %d bytes\n", i+1);
00262             nsv->state = NSV_FOUND_NSVS;
00263             return 0;
00264         }
00265 
00266     }
00267     av_dlog(s, "NSV sync lost\n");
00268     return -1;
00269 }
00270 
00271 static int nsv_parse_NSVf_header(AVFormatContext *s, AVFormatParameters *ap)
00272 {
00273     NSVContext *nsv = s->priv_data;
00274     AVIOContext *pb = s->pb;
00275     unsigned int av_unused file_size;
00276     unsigned int size;
00277     int64_t duration;
00278     int strings_size;
00279     int table_entries;
00280     int table_entries_used;
00281 
00282     av_dlog(s, "%s()\n", __FUNCTION__);
00283 
00284     nsv->state = NSV_UNSYNC; /* in case we fail */
00285 
00286     size = avio_rl32(pb);
00287     if (size < 28)
00288         return -1;
00289     nsv->NSVf_end = size;
00290 
00291     //s->file_size = (uint32_t)avio_rl32(pb);
00292     file_size = (uint32_t)avio_rl32(pb);
00293     av_dlog(s, "NSV NSVf chunk_size %u\n", size);
00294     av_dlog(s, "NSV NSVf file_size %u\n", file_size);
00295 
00296     nsv->duration = duration = avio_rl32(pb); /* in ms */
00297     av_dlog(s, "NSV NSVf duration %"PRId64" ms\n", duration);
00298     // XXX: store it in AVStreams
00299 
00300     strings_size = avio_rl32(pb);
00301     table_entries = avio_rl32(pb);
00302     table_entries_used = avio_rl32(pb);
00303     av_dlog(s, "NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
00304             strings_size, table_entries, table_entries_used);
00305     if (url_feof(pb))
00306         return -1;
00307 
00308     av_dlog(s, "NSV got header; filepos %"PRId64"\n", avio_tell(pb));
00309 
00310     if (strings_size > 0) {
00311         char *strings; /* last byte will be '\0' to play safe with str*() */
00312         char *p, *endp;
00313         char *token, *value;
00314         char quote;
00315 
00316         p = strings = av_mallocz((size_t)strings_size + 1);
00317         if (!p)
00318             return AVERROR(ENOMEM);
00319         endp = strings + strings_size;
00320         avio_read(pb, strings, strings_size);
00321         while (p < endp) {
00322             while (*p == ' ')
00323                 p++; /* strip out spaces */
00324             if (p >= endp-2)
00325                 break;
00326             token = p;
00327             p = strchr(p, '=');
00328             if (!p || p >= endp-2)
00329                 break;
00330             *p++ = '\0';
00331             quote = *p++;
00332             value = p;
00333             p = strchr(p, quote);
00334             if (!p || p >= endp)
00335                 break;
00336             *p++ = '\0';
00337             av_dlog(s, "NSV NSVf INFO: %s='%s'\n", token, value);
00338             av_dict_set(&s->metadata, token, value, 0);
00339         }
00340         av_free(strings);
00341     }
00342     if (url_feof(pb))
00343         return -1;
00344 
00345     av_dlog(s, "NSV got infos; filepos %"PRId64"\n", avio_tell(pb));
00346 
00347     if (table_entries_used > 0) {
00348         int i;
00349         nsv->index_entries = table_entries_used;
00350         if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
00351             return -1;
00352         nsv->nsvs_file_offset = av_malloc((unsigned)table_entries_used * sizeof(uint32_t));
00353         if (!nsv->nsvs_file_offset)
00354             return AVERROR(ENOMEM);
00355 
00356         for(i=0;i<table_entries_used;i++)
00357             nsv->nsvs_file_offset[i] = avio_rl32(pb) + size;
00358 
00359         if(table_entries > table_entries_used &&
00360            avio_rl32(pb) == MKTAG('T','O','C','2')) {
00361             nsv->nsvs_timestamps = av_malloc((unsigned)table_entries_used*sizeof(uint32_t));
00362             if (!nsv->nsvs_timestamps)
00363                 return AVERROR(ENOMEM);
00364             for(i=0;i<table_entries_used;i++) {
00365                 nsv->nsvs_timestamps[i] = avio_rl32(pb);
00366             }
00367         }
00368     }
00369 
00370     av_dlog(s, "NSV got index; filepos %"PRId64"\n", avio_tell(pb));
00371 
00372 #ifdef DEBUG_DUMP_INDEX
00373 #define V(v) ((v<0x20 || v > 127)?'.':v)
00374     /* dump index */
00375     av_dlog(s, "NSV %d INDEX ENTRIES:\n", table_entries);
00376     av_dlog(s, "NSV [dataoffset][fileoffset]\n", table_entries);
00377     for (i = 0; i < table_entries; i++) {
00378         unsigned char b[8];
00379         avio_seek(pb, size + nsv->nsvs_file_offset[i], SEEK_SET);
00380         avio_read(pb, b, 8);
00381         av_dlog(s, "NSV [0x%08lx][0x%08lx]: %02x %02x %02x %02x %02x %02x %02x %02x"
00382            "%c%c%c%c%c%c%c%c\n",
00383            nsv->nsvs_file_offset[i], size + nsv->nsvs_file_offset[i],
00384            b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
00385            V(b[0]), V(b[1]), V(b[2]), V(b[3]), V(b[4]), V(b[5]), V(b[6]), V(b[7]) );
00386     }
00387     //avio_seek(pb, size, SEEK_SET); /* go back to end of header */
00388 #undef V
00389 #endif
00390 
00391     avio_seek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
00392 
00393     if (url_feof(pb))
00394         return -1;
00395     nsv->state = NSV_HAS_READ_NSVF;
00396     return 0;
00397 }
00398 
00399 static int nsv_parse_NSVs_header(AVFormatContext *s, AVFormatParameters *ap)
00400 {
00401     NSVContext *nsv = s->priv_data;
00402     AVIOContext *pb = s->pb;
00403     uint32_t vtag, atag;
00404     uint16_t vwidth, vheight;
00405     AVRational framerate;
00406     int i;
00407     AVStream *st;
00408     NSVStream *nst;
00409     av_dlog(s, "%s()\n", __FUNCTION__);
00410 
00411     vtag = avio_rl32(pb);
00412     atag = avio_rl32(pb);
00413     vwidth = avio_rl16(pb);
00414     vheight = avio_rl16(pb);
00415     i = avio_r8(pb);
00416 
00417     av_dlog(s, "NSV NSVs framerate code %2x\n", i);
00418     if(i&0x80) { /* odd way of giving native framerates from docs */
00419         int t=(i & 0x7F)>>2;
00420         if(t<16) framerate = (AVRational){1, t+1};
00421         else     framerate = (AVRational){t-15, 1};
00422 
00423         if(i&1){
00424             framerate.num *= 1000;
00425             framerate.den *= 1001;
00426         }
00427 
00428         if((i&3)==3)      framerate.num *= 24;
00429         else if((i&3)==2) framerate.num *= 25;
00430         else              framerate.num *= 30;
00431     }
00432     else
00433         framerate= (AVRational){i, 1};
00434 
00435     nsv->avsync = avio_rl16(pb);
00436     nsv->framerate = framerate;
00437 
00438     print_tag("NSV NSVs vtag", vtag, 0);
00439     print_tag("NSV NSVs atag", atag, 0);
00440     av_dlog(s, "NSV NSVs vsize %dx%d\n", vwidth, vheight);
00441 
00442     /* XXX change to ap != NULL ? */
00443     if (s->nb_streams == 0) { /* streams not yet published, let's do that */
00444         nsv->vtag = vtag;
00445         nsv->atag = atag;
00446         nsv->vwidth = vwidth;
00447         nsv->vheight = vwidth;
00448         if (vtag != T_NONE) {
00449             int i;
00450             st = avformat_new_stream(s, NULL);
00451             if (!st)
00452                 goto fail;
00453 
00454             st->id = NSV_ST_VIDEO;
00455             nst = av_mallocz(sizeof(NSVStream));
00456             if (!nst)
00457                 goto fail;
00458             st->priv_data = nst;
00459             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00460             st->codec->codec_tag = vtag;
00461             st->codec->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
00462             st->codec->width = vwidth;
00463             st->codec->height = vheight;
00464             st->codec->bits_per_coded_sample = 24; /* depth XXX */
00465 
00466             avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
00467             st->start_time = 0;
00468             st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
00469 
00470             for(i=0;i<nsv->index_entries;i++) {
00471                 if(nsv->nsvs_timestamps) {
00472                     av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
00473                                        0, 0, AVINDEX_KEYFRAME);
00474                 } else {
00475                     int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
00476                     av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
00477                 }
00478             }
00479         }
00480         if (atag != T_NONE) {
00481 #ifndef DISABLE_AUDIO
00482             st = avformat_new_stream(s, NULL);
00483             if (!st)
00484                 goto fail;
00485 
00486             st->id = NSV_ST_AUDIO;
00487             nst = av_mallocz(sizeof(NSVStream));
00488             if (!nst)
00489                 goto fail;
00490             st->priv_data = nst;
00491             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00492             st->codec->codec_tag = atag;
00493             st->codec->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
00494 
00495             st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
00496 
00497             /* set timebase to common denominator of ms and framerate */
00498             avpriv_set_pts_info(st, 64, 1, framerate.num*1000);
00499             st->start_time = 0;
00500             st->duration = (int64_t)nsv->duration * framerate.num;
00501 #endif
00502         }
00503 #ifdef CHECK_SUBSEQUENT_NSVS
00504     } else {
00505         if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
00506             av_dlog(s, "NSV NSVs header values differ from the first one!!!\n");
00507             //return -1;
00508         }
00509 #endif /* CHECK_SUBSEQUENT_NSVS */
00510     }
00511 
00512     nsv->state = NSV_HAS_READ_NSVS;
00513     return 0;
00514 fail:
00515     /* XXX */
00516     nsv->state = NSV_UNSYNC;
00517     return -1;
00518 }
00519 
00520 static int nsv_read_header(AVFormatContext *s, AVFormatParameters *ap)
00521 {
00522     NSVContext *nsv = s->priv_data;
00523     int i, err;
00524 
00525     av_dlog(s, "%s()\n", __FUNCTION__);
00526     av_dlog(s, "filename '%s'\n", s->filename);
00527 
00528     nsv->state = NSV_UNSYNC;
00529     nsv->ahead[0].data = nsv->ahead[1].data = NULL;
00530 
00531     for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
00532         if (nsv_resync(s) < 0)
00533             return -1;
00534         if (nsv->state == NSV_FOUND_NSVF) {
00535             err = nsv_parse_NSVf_header(s, ap);
00536             if (err < 0)
00537                 return err;
00538         }
00539             /* we need the first NSVs also... */
00540         if (nsv->state == NSV_FOUND_NSVS) {
00541             err = nsv_parse_NSVs_header(s, ap);
00542             if (err < 0)
00543                 return err;
00544             break; /* we just want the first one */
00545         }
00546     }
00547     if (s->nb_streams < 1) /* no luck so far */
00548         return -1;
00549     /* now read the first chunk, so we can attempt to decode more info */
00550     err = nsv_read_chunk(s, 1);
00551 
00552     av_dlog(s, "parsed header\n");
00553     return err;
00554 }
00555 
00556 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
00557 {
00558     NSVContext *nsv = s->priv_data;
00559     AVIOContext *pb = s->pb;
00560     AVStream *st[2] = {NULL, NULL};
00561     NSVStream *nst;
00562     AVPacket *pkt;
00563     int i, err = 0;
00564     uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
00565     uint32_t vsize;
00566     uint16_t asize;
00567     uint16_t auxsize;
00568     uint32_t av_unused auxtag;
00569 
00570     av_dlog(s, "%s(%d)\n", __FUNCTION__, fill_header);
00571 
00572     if (nsv->ahead[0].data || nsv->ahead[1].data)
00573         return 0; //-1; /* hey! eat what you've in your plate first! */
00574 
00575 null_chunk_retry:
00576     if (url_feof(pb))
00577         return -1;
00578 
00579     for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
00580         err = nsv_resync(s);
00581     if (err < 0)
00582         return err;
00583     if (nsv->state == NSV_FOUND_NSVS)
00584         err = nsv_parse_NSVs_header(s, NULL);
00585     if (err < 0)
00586         return err;
00587     if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
00588         return -1;
00589 
00590     auxcount = avio_r8(pb);
00591     vsize = avio_rl16(pb);
00592     asize = avio_rl16(pb);
00593     vsize = (vsize << 4) | (auxcount >> 4);
00594     auxcount &= 0x0f;
00595     av_dlog(s, "NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize);
00596     /* skip aux stuff */
00597     for (i = 0; i < auxcount; i++) {
00598         auxsize = avio_rl16(pb);
00599         auxtag = avio_rl32(pb);
00600         av_dlog(s, "NSV aux data: '%c%c%c%c', %d bytes\n",
00601               (auxtag & 0x0ff),
00602               ((auxtag >> 8) & 0x0ff),
00603               ((auxtag >> 16) & 0x0ff),
00604               ((auxtag >> 24) & 0x0ff),
00605               auxsize);
00606         avio_skip(pb, auxsize);
00607         vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
00608     }
00609 
00610     if (url_feof(pb))
00611         return -1;
00612     if (!vsize && !asize) {
00613         nsv->state = NSV_UNSYNC;
00614         goto null_chunk_retry;
00615     }
00616 
00617     /* map back streams to v,a */
00618     if (s->nb_streams > 0)
00619         st[s->streams[0]->id] = s->streams[0];
00620     if (s->nb_streams > 1)
00621         st[s->streams[1]->id] = s->streams[1];
00622 
00623     if (vsize && st[NSV_ST_VIDEO]) {
00624         nst = st[NSV_ST_VIDEO]->priv_data;
00625         pkt = &nsv->ahead[NSV_ST_VIDEO];
00626         av_get_packet(pb, pkt, vsize);
00627         pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
00628         pkt->dts = nst->frame_offset;
00629         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
00630         for (i = 0; i < FFMIN(8, vsize); i++)
00631             av_dlog(s, "NSV video: [%d] = %02x\n", i, pkt->data[i]);
00632     }
00633     if(st[NSV_ST_VIDEO])
00634         ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
00635 
00636     if (asize && st[NSV_ST_AUDIO]) {
00637         nst = st[NSV_ST_AUDIO]->priv_data;
00638         pkt = &nsv->ahead[NSV_ST_AUDIO];
00639         /* read raw audio specific header on the first audio chunk... */
00640         /* on ALL audio chunks ?? seems so! */
00641         if (asize && st[NSV_ST_AUDIO]->codec->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
00642             uint8_t bps;
00643             uint8_t channels;
00644             uint16_t samplerate;
00645             bps = avio_r8(pb);
00646             channels = avio_r8(pb);
00647             samplerate = avio_rl16(pb);
00648             asize-=4;
00649             av_dlog(s, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
00650             if (fill_header) {
00651                 st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
00652                 if (bps != 16) {
00653                     av_dlog(s, "NSV AUDIO bit/sample != 16 (%d)!!!\n", bps);
00654                 }
00655                 bps /= channels; // ???
00656                 if (bps == 8)
00657                     st[NSV_ST_AUDIO]->codec->codec_id = CODEC_ID_PCM_U8;
00658                 samplerate /= 4;/* UGH ??? XXX */
00659                 channels = 1;
00660                 st[NSV_ST_AUDIO]->codec->channels = channels;
00661                 st[NSV_ST_AUDIO]->codec->sample_rate = samplerate;
00662                 av_dlog(s, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
00663             }
00664         }
00665         av_get_packet(pb, pkt, asize);
00666         pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
00667         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
00668         if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
00669             /* on a nsvs frame we have new information on a/v sync */
00670             pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
00671             pkt->dts *= (int64_t)1000        * nsv->framerate.den;
00672             pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
00673             av_dlog(s, "NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts);
00674         }
00675         nst->frame_offset++;
00676     }
00677 
00678     nsv->state = NSV_UNSYNC;
00679     return 0;
00680 }
00681 
00682 
00683 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
00684 {
00685     NSVContext *nsv = s->priv_data;
00686     int i, err = 0;
00687 
00688     av_dlog(s, "%s()\n", __FUNCTION__);
00689 
00690     /* in case we don't already have something to eat ... */
00691     if (nsv->ahead[0].data == NULL && nsv->ahead[1].data == NULL)
00692         err = nsv_read_chunk(s, 0);
00693     if (err < 0)
00694         return err;
00695 
00696     /* now pick one of the plates */
00697     for (i = 0; i < 2; i++) {
00698         if (nsv->ahead[i].data) {
00699             av_dlog(s, "%s: using cached packet[%d]\n", __FUNCTION__, i);
00700             /* avoid the cost of new_packet + memcpy(->data) */
00701             memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
00702             nsv->ahead[i].data = NULL; /* we ate that one */
00703             return pkt->size;
00704         }
00705     }
00706 
00707     /* this restaurant is not approvisionned :^] */
00708     return -1;
00709 }
00710 
00711 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00712 {
00713     NSVContext *nsv = s->priv_data;
00714     AVStream *st = s->streams[stream_index];
00715     NSVStream *nst = st->priv_data;
00716     int index;
00717 
00718     index = av_index_search_timestamp(st, timestamp, flags);
00719     if(index < 0)
00720         return -1;
00721 
00722     if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
00723         return -1;
00724 
00725     nst->frame_offset = st->index_entries[index].timestamp;
00726     nsv->state = NSV_UNSYNC;
00727     return 0;
00728 }
00729 
00730 static int nsv_read_close(AVFormatContext *s)
00731 {
00732 /*     int i; */
00733     NSVContext *nsv = s->priv_data;
00734 
00735     av_freep(&nsv->nsvs_file_offset);
00736     av_freep(&nsv->nsvs_timestamps);
00737     if (nsv->ahead[0].data)
00738         av_free_packet(&nsv->ahead[0]);
00739     if (nsv->ahead[1].data)
00740         av_free_packet(&nsv->ahead[1]);
00741 
00742 #if 0
00743 
00744     for(i=0;i<s->nb_streams;i++) {
00745         AVStream *st = s->streams[i];
00746         NSVStream *ast = st->priv_data;
00747         if(ast){
00748             av_free(ast->index_entries);
00749             av_free(ast);
00750         }
00751         av_free(st->codec->palctrl);
00752     }
00753 
00754 #endif
00755     return 0;
00756 }
00757 
00758 static int nsv_probe(AVProbeData *p)
00759 {
00760     int i, score = 0;
00761 
00762     av_dlog(NULL, "nsv_probe(), buf_size %d\n", p->buf_size);
00763     /* check file header */
00764     /* streamed files might not have any header */
00765     if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
00766         p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
00767         return AVPROBE_SCORE_MAX;
00768     /* XXX: do streamed files always start at chunk boundary ?? */
00769     /* or do we need to search NSVs in the byte stream ? */
00770     /* seems the servers don't bother starting clean chunks... */
00771     /* sometimes even the first header is at 9KB or something :^) */
00772     for (i = 1; i < p->buf_size - 3; i++) {
00773         if (AV_RL32(p->buf + i) == AV_RL32("NSVs")) {
00774             /* Get the chunk size and check if at the end we are getting 0xBEEF */
00775             int vsize = AV_RL24(p->buf+i+19) >> 4;
00776             int asize = AV_RL16(p->buf+i+22);
00777             int offset = i + 23 + asize + vsize + 1;
00778             if (offset <= p->buf_size - 2 && AV_RL16(p->buf + offset) == 0xBEEF)
00779                 return 4*AVPROBE_SCORE_MAX/5;
00780             score = AVPROBE_SCORE_MAX/5;
00781         }
00782     }
00783     /* so we'll have more luck on extension... */
00784     if (av_match_ext(p->filename, "nsv"))
00785         return AVPROBE_SCORE_MAX/2;
00786     /* FIXME: add mime-type check */
00787     return score;
00788 }
00789 
00790 AVInputFormat ff_nsv_demuxer = {
00791     .name           = "nsv",
00792     .long_name      = NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
00793     .priv_data_size = sizeof(NSVContext),
00794     .read_probe     = nsv_probe,
00795     .read_header    = nsv_read_header,
00796     .read_packet    = nsv_read_packet,
00797     .read_close     = nsv_read_close,
00798     .read_seek      = nsv_read_seek,
00799 };