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 #include "avformat.h"
00022 #include "riff.h"
00023 
00024 //#define DEBUG
00025 //#define DEBUG_DUMP_INDEX // XXX dumbdriving-271.nsv breaks with it commented!!
00026 //#define DEBUG_SEEK
00027 #define CHECK_SUBSEQUENT_NSVS
00028 //#define DISABLE_AUDIO
00029 
00030 /* max bytes to crawl for trying to resync
00031  * stupid streaming servers don't start at chunk boundaries...
00032  */
00033 #define NSV_MAX_RESYNC (500*1024)
00034 #define NSV_MAX_RESYNC_TRIES 300
00035 
00036 /*
00037  * First version by Francois Revol - revol@free.fr
00038  * References:
00039  * (1) http://www.multimedia.cx/nsv-format.txt
00040  * seems someone came to the same conclusions as me, and updated it:
00041  * (2) http://www.stud.ktu.lt/~vitslav/nsv/nsv-format.txt
00042  *     http://www.stud.ktu.lt/~vitslav/nsv/
00043  * official docs
00044  * (3) http://ultravox.aol.com/NSVFormat.rtf
00045  * Sample files:
00046  * (S1) http://www.nullsoft.com/nsv/samples/
00047  * http://www.nullsoft.com/nsv/samples/faster.nsv
00048  * http://streamripper.sourceforge.net/openbb/read.php?TID=492&page=4
00049  */
00050 
00051 /*
00052  * notes on the header (Francois Revol):
00053  *
00054  * It is followed by strings, then a table, but nothing tells
00055  * where the table begins according to (1). After checking faster.nsv,
00056  * I believe NVSf[16-19] gives the size of the strings data
00057  * (that is the offset of the data table after the header).
00058  * After checking all samples from (S1) all confirms this.
00059  *
00060  * Then, about NSVf[12-15], faster.nsf has 179700. When veiwing it in VLC,
00061  * I noticed there was about 1 NVSs chunk/s, so I ran
00062  * strings faster.nsv | grep NSVs | wc -l
00063  * which gave me 180. That leads me to think that NSVf[12-15] might be the
00064  * file length in milliseconds.
00065  * Let's try that:
00066  * 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
00067  * except for nstrailer (which doesn't have an NSVf header), it repports correct time.
00068  *
00069  * nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
00070  * so the header seems to not be mandatory. (for streaming).
00071  *
00072  * index slice duration check (excepts nsvtrailer.nsv):
00073  * 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
00074  */
00075 
00076 /*
00077  * TODO:
00078  * - handle timestamps !!!
00079  * - use index
00080  * - mime-type in probe()
00081  * - seek
00082  */
00083 
00084 #ifdef DEBUG
00085 #define PRINT(_v) printf _v
00086 #else
00087 #define PRINT(_v)
00088 #endif
00089 
00090 #if 0
00091 struct NSVf_header {
00092     uint32_t chunk_tag; /* 'NSVf' */
00093     uint32_t chunk_size;
00094     uint32_t file_size; /* max 4GB ??? no one learns anything it seems :^) */
00095     uint32_t file_length; //unknown1;  /* what about MSB of file_size ? */
00096     uint32_t info_strings_size; /* size of the info strings */ //unknown2;
00097     uint32_t table_entries;
00098     uint32_t table_entries_used; /* the left ones should be -1 */
00099 };
00100 
00101 struct NSVs_header {
00102     uint32_t chunk_tag; /* 'NSVs' */
00103     uint32_t v4cc;      /* or 'NONE' */
00104     uint32_t a4cc;      /* or 'NONE' */
00105     uint16_t vwidth;    /* assert(vwidth%16==0) */
00106     uint16_t vheight;   /* assert(vheight%16==0) */
00107     uint8_t framerate;  /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
00108     uint16_t unknown;
00109 };
00110 
00111 struct nsv_avchunk_header {
00112     uint8_t vchunk_size_lsb;
00113     uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
00114     uint16_t achunk_size;
00115 };
00116 
00117 struct nsv_pcm_header {
00118     uint8_t bits_per_sample;
00119     uint8_t channel_count;
00120     uint16_t sample_rate;
00121 };
00122 #endif
00123 
00124 /* variation from avi.h */
00125 /*typedef struct CodecTag {
00126     int id;
00127     unsigned int tag;
00128 } CodecTag;*/
00129 
00130 /* tags */
00131 
00132 #define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
00133 #define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
00134 #define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
00135 #define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
00136 #define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
00137 #define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
00138 #define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
00139 
00140 #define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
00141 #define TB_NSVS MKBETAG('N', 'S', 'V', 's')
00142 
00143 /* hardcoded stream indexes */
00144 #define NSV_ST_VIDEO 0
00145 #define NSV_ST_AUDIO 1
00146 #define NSV_ST_SUBT 2
00147 
00148 enum NSVStatus {
00149     NSV_UNSYNC,
00150     NSV_FOUND_NSVF,
00151     NSV_HAS_READ_NSVF,
00152     NSV_FOUND_NSVS,
00153     NSV_HAS_READ_NSVS,
00154     NSV_FOUND_BEEF,
00155     NSV_GOT_VIDEO,
00156     NSV_GOT_AUDIO,
00157 };
00158 
00159 typedef struct NSVStream {
00160     int frame_offset; /* current frame (video) or byte (audio) counter
00161                          (used to compute the pts) */
00162     int scale;
00163     int rate;
00164     int sample_size; /* audio only data */
00165     int start;
00166 
00167     int new_frame_offset; /* temporary storage (used during seek) */
00168     int cum_len; /* temporary storage (used during seek) */
00169 } NSVStream;
00170 
00171 typedef struct {
00172     int  base_offset;
00173     int  NSVf_end;
00174     uint32_t *nsvs_file_offset;
00175     int index_entries;
00176     enum NSVStatus state;
00177     AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
00178     /* cached */
00179     int64_t duration;
00180     uint32_t vtag, atag;
00181     uint16_t vwidth, vheight;
00182     int16_t avsync;
00183     AVRational framerate;
00184     uint32_t *nsvs_timestamps;
00185     //DVDemuxContext* dv_demux;
00186 } NSVContext;
00187 
00188 static const AVCodecTag nsv_codec_video_tags[] = {
00189     { CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
00190     { CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
00191     { CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
00192     { CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
00193     { CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
00194     { CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
00195     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
00196     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
00197     { CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
00198 /*
00199     { CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
00200     { CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
00201 */
00202     { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
00203     { CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
00204     { CODEC_ID_NONE, 0 },
00205 };
00206 
00207 static const AVCodecTag nsv_codec_audio_tags[] = {
00208     { CODEC_ID_MP3,       MKTAG('M', 'P', '3', ' ') },
00209     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', ' ') },
00210     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', 'P') },
00211     { CODEC_ID_SPEEX,     MKTAG('S', 'P', 'X', ' ') },
00212     { CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
00213     { CODEC_ID_NONE,      0 },
00214 };
00215 
00216 //static int nsv_load_index(AVFormatContext *s);
00217 static int nsv_read_chunk(AVFormatContext *s, int fill_header);
00218 
00219 #ifdef DEBUG
00220 static void print_tag(const char *str, unsigned int tag, int size)
00221 {
00222     printf("%s: tag=%c%c%c%c\n",
00223            str, tag & 0xff,
00224            (tag >> 8) & 0xff,
00225            (tag >> 16) & 0xff,
00226            (tag >> 24) & 0xff);
00227 }
00228 #endif
00229 
00230 /* try to find something we recognize, and set the state accordingly */
00231 static int nsv_resync(AVFormatContext *s)
00232 {
00233     NSVContext *nsv = s->priv_data;
00234     ByteIOContext *pb = s->pb;
00235     uint32_t v = 0;
00236     int i;
00237 
00238     PRINT(("%s(), offset = %"PRId64", state = %d\n", __FUNCTION__, url_ftell(pb), nsv->state));
00239 
00240     //nsv->state = NSV_UNSYNC;
00241 
00242     for (i = 0; i < NSV_MAX_RESYNC; i++) {
00243         if (url_feof(pb)) {
00244             PRINT(("NSV EOF\n"));
00245             nsv->state = NSV_UNSYNC;
00246             return -1;
00247         }
00248         v <<= 8;
00249         v |= get_byte(pb);
00250 /*
00251         if (i < 8) {
00252             PRINT(("NSV resync: [%d] = %02x\n", i, v & 0x0FF));
00253         }
00254 */
00255 
00256         if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
00257             PRINT(("NSV resynced on BEEF after %d bytes\n", i+1));
00258             nsv->state = NSV_FOUND_BEEF;
00259             return 0;
00260         }
00261         /* we read as big endian, thus the MK*BE* */
00262         if (v == TB_NSVF) { /* NSVf */
00263             PRINT(("NSV resynced on NSVf after %d bytes\n", i+1));
00264             nsv->state = NSV_FOUND_NSVF;
00265             return 0;
00266         }
00267         if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
00268             PRINT(("NSV resynced on NSVs after %d bytes\n", i+1));
00269             nsv->state = NSV_FOUND_NSVS;
00270             return 0;
00271         }
00272 
00273     }
00274     PRINT(("NSV sync lost\n"));
00275     return -1;
00276 }
00277 
00278 static int nsv_parse_NSVf_header(AVFormatContext *s, AVFormatParameters *ap)
00279 {
00280     NSVContext *nsv = s->priv_data;
00281     ByteIOContext *pb = s->pb;
00282     unsigned int file_size, size;
00283     int64_t duration;
00284     int strings_size;
00285     int table_entries;
00286     int table_entries_used;
00287 
00288     PRINT(("%s()\n", __FUNCTION__));
00289 
00290     nsv->state = NSV_UNSYNC; /* in case we fail */
00291 
00292     size = get_le32(pb);
00293     if (size < 28)
00294         return -1;
00295     nsv->NSVf_end = size;
00296 
00297     //s->file_size = (uint32_t)get_le32(pb);
00298     file_size = (uint32_t)get_le32(pb);
00299     PRINT(("NSV NSVf chunk_size %u\n", size));
00300     PRINT(("NSV NSVf file_size %u\n", file_size));
00301 
00302     nsv->duration = duration = get_le32(pb); /* in ms */
00303     PRINT(("NSV NSVf duration %"PRId64" ms\n", duration));
00304     // XXX: store it in AVStreams
00305 
00306     strings_size = get_le32(pb);
00307     table_entries = get_le32(pb);
00308     table_entries_used = get_le32(pb);
00309     PRINT(("NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
00310             strings_size, table_entries, table_entries_used));
00311     if (url_feof(pb))
00312         return -1;
00313 
00314     PRINT(("NSV got header; filepos %"PRId64"\n", url_ftell(pb)));
00315 
00316     if (strings_size > 0) {
00317         char *strings; /* last byte will be '\0' to play safe with str*() */
00318         char *p, *endp;
00319         char *token, *value;
00320         char quote;
00321 
00322         p = strings = av_mallocz((size_t)strings_size + 1);
00323         if (!p)
00324             return AVERROR(ENOMEM);
00325         endp = strings + strings_size;
00326         get_buffer(pb, strings, strings_size);
00327         while (p < endp) {
00328             while (*p == ' ')
00329                 p++; /* strip out spaces */
00330             if (p >= endp-2)
00331                 break;
00332             token = p;
00333             p = strchr(p, '=');
00334             if (!p || p >= endp-2)
00335                 break;
00336             *p++ = '\0';
00337             quote = *p++;
00338             value = p;
00339             p = strchr(p, quote);
00340             if (!p || p >= endp)
00341                 break;
00342             *p++ = '\0';
00343             PRINT(("NSV NSVf INFO: %s='%s'\n", token, value));
00344             av_metadata_set2(&s->metadata, token, value, 0);
00345         }
00346         av_free(strings);
00347     }
00348     if (url_feof(pb))
00349         return -1;
00350 
00351     PRINT(("NSV got infos; filepos %"PRId64"\n", url_ftell(pb)));
00352 
00353     if (table_entries_used > 0) {
00354         int i;
00355         nsv->index_entries = table_entries_used;
00356         if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
00357             return -1;
00358         nsv->nsvs_file_offset = av_malloc((unsigned)table_entries_used * sizeof(uint32_t));
00359         if (!nsv->nsvs_file_offset)
00360             return AVERROR(ENOMEM);
00361 
00362         for(i=0;i<table_entries_used;i++)
00363             nsv->nsvs_file_offset[i] = get_le32(pb) + size;
00364 
00365         if(table_entries > table_entries_used &&
00366            get_le32(pb) == MKTAG('T','O','C','2')) {
00367             nsv->nsvs_timestamps = av_malloc((unsigned)table_entries_used*sizeof(uint32_t));
00368             if (!nsv->nsvs_timestamps)
00369                 return AVERROR(ENOMEM);
00370             for(i=0;i<table_entries_used;i++) {
00371                 nsv->nsvs_timestamps[i] = get_le32(pb);
00372             }
00373         }
00374     }
00375 
00376     PRINT(("NSV got index; filepos %"PRId64"\n", url_ftell(pb)));
00377 
00378 #ifdef DEBUG_DUMP_INDEX
00379 #define V(v) ((v<0x20 || v > 127)?'.':v)
00380     /* dump index */
00381     PRINT(("NSV %d INDEX ENTRIES:\n", table_entries));
00382     PRINT(("NSV [dataoffset][fileoffset]\n", table_entries));
00383     for (i = 0; i < table_entries; i++) {
00384         unsigned char b[8];
00385         url_fseek(pb, size + nsv->nsvs_file_offset[i], SEEK_SET);
00386         get_buffer(pb, b, 8);
00387         PRINT(("NSV [0x%08lx][0x%08lx]: %02x %02x %02x %02x %02x %02x %02x %02x"
00388            "%c%c%c%c%c%c%c%c\n",
00389            nsv->nsvs_file_offset[i], size + nsv->nsvs_file_offset[i],
00390            b[0], b[1], b[2], b[3], b[4], b[5], b[6], b[7],
00391            V(b[0]), V(b[1]), V(b[2]), V(b[3]), V(b[4]), V(b[5]), V(b[6]), V(b[7]) ));
00392     }
00393     //url_fseek(pb, size, SEEK_SET); /* go back to end of header */
00394 #undef V
00395 #endif
00396 
00397     url_fseek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
00398 
00399     if (url_feof(pb))
00400         return -1;
00401     nsv->state = NSV_HAS_READ_NSVF;
00402     return 0;
00403 }
00404 
00405 static int nsv_parse_NSVs_header(AVFormatContext *s, AVFormatParameters *ap)
00406 {
00407     NSVContext *nsv = s->priv_data;
00408     ByteIOContext *pb = s->pb;
00409     uint32_t vtag, atag;
00410     uint16_t vwidth, vheight;
00411     AVRational framerate;
00412     int i;
00413     AVStream *st;
00414     NSVStream *nst;
00415     PRINT(("%s()\n", __FUNCTION__));
00416 
00417     vtag = get_le32(pb);
00418     atag = get_le32(pb);
00419     vwidth = get_le16(pb);
00420     vheight = get_le16(pb);
00421     i = get_byte(pb);
00422 
00423     PRINT(("NSV NSVs framerate code %2x\n", i));
00424     if(i&0x80) { /* odd way of giving native framerates from docs */
00425         int t=(i & 0x7F)>>2;
00426         if(t<16) framerate = (AVRational){1, t+1};
00427         else     framerate = (AVRational){t-15, 1};
00428 
00429         if(i&1){
00430             framerate.num *= 1000;
00431             framerate.den *= 1001;
00432         }
00433 
00434         if((i&3)==3)      framerate.num *= 24;
00435         else if((i&3)==2) framerate.num *= 25;
00436         else              framerate.num *= 30;
00437     }
00438     else
00439         framerate= (AVRational){i, 1};
00440 
00441     nsv->avsync = get_le16(pb);
00442     nsv->framerate = framerate;
00443 #ifdef DEBUG
00444     print_tag("NSV NSVs vtag", vtag, 0);
00445     print_tag("NSV NSVs atag", atag, 0);
00446     PRINT(("NSV NSVs vsize %dx%d\n", vwidth, vheight));
00447 #endif
00448 
00449     /* XXX change to ap != NULL ? */
00450     if (s->nb_streams == 0) { /* streams not yet published, let's do that */
00451         nsv->vtag = vtag;
00452         nsv->atag = atag;
00453         nsv->vwidth = vwidth;
00454         nsv->vheight = vwidth;
00455         if (vtag != T_NONE) {
00456             int i;
00457             st = av_new_stream(s, NSV_ST_VIDEO);
00458             if (!st)
00459                 goto fail;
00460 
00461             nst = av_mallocz(sizeof(NSVStream));
00462             if (!nst)
00463                 goto fail;
00464             st->priv_data = nst;
00465             st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00466             st->codec->codec_tag = vtag;
00467             st->codec->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
00468             st->codec->width = vwidth;
00469             st->codec->height = vheight;
00470             st->codec->bits_per_coded_sample = 24; /* depth XXX */
00471 
00472             av_set_pts_info(st, 64, framerate.den, framerate.num);
00473             st->start_time = 0;
00474             st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
00475 
00476             for(i=0;i<nsv->index_entries;i++) {
00477                 if(nsv->nsvs_timestamps) {
00478                     av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
00479                                        0, 0, AVINDEX_KEYFRAME);
00480                 } else {
00481                     int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
00482                     av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
00483                 }
00484             }
00485         }
00486         if (atag != T_NONE) {
00487 #ifndef DISABLE_AUDIO
00488             st = av_new_stream(s, NSV_ST_AUDIO);
00489             if (!st)
00490                 goto fail;
00491 
00492             nst = av_mallocz(sizeof(NSVStream));
00493             if (!nst)
00494                 goto fail;
00495             st->priv_data = nst;
00496             st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00497             st->codec->codec_tag = atag;
00498             st->codec->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
00499 
00500             st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
00501 
00502             /* set timebase to common denominator of ms and framerate */
00503             av_set_pts_info(st, 64, 1, framerate.num*1000);
00504             st->start_time = 0;
00505             st->duration = (int64_t)nsv->duration * framerate.num;
00506 #endif
00507         }
00508 #ifdef CHECK_SUBSEQUENT_NSVS
00509     } else {
00510         if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
00511             PRINT(("NSV NSVs header values differ from the first one!!!\n"));
00512             //return -1;
00513         }
00514 #endif /* CHECK_SUBSEQUENT_NSVS */
00515     }
00516 
00517     nsv->state = NSV_HAS_READ_NSVS;
00518     return 0;
00519 fail:
00520     /* XXX */
00521     nsv->state = NSV_UNSYNC;
00522     return -1;
00523 }
00524 
00525 static int nsv_read_header(AVFormatContext *s, AVFormatParameters *ap)
00526 {
00527     NSVContext *nsv = s->priv_data;
00528     int i, err;
00529 
00530     PRINT(("%s()\n", __FUNCTION__));
00531     PRINT(("filename '%s'\n", s->filename));
00532 
00533     nsv->state = NSV_UNSYNC;
00534     nsv->ahead[0].data = nsv->ahead[1].data = NULL;
00535 
00536     for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
00537         if (nsv_resync(s) < 0)
00538             return -1;
00539         if (nsv->state == NSV_FOUND_NSVF) {
00540             err = nsv_parse_NSVf_header(s, ap);
00541             if (err < 0)
00542                 return err;
00543         }
00544             /* we need the first NSVs also... */
00545         if (nsv->state == NSV_FOUND_NSVS) {
00546             err = nsv_parse_NSVs_header(s, ap);
00547             if (err < 0)
00548                 return err;
00549             break; /* we just want the first one */
00550         }
00551     }
00552     if (s->nb_streams < 1) /* no luck so far */
00553         return -1;
00554     /* now read the first chunk, so we can attempt to decode more info */
00555     err = nsv_read_chunk(s, 1);
00556 
00557     PRINT(("parsed header\n"));
00558     return 0;
00559 }
00560 
00561 static int nsv_read_chunk(AVFormatContext *s, int fill_header)
00562 {
00563     NSVContext *nsv = s->priv_data;
00564     ByteIOContext *pb = s->pb;
00565     AVStream *st[2] = {NULL, NULL};
00566     NSVStream *nst;
00567     AVPacket *pkt;
00568     int i, err = 0;
00569     uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
00570     uint32_t vsize;
00571     uint16_t asize;
00572     uint16_t auxsize;
00573     uint32_t auxtag;
00574 
00575     PRINT(("%s(%d)\n", __FUNCTION__, fill_header));
00576 
00577     if (nsv->ahead[0].data || nsv->ahead[1].data)
00578         return 0; //-1; /* hey! eat what you've in your plate first! */
00579 
00580 null_chunk_retry:
00581     if (url_feof(pb))
00582         return -1;
00583 
00584     for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
00585         err = nsv_resync(s);
00586     if (err < 0)
00587         return err;
00588     if (nsv->state == NSV_FOUND_NSVS)
00589         err = nsv_parse_NSVs_header(s, NULL);
00590     if (err < 0)
00591         return err;
00592     if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
00593         return -1;
00594 
00595     auxcount = get_byte(pb);
00596     vsize = get_le16(pb);
00597     asize = get_le16(pb);
00598     vsize = (vsize << 4) | (auxcount >> 4);
00599     auxcount &= 0x0f;
00600     PRINT(("NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize));
00601     /* skip aux stuff */
00602     for (i = 0; i < auxcount; i++) {
00603         auxsize = get_le16(pb);
00604         auxtag = get_le32(pb);
00605         PRINT(("NSV aux data: '%c%c%c%c', %d bytes\n",
00606               (auxtag & 0x0ff),
00607               ((auxtag >> 8) & 0x0ff),
00608               ((auxtag >> 16) & 0x0ff),
00609               ((auxtag >> 24) & 0x0ff),
00610               auxsize));
00611         url_fskip(pb, auxsize);
00612         vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming braindead */
00613     }
00614 
00615     if (url_feof(pb))
00616         return -1;
00617     if (!vsize && !asize) {
00618         nsv->state = NSV_UNSYNC;
00619         goto null_chunk_retry;
00620     }
00621 
00622     /* map back streams to v,a */
00623     if (s->nb_streams > 0)
00624         st[s->streams[0]->id] = s->streams[0];
00625     if (s->nb_streams > 1)
00626         st[s->streams[1]->id] = s->streams[1];
00627 
00628     if (vsize && st[NSV_ST_VIDEO]) {
00629         nst = st[NSV_ST_VIDEO]->priv_data;
00630         pkt = &nsv->ahead[NSV_ST_VIDEO];
00631         av_get_packet(pb, pkt, vsize);
00632         pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
00633         pkt->dts = nst->frame_offset;
00634         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
00635 /*
00636         for (i = 0; i < MIN(8, vsize); i++)
00637             PRINT(("NSV video: [%d] = %02x\n", i, pkt->data[i]));
00638 */
00639     }
00640     if(st[NSV_ST_VIDEO])
00641         ((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
00642 
00643     if (asize && st[NSV_ST_AUDIO]) {
00644         nst = st[NSV_ST_AUDIO]->priv_data;
00645         pkt = &nsv->ahead[NSV_ST_AUDIO];
00646         /* read raw audio specific header on the first audio chunk... */
00647         /* on ALL audio chunks ?? seems so! */
00648         if (asize && st[NSV_ST_AUDIO]->codec->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
00649             uint8_t bps;
00650             uint8_t channels;
00651             uint16_t samplerate;
00652             bps = get_byte(pb);
00653             channels = get_byte(pb);
00654             samplerate = get_le16(pb);
00655             asize-=4;
00656             PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate));
00657             if (fill_header) {
00658                 st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
00659                 if (bps != 16) {
00660                     PRINT(("NSV AUDIO bit/sample != 16 (%d)!!!\n", bps));
00661                 }
00662                 bps /= channels; // ???
00663                 if (bps == 8)
00664                     st[NSV_ST_AUDIO]->codec->codec_id = CODEC_ID_PCM_U8;
00665                 samplerate /= 4;/* UGH ??? XXX */
00666                 channels = 1;
00667                 st[NSV_ST_AUDIO]->codec->channels = channels;
00668                 st[NSV_ST_AUDIO]->codec->sample_rate = samplerate;
00669                 PRINT(("NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate));
00670             }
00671         }
00672         av_get_packet(pb, pkt, asize);
00673         pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
00674         pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
00675         if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
00676             /* on a nsvs frame we have new information on a/v sync */
00677             pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
00678             pkt->dts *= (int64_t)1000        * nsv->framerate.den;
00679             pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
00680             PRINT(("NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts));
00681         }
00682         nst->frame_offset++;
00683     }
00684 
00685     nsv->state = NSV_UNSYNC;
00686     return 0;
00687 }
00688 
00689 
00690 static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
00691 {
00692     NSVContext *nsv = s->priv_data;
00693     int i, err = 0;
00694 
00695     PRINT(("%s()\n", __FUNCTION__));
00696 
00697     /* in case we don't already have something to eat ... */
00698     if (nsv->ahead[0].data == NULL && nsv->ahead[1].data == NULL)
00699         err = nsv_read_chunk(s, 0);
00700     if (err < 0)
00701         return err;
00702 
00703     /* now pick one of the plates */
00704     for (i = 0; i < 2; i++) {
00705         if (nsv->ahead[i].data) {
00706                 PRINT(("%s: using cached packet[%d]\n", __FUNCTION__, i));
00707             /* avoid the cost of new_packet + memcpy(->data) */
00708             memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
00709             nsv->ahead[i].data = NULL; /* we ate that one */
00710             return pkt->size;
00711         }
00712     }
00713 
00714     /* this restaurant is not approvisionned :^] */
00715     return -1;
00716 }
00717 
00718 static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
00719 {
00720     NSVContext *nsv = s->priv_data;
00721     AVStream *st = s->streams[stream_index];
00722     NSVStream *nst = st->priv_data;
00723     int index;
00724 
00725     index = av_index_search_timestamp(st, timestamp, flags);
00726     if(index < 0)
00727         return -1;
00728 
00729     url_fseek(s->pb, st->index_entries[index].pos, SEEK_SET);
00730     nst->frame_offset = st->index_entries[index].timestamp;
00731     nsv->state = NSV_UNSYNC;
00732     return 0;
00733 }
00734 
00735 static int nsv_read_close(AVFormatContext *s)
00736 {
00737 /*     int i; */
00738     NSVContext *nsv = s->priv_data;
00739 
00740     av_freep(&nsv->nsvs_file_offset);
00741     av_freep(&nsv->nsvs_timestamps);
00742     if (nsv->ahead[0].data)
00743         av_free_packet(&nsv->ahead[0]);
00744     if (nsv->ahead[1].data)
00745         av_free_packet(&nsv->ahead[1]);
00746 
00747 #if 0
00748 
00749     for(i=0;i<s->nb_streams;i++) {
00750         AVStream *st = s->streams[i];
00751         NSVStream *ast = st->priv_data;
00752         if(ast){
00753             av_free(ast->index_entries);
00754             av_free(ast);
00755         }
00756         av_free(st->codec->palctrl);
00757     }
00758 
00759 #endif
00760     return 0;
00761 }
00762 
00763 static int nsv_probe(AVProbeData *p)
00764 {
00765     int i;
00766 //    PRINT(("nsv_probe(), buf_size %d\n", p->buf_size));
00767     /* check file header */
00768     /* streamed files might not have any header */
00769     if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
00770         p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
00771         return AVPROBE_SCORE_MAX;
00772     /* XXX: do streamed files always start at chunk boundary ?? */
00773     /* or do we need to search NSVs in the byte stream ? */
00774     /* seems the servers don't bother starting clean chunks... */
00775     /* sometimes even the first header is at 9KB or something :^) */
00776     for (i = 1; i < p->buf_size - 3; i++) {
00777         if (p->buf[i+0] == 'N' && p->buf[i+1] == 'S' &&
00778             p->buf[i+2] == 'V' && p->buf[i+3] == 's')
00779             return AVPROBE_SCORE_MAX-20;
00780     }
00781     /* so we'll have more luck on extension... */
00782     if (av_match_ext(p->filename, "nsv"))
00783         return AVPROBE_SCORE_MAX/2;
00784     /* FIXME: add mime-type check */
00785     return 0;
00786 }
00787 
00788 AVInputFormat nsv_demuxer = {
00789     "nsv",
00790     NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
00791     sizeof(NSVContext),
00792     nsv_probe,
00793     nsv_read_header,
00794     nsv_read_packet,
00795     nsv_read_close,
00796     nsv_read_seek,
00797 };