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FFmpeg/libavformat/nsvdec.c

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/*
* NSV demuxer
* Copyright (c) 2004 The FFmpeg Project
*
* first version by Francois Revol <revol@free.fr>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/attributes.h"
#include "libavutil/mathematics.h"
#include "avformat.h"
#include "internal.h"
#include "libavutil/dict.h"
#include "libavutil/intreadwrite.h"
/* max bytes to crawl for trying to resync
* stupid streaming servers don't start at chunk boundaries...
*/
#define NSV_MAX_RESYNC (500*1024)
#define NSV_MAX_RESYNC_TRIES 300
/*
* References:
* (1) http://www.multimedia.cx/nsv-format.txt
* seems someone came to the same conclusions as me, and updated it:
* (2) http://www.stud.ktu.lt/~vitslav/nsv/nsv-format.txt
* http://www.stud.ktu.lt/~vitslav/nsv/
* official docs
* (3) http://ultravox.aol.com/NSVFormat.rtf
* Sample files:
* (S1) http://www.nullsoft.com/nsv/samples/
* http://www.nullsoft.com/nsv/samples/faster.nsv
* http://streamripper.sourceforge.net/openbb/read.php?TID=492&page=4
*/
/*
* notes on the header (Francois Revol):
*
* It is followed by strings, then a table, but nothing tells
* where the table begins according to (1). After checking faster.nsv,
* I believe NVSf[16-19] gives the size of the strings data
* (that is the offset of the data table after the header).
* After checking all samples from (S1) all confirms this.
*
* Then, about NSVf[12-15], faster.nsf has 179700. When viewing it in VLC,
* I noticed there was about 1 NVSs chunk/s, so I ran
* strings faster.nsv | grep NSVs | wc -l
* which gave me 180. That leads me to think that NSVf[12-15] might be the
* file length in milliseconds.
* Let's try that:
* 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
* except for nsvtrailer (which doesn't have an NSVf header), it reports correct time.
*
* nsvtrailer.nsv (S1) does not have any NSVf header, only NSVs chunks,
* so the header seems to not be mandatory. (for streaming).
*
* index slice duration check (excepts nsvtrailer.nsv):
* 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
*/
/*
* TODO:
* - handle timestamps !!!
* - use index
* - mime-type in probe()
* - seek
*/
#if 0
struct NSVf_header {
uint32_t chunk_tag; /* 'NSVf' */
uint32_t chunk_size;
uint32_t file_size; /* max 4GB ??? no one learns anything it seems :^) */
uint32_t file_length; //unknown1; /* what about MSB of file_size ? */
uint32_t info_strings_size; /* size of the info strings */ //unknown2;
uint32_t table_entries;
uint32_t table_entries_used; /* the left ones should be -1 */
};
struct NSVs_header {
uint32_t chunk_tag; /* 'NSVs' */
uint32_t v4cc; /* or 'NONE' */
uint32_t a4cc; /* or 'NONE' */
uint16_t vwidth; /* av_assert0(vwidth%16==0) */
uint16_t vheight; /* av_assert0(vheight%16==0) */
uint8_t framerate; /* value = (framerate&0x80)?frtable[frameratex0x7f]:framerate */
uint16_t unknown;
};
struct nsv_avchunk_header {
uint8_t vchunk_size_lsb;
uint16_t vchunk_size_msb; /* value = (vchunk_size_msb << 4) | (vchunk_size_lsb >> 4) */
uint16_t achunk_size;
};
struct nsv_pcm_header {
uint8_t bits_per_sample;
uint8_t channel_count;
uint16_t sample_rate;
};
#endif
/* variation from avi.h */
/*typedef struct CodecTag {
int id;
unsigned int tag;
} CodecTag;*/
/* tags */
#define T_NSVF MKTAG('N', 'S', 'V', 'f') /* file header */
#define T_NSVS MKTAG('N', 'S', 'V', 's') /* chunk header */
#define T_TOC2 MKTAG('T', 'O', 'C', '2') /* extra index marker */
#define T_NONE MKTAG('N', 'O', 'N', 'E') /* null a/v 4CC */
#define T_SUBT MKTAG('S', 'U', 'B', 'T') /* subtitle aux data */
#define T_ASYN MKTAG('A', 'S', 'Y', 'N') /* async a/v aux marker */
#define T_KEYF MKTAG('K', 'E', 'Y', 'F') /* video keyframe aux marker (addition) */
#define TB_NSVF MKBETAG('N', 'S', 'V', 'f')
#define TB_NSVS MKBETAG('N', 'S', 'V', 's')
/* hardcoded stream indexes */
#define NSV_ST_VIDEO 0
#define NSV_ST_AUDIO 1
#define NSV_ST_SUBT 2
enum NSVStatus {
NSV_UNSYNC,
NSV_FOUND_NSVF,
NSV_HAS_READ_NSVF,
NSV_FOUND_NSVS,
NSV_HAS_READ_NSVS,
NSV_FOUND_BEEF,
NSV_GOT_VIDEO,
NSV_GOT_AUDIO,
};
typedef struct NSVStream {
int frame_offset; /* current frame (video) or byte (audio) counter
(used to compute the pts) */
int scale;
int rate;
int sample_size; /* audio only data */
int start;
int new_frame_offset; /* temporary storage (used during seek) */
int cum_len; /* temporary storage (used during seek) */
} NSVStream;
typedef struct NSVContext {
int base_offset;
int NSVf_end;
uint32_t *nsvs_file_offset;
int index_entries;
enum NSVStatus state;
AVPacket ahead[2]; /* [v, a] if .data is !NULL there is something */
/* cached */
int64_t duration;
uint32_t vtag, atag;
uint16_t vwidth, vheight;
int16_t avsync;
AVRational framerate;
uint32_t *nsvs_timestamps;
} NSVContext;
static const AVCodecTag nsv_codec_video_tags[] = {
{ AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', ' ') },
{ AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', '0') },
{ AV_CODEC_ID_VP3, MKTAG('V', 'P', '3', '1') },
{ AV_CODEC_ID_VP5, MKTAG('V', 'P', '5', ' ') },
{ AV_CODEC_ID_VP5, MKTAG('V', 'P', '5', '0') },
{ AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', ' ') },
{ AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '0') },
{ AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '1') },
{ AV_CODEC_ID_VP6, MKTAG('V', 'P', '6', '2') },
{ AV_CODEC_ID_VP8, MKTAG('V', 'P', '8', '0') },
/*
{ AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', ' ') },
{ AV_CODEC_ID_VP4, MKTAG('V', 'P', '4', '0') },
*/
{ AV_CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
{ AV_CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
{ AV_CODEC_ID_NONE, 0 },
};
static const AVCodecTag nsv_codec_audio_tags[] = {
{ AV_CODEC_ID_MP3, MKTAG('M', 'P', '3', ' ') },
{ AV_CODEC_ID_AAC, MKTAG('A', 'A', 'C', ' ') },
{ AV_CODEC_ID_AAC, MKTAG('A', 'A', 'C', 'P') },
{ AV_CODEC_ID_AAC, MKTAG('V', 'L', 'B', ' ') },
{ AV_CODEC_ID_SPEEX, MKTAG('S', 'P', 'X', ' ') },
{ AV_CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
{ AV_CODEC_ID_NONE, 0 },
};
//static int nsv_load_index(AVFormatContext *s);
static int nsv_read_chunk(AVFormatContext *s, int fill_header);
/* try to find something we recognize, and set the state accordingly */
static int nsv_resync(AVFormatContext *s)
{
NSVContext *nsv = s->priv_data;
AVIOContext *pb = s->pb;
uint32_t v = 0;
int i;
for (i = 0; i < NSV_MAX_RESYNC; i++) {
if (avio_feof(pb)) {
av_log(s, AV_LOG_TRACE, "NSV EOF\n");
nsv->state = NSV_UNSYNC;
return -1;
}
v <<= 8;
v |= avio_r8(pb);
if (i < 8) {
av_log(s, AV_LOG_TRACE, "NSV resync: [%d] = %02x\n", i, v & 0x0FF);
}
if ((v & 0x0000ffff) == 0xefbe) { /* BEEF */
av_log(s, AV_LOG_TRACE, "NSV resynced on BEEF after %d bytes\n", i+1);
nsv->state = NSV_FOUND_BEEF;
return 0;
}
/* we read as big-endian, thus the MK*BE* */
if (v == TB_NSVF) { /* NSVf */
av_log(s, AV_LOG_TRACE, "NSV resynced on NSVf after %d bytes\n", i+1);
nsv->state = NSV_FOUND_NSVF;
return 0;
}
if (v == MKBETAG('N', 'S', 'V', 's')) { /* NSVs */
av_log(s, AV_LOG_TRACE, "NSV resynced on NSVs after %d bytes\n", i+1);
nsv->state = NSV_FOUND_NSVS;
return 0;
}
}
av_log(s, AV_LOG_TRACE, "NSV sync lost\n");
return -1;
}
static int nsv_parse_NSVf_header(AVFormatContext *s)
{
NSVContext *nsv = s->priv_data;
AVIOContext *pb = s->pb;
unsigned int av_unused file_size;
unsigned int size;
int64_t duration;
int strings_size;
int table_entries;
int table_entries_used;
nsv->state = NSV_UNSYNC; /* in case we fail */
size = avio_rl32(pb);
if (size < 28)
return -1;
nsv->NSVf_end = size;
file_size = (uint32_t)avio_rl32(pb);
av_log(s, AV_LOG_TRACE, "NSV NSVf chunk_size %u\n", size);
av_log(s, AV_LOG_TRACE, "NSV NSVf file_size %u\n", file_size);
nsv->duration = duration = avio_rl32(pb); /* in ms */
av_log(s, AV_LOG_TRACE, "NSV NSVf duration %"PRId64" ms\n", duration);
// XXX: store it in AVStreams
strings_size = avio_rl32(pb);
table_entries = avio_rl32(pb);
table_entries_used = avio_rl32(pb);
av_log(s, AV_LOG_TRACE, "NSV NSVf info-strings size: %d, table entries: %d, bis %d\n",
strings_size, table_entries, table_entries_used);
if (avio_feof(pb))
return -1;
av_log(s, AV_LOG_TRACE, "NSV got header; filepos %"PRId64"\n", avio_tell(pb));
if (strings_size > 0) {
char *strings; /* last byte will be '\0' to play safe with str*() */
char *p, *endp;
char *token, *value;
char quote;
p = strings = av_mallocz((size_t)strings_size + 1);
if (!p)
return AVERROR(ENOMEM);
endp = strings + strings_size;
avio_read(pb, strings, strings_size);
while (p < endp) {
while (*p == ' ')
p++; /* strip out spaces */
if (p >= endp-2)
break;
token = p;
p = strchr(p, '=');
if (!p || p >= endp-2)
break;
*p++ = '\0';
quote = *p++;
value = p;
p = strchr(p, quote);
if (!p || p >= endp)
break;
*p++ = '\0';
av_log(s, AV_LOG_TRACE, "NSV NSVf INFO: %s='%s'\n", token, value);
av_dict_set(&s->metadata, token, value, 0);
}
av_free(strings);
}
if (avio_feof(pb))
return -1;
av_log(s, AV_LOG_TRACE, "NSV got infos; filepos %"PRId64"\n", avio_tell(pb));
if (table_entries_used > 0) {
int i;
nsv->index_entries = table_entries_used;
if((unsigned)table_entries_used >= UINT_MAX / sizeof(uint32_t))
return -1;
nsv->nsvs_file_offset = av_malloc_array((unsigned)table_entries_used, sizeof(uint32_t));
if (!nsv->nsvs_file_offset)
return AVERROR(ENOMEM);
for(i=0;i<table_entries_used;i++)
nsv->nsvs_file_offset[i] = avio_rl32(pb) + size;
if(table_entries > table_entries_used &&
avio_rl32(pb) == MKTAG('T','O','C','2')) {
nsv->nsvs_timestamps = av_malloc_array((unsigned)table_entries_used, sizeof(uint32_t));
if (!nsv->nsvs_timestamps)
return AVERROR(ENOMEM);
for(i=0;i<table_entries_used;i++) {
nsv->nsvs_timestamps[i] = avio_rl32(pb);
}
}
}
av_log(s, AV_LOG_TRACE, "NSV got index; filepos %"PRId64"\n", avio_tell(pb));
avio_seek(pb, nsv->base_offset + size, SEEK_SET); /* required for dumbdriving-271.nsv (2 extra bytes) */
if (avio_feof(pb))
return -1;
nsv->state = NSV_HAS_READ_NSVF;
return 0;
}
static int nsv_parse_NSVs_header(AVFormatContext *s)
{
NSVContext *nsv = s->priv_data;
AVIOContext *pb = s->pb;
uint32_t vtag, atag;
uint16_t vwidth, vheight;
AVRational framerate;
int i;
AVStream *st;
NSVStream *nst;
vtag = avio_rl32(pb);
atag = avio_rl32(pb);
vwidth = avio_rl16(pb);
vheight = avio_rl16(pb);
i = avio_r8(pb);
av_log(s, AV_LOG_TRACE, "NSV NSVs framerate code %2x\n", i);
if(i&0x80) { /* odd way of giving native framerates from docs */
int t=(i & 0x7F)>>2;
if(t<16) framerate = (AVRational){1, t+1};
else framerate = (AVRational){t-15, 1};
if(i&1){
framerate.num *= 1000;
framerate.den *= 1001;
}
if((i&3)==3) framerate.num *= 24;
else if((i&3)==2) framerate.num *= 25;
else framerate.num *= 30;
}
else
framerate= (AVRational){i, 1};
nsv->avsync = avio_rl16(pb);
nsv->framerate = framerate;
av_log(s, AV_LOG_TRACE, "NSV NSVs vsize %dx%d\n", vwidth, vheight);
/* XXX change to ap != NULL ? */
if (s->nb_streams == 0) { /* streams not yet published, let's do that */
nsv->vtag = vtag;
nsv->atag = atag;
nsv->vwidth = vwidth;
nsv->vheight = vwidth;
if (vtag != T_NONE) {
int i;
st = avformat_new_stream(s, NULL);
if (!st)
goto fail;
st->id = NSV_ST_VIDEO;
nst = av_mallocz(sizeof(NSVStream));
if (!nst)
goto fail;
st->priv_data = nst;
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_tag = vtag;
st->codecpar->codec_id = ff_codec_get_id(nsv_codec_video_tags, vtag);
st->codecpar->width = vwidth;
st->codecpar->height = vheight;
st->codecpar->bits_per_coded_sample = 24; /* depth XXX */
avpriv_set_pts_info(st, 64, framerate.den, framerate.num);
st->start_time = 0;
st->duration = av_rescale(nsv->duration, framerate.num, 1000*framerate.den);
for(i=0;i<nsv->index_entries;i++) {
if(nsv->nsvs_timestamps) {
av_add_index_entry(st, nsv->nsvs_file_offset[i], nsv->nsvs_timestamps[i],
0, 0, AVINDEX_KEYFRAME);
} else {
int64_t ts = av_rescale(i*nsv->duration/nsv->index_entries, framerate.num, 1000*framerate.den);
av_add_index_entry(st, nsv->nsvs_file_offset[i], ts, 0, 0, AVINDEX_KEYFRAME);
}
}
}
if (atag != T_NONE) {
st = avformat_new_stream(s, NULL);
if (!st)
goto fail;
st->id = NSV_ST_AUDIO;
nst = av_mallocz(sizeof(NSVStream));
if (!nst)
goto fail;
st->priv_data = nst;
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_tag = atag;
st->codecpar->codec_id = ff_codec_get_id(nsv_codec_audio_tags, atag);
st->need_parsing = AVSTREAM_PARSE_FULL; /* for PCM we will read a chunk later and put correct info */
/* set timebase to common denominator of ms and framerate */
avpriv_set_pts_info(st, 64, 1, framerate.num*1000);
st->start_time = 0;
st->duration = (int64_t)nsv->duration * framerate.num;
}
} else {
if (nsv->vtag != vtag || nsv->atag != atag || nsv->vwidth != vwidth || nsv->vheight != vwidth) {
av_log(s, AV_LOG_TRACE, "NSV NSVs header values differ from the first one!!!\n");
//return -1;
}
}
nsv->state = NSV_HAS_READ_NSVS;
return 0;
fail:
/* XXX */
nsv->state = NSV_UNSYNC;
return -1;
}
static int nsv_read_header(AVFormatContext *s)
{
NSVContext *nsv = s->priv_data;
int i, err;
nsv->state = NSV_UNSYNC;
nsv->ahead[0].data = nsv->ahead[1].data = NULL;
for (i = 0; i < NSV_MAX_RESYNC_TRIES; i++) {
if (nsv_resync(s) < 0)
return -1;
if (nsv->state == NSV_FOUND_NSVF) {
err = nsv_parse_NSVf_header(s);
if (err < 0)
return err;
}
/* we need the first NSVs also... */
if (nsv->state == NSV_FOUND_NSVS) {
err = nsv_parse_NSVs_header(s);
if (err < 0)
return err;
break; /* we just want the first one */
}
}
if (s->nb_streams < 1) /* no luck so far */
return -1;
/* now read the first chunk, so we can attempt to decode more info */
err = nsv_read_chunk(s, 1);
av_log(s, AV_LOG_TRACE, "parsed header\n");
return err;
}
static int nsv_read_chunk(AVFormatContext *s, int fill_header)
{
NSVContext *nsv = s->priv_data;
AVIOContext *pb = s->pb;
AVStream *st[2] = {NULL, NULL};
NSVStream *nst;
AVPacket *pkt;
int i, err = 0;
uint8_t auxcount; /* number of aux metadata, also 4 bits of vsize */
uint32_t vsize;
uint16_t asize;
uint16_t auxsize;
int ret;
if (nsv->ahead[0].data || nsv->ahead[1].data)
return 0; //-1; /* hey! eat what you've in your plate first! */
null_chunk_retry:
if (avio_feof(pb))
return -1;
for (i = 0; i < NSV_MAX_RESYNC_TRIES && nsv->state < NSV_FOUND_NSVS && !err; i++)
err = nsv_resync(s);
if (err < 0)
return err;
if (nsv->state == NSV_FOUND_NSVS)
err = nsv_parse_NSVs_header(s);
if (err < 0)
return err;
if (nsv->state != NSV_HAS_READ_NSVS && nsv->state != NSV_FOUND_BEEF)
return -1;
auxcount = avio_r8(pb);
vsize = avio_rl16(pb);
asize = avio_rl16(pb);
vsize = (vsize << 4) | (auxcount >> 4);
auxcount &= 0x0f;
av_log(s, AV_LOG_TRACE, "NSV CHUNK %d aux, %u bytes video, %d bytes audio\n", auxcount, vsize, asize);
/* skip aux stuff */
for (i = 0; i < auxcount; i++) {
uint32_t av_unused auxtag;
auxsize = avio_rl16(pb);
auxtag = avio_rl32(pb);
avio_skip(pb, auxsize);
vsize -= auxsize + sizeof(uint16_t) + sizeof(uint32_t); /* that's becoming brain-dead */
}
if (avio_feof(pb))
return -1;
if (!vsize && !asize) {
nsv->state = NSV_UNSYNC;
goto null_chunk_retry;
}
/* map back streams to v,a */
if (s->nb_streams > 0)
st[s->streams[0]->id] = s->streams[0];
if (s->nb_streams > 1)
st[s->streams[1]->id] = s->streams[1];
if (vsize && st[NSV_ST_VIDEO]) {
nst = st[NSV_ST_VIDEO]->priv_data;
pkt = &nsv->ahead[NSV_ST_VIDEO];
if ((ret = av_get_packet(pb, pkt, vsize)) < 0)
return ret;
pkt->stream_index = st[NSV_ST_VIDEO]->index;//NSV_ST_VIDEO;
pkt->dts = nst->frame_offset;
pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
for (i = 0; i < FFMIN(8, vsize); i++)
av_log(s, AV_LOG_TRACE, "NSV video: [%d] = %02x\n", i, pkt->data[i]);
}
if(st[NSV_ST_VIDEO])
((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset++;
if (asize && st[NSV_ST_AUDIO]) {
nst = st[NSV_ST_AUDIO]->priv_data;
pkt = &nsv->ahead[NSV_ST_AUDIO];
/* read raw audio specific header on the first audio chunk... */
/* on ALL audio chunks ?? seems so! */
if (asize && st[NSV_ST_AUDIO]->codecpar->codec_tag == MKTAG('P', 'C', 'M', ' ')/* && fill_header*/) {
uint8_t bps;
uint8_t channels;
uint16_t samplerate;
bps = avio_r8(pb);
channels = avio_r8(pb);
samplerate = avio_rl16(pb);
if (!channels || !samplerate)
return AVERROR_INVALIDDATA;
asize-=4;
av_log(s, AV_LOG_TRACE, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
if (fill_header) {
st[NSV_ST_AUDIO]->need_parsing = AVSTREAM_PARSE_NONE; /* we know everything */
if (bps != 16) {
av_log(s, AV_LOG_TRACE, "NSV AUDIO bit/sample != 16 (%d)!!!\n", bps);
}
bps /= channels; // ???
if (bps == 8)
st[NSV_ST_AUDIO]->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
samplerate /= 4;/* UGH ??? XXX */
channels = 1;
st[NSV_ST_AUDIO]->codecpar->channels = channels;
st[NSV_ST_AUDIO]->codecpar->sample_rate = samplerate;
av_log(s, AV_LOG_TRACE, "NSV RAWAUDIO: bps %d, nchan %d, srate %d\n", bps, channels, samplerate);
}
}
if ((ret = av_get_packet(pb, pkt, asize)) < 0)
return ret;
pkt->stream_index = st[NSV_ST_AUDIO]->index;//NSV_ST_AUDIO;
pkt->flags |= nsv->state == NSV_HAS_READ_NSVS ? AV_PKT_FLAG_KEY : 0; /* keyframe only likely on a sync frame */
if( nsv->state == NSV_HAS_READ_NSVS && st[NSV_ST_VIDEO] ) {
/* on a nsvs frame we have new information on a/v sync */
pkt->dts = (((NSVStream*)st[NSV_ST_VIDEO]->priv_data)->frame_offset-1);
pkt->dts *= (int64_t)1000 * nsv->framerate.den;
pkt->dts += (int64_t)nsv->avsync * nsv->framerate.num;
av_log(s, AV_LOG_TRACE, "NSV AUDIO: sync:%d, dts:%"PRId64, nsv->avsync, pkt->dts);
}
nst->frame_offset++;
}
nsv->state = NSV_UNSYNC;
return 0;
}
static int nsv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
NSVContext *nsv = s->priv_data;
int i, err = 0;
/* in case we don't already have something to eat ... */
if (!nsv->ahead[0].data && !nsv->ahead[1].data)
err = nsv_read_chunk(s, 0);
if (err < 0)
return err;
/* now pick one of the plates */
for (i = 0; i < 2; i++) {
if (nsv->ahead[i].data) {
/* avoid the cost of new_packet + memcpy(->data) */
memcpy(pkt, &nsv->ahead[i], sizeof(AVPacket));
nsv->ahead[i].data = NULL; /* we ate that one */
return pkt->size;
}
}
/* this restaurant is not provisioned :^] */
return -1;
}
static int nsv_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
{
NSVContext *nsv = s->priv_data;
AVStream *st = s->streams[stream_index];
NSVStream *nst = st->priv_data;
int index;
index = av_index_search_timestamp(st, timestamp, flags);
if(index < 0)
return -1;
if (avio_seek(s->pb, st->index_entries[index].pos, SEEK_SET) < 0)
return -1;
nst->frame_offset = st->index_entries[index].timestamp;
nsv->state = NSV_UNSYNC;
return 0;
}
static int nsv_read_close(AVFormatContext *s)
{
NSVContext *nsv = s->priv_data;
av_freep(&nsv->nsvs_file_offset);
av_freep(&nsv->nsvs_timestamps);
if (nsv->ahead[0].data)
av_packet_unref(&nsv->ahead[0]);
if (nsv->ahead[1].data)
av_packet_unref(&nsv->ahead[1]);
return 0;
}
static int nsv_probe(AVProbeData *p)
{
int i, score = 0;
/* check file header */
/* streamed files might not have any header */
if (p->buf[0] == 'N' && p->buf[1] == 'S' &&
p->buf[2] == 'V' && (p->buf[3] == 'f' || p->buf[3] == 's'))
return AVPROBE_SCORE_MAX;
/* XXX: do streamed files always start at chunk boundary ?? */
/* or do we need to search NSVs in the byte stream ? */
/* seems the servers don't bother starting clean chunks... */
/* sometimes even the first header is at 9KB or something :^) */
for (i = 1; i < p->buf_size - 3; i++) {
if (AV_RL32(p->buf + i) == AV_RL32("NSVs")) {
/* Get the chunk size and check if at the end we are getting 0xBEEF */
int vsize = AV_RL24(p->buf+i+19) >> 4;
int asize = AV_RL16(p->buf+i+22);
int offset = i + 23 + asize + vsize + 1;
if (offset <= p->buf_size - 2 && AV_RL16(p->buf + offset) == 0xBEEF)
return 4*AVPROBE_SCORE_MAX/5;
score = AVPROBE_SCORE_MAX/5;
}
}
/* so we'll have more luck on extension... */
if (av_match_ext(p->filename, "nsv"))
return AVPROBE_SCORE_EXTENSION;
/* FIXME: add mime-type check */
return score;
}
AVInputFormat ff_nsv_demuxer = {
.name = "nsv",
.long_name = NULL_IF_CONFIG_SMALL("Nullsoft Streaming Video"),
.priv_data_size = sizeof(NSVContext),
.read_probe = nsv_probe,
.read_header = nsv_read_header,
.read_packet = nsv_read_packet,
.read_close = nsv_read_close,
.read_seek = nsv_read_seek,
};