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ffmpeg.wasm-core
Commit 8b84af74 authored by Alex Converse's avatar Alex Converse
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avidec: Factor out the sync fucntionality.

parent 29651e1d
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Showing with 128 additions and 116 deletions
libavformat/avidec.c
View file @ 8b84af74
......@@ -836,13 +836,137 @@ static int get_stream_idx(int *d){
}
}
static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
static int avi_sync(AVFormatContext *s)
{
AVIContext *avi = s->priv_data;
AVIOContext *pb = s->pb;
int n, d[8];
unsigned int size;
int64_t i, sync;
start_sync:
memset(d, -1, sizeof(int)*8);
for(i=sync=avio_tell(pb); !pb->eof_reached; i++) {
int j;
for(j=0; j<7; j++)
d[j]= d[j+1];
d[7]= avio_r8(pb);
size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
n= get_stream_idx(d+2);
//av_log(s, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %"PRId64" %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
if(i + (uint64_t)size > avi->fsize || d[0]<0)
continue;
//parse ix##
if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
//parse JUNK
||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
avio_skip(pb, size);
//av_log(s, AV_LOG_DEBUG, "SKIP\n");
goto start_sync;
}
//parse stray LIST
if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
avio_skip(pb, 4);
goto start_sync;
}
n= get_stream_idx(d);
if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
continue;
//detect ##ix chunk and skip
if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
avio_skip(pb, size);
goto start_sync;
}
//parse ##dc/##wb
if(n < s->nb_streams){
AVStream *st;
AVIStream *ast;
st = s->streams[n];
ast = st->priv_data;
if(s->nb_streams>=2){
AVStream *st1 = s->streams[1];
AVIStream *ast1= st1->priv_data;
//workaround for broken small-file-bug402.avi
if( d[2] == 'w' && d[3] == 'b'
&& n==0
&& st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
&& st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
&& ast->prefix == 'd'*256+'c'
&& (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
){
n=1;
st = st1;
ast = ast1;
av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
}
}
if( (st->discard >= AVDISCARD_DEFAULT && size==0)
/*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering
|| st->discard >= AVDISCARD_ALL){
ast->frame_offset += get_duration(ast, size);
avio_skip(pb, size);
goto start_sync;
}
if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
int k = avio_r8(pb);
int last = (k + avio_r8(pb) - 1) & 0xFF;
avio_rl16(pb); //flags
for (; k <= last; k++)
ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);
ast->has_pal= 1;
goto start_sync;
} else if( ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
d[2]*256+d[3] == ast->prefix /*||
(d[2] == 'd' && d[3] == 'c') ||
(d[2] == 'w' && d[3] == 'b')*/) {
//av_log(s, AV_LOG_DEBUG, "OK\n");
if(d[2]*256+d[3] == ast->prefix)
ast->prefix_count++;
else{
ast->prefix= d[2]*256+d[3];
ast->prefix_count= 0;
}
avi->stream_index= n;
ast->packet_size= size + 8;
ast->remaining= size;
if(size || !ast->sample_size){
uint64_t pos= avio_tell(pb) - 8;
if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
}
}
return 0;
}
}
}
return AVERROR_EOF;
}
static int avi_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIContext *avi = s->priv_data;
AVIOContext *pb = s->pb;
int err;
void* dstr;
if (CONFIG_DV_DEMUXER && avi->dv_demux) {
......@@ -993,121 +1117,9 @@ resync:
return size;
}
memset(d, -1, sizeof(int)*8);
for(i=sync=avio_tell(pb); !pb->eof_reached; i++) {
int j;
for(j=0; j<7; j++)
d[j]= d[j+1];
d[7]= avio_r8(pb);
size= d[4] + (d[5]<<8) + (d[6]<<16) + (d[7]<<24);
n= get_stream_idx(d+2);
//av_log(s, AV_LOG_DEBUG, "%X %X %X %X %X %X %X %X %"PRId64" %d %d\n", d[0], d[1], d[2], d[3], d[4], d[5], d[6], d[7], i, size, n);
if(i + (uint64_t)size > avi->fsize || d[0]<0)
continue;
//parse ix##
if( (d[0] == 'i' && d[1] == 'x' && n < s->nb_streams)
//parse JUNK
||(d[0] == 'J' && d[1] == 'U' && d[2] == 'N' && d[3] == 'K')
||(d[0] == 'i' && d[1] == 'd' && d[2] == 'x' && d[3] == '1')){
avio_skip(pb, size);
//av_log(s, AV_LOG_DEBUG, "SKIP\n");
goto resync;
}
//parse stray LIST
if(d[0] == 'L' && d[1] == 'I' && d[2] == 'S' && d[3] == 'T'){
avio_skip(pb, 4);
goto resync;
}
n= get_stream_idx(d);
if(!((i-avi->last_pkt_pos)&1) && get_stream_idx(d+1) < s->nb_streams)
continue;
//detect ##ix chunk and skip
if(d[2] == 'i' && d[3] == 'x' && n < s->nb_streams){
avio_skip(pb, size);
goto resync;
}
//parse ##dc/##wb
if(n < s->nb_streams){
AVStream *st;
AVIStream *ast;
st = s->streams[n];
ast = st->priv_data;
if(s->nb_streams>=2){
AVStream *st1 = s->streams[1];
AVIStream *ast1= st1->priv_data;
//workaround for broken small-file-bug402.avi
if( d[2] == 'w' && d[3] == 'b'
&& n==0
&& st ->codec->codec_type == AVMEDIA_TYPE_VIDEO
&& st1->codec->codec_type == AVMEDIA_TYPE_AUDIO
&& ast->prefix == 'd'*256+'c'
&& (d[2]*256+d[3] == ast1->prefix || !ast1->prefix_count)
){
n=1;
st = st1;
ast = ast1;
av_log(s, AV_LOG_WARNING, "Invalid stream + prefix combination, assuming audio.\n");
}
}
if( (st->discard >= AVDISCARD_DEFAULT && size==0)
/*|| (st->discard >= AVDISCARD_NONKEY && !(pkt->flags & AV_PKT_FLAG_KEY))*/ //FIXME needs a little reordering
|| st->discard >= AVDISCARD_ALL){
ast->frame_offset += get_duration(ast, size);
avio_skip(pb, size);
goto resync;
}
if (d[2] == 'p' && d[3] == 'c' && size<=4*256+4) {
int k = avio_r8(pb);
int last = (k + avio_r8(pb) - 1) & 0xFF;
avio_rl16(pb); //flags
for (; k <= last; k++)
ast->pal[k] = avio_rb32(pb)>>8;// b + (g << 8) + (r << 16);
ast->has_pal= 1;
goto resync;
} else if( ((ast->prefix_count<5 || sync+9 > i) && d[2]<128 && d[3]<128) ||
d[2]*256+d[3] == ast->prefix /*||
(d[2] == 'd' && d[3] == 'c') ||
(d[2] == 'w' && d[3] == 'b')*/) {
//av_log(s, AV_LOG_DEBUG, "OK\n");
if(d[2]*256+d[3] == ast->prefix)
ast->prefix_count++;
else{
ast->prefix= d[2]*256+d[3];
ast->prefix_count= 0;
}
avi->stream_index= n;
ast->packet_size= size + 8;
ast->remaining= size;
if(size || !ast->sample_size){
uint64_t pos= avio_tell(pb) - 8;
if(!st->index_entries || !st->nb_index_entries || st->index_entries[st->nb_index_entries - 1].pos < pos){
av_add_index_entry(st, pos, ast->frame_offset, size, 0, AVINDEX_KEYFRAME);
}
}
goto resync;
}
}
}
return AVERROR_EOF;
if ((err = avi_sync(s)) < 0)
return err;
goto resync;
}
/* XXX: We make the implicit supposition that the positions are sorted
......
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