[MPlayer-dev-eng] [Patch] Even better seeking in ogg ;-)
Michael Behrisch
behrisch at informatik.hu-berlin.de
Sun Apr 18 17:06:30 CEST 2004
On Tue, Apr 13, 2004 at 08:16:32PM +0200, Moritz Bunkus wrote:
> Hi,
>
> > just another try, this time with theora seeking fixed as well
>
> Doesn't apply anymore. Please re-send, thanks.
>
Here it is,
Michael
-------------- next part --------------
--- libmpdemux/demux_ogg.c.orig 2004-04-08 14:14:17.000000000 +0200
+++ libmpdemux/demux_ogg.c 2004-04-16 21:14:29.000000000 +0200
@@ -350,21 +350,22 @@
decoder. */
if (context != NULL && !(*data&0x80))
{
- theora_state *st;
- int64_t usable_granulepos;
+ theora_info *thi = ((theora_struct_t*)context)->st.i;
+ int keyframe_granule_shift=_ilog(thi->keyframe_frequency_force-1);
+ int64_t iframemask = (1 << keyframe_granule_shift) - 1;
- st = &((theora_struct_t*)context)->st;
- *pts = theora_granule_time (st, pack->granulepos);
- if (*pts >= 0)
+ if (pack->granulepos >= 0)
{
- usable_granulepos = (int64_t)ceil (*pts * os->samplerate - 0.5);
- os->lastpos = usable_granulepos;
+ os->lastpos = pack->granulepos >> keyframe_granule_shift;
+ os->lastpos += pack->granulepos & iframemask;
+ *flags = ((pack->granulepos & iframemask) == 0);
}
else
{
os->lastpos++;
- *pts = (double)os->lastpos / (double)os->samplerate;
}
+ pack->granulepos = os->lastpos;
+ *pts = (double)os->lastpos / (double)os->samplerate;
}
#endif /* HAVE_OGGTHEORA */
# ifdef HAVE_FLAC
@@ -373,13 +374,16 @@
data = pack->packet;
#endif /* HAVE_FLAC */
} else {
+ if(*pack->packet & PACKET_TYPE_HEADER)
+ os->hdr_packets++;
+ else {
// Find data start
int16_t hdrlen = (*pack->packet & PACKET_LEN_BITS01)>>6;
hdrlen |= (*pack->packet & PACKET_LEN_BITS2) <<1;
data = pack->packet + 1 + hdrlen;
// Calculate the timestamp
if(pack->granulepos == -1)
- pack->granulepos = os->lastpos + os->lastsize;
+ pack->granulepos = os->lastpos + (os->lastsize ? os->lastsize : 1);
// If we alredy have a timestamp it can be a syncpoint
if(*pack->packet & PACKET_IS_SYNCPOINT)
*flags = 1;
@@ -393,6 +397,7 @@
}
os->lastpos = pack->granulepos;
}
+ }
return data;
}
@@ -517,12 +522,13 @@
dp->pts = pts;
dp->flags = flags;
ds_add_packet(ds,dp);
- if(verbose>1)printf("New dp: %p ds=%p pts=%5.3f len=%d flag=%d \n",
+ mp_msg(MSGT_DEMUX,MSGL_DBG2,"New dp: %p ds=%p pts=%5.3f len=%d flag=%d \n",
dp, ds, pts, dp->len, flags);
return 1;
}
-/// Build a table of all syncpoints to make seeking easier
+/// if -forceidx build a table of all syncpoints to make seeking easier
+/// otherwise try to get at least the final_granulepos
void demux_ogg_scan_stream(demuxer_t* demuxer) {
ogg_demuxer_t* ogg_d = demuxer->priv;
stream_t *s = demuxer->stream;
@@ -539,9 +545,9 @@
// Reset the stream
if(index_mode == 2) {
stream_seek(s,demuxer->movi_start);
- }
- else {
- stream_seek(s,demuxer->movi_end-20*BLOCK_SIZE);
+ } else {
+ //the 270000 are just a wild guess
+ stream_seek(s,max(ogg_d->pos,demuxer->movi_end-270000));
}
ogg_sync_reset(sync);
@@ -592,15 +598,13 @@
float pts;
int flags;
demux_ogg_read_packet(os,&op,context,&pts,&flags);
- if(flags || (os->vorbis && op.granulepos >= 0)) {
- if(index_mode == 2) {
+ if(op.granulepos >= 0) ogg_d->final_granulepos = op.granulepos;
+ if(index_mode == 2 && (flags || (os->vorbis && op.granulepos >= 0))) {
ogg_d->syncpoints = (ogg_syncpoint_t*)realloc(ogg_d->syncpoints,(ogg_d->num_syncpoint+1)*sizeof(ogg_syncpoint_t));
ogg_d->syncpoints[ogg_d->num_syncpoint].granulepos = op.granulepos;
ogg_d->syncpoints[ogg_d->num_syncpoint].page_pos = (ogg_page_continued(page) && p == 0) ? last_pos : pos;
ogg_d->num_syncpoint++;
}
- ogg_d->final_granulepos = op.granulepos;
- }
p++;
}
if(p > 1 || (p == 1 && ! ogg_page_continued(page)))
@@ -941,6 +945,11 @@
ogg_d->num_sub++;
}
+ if(!n_video && !n_audio) {
+ free(ogg_d);
+ return 0;
+ }
+
/// Finish to setup the demuxer
demuxer->priv = ogg_d;
@@ -1162,16 +1171,23 @@
sh_audio_t* sh_audio = demuxer->audio->sh;
ogg_packet op;
float rate;
- int i,sp,first;
+ int i,sp,first,precision=1,do_seek=1;
vorbis_info* vi = NULL;
- int64_t gp = 0;
- off_t pos;
+ int64_t gp = 0, old_gp;
+ void *context = NULL;
+ off_t pos, old_pos;
if(demuxer->video->id >= 0) {
ds = demuxer->video;
+ /* demux_ogg_read_packet needs decoder context for Theora streams */
+ if (((sh_video_t*)demuxer->video->sh)->format == 0xFFFC)
+ context = ((sh_video_t*)demuxer->video->sh)->context;
rate = ogg_d->subs[ds->id].samplerate;
} else {
ds = demuxer->audio;
+ /* demux_ogg_read_packet needs decoder context for Vorbis streams */
+ if(((sh_audio_t*)demuxer->audio->sh)->format == 0xFFFE)
+ context = ((sh_audio_t*)demuxer->audio->sh)->context;
vi = &((ov_struct_t*)((sh_audio_t*)ds->sh)->context)->vi;
rate = (float)vi->rate;
}
@@ -1179,37 +1195,52 @@
os = &ogg_d->subs[ds->id];
oss = &os->stream;
- if(ogg_d->syncpoints) {
+ old_gp = os->lastpos;
+ old_pos = ogg_d->pos;
+
+ //calculate the granulepos to seek to
gp = flags & 1 ? 0 : os->lastpos;
- if(flags & 2)
- gp += ogg_d->syncpoints[ogg_d->num_syncpoint].granulepos * rel_seek_secs;
+ if(flags & 2) {
+ if (ogg_d->final_granulepos > 0)
+ gp += ogg_d->final_granulepos * rel_seek_secs;
else
+ gp += rel_seek_secs * (demuxer->movi_end - demuxer->movi_start) * os->lastpos / ogg_d->pos;
+ } else
gp += rel_seek_secs * rate;
+ if (gp < 0) gp = 0;
+ //calculate the filepos to seek to
+ if(ogg_d->syncpoints) {
for(sp = 0; sp < ogg_d->num_syncpoint ; sp++) {
if(ogg_d->syncpoints[sp].granulepos >= gp) break;
}
- if(sp >= ogg_d->num_syncpoint)
- return;
+ if(sp >= ogg_d->num_syncpoint) return;
+ if (sp > 0 && ogg_d->syncpoints[sp].granulepos - gp > gp - ogg_d->syncpoints[sp-1].granulepos)
+ sp--;
+ if (ogg_d->syncpoints[sp].granulepos == os->lastpos) {
+ if (sp > 0 && gp < os->lastpos) sp--;
+ if (sp < ogg_d->num_syncpoint-1 && gp > os->lastpos) sp++;
+ }
pos = ogg_d->syncpoints[sp].page_pos;
-
+ precision = 0;
} else {
pos = flags & 1 ? 0 : ogg_d->pos;
if(flags & 2)
pos += (demuxer->movi_end - demuxer->movi_start) * rel_seek_secs;
else {
- if (ogg_d->final_granulepos > 0)
+ if (ogg_d->final_granulepos > 0) {
pos += rel_seek_secs * (demuxer->movi_end - demuxer->movi_start) / (ogg_d->final_granulepos / rate);
- else
+ } else if (os->lastpos > 0) {
pos += rel_seek_secs * ogg_d->pos / (os->lastpos / rate);
}
- if (pos < 0)
- pos = 0;
- else if (pos > (demuxer->movi_end - demuxer->movi_start))
- return;
}
+ if (pos < 0) pos = 0;
+ if (pos > (demuxer->movi_end - demuxer->movi_start)) return;
+ } // if(ogg_d->syncpoints)
+ while(1) {
+ if (do_seek) {
stream_seek(demuxer->stream,pos+demuxer->movi_start);
ogg_sync_reset(sync);
for(i = 0 ; i < ogg_d->num_sub ; i++) {
@@ -1218,9 +1249,12 @@
}
ogg_d->pos = pos;
ogg_d->last_size = 0;
-
- first = 1;
- while(1) {
+ /* we just guess that we reached correct granulepos, in case a
+ subsequent search occurs before we read a valid granulepos */
+ os->lastpos = gp;
+ first = !(ogg_d->syncpoints);
+ do_seek=0;
+ }
int np;
ogg_d->pos += ogg_d->last_size;
ogg_d->last_size = 0;
@@ -1257,15 +1291,34 @@
first = 0;
break;
}
-
- /* the detection of keyframes for theora is somewhat a hack: granulepos
- for theora packets is `keyframeNumber<<shift | iframeNumber'; `shift'
- is *variable*, with its excact value encoded in the theora header.
- This code just hopes that it is greater than 9 and that keyframes
- distance will never overflow 512. */
- if( (((*op.packet & PACKET_IS_SYNCPOINT) && !os->theora) ||
- os->vorbis || (os->theora && (op.granulepos&0x1FF) == 0)) &&
- (!ogg_d->syncpoints || op.granulepos >= gp) ) {
+ int is_gp_valid = (op.granulepos >= 0);
+ float pts;
+ int is_keyframe;
+ demux_ogg_read_packet(os,&op,context,&pts,&is_keyframe);
+ if (precision && is_gp_valid) {
+ precision--;
+ if (abs(gp - op.granulepos) > rate && (op.granulepos != old_gp)) {
+ //prepare another seek because we are off by more than 1s
+ pos += (gp - op.granulepos) * (pos - old_pos) / (op.granulepos - old_gp);
+ if (pos < 0) pos = 0;
+ if (pos < (demuxer->movi_end - demuxer->movi_start)) {
+ do_seek=1;
+ break;
+ }
+ }
+ }
+ if (is_gp_valid && (pos > 0) && (old_gp > gp)
+ && (2 * (old_gp - op.granulepos) < old_gp - gp)) {
+ /* prepare another seek because looking for a syncpoint
+ destroyed the backward search */
+ pos = old_pos - 1.5 * (old_pos - pos);
+ if (pos < 0) pos = 0;
+ if (pos < (demuxer->movi_end - demuxer->movi_start)) {
+ do_seek=1;
+ break;
+ }
+ }
+ if(!precision && (is_keyframe || os->vorbis) ) {
ogg_sub.lines = 0;
vo_sub = &ogg_sub;
vo_osd_changed(OSDTYPE_SUBTITLE);
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