[MPlayer-dev-eng] Proposed support for Kate streams

[Reimar Döffinger]

On Tue, Mar 18, 2008 at 11:17:40AM +0100, Reimar Döffinger wrote:
> On Tue, Mar 18, 2008 at 12:24:52PM +0300, Evgeniy Stepanov wrote:
> > On Tuesday 18 March 2008 11:28:00 Reimar Döffinger wrote:
> > > > Slightly off-topic, it seems too early to switch to lavf demuxer at least
> > > > for ogg and avi: the former does not support seeking to keyframes
> > >
> > > I never considered that really relevant I must admit, but I assumed it
> > > would be a rather simple, although maybe ugly fix.
> > 
> > I'm not sure about that. Lavf ogg demuxer misses seeking code, and generic 
> > seeking routines simply ignore keyframe information. I really think it cannot 
> > be ignored, because it makes seeking almost unusable.
> 
> Just make ogg_read_timestamp only return keyframes and seeking will only
> go to keyframes. Not sure if this is the intended behaviour and if it
> would be accepted, but it does not look difficult to me (beyond needing
> a reliable way of detecting keyframes, which IIRC can be quite painful).

More specifically, you could just try attached patch (I have not tested it yet).
-------------- next part --------------
Index: libavformat/oggdec.c
===================================================================
--- libavformat/oggdec.c	(revision 12478)
+++ libavformat/oggdec.c	(working copy)
@@ -559,13 +559,17 @@
     int i;
     url_fseek(bc, *pos_arg, SEEK_SET);
     while (url_ftell(bc) < pos_limit && !ogg_read_page (s, &i)) {
+        ogg->streams[i].pflags = 0;
         if (ogg->streams[i].granule != -1 && ogg->streams[i].granule != 0 &&
             ogg->streams[i].codec && i == stream_index) {
-            pts = ogg_gptopts(s, i, ogg->streams[i].granule);
+            int64_t next_pts = ogg_gptopts(s, i, ogg->streams[i].granule);
+            if (ogg->streams[i].pflags & PKT_FLAG_KEY) {
+            pts = next_pts;
             // FIXME: this is the position of the packet after the one with above
             // pts.
             *pos_arg = url_ftell(bc);
             break;
+            }
         }
     }
     ogg_reset(ogg);