demux: make determining seek capability generic

Instead of having each demuxer do it (only demux_mkv actually did...),
let generic code determine whether the file is seekable. This requires
adding exceptions to demuxers where the stream is not seekable, but the
demuxer is.

Sort-of try to improve handling of unseekable files in the player. Exit
early if the file is determined to be unseekable, instead of resetting
all decoders and then performing a pointless seek.

Add an exception to allow seeking if the file is not seekable, but the
stream cache is enabled. Print a warning in this case, because seeking
outside the cache (which we can't prevent since the demuxer is not aware
of this problem) still messes everything up.

1 files changed, 0 insertions, 6 deletions

diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index d6948e9979..4181aa4850 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -1844,12 +1844,6 @@ static int demux_mkv_open(demuxer_t *demuxer, enum demux_check check)
 
     display_create_tracks(demuxer);
 
-    if (s->end_pos == 0) {
-        demuxer->seekable = 0;
-    } else {
-        demuxer->seekable = 1;
-    }
-
     return 0;
 }