core: add demux_sub pseudo demuxer

Subtitle files are opened in mplayer.c, not using the demuxer
infrastructure in general. Pretend that this is not the case (outside of
the loading code) by opening a pseudo demuxer that does nothing. One
advantage is that the initialization code is now the same, and there's
no confusion about what the difference between track->stream,
track->sh_sub and mpctx->sh_sub is supposed to be.

This is a bit stupid, and it would be much better if there were proper
subtitle demuxers (there are many in recent FFmpeg, but not Libav). So
for now this is just a transition to a more proper architecture. Look
at demux_sub like an artifical limb: it's ugly, but don't hate it - it
helps you to get on with your life.

1 files changed, 4 insertions, 3 deletions

diff --git a/demux/demux.h b/demux/demux.h
index 886252fa85..e58c56141f 100644
--- a/demux/demux.h
+++ b/demux/demux.h
@@ -77,6 +77,7 @@ enum demuxer_type {
     DEMUXER_TYPE_END,
 
     DEMUXER_TYPE_PLAYLIST,
+    DEMUXER_TYPE_SUB,
 };
 
 enum timestamp_type {
@@ -304,9 +305,9 @@ static inline void *realloc_struct(void *ptr, size_t nmemb, size_t size)
     return realloc(ptr, nmemb * size);
 }
 
-struct demuxer *new_demuxer(struct MPOpts *opts, struct stream *stream,
-                            int type, int a_id, int v_id, int s_id,
-                            char *filename);
+demuxer_t *new_sub_pseudo_demuxer(struct MPOpts *opts);
+
+
 void free_demuxer(struct demuxer *demuxer);
 
 void demuxer_add_packet(demuxer_t *demuxer, struct sh_stream *stream,