core: manage tracks in the frontend

Introduce a general track struct for every audio/video/subtitle track
known to the frontend. External files (subtitles) are now represented
as tracks too. This mainly serves to clean up the subtitle selection
code: now every subtitle is simply a track, instead of using a messy
numbering that goes by subtitle type (as it was stored in the
global_sub_pos field). The mplayer fontend will list external subtitle
files as additional tracks.

The timeline code now tries to match the exact demuxer IDs of all
tracks. This may cause problems when Matroska files with different
track numberings are used with EDL timelines. Change demux_lavf not
to set demuxer IDs, since most time they are not set.

1 files changed, 58 insertions, 18 deletions

diff --git a/mp_core.h b/mp_core.h
index 6eea692acd..04a3dac735 100644
--- a/mp_core.h
+++ b/mp_core.h
@@ -25,6 +25,7 @@
 #include "mixer.h"
 #include "sub/subreader.h"
 #include "sub/find_subfiles.h"
+#include "libmpdemux/demuxer.h"
 
 // definitions used internally by the core player code
 
@@ -75,6 +76,46 @@ struct chapter {
     char *name;
 };
 
+struct track {
+    enum stream_type type;
+    // The type specific ID, also called aid (audio), sid (subs), vid (video).
+    // For UI purposes only; this ID doesn't have anything to do with any
+    // IDs coming from demuxers or container files.
+    int user_tid;
+
+    // Same as stream->demuxer_id. -1 if not set.
+    int demuxer_id;
+
+    char *title;
+    bool default_track;
+    char *lang;
+
+    // If this track is from an external file (e.g. subtitle file).
+    bool is_external;
+
+    // If the track's stream changes with the timeline (ordered chapters).
+    bool under_timeline;
+
+    // NULL if not backed by a demuxer (e.g. external subtitles).
+    // Value can change if under_timeline==true.
+    struct demuxer *demuxer;
+    // Invariant: (!demuxer && !stream) || stream->demuxer == demuxer
+    struct sh_stream *stream;
+
+    // NOTE: demuxer subtitles, i.e. if stream!=NULL, do not use the following
+    //       fields. The data is stored in stream->sub this case.
+
+    // External text subtitle using libass subtitle renderer.
+    struct ass_track *ass_track;
+    bool native_ass_track;
+
+    // External text subtitle using non-libass subtitle renderer.
+    struct sub_data *subdata;
+
+    // External image subtitle (data is in vo_vobsub). 0 if not set.
+    int vobsub_id_plus_one;
+};
+
 typedef struct MPContext {
     struct MPOpts opts;
     struct m_config *mconfig;
@@ -83,7 +124,7 @@ typedef struct MPContext {
     struct osd_state *osd;
     struct mp_osd_msg *osd_msg_stack;
     char *terminal_osd_text;
-    struct sub_data *subdata; // current sub_data style subtitles if any
+    subtitle subs; // subtitle list used when reading subtitles from demuxer
 
     bool add_osd_seek_info;
     unsigned int osd_visible;
@@ -99,6 +140,7 @@ typedef struct MPContext {
 
     struct demuxer **sources;
     int num_sources;
+
     struct timeline_part *timeline;
     int num_timeline_parts;
     int timeline_part;
@@ -110,11 +152,17 @@ typedef struct MPContext {
 
     struct stream *stream;
     struct demuxer *demuxer;
-    struct sh_audio *sh_audio;
-    struct sh_video *sh_video;
-    struct demux_stream *d_audio;
-    struct demux_stream *d_video;
-    struct demux_stream *d_sub;
+
+    struct track **tracks;
+    int num_tracks;
+
+    // Selected tracks. NULL if no track selected.
+    struct track *current_track[STREAM_TYPE_COUNT];
+
+    struct sh_stream *sh[STREAM_TYPE_COUNT];
+    struct sh_audio *sh_audio;          // same as sh[STREAM_AUDIO]->audio
+    struct sh_video *sh_video;          // same as sh[STREAM_VIDEO]->video
+    struct sh_sub *sh_sub;              // same as sh[STREAM_SUB]->sub
 
     // Uses: accessing metadata (consider ordered chapters case, where the main
     // demuxer defines metadata), or special purpose demuxers like TV.
@@ -185,16 +233,6 @@ typedef struct MPContext {
 
     float begin_skip; ///< start time of the current skip while on edlout mode
 
-    int global_sub_size; // this encompasses all subtitle sources
-    int global_sub_pos; // this encompasses all subtitle sources
-    int set_of_sub_pos;
-    int set_of_sub_size;
-    int sub_counts[SUB_SOURCES];
-    // set_of_ass_tracks[i] contains subtitles from set_of_subtitles[i]
-    // parsed by libass or NULL if format unsupported
-    struct ass_track *set_of_ass_tracks[MAX_SUBTITLE_FILES];
-    sub_data* set_of_subtitles[MAX_SUBTITLE_FILES];
-    bool track_was_native_ass[MAX_SUBTITLE_FILES];
     struct ass_library *ass_library;
 
     int file_format;
@@ -240,8 +278,10 @@ char *chapter_display_name(struct MPContext *mpctx, int chapter);
 char *chapter_name(struct MPContext *mpctx, int chapter);
 double chapter_start_time(struct MPContext *mpctx, int chapter);
 int get_chapter_count(struct MPContext *mpctx);
-void update_subtitles(struct MPContext *mpctx, double refpts, bool reset);
-
+void mp_switch_track(struct MPContext *mpctx, enum stream_type type,
+                     struct track *track);
+struct track *mp_track_by_tid(struct MPContext *mpctx, enum stream_type type,
+                              int tid);
 
 // timeline/tl_matroska.c
 void build_ordered_chapter_timeline(struct MPContext *mpctx);