demux_edl, cue, mkv: clean up timeline stuff slightly

Remove the singly linked list hack, replace it with a slightly more
proper data structure. This probably gets rid of a few minor bugs along
the way, caused by the awkward nonsensical sharing/duplication of some
fields.

Another change (because I'm touching everything related to timeline
anyway) is that I'm removing the special semantics for parts[num_parts].
This is now strictly out of bounds, and instead of using the start time
of the next/beyond-last part, there is an end time field now.

Unfortunately, this also requires touching the code for cue and mkv
ordered chapters. From some superficial testing, they still seem to
mostly work.

One observable change is that the "no_chapters" header is per-stream
now, which is arguably more correct, and getting the old behavior would
require adding code to handle it as special-case, so just adjust
ytdl_hook.lua to the new behavior.

1 files changed, 25 insertions, 19 deletions

diff --git a/demux/demux_mkv_timeline.c b/demux/demux_mkv_timeline.c
index 1408ddf8f5..6d52995e26 100644
--- a/demux/demux_mkv_timeline.c
+++ b/demux/demux_mkv_timeline.c
@@ -455,12 +455,10 @@ static void build_timeline_loop(struct tl_ctx *ctx,
         ctx->missing_time += info->limit - local_starttime;
 }
 
-static void check_track_compatibility(struct timeline *tl)
+static void check_track_compatibility(struct tl_ctx *tl, struct demuxer *mainsrc)
 {
-    struct demuxer *mainsrc = tl->track_layout;
-
     for (int n = 0; n < tl->num_parts; n++) {
-        struct timeline_part *p = &tl->parts[n];
+        struct timeline_part *p = &tl->timeline[n];
         if (p->source == mainsrc)
             continue;
 
@@ -593,10 +591,11 @@ void build_ordered_chapter_timeline(struct timeline *tl)
         MP_TARRAY_APPEND(NULL, ctx->timeline, ctx->num_parts, new);
     }
 
-    struct timeline_part new = {
-        .start = ctx->start_time / 1e9,
+    for (int n = 0; n < ctx->num_parts; n++) {
+        ctx->timeline[n].end = n == ctx->num_parts - 1
+            ? ctx->start_time / 1e9
+            : ctx->timeline[n + 1].start;
     };
-    MP_TARRAY_APPEND(NULL, ctx->timeline, ctx->num_parts, new);
 
     /* Ignore anything less than a millisecond when reporting missing time. If
      * users really notice less than a millisecond missing, maybe this can be
@@ -606,22 +605,29 @@ void build_ordered_chapter_timeline(struct timeline *tl)
                ctx->missing_time / 1e9);
     }
 
-    tl->sources = ctx->sources;
-    tl->num_sources = ctx->num_sources;
-    tl->parts = ctx->timeline;
-    tl->num_parts = ctx->num_parts - 1; // minus termination
-    tl->chapters = chapters;
-    tl->num_chapters = m->num_ordered_chapters;
-
     // With Matroska, the "master" file usually dictates track layout etc.,
     // except maybe with playlist-like files.
-    tl->track_layout = tl->parts[0].source;
-    for (int n = 0; n < tl->num_parts; n++) {
-        if (tl->parts[n].source == ctx->demuxer) {
-            tl->track_layout = ctx->demuxer;
+    struct demuxer *track_layout = ctx->timeline[0].source;
+    for (int n = 0; n < ctx->num_parts; n++) {
+        if (ctx->timeline[n].source == ctx->demuxer) {
+            track_layout = ctx->demuxer;
             break;
         }
     }
 
-    check_track_compatibility(tl);
+    check_track_compatibility(ctx, track_layout);
+
+    tl->sources = ctx->sources;
+    tl->num_sources = ctx->num_sources;
+
+    struct timeline_par *par = talloc_ptrtype(tl, par);
+    *par = (struct timeline_par){
+        .parts = ctx->timeline,
+        .num_parts = ctx->num_parts,
+        .track_layout = track_layout,
+    };
+    MP_TARRAY_APPEND(tl, tl->pars, tl->num_pars, par);
+    tl->chapters = chapters;
+    tl->num_chapters = m->num_ordered_chapters;
+    tl->meta = track_layout;
 }