player: rearrange how subtitle context and stream headers are used

Use sh_stream over sh_sub. Use dec_sub (and mpctx->d_sub) instead of the
stream header. This aligns the subtitle code with the recent audio and
video refactoring.

sh_sub still has the decoder context, though. This is because we want to
avoid reinit when switching segments with ordered chapters. (Reinit is
fast, except for creating the ASS_Renderer, which in turn triggers
fontconfig.) Not sure how much this matters, though, because the initial
segment switch will lazily initialize the decoder anyway.

5 files changed, 57 insertions, 54 deletions

diff --git a/mpvcore/player/loadfile.c b/mpvcore/player/loadfile.c
index 51d3f2ec7e..33ee770b08 100644
--- a/mpvcore/player/loadfile.c
+++ b/mpvcore/player/loadfile.c
@@ -80,9 +80,10 @@ void uninit_player(struct MPContext *mpctx, unsigned int mask)
 
     if (mask & INITIALIZED_SUB) {
         mpctx->initialized_flags &= ~INITIALIZED_SUB;
-        if (mpctx->sh_sub)
-            sub_reset(mpctx->sh_sub->dec_sub);
+        if (mpctx->d_sub)
+            sub_reset(mpctx->d_sub);
         cleanup_demux_stream(mpctx, STREAM_SUB);
+        mpctx->d_sub = NULL; // Note: not free'd.
         mpctx->osd->dec_sub = NULL;
         reset_subtitles(mpctx);
     }
@@ -108,13 +109,15 @@ void uninit_player(struct MPContext *mpctx, unsigned int mask)
 
     if (mask & INITIALIZED_DEMUXER) {
         mpctx->initialized_flags &= ~INITIALIZED_DEMUXER;
+        assert(!(mpctx->initialized_flags &
+                 (INITIALIZED_VCODEC | INITIALIZED_ACODEC | INITIALIZED_SUB)));
         for (int i = 0; i < mpctx->num_tracks; i++) {
             talloc_free(mpctx->tracks[i]);
         }
         mpctx->num_tracks = 0;
         for (int t = 0; t < STREAM_TYPE_COUNT; t++)
             mpctx->current_track[t] = NULL;
-        assert(!mpctx->d_video && !mpctx->d_audio && !mpctx->sh_sub);
+        assert(!mpctx->d_video && !mpctx->d_audio && !mpctx->d_sub);
         mpctx->master_demuxer = NULL;
         for (int i = 0; i < mpctx->num_sources; i++) {
             uninit_subs(mpctx->sources[i]);
@@ -264,22 +267,12 @@ static void print_file_properties(struct MPContext *mpctx)
     }
 }
 
-static void set_demux_field(struct MPContext *mpctx, enum stream_type type,
-                            struct sh_stream *s)
-{
-    mpctx->sh[type] = s;
-    // redundant fields for convenience access
-    switch(type) {
-        case STREAM_SUB: mpctx->sh_sub = s ? s->sub : NULL; break;
-    }
-}
-
 struct sh_stream *init_demux_stream(struct MPContext *mpctx,
                                     enum stream_type type)
 {
     struct track *track = mpctx->current_track[type];
-    set_demux_field(mpctx, type, track ? track->stream : NULL);
-    struct sh_stream *stream = mpctx->sh[type];
+    struct sh_stream *stream = track ? track->stream : NULL;
+    mpctx->sh[type] = stream;
     if (stream) {
         demuxer_switch_track(stream->demuxer, type, stream);
         if (track->is_external) {
@@ -295,7 +288,7 @@ void cleanup_demux_stream(struct MPContext *mpctx, enum stream_type type)
     struct sh_stream *stream = mpctx->sh[type];
     if (stream)
         demuxer_switch_track(stream->demuxer, type, NULL);
-    set_demux_field(mpctx, type, NULL);
+    mpctx->sh[type] = NULL;
 }
 
 // Switch the demuxers to current track selection. This is possibly important
@@ -1051,7 +1044,7 @@ static void play_current_file(struct MPContext *mpctx)
     assert(mpctx->demuxer == NULL);
     assert(mpctx->d_audio == NULL);
     assert(mpctx->d_video == NULL);
-    assert(mpctx->sh_sub == NULL);
+    assert(mpctx->d_sub == NULL);
 
     char *stream_filename = mpctx->filename;
     mpctx->resolve_result = resolve_url(stream_filename, opts);
diff --git a/mpvcore/player/mp_core.h b/mpvcore/player/mp_core.h
index f372c4e137..0be7e1df1f 100644
--- a/mpvcore/player/mp_core.h
+++ b/mpvcore/player/mp_core.h
@@ -199,10 +199,10 @@ typedef struct MPContext {
     struct track *current_track[STREAM_TYPE_COUNT];
 
     struct sh_stream *sh[STREAM_TYPE_COUNT];
-    struct sh_sub *sh_sub;              // same as sh[STREAM_SUB]->sub
 
     struct dec_video *d_video;
     struct dec_audio *d_audio;
+    struct dec_sub *d_sub;
 
     // Uses: accessing metadata (consider ordered chapters case, where the main
     // demuxer defines metadata), or special purpose demuxers like TV.
diff --git a/mpvcore/player/sub.c b/mpvcore/player/sub.c
index d659e74851..bdcb9def09 100644
--- a/mpvcore/player/sub.c
+++ b/mpvcore/player/sub.c
@@ -67,8 +67,8 @@ static bool is_interleaved(struct MPContext *mpctx, struct track *track)
 
 void reset_subtitles(struct MPContext *mpctx)
 {
-    if (mpctx->sh_sub)
-        sub_reset(mpctx->sh_sub->dec_sub);
+    if (mpctx->d_sub)
+        sub_reset(mpctx->d_sub);
     set_osd_subtitle(mpctx, NULL);
     osd_changed(mpctx->osd, OSDTYPE_SUB);
 }
@@ -80,9 +80,8 @@ void update_subtitles(struct MPContext *mpctx)
         return;
 
     struct track *track = mpctx->current_track[STREAM_SUB];
-    struct sh_sub *sh_sub = mpctx->sh_sub;
-    assert(track && sh_sub);
-    struct dec_sub *dec_sub = sh_sub->dec_sub;
+    struct dec_sub *dec_sub = mpctx->d_sub;
+    assert(track && dec_sub);
 
     if (mpctx->d_video && mpctx->d_video->vf_input) {
         struct mp_image_params params = *mpctx->d_video->vf_input;
@@ -94,14 +93,17 @@ void update_subtitles(struct MPContext *mpctx)
     double refpts_s = mpctx->playback_pts - mpctx->osd->video_offset;
     double curpts_s = refpts_s + opts->sub_delay;
 
-    if (!track->preloaded) {
+    if (!track->preloaded && track->stream) {
+        struct sh_stream *sh_stream = track->stream;
         bool interleaved = is_interleaved(mpctx, track);
 
+        assert(sh_stream->sub->dec_sub == dec_sub);
+
         while (1) {
-            if (interleaved && !demux_has_packet(sh_sub->gsh))
+            if (interleaved && !demux_has_packet(sh_stream))
                 break;
-            double subpts_s = demux_get_next_pts(sh_sub->gsh);
-            if (!demux_has_packet(sh_sub->gsh))
+            double subpts_s = demux_get_next_pts(sh_stream);
+            if (!demux_has_packet(sh_stream))
                 break;
             if (subpts_s > curpts_s) {
                 mp_dbg(MSGT_CPLAYER, MSGL_DBG2,
@@ -114,7 +116,7 @@ void update_subtitles(struct MPContext *mpctx)
                 if (subpts_s > curpts_s + 1 && !interleaved)
                     break;
             }
-            struct demux_packet *pkt = demux_read_packet(sh_sub->gsh);
+            struct demux_packet *pkt = demux_read_packet(sh_stream);
             mp_dbg(MSGT_CPLAYER, MSGL_V, "Sub: c_pts=%5.3f s_pts=%5.3f "
                    "duration=%5.3f len=%d\n", curpts_s, pkt->pts, pkt->duration,
                    pkt->len);
@@ -177,21 +179,27 @@ void reinit_subs(struct MPContext *mpctx)
     assert(!(mpctx->initialized_flags & INITIALIZED_SUB));
 
     init_demux_stream(mpctx, STREAM_SUB);
-    if (!mpctx->sh_sub)
+    struct sh_stream *sh = mpctx->sh[STREAM_SUB];
+
+    // No track selected, or lazily added DVD track (will actually be created
+    // on first sub packet)
+    if (!sh)
         return;
 
-    if (!mpctx->sh_sub->dec_sub)
-        mpctx->sh_sub->dec_sub = sub_create(opts);
+    if (!sh->sub->dec_sub) {
+        assert(!mpctx->d_sub);
+        sh->sub->dec_sub = sub_create(opts);
+    }
 
-    assert(track->demuxer);
-    // Lazily added DVD track - will be created on first sub packet
-    if (!track->stream)
-        return;
+    assert(!mpctx->d_sub || sh->sub->dec_sub == mpctx->d_sub);
+
+    // The decoder is kept in the stream header in order to make ordered
+    // chapters work well.
+    mpctx->d_sub = sh->sub->dec_sub;
 
     mpctx->initialized_flags |= INITIALIZED_SUB;
 
-    struct sh_sub *sh_sub = mpctx->sh_sub;
-    struct dec_sub *dec_sub = sh_sub->dec_sub;
+    struct dec_sub *dec_sub = mpctx->d_sub;
     assert(dec_sub);
 
     if (!sub_is_initialized(dec_sub)) {
@@ -206,14 +214,14 @@ void reinit_subs(struct MPContext *mpctx)
         sub_set_video_fps(dec_sub, fps);
         sub_set_ass_renderer(dec_sub, mpctx->osd->ass_library,
                              mpctx->osd->ass_renderer);
-        sub_init_from_sh(dec_sub, sh_sub);
+        sub_init_from_sh(dec_sub, sh);
 
         // Don't do this if the file has video/audio streams. Don't do it even
         // if it has only sub streams, because reading packets will change the
         // demuxer position.
         if (!track->preloaded && track->is_external) {
             demux_seek(track->demuxer, 0, SEEK_ABSOLUTE);
-            track->preloaded = sub_read_all_packets(dec_sub, sh_sub);
+            track->preloaded = sub_read_all_packets(dec_sub, sh);
         }
     }
 
diff --git a/sub/dec_sub.c b/sub/dec_sub.c
index 1a6cc6b0aa..cb76acc248 100644
--- a/sub/dec_sub.c
+++ b/sub/dec_sub.c
@@ -162,15 +162,16 @@ static int sub_init_decoder(struct dec_sub *sub, struct sd *sd)
     return 0;
 }
 
-void sub_init_from_sh(struct dec_sub *sub, struct sh_sub *sh)
+void sub_init_from_sh(struct dec_sub *sub, struct sh_stream *sh)
 {
     assert(!sub->num_sd);
+    assert(sh && sh->sub);
 
-    if (sh->extradata && !sub->init_sd.extradata)
-        sub_set_extradata(sub, sh->extradata, sh->extradata_len);
+    if (sh->sub->extradata && !sub->init_sd.extradata)
+        sub_set_extradata(sub, sh->sub->extradata, sh->sub->extradata_len);
     struct sd init_sd = sub->init_sd;
-    init_sd.codec = sh->gsh->codec;
-    init_sd.ass_track = sh->track;
+    init_sd.codec = sh->codec;
+    init_sd.ass_track = sh->sub->track;
 
     while (sub->num_sd < MAX_NUM_SD) {
         struct sd *sd = talloc(NULL, struct sd);
@@ -199,7 +200,7 @@ void sub_init_from_sh(struct dec_sub *sub, struct sh_sub *sh)
 
     sub_uninit(sub);
     mp_msg(MSGT_OSD, MSGL_ERR, "Could not find subtitle decoder for format '%s'.\n",
-           sh->gsh->codec ? sh->gsh->codec : "<unknown>");
+           sh->codec ? sh->codec : "<unknown>");
 }
 
 static struct demux_packet *get_decoded_packet(struct sd *sd)
@@ -362,11 +363,12 @@ static void add_packet(struct packet_list *subs, struct demux_packet *pkt)
 
 // Read all packets from the demuxer and decode/add them. Returns false if
 // there are circumstances which makes this not possible.
-bool sub_read_all_packets(struct dec_sub *sub, struct sh_sub *sh)
+bool sub_read_all_packets(struct dec_sub *sub, struct sh_stream *sh)
 {
+    assert(sh && sh->sub);
     struct MPOpts *opts = sub->opts;
 
-    if (!sub_accept_packets_in_advance(sub) || sh->track || sub->num_sd < 1)
+    if (!sub_accept_packets_in_advance(sub) || sh->sub->track || sub->num_sd < 1)
         return false;
 
     struct packet_list *subs = talloc_zero(NULL, struct packet_list);
@@ -385,7 +387,7 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_sub *sh)
         preprocess = 1;
 
     for (;;) {
-        struct demux_packet *pkt = demux_read_packet(sh->gsh);
+        struct demux_packet *pkt = demux_read_packet(sh);
         if (!pkt)
             break;
         if (preprocess) {
@@ -403,7 +405,7 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_sub *sh)
         }
     }
 
-    if (opts->sub_cp && !sh->is_utf8)
+    if (opts->sub_cp && !sh->sub->is_utf8)
         sub->charset = guess_sub_cp(subs, opts->sub_cp);
 
     if (sub->charset && sub->charset[0] && !mp_charset_is_utf8(sub->charset))
@@ -412,7 +414,7 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_sub *sh)
     double sub_speed = 1.0;
 
     // 23.976 FPS is used as default timebase for frame based formats
-    if (sub->video_fps && sh->frame_based)
+    if (sub->video_fps && sh->sub->frame_based)
         sub_speed *= sub->video_fps / 23.976;
 
     if (opts->sub_fps && sub->video_fps)
@@ -426,7 +428,7 @@ bool sub_read_all_packets(struct dec_sub *sub, struct sh_sub *sh)
     if (!opts->suboverlap_enabled)
         fix_overlaps_and_gaps(subs);
 
-    if (sh->gsh->codec && strcmp(sh->gsh->codec, "microdvd") == 0) {
+    if (sh->codec && strcmp(sh->codec, "microdvd") == 0) {
         // The last subtitle event in MicroDVD subs can have duration unset,
         // which means show the subtitle until end of video.
         // See FFmpeg FATE MicroDVD_capability_tester.sub
diff --git a/sub/dec_sub.h b/sub/dec_sub.h
index b269326cac..9ff2b366bd 100644
--- a/sub/dec_sub.h
+++ b/sub/dec_sub.h
@@ -6,7 +6,7 @@
 
 #include "sub/sub.h"
 
-struct sh_sub;
+struct sh_stream;
 struct ass_track;
 struct MPOpts;
 struct demux_packet;
@@ -29,11 +29,11 @@ void sub_set_video_fps(struct dec_sub *sub, double fps);
 void sub_set_extradata(struct dec_sub *sub, void *data, int data_len);
 void sub_set_ass_renderer(struct dec_sub *sub, struct ass_library *ass_library,
                           struct ass_renderer *ass_renderer);
-void sub_init_from_sh(struct dec_sub *sub, struct sh_sub *sh);
+void sub_init_from_sh(struct dec_sub *sub, struct sh_stream *sh);
 
 bool sub_is_initialized(struct dec_sub *sub);
 
-bool sub_read_all_packets(struct dec_sub *sub, struct sh_sub *sh);
+bool sub_read_all_packets(struct dec_sub *sub, struct sh_stream *sh);
 bool sub_accept_packets_in_advance(struct dec_sub *sub);
 void sub_decode(struct dec_sub *sub, struct demux_packet *packet);
 void sub_get_bitmaps(struct dec_sub *sub, struct mp_osd_res dim, double pts,