From 385febe27632075160c903a22502fcb78b160ae4 Mon Sep 17 00:00:00 2001 From: wm4 Date: Mon, 6 Jul 2015 21:55:37 +0200 Subject: sub: protect ASS_Renderer state Each subtitle track gets its own decoder instance (sd_ass). But they use a shared ASS_Renderer. This is done mainly because of fontconfig. Initializing fontconfig is very slow when using it with memory fonts, so there's a practical need to cache this memory font state, which is done by not creating separate ASS_Renderers. This is very dirty and very evil, but we probably can't get rid of it any time soon. The shared ASS_Renderer was not properly synchronized. While the program logic guarantees that only one sd_ass instance is visible at a time, there are other interactions that require synchronization. In particular, I suspect concurrent execution of mp_ass_configure_fonts() and sd_ass.get_bitmaps cause issues in a newer libass development branch. So here's a shitty hack that hopefully fixes things, hopefully only until libass becomes less dependent on fontconfig. --- player/core.h | 1 + player/main.c | 3 +++ player/sub.c | 5 ++++- 3 files changed, 8 insertions(+), 1 deletion(-) (limited to 'player') diff --git a/player/core.h b/player/core.h index 907c997b96..7b3e47d8d2 100644 --- a/player/core.h +++ b/player/core.h @@ -317,6 +317,7 @@ typedef struct MPContext { * loaded across ordered chapters, instead of reloading and rescanning * them on each transition. (Both of these objects contain this state.) */ + pthread_mutex_t ass_lock; struct ass_renderer *ass_renderer; struct ass_library *ass_library; struct mp_log *ass_log; diff --git a/player/main.c b/player/main.c index 06b1867ebe..b5d019db81 100644 --- a/player/main.c +++ b/player/main.c @@ -222,6 +222,7 @@ void mp_destroy(struct MPContext *mpctx) pthread_detach(pthread_self()); mp_msg_uninit(mpctx->global); + pthread_mutex_destroy(&mpctx->ass_lock); talloc_free(mpctx); } @@ -329,6 +330,8 @@ struct MPContext *mp_create(void) .playback_abort = mp_cancel_new(mpctx), }; + pthread_mutex_init(&mpctx->ass_lock, NULL); + mpctx->global = talloc_zero(mpctx, struct mpv_global); // Nothing must call mp_msg*() and related before this diff --git a/player/sub.c b/player/sub.c index 89da9f719c..548e7b22d9 100644 --- a/player/sub.c +++ b/player/sub.c @@ -306,12 +306,15 @@ static void reinit_subdec(struct MPContext *mpctx, struct track *track, sub_set_video_res(dec_sub, w, h); sub_set_video_fps(dec_sub, fps); - sub_set_ass_renderer(dec_sub, mpctx->ass_library, mpctx->ass_renderer); + sub_set_ass_renderer(dec_sub, mpctx->ass_library, mpctx->ass_renderer, + &mpctx->ass_lock); sub_init_from_sh(dec_sub, track->stream); if (mpctx->ass_renderer) { + pthread_mutex_lock(&mpctx->ass_lock); mp_ass_configure_fonts(mpctx->ass_renderer, opts->sub_text_style, mpctx->global, mpctx->ass_log); + pthread_mutex_unlock(&mpctx->ass_lock); } // Don't do this if the file has video/audio streams. Don't do it even -- cgit v1.2.3