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. --- sub/sd_ass.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'sub/sd_ass.c') diff --git a/sub/sd_ass.c b/sub/sd_ass.c index 6f3e24a6f9..f8b1180560 100644 --- a/sub/sd_ass.c +++ b/sub/sd_ass.c @@ -59,7 +59,7 @@ static bool supports_format(const char *format) static int init(struct sd *sd) { struct MPOpts *opts = sd->opts; - if (!sd->ass_library || !sd->ass_renderer || !sd->codec) + if (!sd->ass_library || !sd->ass_renderer || !sd->ass_lock || !sd->codec) return -1; struct sd_ass_priv *ctx = talloc_zero(NULL, struct sd_ass_priv); @@ -67,6 +67,8 @@ static int init(struct sd *sd) ctx->is_converted = sd->converted_from != NULL; + pthread_mutex_lock(sd->ass_lock); + ctx->ass_track = ass_new_track(sd->ass_library); if (!ctx->is_converted) ctx->ass_track->track_type = TRACK_TYPE_ASS; @@ -78,6 +80,8 @@ static int init(struct sd *sd) mp_ass_add_default_styles(ctx->ass_track, opts); + pthread_mutex_unlock(sd->ass_lock); + return 0; } @@ -197,6 +201,8 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res dim, double pts, if (pts == MP_NOPTS_VALUE || !sd->ass_renderer) return; + pthread_mutex_lock(sd->ass_lock); + ASS_Renderer *renderer = sd->ass_renderer; double scale = dim.display_par; if (!ctx->is_converted && (!opts->ass_style_override || @@ -224,6 +230,8 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res dim, double pts, if (!ctx->is_converted) mangle_colors(sd, res); + + pthread_mutex_unlock(sd->ass_lock); } struct buf { -- cgit v1.2.3