deps-libff: Add reference counting to clock

Add referencing counting to determine when to release a clock Due to no fixed ownership of clocks (packets, frames, decoders and  refresh thread all may own a clock at some point).

deps/libff/libff/ff-clock.c

@@ -15,8 +15,60 @@
  */
 
 #include "ff-clock.h"
+#include "ff-threading.h"
+
+#include <libavutil/avutil.h>
 
 double ff_get_sync_clock(struct ff_clock *clock)
 {
 	return clock->sync_clock(clock->opaque);
 }
+
+struct ff_clock *ff_clock_init(struct ff_clock *clock)
+{
+	clock = av_mallocz(sizeof(struct ff_clock));
+
+	if (clock == NULL)
+		return NULL;
+
+	if (pthread_mutex_init(&clock->mutex, NULL) != 0)
+		goto fail;
+
+	if (pthread_cond_init(&clock->cond, NULL) != 0)
+		goto fail1;
+
+	return clock;
+
+fail1:
+	pthread_mutex_destroy(&clock->mutex);
+fail:
+	av_free(clock);
+
+	return NULL;
+}
+
+struct ff_clock *ff_clock_retain(struct ff_clock *clock)
+{
+	ff_atomic_inc_long(&clock->retain);
+
+	return clock;
+}
+
+struct ff_clock *ff_clock_move(struct ff_clock **clock)
+{
+	struct ff_clock *retained_clock = ff_clock_retain(*clock);
+	ff_clock_release(clock);
+
+	return retained_clock;
+}
+
+void ff_clock_release(struct ff_clock **clock)
+{
+	if (ff_atomic_dec_long(&(*clock)->retain) == 0) {
+		pthread_cond_destroy(&(*clock)->cond);
+		pthread_mutex_destroy(&(*clock)->mutex);
+		av_free(*clock);
+	}
+
+	*clock = NULL;
+}

deps/libff/libff/ff-clock.h

@@ -19,6 +19,9 @@
 #define AV_SYNC_THRESHOLD 0.01
 #define AV_NOSYNC_THRESHOLD 10.0
 
+#include <stdbool.h>
+#include <pthread.h>
+
 enum ff_av_sync_type {
 	AV_SYNC_AUDIO_MASTER,
 	AV_SYNC_VIDEO_MASTER,
@@ -30,9 +33,18 @@ typedef double (*ff_sync_clock)(void *opaque);
 struct ff_clock {
 	ff_sync_clock sync_clock;
 	enum ff_av_sync_type sync_type;
+
+	pthread_mutex_t mutex;
+	pthread_cond_t cond;
+	volatile long retain;
+
 	void *opaque;
 };
 
 typedef struct ff_clock ff_clock_t;
 
+struct ff_clock * ff_clock_init();
 double ff_get_sync_clock(struct ff_clock *clock);
+struct ff_clock *ff_clock_retain(struct ff_clock *clock);
+struct ff_clock *ff_clock_move(struct ff_clock **clock);
+void ff_clock_release(struct ff_clock **clock);