From 6ed694f6174fefb434c95d38f7d47b73bacc1c6e Mon Sep 17 00:00:00 2001
From: jp9000 <obs.jim@gmail.com>
Date: Sat, 4 Jul 2015 21:57:00 -0700
Subject: [PATCH] deps-libff: Fix starting timestamp bug

Certain input streams (such as remote streams that are already active)
can start up mid-stream with a very high initial timestamp values.
Because of this, it would cause the libff timer to delay for that
initial timestamp, which often would cause it to not render at all
because it was stuck waiting.

To fix the problem, we should ignore the timestamp difference of the
first frame when it's above a certain threshold.
---
 deps/libff/libff/ff-decoder.c | 13 ++++++++++++-
 deps/libff/libff/ff-decoder.h |  1 +
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/deps/libff/libff/ff-decoder.c b/deps/libff/libff/ff-decoder.c
index 70125d694..3eb658ca8 100644
--- a/deps/libff/libff/ff-decoder.c
+++ b/deps/libff/libff/ff-decoder.c
@@ -52,6 +52,7 @@ struct ff_decoder *ff_decoder_init(AVCodecContext *codec_context,
 	decoder->current_pts_time = av_gettime();
 	decoder->start_pts = 0;
 	decoder->predicted_pts = 0;
+	decoder->first_frame = true;
 
 	success = ff_timer_init(&decoder->refresh_timer, ff_decoder_refresh,
 			decoder);
@@ -195,6 +196,8 @@ void ff_decoder_refresh(void *opaque)
 		} else {
 			double pts_diff;
 			double delay_until_next_wake;
+			bool late_first_frame = false;
+
 			frame = ff_circular_queue_peek_read(
 					&decoder->frame_queue);
 
@@ -234,7 +237,15 @@ void ff_decoder_refresh(void *opaque)
 			// frame
 			pts_diff = frame->pts - decoder->previous_pts;
 
-			if (pts_diff <= 0) {
+			// if the first frame is a very large value, we've most
+			// likely started mid-stream, and the initial diff
+			// should be ignored.
+			if (decoder->first_frame) {
+				late_first_frame = pts_diff >= 1.0;
+				decoder->first_frame = false;
+			}
+
+			if (pts_diff <= 0 || late_first_frame) {
 				// if diff is invalid, use previous
 				pts_diff = decoder->previous_pts_diff;
 			}
diff --git a/deps/libff/libff/ff-decoder.h b/deps/libff/libff/ff-decoder.h
index ed05fd552..c0df5fc15 100644
--- a/deps/libff/libff/ff-decoder.h
+++ b/deps/libff/libff/ff-decoder.h
@@ -53,6 +53,7 @@ struct ff_decoder {
 	struct ff_clock *clock;
 	enum ff_av_sync_type natural_sync_clock;
 
+	bool first_frame;
 	bool eof;
 	bool abort;
 };