From 5d82c078ea93d7eee12ff863a4f9eb5fb2d30d16 Mon Sep 17 00:00:00 2001
From: Gyan Doshi <ffmpeg@gyani.pro>
Date: Fri, 3 Jan 2020 12:30:09 +0530
Subject: [PATCH] ffmpeg: don't force source-tracked keyframes for duplicates

Prevents a run of consecutive duplicate frames from all being encoded
as keyframes, when force_key_frames is set to source.
---
 fftools/ffmpeg.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 2c5fcc0532..6bcd7b94d2 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -1266,7 +1266,8 @@ static void do_video_out(OutputFile *of,
             ost->forced_keyframes_expr_const_values[FKF_N] += 1;
         } else if (   ost->forced_keyframes
                    && !strncmp(ost->forced_keyframes, "source", 6)
-                   && in_picture->key_frame==1) {
+                   && in_picture->key_frame==1
+                   && !i) {
             forced_keyframe = 1;
         }