From 6614f33a0b3862753f743253afdb8e1944e26167 Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Date: Fri, 26 Mar 2021 12:42:21 +0100
Subject: [PATCH] avcodec/qtrleenc: Use keyframe when no previous frame is
 available

If keeping a reference to an earlier frame failed, the next frame must
be an I frame for lack of reference frame. This commit implements this.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
(cherry picked from commit d5fc16a6a87a24360312b812a560e7a3664e3791)
---
 libavcodec/qtrleenc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavcodec/qtrleenc.c b/libavcodec/qtrleenc.c
index 8b0edf7b3d..0f5bedcdcd 100644
--- a/libavcodec/qtrleenc.c
+++ b/libavcodec/qtrleenc.c
@@ -369,7 +369,8 @@ static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size, 0)) < 0)
         return ret;
 
-    if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
+    if (avctx->gop_size == 0 || !s->previous_frame->data[0] ||
+        (s->avctx->frame_number % avctx->gop_size) == 0) {
         /* I-Frame */
         s->key_frame = 1;
     } else {