From 9f26d670e447767683ed21b1b5ac16423eba4c72 Mon Sep 17 00:00:00 2001
From: jerett <wj.jiang@outlook.com>
Date: Fri, 23 Jun 2017 08:58:35 -0400
Subject: [PATCH] lavc/videotoolboxenc: fix open videotoolbox bug on iOS8.4

Checks for NULL before using object.

Signed-off-by: Rick Kern <kernrj@gmail.com>
---
 libavcodec/videotoolboxenc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/videotoolboxenc.c b/libavcodec/videotoolboxenc.c
index 7b901dbd69..22eaeb0a60 100644
--- a/libavcodec/videotoolboxenc.c
+++ b/libavcodec/videotoolboxenc.c
@@ -1285,7 +1285,7 @@ static av_cold int vtenc_init(AVCodecContext *avctx)
                                    kCFAllocatorDefault,
                                    &has_b_frames_cfbool);
 
-    if (!status) {
+    if (!status && has_b_frames_cfbool) {
         //Some devices don't output B-frames for main profile, even if requested.
         vtctx->has_b_frames = CFBooleanGetValue(has_b_frames_cfbool);
         CFRelease(has_b_frames_cfbool);