From ef9478d2646342b900d156ea64d3a3c9035529ac Mon Sep 17 00:00:00 2001
From: Aman Gupta <aman@tmm1.net>
Date: Thu, 19 Apr 2018 15:34:01 -0700
Subject: [PATCH] avcodec/videotoolbox: fix kVTCouldNotFindVideoDecoderErr
 trying to decode HEVC on iOS

Older iOS devices don't have a hardware HEVC decoder, but the
software decoder offered by VideoToolbox is well-optimized and
performs much better than the ffmpeg decoder.

Signed-off-by: Aman Gupta <aman@tmm1.net>
(cherry picked from commit bcff983dc340e76518935111146c0e1daf4cb37b)
---
 libavcodec/videotoolbox.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/libavcodec/videotoolbox.c b/libavcodec/videotoolbox.c
index 6dd800daf8..8671608a35 100644
--- a/libavcodec/videotoolbox.c
+++ b/libavcodec/videotoolbox.c
@@ -36,6 +36,9 @@
 #ifndef kVTVideoDecoderSpecification_RequireHardwareAcceleratedVideoDecoder
 #  define kVTVideoDecoderSpecification_RequireHardwareAcceleratedVideoDecoder CFSTR("RequireHardwareAcceleratedVideoDecoder")
 #endif
+#ifndef kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder
+#  define kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder CFSTR("EnableHardwareAcceleratedVideoDecoder")
+#endif
 
 #if !HAVE_KCMVIDEOCODECTYPE_HEVC
 enum { kCMVideoCodecType_HEVC = 'hvc1' };
@@ -709,7 +712,9 @@ static CFDictionaryRef videotoolbox_decoder_config_create(CMVideoCodecType codec
                                                                    &kCFTypeDictionaryValueCallBacks);
 
     CFDictionarySetValue(config_info,
-                         kVTVideoDecoderSpecification_RequireHardwareAcceleratedVideoDecoder,
+                         codec_type == kCMVideoCodecType_HEVC ?
+                            kVTVideoDecoderSpecification_EnableHardwareAcceleratedVideoDecoder :
+                            kVTVideoDecoderSpecification_RequireHardwareAcceleratedVideoDecoder,
                          kCFBooleanTrue);
 
     CFMutableDictionaryRef avc_info;