[FFmpeg-devel] [PATCH] avcodec/videotoolbox: fix kVTCouldNotFindVideoDecoderErr trying to decode HEVC on iOS

[Rodger Combs]

If there was a way to indicate this to consumers, or expose an option to turn this off, I'd say it should have that... but there's no good infrastructure to do that in an hwaccel, so whatever.
One nit; otherwise LGTM.

> On Apr 19, 2018, at 17:34, Aman Gupta <ffmpeg at tmm1.net> wrote:
> 
> From: Aman Gupta <aman at tmm1.net>
> 
> 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.
> ---
> libavcodec/videotoolbox.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/libavcodec/videotoolbox.c b/libavcodec/videotoolbox.c
> index 57b6698e1b..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;
> @@ -833,6 +838,9 @@ static int videotoolbox_start(AVCodecContext *avctx)
>     case kVTVideoDecoderUnsupportedDataFormatErr:
>         av_log(avctx, AV_LOG_VERBOSE, "VideoToolbox does not support this format.\n");
>         return AVERROR(ENOSYS);
> +    case kVTCouldNotFindVideoDecoderErr:
> +        av_log(avctx, AV_LOG_VERBOSE, "VideoToolbox decoder for this format not found.\n");
> +        return AVERROR(ENOSYS);
>     case kVTVideoDecoderMalfunctionErr:
>         av_log(avctx, AV_LOG_VERBOSE, "VideoToolbox malfunction.\n");
>         return AVERROR(EINVAL);
> @@ -842,7 +850,7 @@ static int videotoolbox_start(AVCodecContext *avctx)
>     case 0:
>         return 0;
>     default:
> -        av_log(avctx, AV_LOG_VERBOSE, "Unknown VideoToolbox session creation error %u\n", (unsigned)status);
> +        av_log(avctx, AV_LOG_VERBOSE, "Unknown VideoToolbox session creation error %d\n", (int)status);

Bit tangential; should be its own commit. Maybe just combine the two logging changes.

>         return AVERROR_UNKNOWN;
>     }
> }
> -- 
> 2.14.2
>