[vlc-devel] [PATCH] avcodec: only disable frame threading if DXVA2 is likely to be used

[Steve Lhomme]

On Wed, Apr 1, 2015 at 12:44 PM, Jean-Baptiste Kempf <jb at videolan.org> wrote:
> On 31 Mar, Steve Lhomme wrote :
>> +# if defined(_WIN32)
>>      /* Workaround: frame multithreading is not compatible with
>>       * DXVA2. When a frame is being copied to host memory, the frame
>>       * is locked and cannot be used as a reference frame
>>       * simultaneously and thus decoding fails for some frames. This
>>       * causes major image corruption. */
>> -# if defined(_WIN32)
>> -    char *avcodec_hw = var_InheritString( p_dec, "avcodec-hw" );
>> -    if( avcodec_hw == NULL || strcasecmp( avcodec_hw, "none" ) )
>> +    enum PixelFormat test_formats[] = { AV_PIX_FMT_DXVA2_VLD, AV_PIX_FMT_NONE };
>> +    if( AV_PIX_FMT_DXVA2_VLD == ffmpeg_GetFormat( p_context, &test_formats ) )
>
> Are you sure calling ffmpeg_GetFormat from here is a good idea?
> IIRC ffmpeg_GetFormat was first deleting any existing p_va and so on...
> Is it safe?

I could pass a flag to tell to just check for the format without
deleting the previous p_va. Or do a separate function to just check
the right format.

That would make logs a little less verbose too.