Merge commit '40af330a'

* commit '40af330a':
  avconv: vda: Unlock the pixel buffer once it is accessed

See: c06fdaccMerged-by: Michael Niedermayer <michaelni@gmx.at>

ffmpeg_vda.c

@@ -76,9 +76,10 @@ static int vda_retrieve_data(AVCodecContext *s, AVFrame *frame)
                   (const uint8_t **)data, linesize, vda->tmp_frame->format,
                   frame->width, frame->height);
 
-    ret = av_frame_copy_props(vda->tmp_frame, frame);
     CVPixelBufferUnlockBaseAddress(pixbuf, kCVPixelBufferLock_ReadOnly);
 
+    ret = av_frame_copy_props(vda->tmp_frame, frame);
+
     if (ret < 0)
         return ret;