Merge commit 'aa9d15d89bb4ee8a31607d3db1b8c5334eb88d2d'

* commit 'aa9d15d89bb4ee8a31607d3db1b8c5334eb88d2d':
  qsvdec: avoid an infinite loop with no consumed data and no output

Conflicts:
	libavcodec/qsvdec.c

Merged-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/qsvdec.c

@@ -339,6 +339,13 @@ int ff_qsv_decode(AVCodecContext *avctx, QSVContext *q,
             break;
     }
 
+    /* make sure we do not enter an infinite loop if the SDK
+     * did not consume any data and did not return anything */
+    if (!sync && !bs.DataOffset) {
+        av_log(avctx, AV_LOG_WARNING, "A decode call did not consume any data\n");
+        bs.DataOffset = avpkt->size;
+    }
+
     if (buffered) {
         qsv_fifo_relocate(q->input_fifo, bs.DataOffset);
     } else if (bs.DataOffset!=avpkt->size) {