qsvdec: do not sync PIX_FMT_QSV surfaces

Introducing enforced sync points in arbitrary places is bad for
performance. Since the vast majority of receiving code (QSV VPP or
encoders, retrieving frames through hwcontext) will do the syncing, this
change should not be visible to most callers. But bumping micro just in
case.

This is also consistent with what VAAPI hwaccel does.

libavcodec/qsvdec.c

@@ -363,9 +363,11 @@ static int qsv_decode(AVCodecContext *avctx, QSVContext *q,
         av_fifo_generic_read(q->async_fifo, &sync,      sizeof(sync),      NULL);
         out_frame->queued = 0;
 
-        do {
-            ret = MFXVideoCORE_SyncOperation(q->session, *sync, 1000);
-        } while (ret == MFX_WRN_IN_EXECUTION);
+        if (avctx->pix_fmt != AV_PIX_FMT_QSV) {
+            do {
+                ret = MFXVideoCORE_SyncOperation(q->session, *sync, 1000);
+            } while (ret == MFX_WRN_IN_EXECUTION);
+        }
 
         av_freep(&sync);
 

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR 57
 #define LIBAVCODEC_VERSION_MINOR 30
-#define LIBAVCODEC_VERSION_MICRO  3
+#define LIBAVCODEC_VERSION_MICRO  4
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \