Revert "Merge commit '3c53627a'"

This reverts commit d30cf57a, reversing changes made to
acc155ac. The commit d30cf57a
provided irrelevant code complexity and decoding slowdown. But the main disadvantage of this
commit is a decoder crash. So it should be reverted.
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/qsvdec.c

@@ -142,7 +142,7 @@ static int qsv_decode_init(AVCodecContext *avctx, QSVContext *q, AVPacket *avpkt
      */
     if (!q->async_fifo) {
         q->async_fifo = av_fifo_alloc((1 + 16) *
-                                      (sizeof(mfxSyncPoint*) + sizeof(QSVFrame*)));
+                                      (sizeof(mfxSyncPoint) + sizeof(QSVFrame*)));
         if (!q->async_fifo)
             return AVERROR(ENOMEM);
     }
@@ -297,16 +297,6 @@ static void close_decoder(QSVContext *q)
     if (q->session)
         MFXVideoDECODE_Close(q->session);
 
-    while (q->async_fifo && av_fifo_size(q->async_fifo)) {
-        QSVFrame *out_frame;
-        mfxSyncPoint *sync;
-
-        av_fifo_generic_read(q->async_fifo, &out_frame, sizeof(out_frame), NULL);
-        av_fifo_generic_read(q->async_fifo, &sync,      sizeof(sync),      NULL);
-
-        av_freep(&sync);
-    }
-
     cur = q->work_frames;
     while (cur) {
         q->work_frames = cur->next;
@@ -326,7 +316,7 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
     QSVFrame *out_frame;
     mfxFrameSurface1 *insurf;
     mfxFrameSurface1 *outsurf;
-    mfxSyncPoint *sync;
+    mfxSyncPoint sync;
     mfxBitstream bs = { { { 0 } } };
     int ret;
     int n_out_frames;
@@ -359,19 +349,13 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
         bs.TimeStamp  = avpkt->pts;
     }
 
-    sync = av_mallocz(sizeof(*sync));
-    if (!sync) {
-        av_freep(&sync);
-        return AVERROR(ENOMEM);
-    }
-
     while (1) {
         ret = get_surface(avctx, q, &insurf);
         if (ret < 0)
             return ret;
         do {
             ret = MFXVideoDECODE_DecodeFrameAsync(q->session, flush ? NULL : &bs,
-                                                  insurf, &outsurf, sync);
+                                                  insurf, &outsurf, &sync);
             if (ret != MFX_WRN_DEVICE_BUSY)
                 break;
             av_usleep(500);
@@ -385,11 +369,10 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
             continue;
         }
 
-        if (*sync) {
+        if (sync) {
             QSVFrame *out_frame = find_frame(q, outsurf);
 
             if (!out_frame) {
-                av_freep(&sync);
                 av_log(avctx, AV_LOG_ERROR,
                        "The returned surface does not correspond to any frame\n");
                 return AVERROR_BUG;
@@ -400,8 +383,6 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
             av_fifo_generic_write(q->async_fifo, &sync,      sizeof(sync),      NULL);
 
             continue;
-        } else {
-            av_freep(&sync);
         }
         if (MFX_ERR_MORE_SURFACE != ret && ret < 0)
             break;
@@ -409,7 +390,7 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
 
     /* 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 && !flush) {
+    if (!sync && !bs.DataOffset && !flush) {
         av_log(avctx, AV_LOG_WARNING, "A decode call did not consume any data\n");
         bs.DataOffset = avpkt->size;
     }
@@ -423,7 +404,6 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
     }
 
     if (MFX_ERR_MORE_DATA!=ret && ret < 0) {
-        av_freep(&sync);
         av_log(avctx, AV_LOG_ERROR, "Error %d during QSV decoding.\n", ret);
         return ff_qsv_error(ret);
     }
@@ -437,11 +417,9 @@ static int do_qsv_decode(AVCodecContext *avctx, QSVContext *q,
         out_frame->queued = 0;
 
         do {
-            ret = MFXVideoCORE_SyncOperation(q->session, *sync, 1000);
+            ret = MFXVideoCORE_SyncOperation(q->session, sync, 1000);
         } while (ret == MFX_WRN_IN_EXECUTION);
 
-        av_freep(&sync);
-
         src_frame = out_frame->frame;
 
         ret = av_frame_ref(frame, src_frame);