avdevice/decklink_dec: do not copy video data

Create a buffer from the data instead and use the buffer destructor to free the
DeckLink frame. This avoids a memcpy of the frame data.
Signed-off-by: Marton Balint <cus@passwd.hu>

libavdevice/decklink_dec.cpp

@@ -98,6 +98,14 @@ static VANCLineNumber vanc_line_numbers[] = {
     {bmdModeUnknown, 0, -1, -1, -1}
 };
 
+extern "C" {
+static void decklink_object_free(void *opaque, uint8_t *data)
+{
+    IUnknown *obj = (class IUnknown *)opaque;
+    obj->Release();
+}
+}
+
 static int get_vanc_line_idx(BMDDisplayMode mode)
 {
     unsigned int i;
@@ -797,6 +805,10 @@ HRESULT decklink_input_callback::VideoInputFrameArrived(
             }
         }
 
+        pkt.buf = av_buffer_create(pkt.data, pkt.size, decklink_object_free, videoFrame, 0);
+        if (pkt.buf)
+            videoFrame->AddRef();
+
         if (avpacket_queue_put(&ctx->queue, &pkt) < 0) {
             ++ctx->dropped;
         }