*/
#define AV_BUFFERSINK_FLAG_PEEK 1
+/**
+ * Tell av_buffersink_get_buffer_ref() not to request a frame fom its input.
+ * If a frame is already buffered, it is read (and removed from the buffer),
+ * but if no frame is present, return AVERROR(EAGAIN).
+ */
+#define AV_BUFFERSINK_FLAG_NO_REQUEST 2
+
/**
* Get an audio/video buffer data from buffer_sink and put it in bufref.
*