+ * @submit_input_buffer: Function which accepts a new input buffer and pre-processes it.
+ * The default implementation performs caps (re)negotiation, then
+ * QoS if needed, and places the input buffer into the @queued_buf
+ * member variable. If the buffer is dropped due to QoS, it returns
+ * GST_BASE_TRANSFORM_FLOW_DROPPED. If this input buffer is not
+ * contiguous with any previous input buffer, then @is_discont
+ * is set to #TRUE. (Since 1.6)
+ * @generate_output: Called after each new input buffer is submitted repeatedly
+ * until it either generates an error or fails to generate an output
+ * buffer. The default implementation takes the contents of the
+ * @queued_buf variable, generates an output buffer if needed
+ * by calling the class @prepare_output_buffer, and then
+ * calls either @transform or @transform_ip. Elements that don't
+ * do 1-to-1 transformations on input to output buffers can either
+ * return GST_BASE_TRANSFORM_FLOW_DROPPED or simply not generate
+ * an output buffer until they are ready to do so. (Since 1.6)