+ /**
+ * Callback for parameter data (SPS/PPS/VPS etc).
+ *
+ * Useful for hardware decoders which keep persistent state about the
+ * video parameters, and need to receive any changes to update that state.
+ *
+ * @param avctx the codec context
+ * @param type the nal unit type
+ * @param buf the nal unit data buffer
+ * @param buf_size the size of the nal unit in bytes
+ * @return zero if successful, a negative value otherwise
+ */
+ int (*decode_params)(AVCodecContext *avctx, int type, const uint8_t *buf, uint32_t buf_size);
+