* stored in output buffer \p buf.
*
* @note The output buffer should be at least \c FF_MIN_BUFFER_SIZE bytes large.
+ * However, for PCM audio the user will know how much space is needed
+ * because it depends on the value passed in \p buf_size as described
+ * below. In that case a lower value can be used.
*
* @param avctx the codec context
* @param[out] buf the output buffer