* The user can supply an output buffer by setting
* avpkt->data and avpkt->size prior to calling the
* function, but if the size of the user-provided data is not
- * large enough, encoding will fail. All other AVPacket fields
- * will be reset by the encoder using av_init_packet(). If
- * avpkt->data is NULL, the encoder will allocate it.
- * The encoder will set avpkt->size to the size of the
- * output packet.
+ * large enough, encoding will fail. If avpkt->data and
+ * avpkt->size are set, avpkt->destruct must also be set. All
+ * other AVPacket fields will be reset by the encoder using
+ * av_init_packet(). If avpkt->data is NULL, the encoder will
+ * allocate it. The encoder will set avpkt->size to the size
+ * of the output packet.
*
* If this function fails or produces no output, avpkt will be
* freed using av_free_packet() (i.e. avpkt->destruct will be