+/**
+ * Check AVPacket size and/or allocate data.
+ *
+ * Encoders supporting AVCodec.encode2() can use this as a convenience to
+ * ensure the output packet data is large enough, whether provided by the user
+ * or allocated in this function.
+ *
+ * @param avpkt the AVPacket
+ * If avpkt->data is already set, avpkt->size is checked
+ * to ensure it is large enough.
+ * If avpkt->data is NULL, a new buffer is allocated.
+ * avpkt->size is set to the specified size.
+ * All other AVPacket fields will be reset with av_init_packet().
+ * @param size the minimum required packet size
+ * @return 0 on success, negative error code on failure
+ */
+int ff_alloc_packet(AVPacket *avpkt, int size);
+
+/**
+ * Rescale from sample rate to AVCodecContext.time_base.
+ */
+static av_always_inline int64_t ff_samples_to_time_base(AVCodecContext *avctx,
+ int64_t samples)
+{
+ return av_rescale_q(samples, (AVRational){ 1, avctx->sample_rate },
+ avctx->time_base);
+}
+