* in and in_count can be set to 0 to flush the last few samples out at the
* end.
*
- * If more input is provided than output space then the input will be buffered.
- * You can avoid this buffering by providing more output space than input.
- * Conversion will run directly without copying whenever possible.
+ * If more input is provided than output space, then the input will be buffered.
+ * You can avoid this buffering by using swr_get_out_samples() to retrieve an
+ * upper bound on the required number of output samples for the given number of
+ * input samples. Conversion will run directly without copying whenever possible.
*
* @param s allocated Swr context, with parameters set
* @param out output buffers, only the first one need be set in case of packed audio
*/
int64_t swr_get_delay(struct SwrContext *s, int64_t base);
+/**
+ * Find an upper bound on the number of samples that the next swr_convert
+ * call will output, if called with in_samples of input samples. This
+ * depends on the internal state, and anything changing the internal state
+ * (like further swr_convert() calls) will may change the number of samples
+ * swr_get_out_samples() returns for the same number of input samples.
+ *
+ * @param in_samples number of input samples.
+ * @note any call to swr_inject_silence(), swr_convert(), swr_next_pts()
+ * or swr_set_compensation() invalidates this limit
+ * @note it is recommended to pass the correct available buffer size
+ * to all functions like swr_convert() even if swr_get_out_samples()
+ * indicates that less would be used.
+ * @returns an upper bound on the number of samples that the next swr_convert
+ * will output or a negative value to indicate an error
+ */
+int swr_get_out_samples(struct SwrContext *s, int in_samples);
+
/**
* @}
*