+/**
+ * Find the "best" stream in the file.
+ * The best stream is determined according to various heuristics as the most
+ * likely to be what the user expects.
+ * If the decoder parameter is non-NULL, av_find_best_stream will find the
+ * default decoder for the stream's codec; streams for which no decoder can
+ * be found are ignored.
+ *
+ * @param ic media file handle
+ * @param type stream type: video, audio, subtitles, etc.
+ * @param wanted_stream_nb user-requested stream number,
+ * or -1 for automatic selection
+ * @param related_stream try to find a stream related (eg. in the same
+ * program) to this one, or -1 if none
+ * @param decoder_ret if non-NULL, returns the decoder for the
+ * selected stream
+ * @param flags flags; none are currently defined
+ * @return the non-negative stream number in case of success,
+ * AVERROR_STREAM_NOT_FOUND if no stream with the requested type
+ * could be found,
+ * AVERROR_DECODER_NOT_FOUND if streams were found but no decoder
+ * @note If av_find_best_stream returns successfully and decoder_ret is not
+ * NULL, then *decoder_ret is guaranteed to be set to a valid AVCodec.
+ */
+int av_find_best_stream(AVFormatContext *ic,
+ enum AVMediaType type,
+ int wanted_stream_nb,
+ int related_stream,
+ AVCodec **decoder_ret,
+ int flags);
+