* This is the fundamental unit of time (in seconds) in terms
* of which frame timestamps are represented. For fixed-fps content,
* time base should be 1/framerate and timestamp increments should be 1.
+ * decoding: set by libavformat
+ * encoding: set by libavformat in av_write_header
*/
AVRational time_base;
int pts_wrap_bits; /**< number of bits in pts (used for wrapping control) */
/**
* Allocate the stream private data and write the stream header to an
* output media file.
+ * Note: this sets stream time-bases, if possible to stream->codec->time_base
+ * but for some formats it might also be some other time base
*
* @param s media file handle
* @return 0 if OK, AVERROR_xxx on error