/**
* @brief convert fps tag value to AVRational fps
* @param fps fps value from tag
* @return fps as AVRational, or 0 / 0 if unknown
*/
static AVRational fps_tag2avr(int32_t fps) {
/**
* @brief convert fps tag value to AVRational fps
* @param fps fps value from tag
* @return fps as AVRational, or 0 / 0 if unknown
*/
static AVRational fps_tag2avr(int32_t fps) {