virtual Frame video_length () const = 0;
/** @return video sample aspect ratio (if known); must not be called if has_video() == false */
virtual boost::optional<double> sample_aspect_ratio () const {
- return boost::optional<double> ();
+ return {};
}
/** @return true if this video is in YUV; must not be called if has_video() == false */
virtual bool yuv () const = 0;