createVideoSource
Create video source with given parameters. If alignTimestamps is false, the caller is responsible for aligning the frame timestamps to rtc::TimeNanos(). This can be used to achieve higher accuracy if there is a big delay between frame creation and frames being delivered to the returned video source. If alignTimestamps is true, timestamps will be aligned to rtc::TimeNanos() when they arrive to the returned video source.
Same as above with alignTimestamps set to true.