Persist timestamp meta data within buffer (fr ame) in mp4 file(s) and read it after.

Hi.
 
Given following pipeline rtspsrc !  rtph264depay !  h264parse !  splitmuxsink max-size-time=5seconds,
I need to be able to store frame timestamp within mp4 file itself so it could be accessible later, when reading this file.
Now it doesn’t preserved. I mean I can get buffer ts via GetReferenceTimestampMeta, but later on after it saved to
some mp4 file, iterating this mp4 file via appsink.PullSample() return sample with buffer with no ts info.
 
How this timestamp meta info could be persisted and retrieved later on?
 
Thanks in advance.