timestamph.264rtpclockrates

Why RTP's timestamp for video payload use a 90 kHz clock rate?

I find that many RFCs said that:

A 90 kHz clock rate MUST be used.

But I don't get the root reason for this.

Solution

  • You can find the answer in "RTP: Audio and Video for the Internet" by Colin Perkins p.154

    In short, such rate is chosen so that the frame rates that are common to majority of the formats will have integer timestamp increment i.e. the division still can have reminder but it will be of negligible range.