Subject: Re: [AVT] RTP timestamp calculation for MPEG1 Video and Audio ES so that itworks with RTSP client like RealOne/QuickTime

From: Deepak Kotian <[email-masked]>
Date: Tue, 26 Aug 2003 19:33:13 +0530

Hi,

Thanks for the inputs.
But, these RFCs do not mention about the PTS or DTS timestamp
calculation, it seems the RTP timestamp is derived from PTS or DTS
of headers. Which is usually 33 bits, that too is mystery to me as
the RTP timestamp is 32 bits. 
That is what I have heard.

Is there a very simple implementation where Minimal RTSP server
is implemented and works with RealOne via RTP for both MPEG1 audio 
and video Elementary stream.
The helix source is really very big to understand quickly.
Some more inputs would be of great help.

Thanks and Regards
Deepak

  ----- Original Message ----- 
  From: Neo Anderson 
  To: [email-masked] 
  Cc: [email-masked] 
  Sent: Tuesday, August 26, 2003 11:14 AM
  Subject: Re: [AVT] RTP timestamp calculation for MPEG1 Video and Audio ES so that itworks with RTSP client like RealOne/QuickTime

      Hi,

      Since you have mentioned the documents yourself, I think they 
      provide sufficient information for interop with realone. Check out 
      rfc3550 too.

      We need to provide the timestamp with the proper clock rates 
      mentioned for the specific media type payload format (rfc2250).

      For example, if the clock is 90kHz, practically, multiply the 
      timestamp in seconds by 90000. This is the RTP  timestamp value to be 
      transmitted in the packet. Check out the clock rates carefully for 
      each media type and associated payload format is used.

      Take care of putting proper NTP and RTP timestamp correlation while 
      sending SR packets.

      There is also an interoperablity statement for RTP/RTSP in the real 
      networks site. Sorry, I am not able to cite the exact document at 
      present. try downloading from their website.

      --Neo
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