[Live-devel] Calculating rtptime for RTSP/PLAY-Response "RTP-Info" header

[Jerry Johns]

I might be able to help you here - We have a similar setup here where we
use an ARM+DSP to do our real-time encoding/decoding work with AV Sync
for audio+video (DaVinci platform)

 

First of all, let me get the task partitioning here straight, what are
the specific roles of the DSP and your GPP (general purpose processor,
i.e ur embedded processor)?

A sensible approach would be to relegate decoding/encoding activities to
the DSP, and control oriented tasks to run on the GPP (i.e LiveMedia,
synchronization, etc)

 

Does the DSP also take care of outputting the analog stream?

 

I'm assuming you have a buffered interface between the GPP and the DSP -
that is absolutely required when crossing two clock domains as you have.


There should be some feedback from the DSP to the GPP regarding how
fast/slow its decoding samples  - this should allow the GPP to ensure
the buffer never under-runs or over-runs

 

Compensating using hacky techniques like modifying gettimeofday() will
only yield further problems down the line.

 

 

Jerry Johns

Design Engineer

Nuvation Research Corp - Canada

Tel: (519) 746-2304 ext. 225

www.nuvation.com <http://www.nuvation.com> 

 

 

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.live555.com/pipermail/live-devel/attachments/20080811/3cea75ea/attachment-0001.html>