[Live-devel] Help: cause of RTP packet loss

[Shishir Birmiwal]

Xochitl,


> Re:  On my target powerpc I still see lost packets from RTCP when writing
> to /dev/null.  I have just learned that my powerpc does not have DMA, but I
> am told the write speed "should be fast enough".  I have tested that my
> target disk can be written fast enough by using it in the fedora 5
> computer.


> How can I find out / figure out recommended system requirements for the
> streaming I am trying to do?  I want to send a 5 Mbps TS stream to my
> powerpc, how can I learn what I need as minimum for processor, ram, etc. on
> this and other embedded targets?  I would like to be able to predict how
> many simultaneous streams my powerpc box could handle. (Hopefully, DMA can
> be enabled and that could boost this number?)

What file-system do you have on your PowerPC system? You could test
your read (or write, if you have a spare disk to write random data to
and corrupt the file-system) speeds using hdparm (for disk-drives).

Alternately, you can do some elementary tests to read/write chunks of
data (128/256/more MB) from/to your filesystem and measure the time
taken for this action. Be careful while doing a read as you may see
disk-caches speeding up your transfers.

A simple test to measure the write speed:

sync; time dd if=/dev/zero bs=1M count=256 of=/tmp/temp; time sync; rm /tmp/temp

Add up the two time values to get an estimate of time to write 256 MB.

Regards
Shishir