[mythtv] dbox network load
mythmail at richardstraat.homedns.org
Fri Aug 26 14:38:03 UTC 2005
> Now that I got my dbox2 setup as a recording source more questions pop
> up. Might be more fit for the user list but since dbox is only supported
> in latest svn...
> The problem I see is that only very few channels are recorded without
> skips and quirks in the stream. Since my dbox only has a 10MBit
> half-duplex network card I guess it's only the low bitrate channels that
> work ok.
> I'm new to the dbox and it possibilities (only got one to make it work
> in myth) but looking around at other recording software that is
> available I see they mostly use the UDP protocol to record the streams.
> If I look at iptraf on my mythbackend while recording in myth I only see
> TCP packets comming in :
> Statistics for eth0
> Incoming rates: 4980.5 kbits/sec
> Anyone with more experience with ideas to optimize the network traffic?
> Would connecting the dbox directly to the backend with a cross cable to
> a second nic help?
> Not sure if somebody (Levent?) is still working on the code.
> Might it be better to use udp (like some other opensource recording
> tools for linux, like udrec http://www.haraldmaiss.de/, do) to capture
> the streams?
Some more info :
Recorded a short 2 min clip of one of the high-bitrate channels using
udrec (udp) and that worked just fine. So it is possiple to record a
8+Mbit stream of a 10Mbit half-duplex card.
16:09:57:013 INFO 16:09:56 to DBox: VIDEOTS 31341 16 0 1 va 107e 1092
16:09:57:690 INFO 16:09:57 from DBox: INFO: IP a000002 Port 31341
16:09:57:705 INFO 16:09:57 from DBox: PID va 1 107e 1092
16:09:57:762 INFO 16:09:57 to DBox: START
16:09:57:783 INFO 16:09:57 from DBox: INFO: UdpSender() - PID14102 R0 W0
16:09:57:853 INFO 16:09:57 from DBox: INFO: DmxTSReader() - Pid 275232 0 0
16:10:12:776 INFO 16:10:12 data rate > 9Mbit/s
16:11:56:950 INFO 16:11:56 to DBox: STOP
16:11:57:004 INFO 16:11:56 network statistics:
16:11:57:014 INFO max: 9.0 Mbit/s total data rate
16:11:57:017 INFO average: 8.1 Mbit/s total data rate
16:11:57:018 INFO no resends
16:11:57:020 INFO 16:11:56 TcpSender stopped
16:11:58:187 INFO 16:11:58 UdpReceiver stopped
16:11:58:204 INFO 16:11:58 from DBox: EXIT
16:11:58:205 INFO 16:11:58 TcpReceiver stopped
So I guess all it takes is a small change to dbox2recorded.cpp to use
udp and not tcp :-)
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