Nathan, I was able to reduce the PHP's cpu usage and could run recording 1920x1088@25fps, quality 93, with streamer working, single frame size ~300K-~400K, streamer ~60% cpu, camogm ~30% cpu (same w/o streamer).
The problem is that the php calls (status requests) are "too frequent" so that they eat ~30%. I used my own interface (originally for our panorama camera) for recording where the status calls interval can be programmed. So that interval was 5 sec - can be more frequent, 2 sec worked also. It could be a solution if Sebastian implements it in his GUI. Regards, Oleg On 11 October 2011 22:24, Nathan Clark <nat...@nathanclark.com.au> wrote: > Forwarding a short discussion regarding datarate limitations recording to > HDD while running streamer simultaneously. Continuing discussion here so > that others may benefit. > > *Problem: * > Cannot record to HDD with high datarates when streamer is running. > > *Cause:* > Streamer running with high datarate results in high CPU usage causing > bottleneck. > > *Fix:* > • Reduce CPU requirements of webserver > • Reduce CPU requirements of streamer > > *Is it possible to have the streamer skip every n frames?* > This would potentially halve the datarate (if skipping every 2nd frame) and > as such significantly lower the cpu requirement. > The reduced temporal resolution of the stream would still be okay for > viewing in many circumstances. > > Oleg, > > • I get a similar cpu% usage for php instances. > • I do need the use of the streamer, while recording to SSD over sata. > > Cheers, > > Nathan > > ---------- Forwarded message ---------- > From: Oleg K Dzhimiev > > Also, can we move the discussion to our mailing list. > Thanks > > On 11 October 2011 12:41, Oleg K Dzhimiev wrote: > >> Nathan, >> >> What's the CPU usage for php while recording? I got ~(24+27)% from two php >> instances. That might be causing the problem - too many php calls from the >> GUI. >> >> In your application do you use the streamer while recording? >> >> Best regards, >> Oleg >> >> >> On 11 October 2011 05:55, Nathan Clark wrote: >> >>> As Sebastian advised, I tested the CPU with streamer enabled... >>> We have a problem! >>> >>> CPU usage for streamer is up at 67% >>> (at 1920x1088, rgb, 25fps, quality 90 - data rate 6.9MB/s) >>> >>> The CPU usage directly correlates with data rate, reducing quality to 20 >>> (0.86MB/s) results in streamer CPU usage between 3-9% >>> >>> It looks like the streamer is causing this recording issue by >>> bottlenecking the CPU and thus causing the buffer to overrun... >>> >>> But how to circumvent this issue? >>> >>> >>> On 11/10/2011, at 21:23, Sebastian Pichelhofer wrote: >>> >>> > Hi Oleg, I suggested we continue this discussion via email. >>> > >>> > Below is Nathans original PM to me: >>> > >>> > >>> > >>> > Hey Sebastian, >>> > >>> > As time escapes me, its getting closer and closer to Winnie shooting >>> > her experimental film for her stereoscopic PHD research... >>> > I am not ready :| >>> > >>> > With problems with my lenses and this sata datarate pain, it's >>> > becoming quite scary :shock: >>> > >>> > But there is always times of stress with all projects! And ultimately, >>> > I just remind myself how amazing what we have created really is! :D >>> > >>> > ---------------- >>> > >>> > Did you have time to verify the external HDD recording datarate limits >>> > we talked about some time ago? >>> > >>> > Regards Sebastian >>> >>> > _______________________________________________ > Support-list mailing list > Support-list@support.elphel.com > http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com > >
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