What would the implications be for the host PC recieving the stream? If the streamer goes to sleep for n frames... Wouldn't the host PC "think" that the connection is lost?
On Wed, Oct 12, 2011 at 3:36 PM, Andrey Filippov < support-list@support.elphel.com> wrote: > Nathan, > > The intended solution would be to tell streamer minimal size of the camogm > buffer to maintain. And make the streamer "nice" - when the streamer is > awaken by the driver (it happens at each frame, if needed - can sleep for > several frames or until frame #xxx is ready, but it would not take much of > the CPU for the streamer to just check "how is it going" at each frame and > go back to sleep if needed. > > At each frame, streamer can read the buffer size for camogm -- driver > will tell that (if camogm is set to update "global read pointer"), compare > to the preset minimum and either stream the current frame or go back to > sleep and skip it. > > All the data structures (accessible over mmap) are already initialized in > the streamer. I think there needs to be just 10 to 20 (with passing the new > parameter - minimal buffer size) additional lines of code - the most time > consuming would be to get inside the code and find the right place - it was > written/modified by several people at different time (even I touched it > once, but was not the last) so it may not be extremely straightforward. But > if somebody will start working on it - I'll try to help/answer the > questions. > > Andrey > > > On Tue, Oct 11, 2011 at 10:24 PM, 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 >> >> >
_______________________________________________ Support-list mailing list Support-list@support.elphel.com http://support.elphel.com/mailman/listinfo/support-list_support.elphel.com