Buffer slippage

[Bob L]

If you are having latency drift issues with the current SAC pre-release, I have just discovered that some dual cpu systems are causing the problem.

Try setting SAC to one cpu inside the task manager and see if that stops the problem... or boot to a single processor with the boot.ini /onecpu option.

The force single cpu inside SAC does not correct the problem as I am guessing the drivers themseleves may be assigned to the second cpu by the system and this may be causing the problems.

I am deep into the low level aspects of the engine to see if I can find the problem... but for now... you may solve drift problems by going back to single cpu.

Bob L

[mako]

Thanks Bob - I'm now using a dual core during rehearsals and find it does slip a little over time (Asus P5K Pro, C2D 6300 with RME Digiface/PCI) but overall is rock solid at 32x2.

I'd be very happy if I could just hit F12 or similar to resynch the engine.

Great stuff

Thanks

mako

[Bob L]

The new engine detects and resyncs automatically... update coming soon.

Bob L

[AudioAstronomer]

The new engine detects and resyncs automatically... update coming soon.

Bob L

Is the resynch a full engine restart, or is it invisible to the operator?

[Bob L]

The resync is invisible... but, of course, the slipped buffers cause a small glitch.

Its still not ready.... but I am testing everything now... just did an hour and a half at the church rehearsal with zero slipped buffers on the new engine... but still was forced to boot in single cpu mode.... that one is a bear... very difficult to pinpoint.

Bob L

[Iain Westland]

still cant work out how saw/sac will live with each other:o tis this buffer malarkey that has me stumped.

will this glitching happen on the virtual buffers saw will use? im missing the point again arnt i:o

[DominicPerry]

Iain,

I think you will use ASIO or MME or DWave(maybe) at low latency to SAC. SAC will generate a virtual output (not yet implemented) and SAW will be updated to let you choose "SAC Virtual Output 1" thru "SAC Virtual Output 72" as inputs instead of the usual mono or stereo ASIO/MME/DWave devices.
Those virtual inputs can have big buffers set and so won't tax the CPU.
How or even if you might output SAW back to SAC for overdubbing, well, I haven't thought of that, but I bet Bob has.

Dominic

[Bob L]

Dominic is on the right track... SAC will output its audio data to internal virtual buffers as it collects the data... SAWStudio will be able to see and access these buffers and instead of looking at the soundcard will pull its input data from these buffers... and... SAWStudio will also be able to output its playback data to another set of internal virtual buffers that SAC will be able to see and access and instead of looking at a soundcard input, it can take its data from these buffers... not ready yet... but coming...

I must solidify the SAC engine design first before writing all the code that links the two programs.

Bob L

[Carlos Mills]

Hi Bob and All,

It is exiting to see how SAC evolves with this group´s help. I would love to take part in this testing and help you out, but unfortunately my time is very reduced right now. Nonetheless, I try to read the threads and I am absolutely confident that SAC is going to be a new breakthrough from RMLLabs very soon. :)
I am using SAWStudio every week to record a live show from a popular radio station here in Rio. The best artists of Brazilian Music attend this show. Soon I will be recording Milton Nascimento and Jobim Trio. I am looking forward to being able to use SAC and maybe, who knows, substitute the monitor console and the PA all at once! :D

Good luck and all the best!

[Iain Westland]

ok, so its ...

mic -> pre -> soundcard - and now it all falls to bits for me:o if the s/card glitches every now and then at very low samples, but is being used live, then nobodys gonna notice, but when recording the pull point is gonna be apres sac and surely will include that glitch.

or is it that the computer and its drivers cant input/output at those speeds and as such drops things in an effort to keep up and as saw will be able to read from these inputs at its leasure it wont suffer the same even though its following the same audio.

as for the overdubs, i'm just going to do the samples record adjust thing, it works perfectly for me in saw so cant see it being a prob

[Bob L]

The input audio should not glitch if the system is working properly... SAWStudio will pick up the audio data as it streams into the start of the SAC loop... the buffer slippage we are experiencing now will not be a factor soon... and it is currently occurring as the data is assembled and sent back out to the soundcard... the input data is all there.

Bob L

[Bud Johnson]

The input audio should not glitch if the system is working properly... SAWStudio will pick up the audio data as it streams into the start of the SAC loop... the buffer slippage we are experiencing now will not be a factor soon... and it is currently occurring as the data is assembled and sent back out to the soundcard... the input data is all there.

Bob L
With SAC 1.0D, and SS recording in asio mode, If I take SAC out of live mode, then restart, did it continue recording without a break?.
just curious.
I know this is a different setup than what will be after the engine is stablized and the hooks are coded in.

[Bob L]

That would all depend on how the driver differentiates between multi-client driver accesses... stopping one app may or may not interrupt the other... not sure... try it and see.

Bob L

[Bud Johnson]

That would all depend on how the driver differentiates between multi-client driver accesses... stopping one app may or may not interrupt the other... not sure... try it and see.

Bob L
It continues recording without a break. Turning SAC on and off seems to have no effect.

Next question. In the setup mentioned before, with the tower by the stage and laptop with me, can I run SAC minimized on the tower with SS on the screen and still control SAC from the laptop?
I mean the laptop sees the app, not the graphic right?
It would be nice to have the visual reassurance that SS is still recording even if from a distance.
I would "try it and find out":rolleyes: but I'm not sure how much more testing time I'll have before I have to do it for real. Still have to configure a router, set up preferences for single monitor, etc. Test the Behringers...see ADA8000 and GC thread.

[Bob L]

Yes... the remote talks directly to the app in the background.

Make sure to use single cpu on your system if its a dual so there will be no slippage... unless I have the new engine update up before the gig.

Bob L

[Leadfoot]

hi bob, do you think the new engine update(buffer slip fix) might be available before the weekend? i think i'm gonna use sac at a show saturday nite if i have time to get everything set up properly.

everyone i know is so excited about sac. one guy not too long ago bought two pm5d's, with doghouse cases, backup power supplies, etc, almost $200,000.00 ! and that's not including his multi thousand dollar split snake setup! so, thanks again for your vision and hard work for sac!

tony

[Bob L]

I am still digging out the issues with the new engine... if I do not have it ready, I suggest using the CPU 0 option in the task manager process affinity setting... that will stabilize the current engine to be pretty darn solid.

Bob L

[Bud Johnson]

I am still digging out the issues with the new engine... if I do not have it ready, I suggest using the CPU 0 option in the task manager process affinity setting... that will stabilize the current engine to be pretty darn solid.

Bob L
Bob,
Just want to say thanks again for all the hard work, attention to detail, thinking outside the box so we can work ITB, and hugely for support over the years unequalled in my experience.

[Bob L]

You are welcome.

Thank you for the recognition.

Bob L

[AudioAstronomer]

Bob,
Just want to say thanks again for all the hard work, attention to detail, thinking outside the box so we can work ITB, and hugely for support over the years unequalled in my experience.

+1 !

It's easy to become spoiled by the nearly unparalled service and quality of the product.

[Mountain Media]

+1 !

It's easy to become spoiled by the nearly unparalled service and quality of the product.

+2! ;)

[Bruce Callaway]

Me 3, I get my Digiface next week so the real fun can start....dying to see the performance with SAC and saw separated onto separate CPUs......

[William Bushnell]

+1 !

It's easy to become spoiled by the nearly unparalled service and quality of the product.
__________________
Lovingly signed,
Robert Randolph (727)-385-5260

Make mine +4!
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William Bushnell