> On Oct 23, 2016, at 11:48 , John Ruf <[email protected]> wrote: > > We have been experiencing very rare random delays in the audio buffers in > core audio. This is occurring in our audio mixer application which runs > flawlessly on Snow Leopard and Mountain Lion. > This problem has been noted many times by people using professional audio > applications with various hardware interfaces and digitizing hardware. When > running on any of the newer operating systems they will occasionally > experience delays after running the application for long periods of time > (sometimes hours, sometimes days). Sometimes there is also distortion in the > sound. All of this is killing our reputation with customers. > Often it can be cured by restarting our mixer application and we have > implemented a "Restart" button to very quickly bring down the whole audio > chain and restart it in about 1 second. However, there are times when that > will not cure it and we have customers rebooting the computer to cure it. We > have seen discussions that indicate that just killing Coreaudiod (and > allowing it to automatically restart) is what is necessary. > We have run bench tests on our system with extra diagnostic messages letting > us know when the time stamps of the input and output buffers are out of sync. > We have run a system for weeks continuously and then it may pop up one day > and the messages indicate that the buffers are out of sync. This buffers are > outside the control of our program and therefore there is nothing we can do > to trace down the cause and fix it. The only thing we can do right now to > preserve some of our reputation is to automatically kill and restart core > audio with our "Restart" button. We are currently running an extended bench > test using Sierra in the possibly vain hope that it has cured this problem, > but without Apple indicating that they have worked on this defect, there's > not much hope. > SInce this has been occurring for several years now and we do not see Apple > taking any action to address this problem directlyI am appealing to this > group to see how we can have Apple investigate the cause of these very > infrequent random delays.
Please write a Radar and be as detailed as you can about what your application observes the system doing when the bad state is detected. Thanks, Doug > Of course, the problem is that no one can supply a real test case that > demonstrates the problem reliably since it can take hours to weeks to occur. > Unless we can eliminate this random sporadic delay we may ultimately be > forced to abandon Apple computers and move to another platform for our audio > applications. That would be a terrible shame. > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Coreaudio-api mailing list ([email protected]) > Help/Unsubscribe/Update your Subscription: > https://lists.apple.com/mailman/options/coreaudio-api/dwyatt%40apple.com > > This email sent to [email protected] _______________________________________________ Do not post admin requests to the list. They will be ignored. Coreaudio-api mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/coreaudio-api/archive%40mail-archive.com This email sent to [email protected]
