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 directly I am appealing to this group to see how we can have Apple investigate the cause of these very infrequent random delays. 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/archive%40mail-archive.com
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