Re: iOS : ExtAudioFileWriteAsync alternatives / Audio Queue Services availability?
Re: iOS : ExtAudioFileWriteAsync alternatives / Audio Queue Services availability?
- Subject: Re: iOS : ExtAudioFileWriteAsync alternatives / Audio Queue Services availability?
- From: Arshia Cont <email@hidden>
- Date: Wed, 14 Feb 2018 20:24:17 +0100
Matt,
Thanks for the reply! :)
AVAudioFile would be one way to go except that I am recording live streams, and
using AVAudioFile I should make the ‘write’ asynchronous myself and make sure
the direct-to-disk stuff won’t hic the AudioIO thread.
This is supposed to be the promise of ‘ExtAudioFileWriteAsync’.
Has anyone tried playing around with the
kExtAudioFileProperty_IOBufferSizeBytes property of Extended Audio File
Services? I have feeling that this is the way to go (increasing the buffer so
that writing would occur less frequently.
Apparently the kExtAudioFileError_AsyncWriteBufferOverflow is thrown when write
requests are arriving faster than the system’s ability to access disk (can
happen at any time and all of a sudden). The bad news is that when this is
thrown it actually halts the IOThread! Can’t figure out why… .
Hint that can help: I am recording two live streams (stereo) at the same time
(i.e. two audio files).
Any hints?
> On 14 Feb 2018, at 19:01, Matt Ingalls <email@hidden> wrote:
>
> Have you tried AVAudioFile?
>
>> On Feb 13, 2018, at 12:59 PM, Arshia Cont <email@hidden> wrote:
>>
>> Hello list,
>>
>> This is my first post here so sorry if this is already asked!
>>
>> We have been using ExtAudioFileWriteAsync on iOS successfully to write two
>> PCM Audio Streams to disk. We have been getting reports from users nagging
>> on sudden audio drop outs on some [older] devices and during “performance”.
>> We managed finally to find the root of the problem to the thrown
>> kExtAudioFileError_AsyncWriteBufferOverflow exception which means
>> (probably?) that ExtAudioFileWriteAsync is not keeping the pace with the
>> system writing to disk.
>>
>> So I believe we must use lower level calls here (?).
>>
>> What would be an alternative for ExtAudioFileWriteAsync?
>
>>
>> I have been looking at Audio Queue Services for months but
>> documentation/examples are so old that it keeps me away from it… or should
>> we dive in?
>>
>> Thanks in advance,
>>
>>
>> Arshia Cont
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