Re: iPad Pro USB audio
Re: iPad Pro USB audio
- Subject: Re: iPad Pro USB audio
- From: Jean-Charles Rousset <email@hidden>
- Date: Sun, 17 Mar 2019 15:01:57 +0100
Hi Andrew,
Thanks for your feedback.
I submitted a new bug on the Apple bug reporter as I could not find out what is
wrong here.
The problem appears only with inputs (ADC) as playing sound works great (even
though the devices are still detected as Headphones…).
Dividing all the coming samples in the callback by 28.18 is a dirty workaround,
but it did work.
I guess this will be solve in a next iOS release.
Best,
JC
> Le 15 mars 2019 à 20:11, Andrew Smith <email@hidden> a écrit :
>
> Yes, I found the same thing!
>
> One thing I did find is that I had some old code that was trying to set the
> gain of the input ADC, assuming that the internal mic was being used, and
> this got converted to sending out USB HID volume changes, which resulted in
> the USB audio device I had connected increasing its gain. When I lowered the
> gain I was setting, the USB gain went down as well.
>
> Seems a little buggy.
>
> Best,
> Andrew Smith
>
>
>
>
>
>> On Mar 15, 2019, at 12:00 PM, email@hidden
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>> 1. iPad Pro USB audio (Jean-Charles Rousset)
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>> ----------------------------------------------------------------------
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>> Message: 1
>> Date: Thu, 14 Mar 2019 21:55:09 +0100
>> From: Jean-Charles Rousset <email@hidden>
>> To: email@hidden
>> Subject: iPad Pro USB audio
>> Message-ID: <email@hidden>
>> Content-Type: text/plain; charset=utf-8
>>
>> Hi everyone,
>>
>> I just got the new iPad Pro with the USB-C connector.
>> Our iOS app works with different external USB audio devices.
>> I wanted to check if everything works fine but I am quite surprised about
>> the results I got:
>> All USB devices seem to be recognized as « Headsets », not as USB devices
>> like it used to be. The number of In an Out channels seems to be correct
>> though.
>> Furthermore, there seems to be a higher « gain ». I could dig a bit and all
>> samples seem to around 28.18 bigger.
>> There is very probably a reason about all of this but I have to say that I
>> am a bit lost here…
>> Note that this is not related to our app as the genuine recorder gives the
>> same results. Our audio devices integrate a XMOS, but I also got the same
>> results with basic other sound cards.
>> Am I missing something?
>> Thanks a lot.
>> JC
>>
>>
>>
>>
>>
>>
>>
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