[wdmaudiodev] Re: MultiChannel Handling
- From: "nugen" <nugen@xxxxxxxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Tue, 16 May 2006 10:21:24 +0200
thanks for your reply.
>>Have you checked to make sure you are doing the interleave of the audio data
>>correctly?
i think so. Anyway i will control.
>>You need to make sure you set WaveFormatPCMEx.dwChannelMask AND
>>WaveFormatPCMEx.Format.nChannels correctly as both are used in the
>>DataRangeIntersection.
yes. If i want to assign 1 mono channel from my buffer to 1 channel on my
device do i have to set WaveFormatPCMEx.dwChannelMask to 0?
thanks
emilie
----- Original Message -----
From: David A. Hoatson
To: wdmaudiodev@xxxxxxxxxxxxx
Sent: Monday, May 15, 2006 7:58 PM
Subject: [wdmaudiodev] Re: MultiChannel Handling
Hello,
Hi everybody,
I'm using Direct KS, in a client application to capture audio from an audio
Device.
I have some questions and some problem to handle multichannel hardware:
I tried on Edirol USB device and MOTU firewire device.
With the Motu, i can create a capture pin with 8 channels (my motu have 8
analog input and output).
I can also create a render pin with 8 channels.
I would like to be able to capture individual channel or render on
individual channel.
I understand that i have to capture all channels and read the one i want to
deal with,
or render all channels sending audio data on channels i want to use, and
silence on the others.
That's right?
Right - unless the audio device has mutiple filters for each channel.
I tried to render in this way, but i get signal on all channels.
If you render to a multichannel pin with only one channel having valid data
(an all the other channels sending silence), then you shouldn't be seeing
signal on all channels. Have you checked to make sure you are doing the
interleave of the audio data correctly?
I used the dwChannelMask also but it doesn't seem to work anyway.
I'm not sure with my method. Could you please tell me more about that,
or give me some link where i can find info? I can send you more code if
needed.
You need to make sure you set WaveFormatPCMEx.dwChannelMask AND
WaveFormatPCMEx.Format.nChannels correctly as both are used in the
DataRangeIntersection.
Also How can i know how many output or input channels has a device?
Overall or for a specific pin?
And how can i determine if inputs are analog or digital?
There really isn't much of a standard way of doing this. You can see what
kind of pin is exposed (the name), but most devices don't set the name
'correctly' to tell the app if the pin is analog or digital. Do some exploring
with KsStudio and you can see the filter structure of the device in question
and the names associated with the pins.
Thanks in advance,
emilie
Good luck!
David A. Hoatson
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