Re: Downsampling / channel reduction
Re: Downsampling / channel reduction
- Subject: Re: Downsampling / channel reduction
- From: Peter Rebholz <email@hidden>
- Date: Thu, 5 Jun 2008 12:10:42 -0500
On Jun 5, 2008, at 11:11 AM, Bill Cunning wrote:
Thanks for the responses to my original question, but I am still lost.
A couple of things / questions ...
Audio will not be written to a file .. it is being sent to speex
voice compression library .. which requires 8khz, 16bit pcm ... I
have figured out how to set up the pcm stuff and I have it all
working except the case where the input device does not support 8khz
sample rate.
Could you explain how your app is setup (how it gets the input and how
the signal 'flows') when it works with devices that support 8khz? I
think that might help us determine how you should introduce the
converter to your app.
I thought I could create a varispeed unit and create an AUGraph on
the audio input side of things .. but the only samples I have seen
use this for output only and 'reversing' things seem to not work and
I get various errors setting properties on the different audio
units .. usually 10879 .. invalid property
A) is this method viable and I am just doing it wrong ?
b) is there a sample somewhere that creates something along these
lines?
The CAPlayThrough example demonstrates usage of the varispeed unit in
an AUGraph
c) is there a list somewhere of all the properties and what they are
used for / how they can be used, I thought I had stumbled accross on
once .. but can not find it again.
You should be able to use the research assistant (Help > Research
Assistant) and just put the cursor on the property you want info on.
Also, try searching the documentation for a property name, thats how I
usually find a list of all properties. Lastly, you could just look at
the header file which contains the headerdoc source.
d) I looked at the AUconverter stuff that both reponses mentioned ..
but the file sample did not seem to be to much help and more vague
on how to use it in any case other than that one specific case than
the varispeed unit samples and doumentation I came accross.
Thanks!
Bill Cunning
<winmail.dat> _______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
_______________________________________________
Do not post admin requests to the list. They will be ignored.
Coreaudio-api mailing list (email@hidden)
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden