Re: Stream format
Re: Stream format
- Subject: Re: Stream format
- From: Steven Spencer <email@hidden>
- Date: Tue, 25 Mar 2003 21:15:58 +0000
Does this mean that for linear PCM, the stream format flags change the type of
float32 presented in the IOProc ?
I ask this because I'm writing a programme to monitor the input from an audio device and
send it to the default output unit as follows :
input -> ring buffer -> mixer -> default output
and need to know if it is necessary to use one or more audio converters to change the input IOProc data to a
common type before it is written to the ring buffer (so all channels have the same data type for the mixer).
If audio converters are required, I don't think they need to do sample rate conversion since this will be done
by the default output unit and the input streams share the same sample rate.
Are audio converters required ?
- Steven Spencer
On Tuesday, March 25, 2003, at 07:48PM, Jeff Moore <email@hidden> wrote:
>
Everything about the ASBDs returned via
>
kAudioDevicePropertyStreamFormat and friends applies. You should be
>
paying attention to everything they say.
>
>
If you are doing output, you should probably be using the HAL output
>
Audio Unit. It will take care of a lot of the work that goes in to
>
being a client of the HAL. It also interfaces with the AudioConverter
>
to massage the data into the form the device wants.
>
>
On Tuesday, March 25, 2003, at 08:37 AM, Steven Spencer wrote:
>
>
> In AudioHardware.h, it states that linear PCM streams are presented as
>
> floating point
>
> data in the IOProc. Do the stream format flags (big endian, packed
>
> etc.)
>
> affect the floating point formatting in the IOProc or do these just
>
> apply to the
>
> stream hardware formatting ?
>
>
>
> Thanks,
>
> Steven Spencer
>
> _______________________________________________
>
> coreaudio-api mailing list | email@hidden
>
> Help/Unsubscribe/Archives:
>
> http://www.lists.apple.com/mailman/listinfo/coreaudio-api
>
> Do not post admin requests to the list. They will be ignored.
>
>
>
>
>
>
--
>
>
Jeff Moore
>
Core Audio
>
Apple
>
_______________________________________________
>
coreaudio-api mailing list | email@hidden
>
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/coreaudio-api
>
Do not post admin requests to the list. They will be ignored.
_______________________________________________
coreaudio-api mailing list | email@hidden
Help/Unsubscribe/Archives:
http://www.lists.apple.com/mailman/listinfo/coreaudio-api
Do not post admin requests to the list. They will be ignored.