Re: AudioConverterConvertBuffer artifacts
Re: AudioConverterConvertBuffer artifacts
- Subject: Re: AudioConverterConvertBuffer artifacts
- From: Doug Wyatt <email@hidden>
- Date: Fri, 21 Jun 2002 13:56:34 -0700
AudioConverterConvertBuffer can only be used reliably when there is a
constant ratio between the number of input bytes required to produced a
given number of output bytes. This isn't true for sample rate
conversion, because these algorithms tend to pull input for slightly
varying numbers of samples.
You can use AudioConverterFillBuffer for reliable sample rate
conversion. Here, your callback function gets called to provide
pointers to input buffers -- which aren't copied, BTW, and thus must
remain valid until you get called for more input or stop calling
AudioConverterFillBuffer.
Doug
On Friday, Jun 21, 2002, at 13:29 US/Pacific, Harry Mahoney wrote:
I am using AudioConverterConvertBuffer to convert my audio data from
8k,
16-bit, 2-channel, linear to the required 44.1k, float, 2-channel,
linear needed for coreaudio. Unfortunately, I am getting
discontinuities
in the output data resulting in clicking sounds.
By sending 44.1k data into the AudioConverterConvertBuffer routine, I
can eliminate the clicking. Passing in 8k, floats still clicks. Thus, I
have determined it is the upsampling that is creating the clicks.
Is there any way of correcting this through coreaudio, or do I need to
come up with my own upsampling routine?
Thanks,
Harry Mahoney
_______________________________________________
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.
--
Doug Wyatt
work: email@hidden (CoreAudio)
personal: email@hidden
http://www.sonosphere.com
"There is no way to peace. Peace is the way."
-- A.J. Muste
_______________________________________________
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.