I am working on a project that the audio signal is interpolated from 8kHz
sampling rate to 48kHz. I am using C6713
DSK broad. I configure the AIC32 codec with ADC of 8kHz and DAC of 48kHz. At
the same time, I use ping-pong buffer
to save incoming and outgoing data. Interpolation is achieved. However, I get
the noise output. When I configure
AIC32 codec with ADC of 8kHz and DAC of 8kHz, and then directly copy data
between ping-pong buffer ( means
interpolation is not performed), it works right.
What's wrong with my codes?
interpolation problem on 6713 DSK
Started by ●December 6, 2006
Reply by ●December 7, 20062006-12-07
YF Fushop-
> I am working on a project that the audio signal is interpolated from 8kHz
> sampling rate to 48kHz. I am using C6713 DSK broad. I configure the AIC32
> codec with ADC of 8kHz and DAC of 48kHz. At the same time, I use ping-pong
> buffer to save incoming and outgoing data. Interpolation is achieved.
> However, I get the noise output. When I configure AIC32 codec with ADC of
> 8kHz and DAC of 8kHz, and then directly copy data between ping-pong buffer
> ( means interpolation is not performed), it works right.
>
> What's wrong with my codes?
Did you download the AIC23B data sheet? I found one here:
http://focus.ti.com/lit/ds/symlink/tlv320aic23b-q1.pdf
If you read section 3.3.2, Sampling Rate, you will find the AIC23B codec device
cannot be programmed with separate input and output sampling rates. It eats one
master clock rate, and derives one internal sampling rate, based on programmable
register options.
This is a student project, correct? I think what your Prof may be expecting with the
DSK 6713 board is that you will *effectively* sample at 8 kHz by taking every 6th
input sample, then use that stream to interpolate to 48 kHz output.
-Jeff
> I am working on a project that the audio signal is interpolated from 8kHz
> sampling rate to 48kHz. I am using C6713 DSK broad. I configure the AIC32
> codec with ADC of 8kHz and DAC of 48kHz. At the same time, I use ping-pong
> buffer to save incoming and outgoing data. Interpolation is achieved.
> However, I get the noise output. When I configure AIC32 codec with ADC of
> 8kHz and DAC of 8kHz, and then directly copy data between ping-pong buffer
> ( means interpolation is not performed), it works right.
>
> What's wrong with my codes?
Did you download the AIC23B data sheet? I found one here:
http://focus.ti.com/lit/ds/symlink/tlv320aic23b-q1.pdf
If you read section 3.3.2, Sampling Rate, you will find the AIC23B codec device
cannot be programmed with separate input and output sampling rates. It eats one
master clock rate, and derives one internal sampling rate, based on programmable
register options.
This is a student project, correct? I think what your Prof may be expecting with the
DSK 6713 board is that you will *effectively* sample at 8 kHz by taking every 6th
input sample, then use that stream to interpolate to 48 kHz output.
-Jeff
