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Massimo B.
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Location: PB, Germany
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 Posted: Fri May 07, 2010 5:14 pm Post subject: Apple Audio Onyx(pcm3052) SPDIF Rate? |
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Hello.
Does anyone know how to change the digital S/P-DIF output rate of the Onyx (pcm3052) codec chip? Playing 44.1 kHz files my DAC reports 48 kHz. According to the dev-notes (see my signature) the hardware is capable of different sample rates.
How is the sample rate changed generally? I think this could be by module parameters, but for this driver I cannot find any: /usr/src/linux/Documentation/sound/alsa/ALSA-Configuration.txt
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aCOSwt
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| Posted: Fri May 07, 2010 6:13 pm Post subject: Re: Apple Audio Onyx(pcm3052) SPDIF Rate? |
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| Massimo B. wrote: | | Does anyone know how to change the digital S/P-DIF output rate of the Onyx (pcm3052) codec chip? Playing 44.1 kHz files my DAC reports 48 kHz. |
I apologize for not exactly understanding what you mean.
1/ What is your DAC involved in if you ouput to S/P-DIF ?
2/ If you are playing a 44.1 Khz file, why would you expect/like something else than 44.1 Khz on output ?
3/ Changing the rate is very useful when Converting from Analog to Digital. In other words when recording. If you are recording then you should have tools like jack, ardour... These tools enable you to control the sampling rate. |
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Massimo B.
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| Posted: Mon May 10, 2010 10:33 am Post subject: |
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- Using S/P-DIF means the output is a digital signal in general. That means it needs to pass a Digital-Analog-Converter to get a analogue signal. That's what I do by connecting an external DAC.
- I don't expect the changed signal, it is changed in fact. The outputted signal is resampled from 44.1 to 48 kHz. Many sound cards are doing this. But this hardware is able to output both rates so I'd like to avoid the resampling.
I know for sure because the DAC does show the actual sample rate. I can also see it when using mplayer, there a 44.1 kHz file is playing while the output is 48 kHz.
- I don't speak about analogue recording. You are right there you can choose a sample rate too.
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