ASRC Custom Sample Rate

Sub forums for various specialist XMOS applications. e.g. USB audio, motor control and robotics.
kevpatt
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ASRC Custom Sample Rate

Post by kevpatt »

I have an application where I need to convert from a custom sample rate (42 kHz) to a standard sample rate (either 44.1 kHz or 48 kHz). Can I use the SRC library to do this? 44.1/42 is about 5%, which is more than the 10,000 ppm limit specified for ASRC. Maybe this can be accomplished by modifying the SRC code a bit?


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akp
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Post by akp »

Are the two sources truly asynchronous? If not then you might be able to get synchronous sample rate conversion to work. 8/7 to get 48kHz.
kevpatt
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Post by kevpatt »

The input is 42 kHz and the output will be generated at 48 kHz. The output clock can be derived from / driven by the input at 8/7, so synchronous is fine. But I don't see any option to put a ratio like 8/7 in the SRC library... am I missing something?
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akp
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Post by akp »

I suggest you take the SSRC code and generate your own 8:7 filters. Or 21:20 if you want 44.1 output.