[alsa-devel] Stream format conversion in SoC driver

[Clemens Ladisch]

Giedrius Trainavičius wrote:
>It uses I2S for sending / receiving audio. However, the master clock on our
>sound card is generated by the ADC, which supports only 24 bit data, so
>getting other sample formats is not possible.

The I2S sample format need not be the same as what the DMA
controller reads/writes from/to memory.

>A question on 'plug' - it accepts 'nearest' as the argument for format,
>rate, what happens in case the slave pcm stream supports the exact same
>format as requested by user software?

The plug plugin instantiates the actual conversion plugins only
as needed; with no conversion, it vanishes entirely.


Regards,
Clemens