Rafael Guayer wrote:
> The plataform driver and the I2S hardware on the ARM SoC supports sample
> resolutions of 16, 20 and 24 bits, and word sizes of 16, 20, 24 and 32
> bits. Signed, little or big endian.
>
> The i2s-DMA plataform driver and hardware, only 8, 16 and 32 bits transfers
> are possible.
>
> The problem is the CODEC (CS4245 Cirrus Logic), that, for I2S format,
> supports only 24 bit resolution in 32 bit words, signed, litle endian
The format on the I²S bus is pretty much independent from the format that
the DMA controller reads from/writes to memory.
> In the i2s plataform driver, in *_hw_params, when params_format(params) ==
> SNDRV_PCM_FMTBIT_S24_3LE,
24-bit words not supported by the DMA platform driver.
> What is this widely used format for 24bits on ALSA?
SNDRV_PCM_FORMAT_S32_LE. Apparently, it's the only one that your DMA
hardware supports for 24-bit samples.
Regards,
Clemens
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Received on Fri Oct 24 00:15:01 2014
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