[alsa-devel] Noise using pulseaudio with ymf724f

Clemens Ladisch clemens at ladisch.de
Wed Sep 14 11:05:34 CEST 2011

Raymond Yau wrote:
> Is 256 frames/period in s16 stereo since the card support mono ,
> stereo , U8 and S16 ,

The hardware uses S16 stereo at 48 kHz internally; everything else is
converted and resampled to that.

> What is the meaning of SNDRV_PCM_INFO_BLOCK_TRANSFER

That the card transfers samples in blocks.

> since the rewind_safeguard of PA server is 256 bytes ?

A block in the native format has 1024 bytes.

> Will this

What's "this"?

> help since minimum period time of snd_ymfpci is 5.333ms but
> alsa-pulse plugin announce a lower value 128 bytes (period_bytes_min)
> to the alsa application ?

Doesn't PA assume that the hardware has accurate pointer positions?
Without this, smaller periods do not make sense unless PA can
interpolate from the period interrupts.


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