[alsa-devel] regarding setting of fragment size in usbaudio driver

[Clemens Ladisch]

Amit Nagal wrote:
> i am using a OSS based usbaudio application for usb audio streaming .
> 
> my usb audio device is capture only device .
> 
> i want to set the fragment size of usbaudio alsa driver to reduce
> latency problem coming in my application .
> 
> currently even if my application reads 4k data from userspace , i
> observed driver will buffer for 100 ms data ( period size data )= 16 k
> at 44100 frquency
> 
> and after driver  reads 16k data , read call will return with 4k data
> .  so read() call remains blocked for 100ms which is causing some
> latency problem .

There is no extra buffer in the driver.
There seems to be something wrong with your algorithm.

Does recording with the arecord tool work?


Regards,
Clemens