Hi Jaroslav,
Just to let you know I'm running this on Ubuntu 7.10 (alsa-lib-1.0.14), though I've been seeing this underrun problem for a while on a few systems (Ubuntu 7.04/6.10, and Gentoo 2006.1). It hasn't been clear to me what the key parameters are that control underrun behaviour. (It would be great if someone wrote a comprehensive book/article on ALSA....)
BTW you mentioned doing the rate resampling in RAT - which it can do - how does one discover if rate conversion is occurring in ALSA and obtain that 'base' rate? (Though I has assumed that ALSA would do the better job of rate resampling if it was necessary...).
Thanks,
Piers.
On 09/11/2007, Jaroslav Kysela perex@perex.cz wrote:
On Fri, 9 Nov 2007, Piers O'Hanlon wrote:
===snd_pcm_dump_setup:=============== stream : PLAYBACK access : RW_INTERLEAVED format : S16_LE subformat : STD channels : 1 rate : 16000 exact rate : 16000 (16000/1) msbits : 16 buffer_size : 2048 period_size : 341 period_time : 21333 tick_time : 0 tstamp_mode : NONE period_step : 1 sleep_min : 0 avail_min : 341 xfer_align : 1 start_threshold : 341 stop_threshold : 2048 silence_threshold: 0 silence_size : 0 boundary : 536870912
Could you do whole dump (snd_pcm_dump()) to see all plugins in chain? I judge from period_size that we have another problem with rate plugin. It would be better to do rate resampling in RAT.
Jaroslav
Jaroslav Kysela perex@perex.cz Linux Kernel Sound Maintainer ALSA Project