[pulseaudio-discuss] Playback pauses

[Dmitri Paduchikh]

David Henningsson wrote:

> On 02/11/2013 11:03 AM, Dmitri Paduchikh wrote:

>> Hello,
>>
>> When I play a sound using paplay (or aplay with ALSA configured to use
>> PulseAudio) there is a big pause between two successive runs. For
>> example:
>>
>> $ paplay sound1.wav; paplay sound2.wav
>>
>> The pause between these sounds is something about two seconds. I've
>> tried to adjust latency (through --latency-msec=50) but this doesn't
>> seem to change much.
>>
>> Couldn't you explain what is the cause of this pause? Is it possible to
>> eliminate it?
>>

> This is a well-known issue which we discussed briefly at PulseConf. Fixing
> it is not trivial, unfortunately.

> I did a quick test here; and for me the delay is 250 - 500 ms, which is
> consistent with the output of pacmd list-sinks:

>         configured latency: 0.00 ms; range is 0.50 .. 371.52 ms

> Is your maximum latency going up to about 2000 ms?

Hmm, in my case the upper bound in this range is 1837,50 ms. May be this
explains huge pauses. Though I'd expect that command-line option
--latency-msec=50 should change the used latency. Is the maximal value
configurable or is only calculated from the buffer size in kernel?

> What distro are you running?

I am on Arch Linux. PulseAudio 3.0, Linux kernel 3.7.6. The buffer size
pointed out by Tanu Kaskinen is

CONFIG_SND_HDA_PREALLOC_SIZE=4096

Let me explain. I am blind and try to use these command-line utilities
to play a speech output. The controlling program waits for termination
of one player process and only then starts playing next portion of
speech. In this scenario such huge pauses (one or two seconds) are
rather painful. I am aware of Speech Dispatcher, just want to do it
other way.

-- 
With best regards
Dmitri Paduchikh