>Пятница, 8 января 2016, 10:14 +01:00 от Clemens Ladisch
><cladi...@googlemail.com>:
>
>Sergei Steshenko wrote:
>> Понедельник, 4 января 2016, 18:45 +01:00 от Clemens Ladisch <
>> cladi...@googlemail.com >:
>>
>> Sergei Steshenko wrote:
>> > I have developed a piece of code (as LADSPA plugin) which among other
>> things multiplexes one of two input streams into output stream.
>> >
>> > Though switching worked, latency was several seconds long instead
>> fraction of a second.
>> >
>> > Because of the latency I suspected a problem with my code, but after
>> creating a special test audio files I've established that the multiplexing
>> happens fast - within my LADSPA host buffer length, as expected. And the
>> buffer length was 1024 samples @44100KHz.
>>
>> What is the buffer length of the device?
>> (see /proc/asound/card*/pcm0p/sub0/hw_params)
>>
>> "buffer_size: 262144", and 262144/48000 is about 5.46 seconds - feels about
>> right.
>
>The audio device is configured by whatever program actually writes to it,
>probably your host. What is it? How is it configured?
>
>
>Regards,
>Clemens
"The audio device is configured by whatever program actually writes to it" -
the program is 'ecasound'. But the point is the buffer length is different for
USB and non-USB cards.
For example, at the moment I am using "M-Audio Revolution 7.1", and for it I
see:
"
sergei@amdam2:~/tmp> cat /proc/asound/card1/id
Revolution71
sergei@amdam2:~/tmp> cat /proc/asound/card1/pcm0p/sub0/hw_params
access: MMAP_INTERLEAVED
format: S32_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 1024
buffer_size: 32768
".
Again, it's the same 'ecasound' with my audio stuff as LADSPA plugin for it.
I.e. the code I wrote has no access to audio device.
For that matter, for on board "Nvidia", with a Youtube video playing through
Firefox:
"at /proc/asound/card0/pcm0p/sub0/hw_params
access: MMAP_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 44096
buffer_size: 88192
".
Regards,
Sergei.
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