[alsa-devel] Audio quality issues with dmix plugin
Hi, When I play a 44Khz file without using any ALSA plugin like
#aplay -Dhw:0,0 44k.wav
the sound quality is awesome but when I play the same file using dmix, clicks are introduced.
#aplay -Dplug:dmix 44k.wav
changing period size and buffer size doesn't help. I am testing my ALSA driver on an OMAP850 based board.
Regards, Pharaoh.
On 06-11-07 09:16, Pharaoh . wrote:
When I play a 44Khz file without using any ALSA plugin like
#aplay -Dhw:0,0 44k.wav
the sound quality is awesome but when I play the same file using dmix, clicks are introduced.
#aplay -Dplug:dmix 44k.wav
changing period size and buffer size doesn't help. I am testing my ALSA driver on an OMAP850 based board.
dmix does 48 kHz by default. Does it sound "awesome" when you play a 48 kHz file directly to hw:0,0? If that also clicks, the problem will be your driver's handling of the 48 kHz rate -- if not, it'll be the resampling, and I'll probably need to bow out...
Rene.
On 11/7/07, Rene Herman rene.herman@keyaccess.nl wrote:
On 06-11-07 09:16, Pharaoh . wrote:
When I play a 44Khz file without using any ALSA plugin like
#aplay -Dhw:0,0 44k.wav
the sound quality is awesome but when I play the same file using dmix, clicks are introduced.
#aplay -Dplug:dmix 44k.wav
changing period size and buffer size doesn't help. I am testing my ALSA driver on an OMAP850 based board.
dmix does 48 kHz by default. Does it sound "awesome" when you play a 48 kHz file directly to hw:0,0? If that also clicks, the problem will be your driver's handling of the 48 kHz rate -- if not, it'll be the resampling, and I'll probably need to bow out...
Rene.
Hi Rene, I changed alsa.conf so that dmix does 44.1kHz and tried, without dmix 44.1 and 48kHz files sound 'awesome' but with dmix some clicks appear at both the rates. Going ahead, I recorded a 8Khz mono sound using my driver and played it back without dmix, it plays without any clicks, but use dmix and clicks appear. So basically, clicks appear at all the sample rates with dmix and without it I could play all the sample rate files well since my hw supports hw upsampling.
-Pharaoh.
On 07-11-07 09:49, Pharaoh . wrote:
I changed alsa.conf so that dmix does 44.1kHz and tried, without dmix 44.1 and 48kHz files sound 'awesome' but with dmix some clicks appear at both the rates. Going ahead, I recorded a 8Khz mono sound using my driver and played it back without dmix, it plays without any clicks, but use dmix and clicks appear. So basically, clicks appear at all the sample rates with dmix and without it I could play all the sample rate files well since my hw supports hw upsampling.
Okay -- I don't even use dmix, so will defer to someone else. If there's anything special about your driver/hardware such as non-interleaved PCM and/or endianness conversions this is probably the time to say so...
Rene.
On Nov 8, 2007 3:33 AM, Rene Herman rene.herman@keyaccess.nl wrote:
On 07-11-07 09:49, Pharaoh . wrote:
I changed alsa.conf so that dmix does 44.1kHz and tried, without dmix 44.1 and 48kHz files sound 'awesome' but with dmix some clicks appear at both the rates. Going ahead, I recorded a 8Khz mono sound using my driver and played it back without dmix, it plays without any clicks, but use dmix and clicks appear. So basically, clicks appear at all the sample rates with dmix and without it I could play all the sample rate files well since my hw supports hw upsampling.
Okay -- I don't even use dmix, so will defer to someone else. If there's anything special about your driver/hardware such as non-interleaved PCM and/or endianness conversions this is probably the time to say so...
Rene.
No issues as endianness or non-interleaved pcm.
participants (2)
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Pharaoh . -
Rene Herman