On Thu, 10 Oct 2002, Juhana Sadeharju wrote:
> On the SB Live problems: recorded signal levels differs from MS Windows
> driver, and the capture faders of alsamixer seems to do nothing.
> I posted this to alsa-user as well if there are people who has
> the SB Live card. Please join us for testing.
>
> If I start to understand how the SB Live driver works, then I will
> fix the driver myself. But I would like to have reports from other
> SB Live users if their driver works the same way.
>
> -*-
>
> Below are the settings which works for Drive/line-in2 (Line LiveDrive)
> recording. All other faders are 0, mute switches are on, and capture
> switches are off.
>
> name | capture switch | mute switch | level
> -------------------------------------------------------------
> PCM | <none> | off | 100
> Line LiveDrive | off | <none> | 100
> Line LiveDrive Capture | <none> | <none> | 0
> Capture | on | <none> | 0
> Mix | on | <none> | 0
> AC97 Capture | <none> | <none> | 100
>
> <none> means that there is no such a switch.
>
> Line LiveDrive's capture switch has no effect. Strange!
> Line LiveDrive's level must be 100 because it controls both the monitor
> signal and the capture signal gains.
> Line LiveDrive Capture's level has no effect. Strange!
> Capture level 0 seems to mean unity gain.
> Mix level is fixed to 0.
It seems that you're routing your signal over AC97 ;-)
Have you tried a combination in this table?
name | capture switch | mute switch | level
-------------------------------------------------------------
PCM | <none> | off | 100
Line LiveDrive | on | <none> | 0
Line LiveDrive Capture | <none> | <none> | 100
Capture | off | <none> | 0
Mix | on | <none> | 0
AC97 Capture | <none> | <none> | 0
> Where all those controls are physically located? A flow diagram could
> also help in understanding all the relations.
>
> By seeing the whole signal path diagram of Alsa, I could check if there
> is a direct signal path from Line LiveDrive to disk with all gains
> inbetween set to unity. Is there such a path?
>
> -*-
>
> MS Windows driver allows one to set the quality of the resamplers
> (48000 Hz to/from 44100 Hz). Are those resamplers in firmware or
> in dsp code of emu10k1? Does Alsa use those resamplers or has
> equivalents? Could Alsa be programmed to allow an application
> software to use those resamplers? Or are the resamplers tied up
> to A/D and D/A conversion?
It's a software thing. Sure, this software might be in DSP or in driver.
ALSA uses only synthesizer voices for PCM where the resampling is done
inside wavetable synthesizer.
> Does emu10k1 work at a user settable sample rate? 44100 Hz? 32000Hz?
>
> MS Windows driver has a good sounding reverb. Could this reverb dsp
> code be extracted from the MS Windows driver and used "as is" in Alsa?
It's not so easy and I'm sure that we'll violate some patent doing things
in this way.
> -*-
>
> Alsamixer shows the following additional controls only if alsamixer
> is executed at the play time. What they are? The controls are not
> available at record time.
>
> name | value (left right)
> -------------------------------------------------------
> EMU10K1 PCM | 100 100
> EMU10K1 PCM | 100 100
Volume applied to playback samples.
> EMU10K1 PCM Send | 100 100
> EMU10K1 PCM Send | 0 100
> EMU10K1 PCM Send | 0 0
> EMU10K1 PCM Send | 0 0
Send volumes to FX BUS destinations.
> EMU10K1 PCM Send Routing | 0 7
> EMU10K1 PCM Send Routing | 20 0
> EMU10K1 PCM Send Routing | 13 13
> EMU10K1 PCM Send Routing | 7 7
FX BUS destination.
EMU10K1 hardware is complex. There is a synthesizer (wavetable engine), FX
BUS accumulators to route signals from this syntesizer to DSP and finally
DSP, managing inputs and outputs (inputs from syntesizer, external inputs,
inputs from PCI bus, outputs to PCI bus, external outputs).
So it very depends how the firmware behaves. You can build completely
different mixing system with another firmware.
Jaroslav
-----
Jaroslav Kysela <[EMAIL PROTECTED]>
Linux Kernel Sound Maintainer
ALSA Project http://www.alsa-project.org
SuSE Linux http://www.suse.com
-------------------------------------------------------
This sf.net email is sponsored by:ThinkGeek
Welcome to geek heaven.
http://thinkgeek.com/sf
_______________________________________________
Alsa-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/alsa-devel
