Re: [linrad] Was: How to configure sound mixer

[Edson Pereira <edson@xxxxxxxxxxxxx>]

I have also had my share of problems and frustrations regarding sound
cards few occasions. The state of affairs of sound cards and sound drivers
is quite messy and although there are Linux drivers for many cards, the
drivers not always support all the card features. The lack of
standardization is also a nightmare for developers and any attempt to make
a software control the sound card will have problems. For this reason,
from a programming point of view it is safer to leave the sound card
controls out of the application.

After suffering in hell, I recommend anyone trying to configure a sound
card to get to know exactly what chipset the card uses and what functions
the sound card support in hardware, i.e., full-duplex, what type of mixer
controls, etc. Once the card features are known and the specs match the
needs, look for the best sound driver. In Linux there are basically three
choices. OSS-Free, OSS, and ALSA. OSS-Free is the most wide spread but it
does not support all sound cards 100%. It will also be obsoleted at some
time soon once ALSA is fully included in the Linux kernel tree. OSS is
better since it supports many if not most sound cards, but it is
commercial. ALSA is also better than OSS-Free, but its implementation is
not too clean and many have difficulties in setting it up. ALSA also uses
a different API than OSS and OSS-Free (although it does emulate the OSS
API). But even with some problems, ALSA is maturing and is here to stay.

If you can't find too much information about a card, don't give up. You may 
need to try to make things work through trial and error, but you may 
eventually succeed. Try OSS-Free, OSS, and ALSA. It is painful, but it 
may be necessary.

Resuming, get to know your card and once you know it look for the best
driver support. For amateur radio use, I would recommend the simplest
possible card. No need for MIDI, special effects, 6 channels, etc. All
these features make the card configuration (specially the mixer) quite
complex. Just a good full-duplex ADC/DAC is enough.

73,

-- Edson [pu1jte/n1vtn/7n4ncl]



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