"Bob Masta" wrote in message
...

On 14 Jan 2006 23:35:30 -0800, "Rubon" wrote:

I would like to develop an application under WINDOWS-os using my PC

From your question, I wonder if you have any idea what a PITA Windows
development is -- especially when it relates to dealing with hardware at a
low level.

Sorry, all sound cards that I know of are AC-coupled, with a roll-off

I've never studied them, but I would expect this to be the case. And even
if it were not, I can't imagine why the DAC would be designed to support DC

...

{handful of crosspostings clipped]

In article ,
says...
From your question, I wonder if you have any idea what a PITA Windows
development is -- especially when it relates to dealing with hardware at a
low level.

1994 was a long time ago.

Sorry, all sound cards that I know of are AC-coupled, with a roll-off

I've never studied them, but I would expect this to be the case. And even
if it were not, I can't imagine why the DAC would be designed to support DC

Hmm. I'm not sure how to design one that doesn't.

Usually, all that's necessary is to locate the output coupling
capacitors on the sound card and bridge them. This may be easier with
older Sound Blaster 16-era sound cards, before they all went to SMT.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

On Sun, 15 Jan 2006 14:50:01 -0800, John Miles
wrote:

In article ,
says...

Sorry, all sound cards that I know of are AC-coupled, with a roll-off

I've never studied them, but I would expect this to be the case. And even
if it were not, I can't imagine why the DAC would be designed to support DC

Hmm. I'm not sure how to design one that doesn't.

Usually, all that's necessary is to locate the output coupling
capacitors on the sound card and bridge them. This may be easier with
older Sound Blaster 16-era sound cards, before they all went to SMT.

IIRC, at least some of the Crystal/Cirrus data sheets for ADCs (and
codecs) indicated that there was a 3 Hz lower frequency limit,
apparently due to some DC offset drift compensation circuitry on the
chip itself.

Even if the sound card is AC coupled with a capacitor, various diode
clamping tricks can be used (as in clamping the sync tip to a known DC
level in video equipment).

Paul OH3LWR

...[ how to use sound cards]...

Usually, all that's necessary is to locate the output coupling
capacitors on the sound card and bridge them....

IIRC, part of the original question was something like:

"Where/How can one learn to program soundcards?"

I, too, would be interested in the answer to that question.

--Myron.
--
--Myron A. Calhoun.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge
PhD EE (retired). "Barbershop" tenor. CDL(PTXS). W0PBV. (785) 539-4448
NRA Life Member and Certified Instructor (Home Firearm Safety, Rifle, Pistol)

In article , says...
...[ how to use sound cards]...

Usually, all that's necessary is to locate the output coupling
capacitors on the sound card and bridge them....

IIRC, part of the original question was something like:

"Where/How can one learn to program soundcards?"

I, too, would be interested in the answer to that question.

--Myron.


It's kind of an open-ended question... one that depends entirely on what
sort of application you want to build and what development environment
you prefer to build it with. A quick and dirty console app to record a
raw PCM audio file using the waveIn API will be on the order of 100
lines of C code. A more-sophisticated app that has to parse various
sound file formats, handle streaming audio, or otherwise do a lot of
network and/or UI interaction will of course be longer and hairier.

Either way, it's not necessary (or appropriate) to deal with low-level
hardware coding, and in neither case are the basic programming concepts
obscure or difficult. The Win32 APIs for audio input and output --
namely waveIn, waveOut, and DirectSound -- have been around forever,
work very reliably, and are very well-documented.

A good first step is plugging phrases like "sound programming" into your
favorite search engine, tweaking the search terms based on the language
and intended application. Once your questions become more specific,
there are a lot of ways to get help with them.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

wrote:

IIRC, part of the original question was something like:

"Where/How can one learn to program soundcards?"

I, too, would be interested in the answer to that question.

Windows is not your friend in this area. Linux, on the other
hand makes this easy. The sound card is a device like
any other. Read from /dev/dsp and you get samples. Write to
/dev/dsp and you make noise.

There is a little bit more setup to buffer things properly,
and you use ioctl() to configure the sample rate, sample
size, and so on, but it's nothing compared to the contortions
Windows programmers go through.

What to do with the samples once you've got them, or
how to generate interesting samples for output is another
matter. Any decent textbook on DSP will help you. I
like Ifeachor & Jervis as a good nuts and bolts introduction.

Laura Halliday VE7LDH "Que les nuages soient notre
Grid: CN89mg pied a terre..."
ICBM: 49 16.05 N 122 56.92 W - Hospital/Shafte

In article .com,
says...
wrote:

Windows is not your friend in this area.
There is a little bit more setup to buffer things properly,
and you use ioctl() to configure the sample rate, sample
size, and so on, but it's nothing compared to the contortions
Windows programmers go through.

I hope you're not under the impression that you're doing the Linux
community a service by spreading FUD about how difficult it is to code
for waveOut or DirectSound, or (for that matter) by extolling the
virtues of ioctl(). :-)

There's got to be ten thousand pages of example audio recording and
playback code for both operating systems out there by this point.
Choose your poison and Google for a willing supplier.

-- jm

------------------------------------------------------
http://www.qsl.net/ke5fx
Note: My E-mail address has been altered to avoid spam
------------------------------------------------------

"laura halliday" wrote in message
oups.com...

Windows is not your friend in this area.

Actually, depending on where you are coming from and what you are doing,
Windows can be your friend. Once you have gotten over the initial jolt of
Windows development (admittedly, no small feat), then doing "normal" things
with sound is pretty easy -- probably quite a bit easier than Linux.
However, OP wanted to do some unusal things, and in that sort of case, the
help that Windows gives you definitely gets in the way.

One thing that Windows and Linux development have in common -- everything is
documented and it is virtually impossible to find what you want in the docs.

...