[fpc-pascal] SPDIF

Marc Santhoff M.Santhoff at t-online.de
Fri Jan 28 16:23:44 CET 2005

Am Fr, den 28.01.2005 schrieb Christophe Fantoni um 15:13:
> Hello again,
> I have found many pascal sources to interface the Sound Blaster compatible
> drivers, but only for the analog output/input. Nothing for the SPDIF or
> optical input/output. With sound card like SB Live! or SB Audigy, the DOS
> driver to interface DOS program exist... like the SPDIF input/output. But no
> program to use it (maybe DOS is too old, and programmers don't support this
> new feature in their old program)
> For me, the problem is to found the technicals informations explain how to
> include the digital output structure in the analog ouput sources coded in
> Pascal. For example, the SoundLib 2 library in
> http://www.crossfire-designs.de/index.php?lang=en&what=sourcecode&name=sl2.h
> tm , compatible vith FPC, Delphi and BP7, car easilly input and output sound
> stream but only in an analog way. No informations in the pascal code souce
> to structure and activate the digital input/output... Under Windows, this
> problem doesn't exist. Normal, the analog and digital input/out is managed
> by the Windows driver, and maybe by DirectX. But under DOS, the problem is
> not the same.

I think (and would like to know, too) using a digital output makes no
difference on the software side. The only matter is to switch to the
right output.

If you look at it, you're writing out bytes to the analog output. This
output is some form of D/A-converter for analog signals and nothing but
a driver for digital signals.

So, if you use the right enconding for sending your sound data stream
(this may require some software) and switched the soundcard to the SPDIF
out then anything should work.


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