This is a direct D binding of the PortAudio C library, meaning it's not OOP but a plain D conversion of its headers. PortAudio is MIT-licensed, and these bindings are Boost-licensed.

There are already two bindings that exist for PortAudio. One is at http://www.dsource.org/projects/bindings/wiki/Portaudio, and the other is Derelict which has its own binding as well.

However the dsource bindings have missing symbols, and the 1-byte alignment of struct members crashes the tests which I've ported to D. When using default 4-byte alignment the tests will run without issues (the PortAudio documentation recommends 4-byte alignment, so I don't know why 1-byte alignment was used).

Derelict also has 1-byte aligned struct members and it might suffer from the same issues, but I haven't tested it out so I can't confirm. In either case Derelict is a game-oriented library, and contains no examples on how to use PortAudio, plus it's on dsource which is a graveyard of dead projects anyway.

For the above reasons (and because I've worked on PortMidi as well), I've started my own bindings to PortAudio. Currently it's only built on Win32 platforms, but I'll see about getting it to work on Linux as well.

Project link: https://github.com/AndrejMitrovic/DPortAudio

It has about 15 ported tests, with a few dozen more to do.

It also has one standalone example, in which you can play your qwerty keyboard and the app will play a sinewave at a certain tone in the left and right channles, and draw the sinewaves on the screen for both channels. The visuals are updated as you "play" your keyboard. :) This example is currently built on win32 only.

Here's a screenshot:

http://i.imgur.com/7zsdJ.png

More samples will be coming by, including how to use PortAudio with PortMidi to make some cool realtime manipulation of audio data and visuals via a MIDI interface.

> Derelict also has 1-byte aligned struct members and it might suffer from the same issues, but I haven't tested it out so I can't confirm. In either case Derelict is a game-oriented library, and contains no examples on how to use PortAudio, plus it's on dsource which is a graveyard of dead projects anyway.

Hi, I'm the one which once made a PortAudio derelict binding based on previous work (http://www.dsource.org/projects/bindings/wiki/Portaudio). I made a derelict extension because I didn't know how to do otherwise :)

Portaudio is not a library choice I would make again. I was bitten hard with sound-card dependent synchronization issues, perhaps related to this alignment problem I did not see. BASS and FMOD are the ones I would use now. I made a partial BASS derelict binding too later on.

Cool project btw.


> 
> For the above reasons (and because I've worked on PortMidi as well), I've started my own bindings to PortAudio. Currently it's only built on Win32 platforms, but I'll see about getting it to work on Linux as well.
> 
> Project link: https://github.com/AndrejMitrovic/DPortAudio
> 
> It has about 15 ported tests, with a few dozen more to do.
> 
> It also has one standalone example, in which you can play your qwerty keyboard and the app will play a sinewave at a certain tone in the left and right channles, and draw the sinewaves on the screen for both channels. The visuals are updated as you "play" your keyboard. :) This example is currently built on win32 only.
> 
> Here's a screenshot:
> 
> http://i.imgur.com/7zsdJ.png
> 
> More samples will be coming by, including how to use PortAudio with PortMidi to make some cool realtime manipulation of audio data and visuals via a MIDI interface.

PortAudio is really just a uniform layer over APIs which already exist on the platform, so any synchronization problems those APIs have will be reflected in PortAudio. I did some reading about this in the portaudio newsgroups, and synchronization seems to be a difficult issue to solve.

I'll research this more and add synchronization samples to the bindings project as I figure things out.

FMOD and BASS are good libraries too! :)

14.7.2011 22.34, Andrej Mitrovic kirjoitti:
> There are already two bindings that exist for PortAudio. One is at
> http://www.dsource.org/projects/bindings/wiki/Portaudio, and the other
> is Derelict which has its own binding as well.
> However the dsource bindings have missing symbols, and the 1-byte
> alignment of struct members crashes the tests which I've ported to D.
> When using default 4-byte alignment the tests will run without issues
> (the PortAudio documentation recommends 4-byte alignment, so I don't
> know why 1-byte alignment was used).


I made the bindings on dsource... I don't know about the alignment stuff. The decision to use 1-byte alignment was made with trial and error. I think it was propably the only way the whole thing worked on Linux at the time. (A couple of years ago.) It still works "fine" on Linux and Mac OS X with the 1-byte alignment. I should propably test 4-byte alignment again. (If I get the time...) I'm using GDC as the compiler.

There were some performance issues with the D versions. It was much easier for the D versions to drop audio, than the corresponding C versions, but that might have been due to the alignment or other issues... I remember there were some issues with threads, GC and crashes. But it eventually worked. By trial and error, which isn't such a good way to write software.

> For the above reasons (and because I've worked on PortMidi as well),
> I've started my own bindings to PortAudio. Currently it's only built
> on Win32 platforms, but I'll see about getting it to work on Linux as
> well.
>
> Project link: https://github.com/AndrejMitrovic/DPortAudio
>
> It has about 15 ported tests, with a few dozen more to do.

Great stuff. I hope you get it to work on Linux as well, as I don't want to start messing with it until somebody else has gotten it working. You are obviously doing a much better job at making the bindings complete with good examples. That is great!

> More samples will be coming by, including how to use PortAudio with
> PortMidi to make some cool realtime manipulation of audio data and
> visuals via a MIDI interface.

That would be nice. I've been meaning to test PortMidi to get some midi controls for my app (the Pihlaja video viewer thing).

On a related note, I've also made bindings (barely working) for Jack.
http://www.dsource.org/projects/bindings/browser/trunk/jack
It might not be much interest for Windows users, and it's a bit more complex system, but I found it to perform a little better than PortAudio. (But that might be due to the alignment issues in my PortAudio bindings, as discussed above.) Oh, and Jack also works on Windows nowadays.

I'm still using PortAudio for my app, as it was easier to bundle into my installer, but I might change to Jack (it also has midi support) if my app ever becomes more audio oriented. I can change between the two with a compile switch (hurray, how wonderful).

Jonas Kivi

On 7/20/11, Jonas Kivi <seewebsite@foremail.fom> wrote:
> That would be nice. I've been meaning to test PortMidi to get some midi controls for my app (the Pihlaja video viewer thing).

There's bindings for that too (although only Windows was tested): https://github.com/AndrejMitrovic/DPortMidi

You might be interested in this example: https://github.com/AndrejMitrovic/DPortMidi/blob/master/samples/win32_drawshapes.d

It draws midi CC control changes as envelopes, it uses a plain C binding to Cairo to draw on a Win32 surface. Here's a screenshot: http://i.imgur.com/19vKa.png

It's not my best code, I should be using a cyclic buffer to pass data from the Midi worker thread to the GUI drawing thread, but instead I've used some hackish array duplication. :)

On 7/20/11, Jonas Kivi <seewebsite@foremail.fom> wrote:
> Great stuff. I hope you get it to work on Linux as well, as I don't want to start messing with it until somebody else has gotten it working.

Sure, I'll test it on Ubuntu sometime soon and see how it works there.

Someone mentioned that Linux doesn't need import libs. But I'm having linker errors when trying to compile a test file on Linux. I've built PortAudio as a shared lib, and installed via make install, and also exported an environment variable:

LD_LIBRARY_PATH=/usr/local/lib
export LD_LIBRARY_PATH

I've also tried manually copying the two (I don't know why there's two) shared libraries to the local folder, the libportaudio.so and libportaudio.so.2 files.

Command was:
andrej@andrej-VirtualBox:~/Desktop/dev/DPortAudio/tests$ dmd pa_devs.d
../portaudio/portaudio.a -I..

portaudio.a is the static lib of DPortAudio which has the converted header file that lists all extern(C) function prototypes.

Errors:
http://codepad.org/AIhYkqiZ

Any ideas?

IOW is there a utility I can use on Linux to list .so exports?

Ok this does the trick: nm -D libportaudio.so

It does list all of those functions though.

The C examples compile and run fine, so I must be doing something wrong on the D side.