Anyone using Portaudio?

Andrej Mitrovic andrej.mitrovich at
Sun Oct 17 14:10:31 PDT 2010

There's a .d header file in the Bindings project on dsource which I'm using with the Portaudio DLL v19, and I'm implicitly loading the DLL. There's a  sine playback example, and I'm comparing the usage of Portaudio from the C sine example (patest_sine.c) compared to the D one (patest_sine_hello.d). The C and D code are almost identical, however there seems to be a pretty big overhead when using D.

I can safely use a buffer size of 64 frames in the C example, but in the D one the minimum I could get was around 1800 frames.

I've tried compiling with-O -release -inline, and issuing a call to GC.disable() before the call to Pa_StartStream(). I've also tried compiling the portaudio DLL in Release mode. But none of this had any effect. Anything lower than 1800 for the buffer size gives me choppy sound in D. 

There shouldn't be a problem with such a small buffer size, all the data is preallocated and the buffers are prefilled with data, so it can't be a CPU bottleneck issue. Since D uses C functions directly, I just don't see where the overhead could be.

Has anyone used Portaudio with D2 (or D1 for that matter) with close-to-equal performance as when using C?

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