Here's the update, I hope someone puts it in the repo: http://www.dsource.org/forums/viewtopic.php?p=25726#25726
On 10/18/10, Andrej Mitrovic <[email protected]> wrote: > Problem solved! > > The D header file for Portaudio was bugged, I'll update it in the > Bindings project. > > On 10/18/10, Andrej Mitrovic <[email protected]> wrote: >> This is interesting. It appears the callback function is not called >> frequently enough. Really weird.. it must be some bug in my code. >> >> You see, I have a sample rate of 44100hz per second, and a buffer size >> of 64. This basically means that for 1 second of audio I need to fill >> ~680buffers per second in my callback (the callback is called ~680 >> times per second, and each buffer is 64 frames in size), so ~680 * 64 >> = ~44100. The C code gets its callback called around 680 times, but >> interestingly the D code gets its callback called only 29 times. This >> is why I hear the sound stuttering, its because my callback isn't >> getting called frequently enough and the audio card is filling the >> missing buffers with zeros. >> >> Now I have to figure out why it's not getting called often enough. >> >> On 10/18/10, Andrej Mitrovic <[email protected]> wrote: >>> Yeah, that's what I would usually do. The trouble is there's a library >>> in DLL format, and there's only a couple of calls to it and that's it. >>> But somehow the C client code performs better. I've just tried a D1 >>> sample, with the same result. I'll have to investigate.. >>> >>> On 10/17/10, Denis Koroskin <[email protected]> wrote: >>>> On Mon, 18 Oct 2010 01:10:31 +0400, Andrej Mitrovic >>>> <[email protected]> wrote: >>>> >>>>> 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? >>>> >>>> From my experience, starting with D that purely calls C code and then >>>> slowly porting it to D (one piece of code at a time) usually helps >>>> revealing the problem. Just try to keep it the same (i.e. >>>> interchangeable). You can do that by marking functions as extern (C) >>>> and >>>> optionally having some of the variables as extern (C) __gshared. >>>> >>> >> >
