Thanks for the information.

Yes, performKsmps produces one spout buffer per kperiod. So if you have ksmps == 1 (kr == sr), this will be way slower than buffer access.

Another thought is to use the Lua interface to Csound. If you are working on Windows, there is a just-in-time compiler for Lua that runs considerably faster than Python.

I take it, then, that you are sending scores only as real-time events, and that you are sending output only through fout?

Regards,
Mike

-----Original Message-----
>From: Lilith Bryant 
>Sent: Apr 3, 2008 3:00 PM
>To: csound@lists.bath.ac.uk
>Subject: [Csnd] Re: Re: CSound (Python) API & Output Buffers
>
>a) python is most certainly too slow.  even just running a loop of 
>csoundPerformKsmps is noticably (i.e. 5-10 times) slower than running a loop 
>of csoundPerformBuffer, even without processing any samples in python. 
>especially when kr=sr
>
>b) recompiling the orchestra is slow enough (especially when there are 
>soundfonts involved) for me to want to avoid it at all costs.  i run csound 
>sometimes on a 300Mhz celeron laptop.   
>
>c) fout does the trick, thanks for the offer though.
>
>On Friday 04 April 2008 00:51, Michael Gogins wrote:
>> Python probably isn't too slow for this. You don't need the host IO calls
>> either. Just get the samples from the spout buffer and stream them to your
>> own soundfile. That means calling csoundPerformKsmps do compute one spout
>> buffer at a time. There is a Python wrapper for libsndfile in the CsoundAC
>> module you can use to write your output. If the Python access to spout
>> doesn't work, let me know and I will make it work.
>>
>> Perhaps more to the point, Csound can recompile the orchestra and re-create
>> the soundfile plenty fast -- usually in a few seconds or less. Loading
>> soundfonts, samples, or VST plugins slows it down somewhat but it is still
>> tolerable (to me, anyway).
>>
>> Regards,
>> Mike
>>
>> ----- Original Message -----
>> From: "Lilith Bryant" 
>> To: 
>> Sent: Wednesday, April 02, 2008 11:10 PM
>> Subject: [Csnd] CSound (Python) API & Output Buffers
>>
>> >I wonder if I could tap the list here for some advice.
>> >
>> > I'm writing a score writer front-end in python using the csound API.
>> >
>> > The big idea with this project, is to be able to quickly change the score
>> > and
>> > re-render with having csound reload the whole orchestra/csd file for
>> > every simple score change.  So i'm simply calling the csoundCompile and
>> > all the prequisites once at the beginning of my application (or whenever
>> > the user asks to reload the orchestra/csd)
>> >
>> > Then for each renderering, I call csoundScoreRewind and then
>> > csoundScoreEvent
>> > for each note.
>> >
>> > Which works as expected, except the output wav file simply grows with
>> > easy pass.  i.e. it  csoundScoreRewind doesn't clear it, like would be
>> > useful for
>> > this case.
>> >
>> > Now I can alternatively not use wav file output at all, and use
>> > csoundSetHostImplementedAudioIO and manually fish out the samples, and
>> > write
>> > them to a wav file myself.  But this is python and that hideously slow.
>> >
>> > So the questions are:
>> > 1) Is there a way to restart the wav file output without reloading the
>> > orchestra/csd?
>> >
>> > OR
>> >
>> > 2) Is there a quick way to fish out the output buffer samples into a
>> > python
>> > string or array, for writing out to file using the python wav module?
>> >
>> > The best i have so far is something like:
>> >
>> > ob=csnd.csoundGetOutputBuffer(self.cs)
>> > fa=csnd.floatArray.frompointer(ob)
>> > sa=array.Array('h',[0]*buffersize*2)
>> > for n in range(buffersize*2):
>> > sa[n]=fa[n]*32767
>> > wavdata=sa.tostring()
>> >
>> > which really SUCKS performance-wise (not surprisingly).
>> >
>> > I don't want to write a C/SWIG function to do just this, since i want to
>> > be
>> > able to give this to people who aren't up to running compilers.
>> >
>> >
>> > Send bugs reports to this list.
>> > To unsubscribe, send email sympa@lists.bath.ac.uk with body "unsubscribe
>> > csound"
>>
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