[linux-audio-user] noise problem with ImproSculpt: solved !

Dave Phillips dlphilp at bright.net
Mon Feb 16 11:15:59 EST 2004


  I finally resolved the mouse noise problem with ImproSculpt. Here's 
what I did:

    1. Made the csound binary suid root.
    2. Erased the CsOptions for Linux in the ImproSculpt.csd file 
(they're ignored when csound is suid root).
    3. Ran the app so:

        csound --sched -d -i devaudio -o devaudio -b 512 -B 4096 -m6 

  Screen redraws are slower, but the mouse noise is gone. I'm still 
confused as to why all this trouble just "suddenly" occurred, but I'm 
glad to have discovered a solution. I also learned a lot about PCI 
latency timing, graphics card priority, hard/software buffering, and 
lots of other stuff that chewed up a bunch of my time.

  Many thanks to all who responded to my dilemma, I appreciate all the 
assistance and advice.

Best regards,


Gabriel Maldonado wrote:

> Hi Dave,
> It could depend on the massive CPU resources required by improsculpt, 
> so any movement on the GUI can subtract processor time, causing 
> drop-outs. Have you tried to increase the buffer size? However, try to 
> ask Oeyvind if this could be a possible cause. Notice that in 
> CsoundAV, there is still the original FLTK code, not that modified by 
> Istvan. I still have to study Istvan code, to see if there are 
> substantial differences, besides merging all code in a unique cpp file.
> Gabriel
> Dave Phillips wrote:
>> Greetings:
>>  I've been testing various CSD files to see and hear how the FLTK 
>> opcodes are supported in the most recent canonical CVS sources. Many 
>> files work fine (e.g., J. M. Comajuncosas' 303 emulator, his Synth 
>> Toot, and his Direct Hammond2), but I'm having a problem with Oeyvind 
>> Brandtsegg's ImproSculpt. When I move the mouse in this program I 
>> hear a nasty ripping noise tracking the mouse movement. Noise occurs 
>> when I change window focus or move a window. Note that this noise 
>> does not occur with other FLTK-based apps, so I'm wondering what 
>> there might be in ImproSculpt to cause this trouble. Steven Yi 
>> suggested that the FLTK updating may itself be a problem, but the 
>> other apps tested work fine. So I'm at an impasse and can use some 
>> suggestions for troubleshooting. Sorry to bother the developer's list 
>> but it seemed the better forum to ask in. Could Steven be right about 
>> the FLTK opcodes themselves causing the problem ? Would there be any 
>> advantage compiling Csound against a static libfltk ?
>> Best,
>> Dave Phillips

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