[Qutecsound-users] A few issues

[Matthew Walworth <matthew.walworth@gm...>]

Have been playing with qutecsound for a couple of days now. Thank you for a
wonderful application. It is rapidly becoming my environment of choice. I
have run across a few issues:

1. MIDI latency seems quite high. I am trying to play from an external
keyboard and am getting about 0.5 seconds of delay on each keypress. I've
tried all the different thread/api options, but they don't seem to make a
difference. I get little or no latency running the same csd from the command
line.  Also interesting is that if I use a widget to output information
about the midi message, the widget seems to update almost instantly on key
press/release as does the information written to the console.

2. The option to "run in terminal" doesn't seem to do anything. I've checked
the path to Terminal.app and it is correct. Nothing seems to happen when I
try it including that no messages are written to the console.

3. The option to graph the csd using graphviz has a problem writing its
output file. I get an error dialog that says, "Cannot create temp dot/png
file." I'm guessing it is a permissions problem?

4. This is certainly not a big deal, but rendering is cut short by a
fraction of a second. I noticed this with a simple instrument that had a
de-clicking envelope applied when it still clicked on the cutoff. The
fraction of a second seems to vary a little bit around 0.25. It can be
worked around by adding a time to the "e" statement, but that also must have
an extra amount added to it to keep the render from being cut short. You can
see the discrepancy if you check the "Elapsed time at end of performance" in
the console.

My environment is a Mac mini running 10.5.6, 2Ghz Intel Core 2 Duo, 2GB ram,
various MIDI interfaces including an M-Audio KeyRig 25 usb keyboard and an
Edirol UM-1.

(funny aside: when spell checking this message, the spellchecker offered
"godsend" as a substitution for "qutecsound")

...mathom...

Re: [Qutecsound-users] A few issues

[Andres Cabrera <mantaraya36@gm...>]

HI Matthew,


On Fri, Jan 30, 2009 at 1:53 PM, Matthew Walworth
<matthew.walworth@...> wrote:
> Have been playing with qutecsound for a couple of days now. Thank you for a
> wonderful application. It is rapidly becoming my environment of choice. I
> have run across a few issues:
>
> 1. MIDI latency seems quite high. I am trying to play from an external
> keyboard and am getting about 0.5 seconds of delay on each keypress. I've
> tried all the different thread/api options, but they don't seem to make a
> difference. I get little or no latency running the same csd from the command
> line.  Also interesting is that if I use a widget to output information
> about the midi message, the widget seems to update almost instantly on key
> press/release as does the information written to the console.
>

Latency is due to the hardware buffer size. In my limited testing, I
found portaudio to be able to handle low latencies. Try setting the -b
buffer to 128 and the -B buffer to 256. This should give you
acceptable latency.
What you mention about widgets might be an optical illusion, or might
be due to Csound sending the values to the software bus on every
control period, and since ksmps is much lower than the hardware
latency, the values are displayed faster.

> 2. The option to "run in terminal" doesn't seem to do anything. I've checked
> the path to Terminal.app and it is correct. Nothing seems to happen when I
> try it including that no messages are written to the console.
>

That's odd... its working here on 10.4. Are you completely sure the
path is: /Applications/Utilities/Terminal.app?
(case sensitive)

> 3. The option to graph the csd using graphviz has a problem writing its
> output file. I get an error dialog that says, "Cannot create temp dot/png
> file." I'm guessing it is a permissions problem?
>

I also noticed this. The workaround for now is to put the QuteCsound
application in another directory, e.g. the desktop, the documents
directory, etc.


> 4. This is certainly not a big deal, but rendering is cut short by a
> fraction of a second. I noticed this with a simple instrument that had a
> de-clicking envelope applied when it still clicked on the cutoff. The
> fraction of a second seems to vary a little bit around 0.25. It can be
> worked around by adding a time to the "e" statement, but that also must have
> an extra amount added to it to keep the render from being cut short. You can
> see the discrepancy if you check the "Elapsed time at end of performance" in
> the console.
>

Interesting. I'll check.

> My environment is a Mac mini running 10.5.6, 2Ghz Intel Core 2 Duo, 2GB ram,
> various MIDI interfaces including an M-Audio KeyRig 25 usb keyboard and an
> Edirol UM-1.
>
> (funny aside: when spell checking this message, the spellchecker offered
> "godsend" as a substitution for "qutecsound")
>

 =)


Cheers,
Andrés

Re: [Qutecsound-users] A few issues

[Matthew Walworth <matthew.walworth@gm...>]

On Fri, Jan 30, 2009 at 1:01 PM, Andres Cabrera <mantaraya36@...>wrote:

> HI Matthew,
>
>
> On Fri, Jan 30, 2009 at 1:53 PM, Matthew Walworth
> <matthew.walworth@...> wrote:
> > Have been playing with qutecsound for a couple of days now. Thank you for
> a
> > wonderful application. It is rapidly becoming my environment of choice. I
> > have run across a few issues:
> >
> > 1. MIDI latency seems quite high. I am trying to play from an external
> > keyboard and am getting about 0.5 seconds of delay on each keypress. I've
> > tried all the different thread/api options, but they don't seem to make a
> > difference. I get little or no latency running the same csd from the
> command
> > line.  Also interesting is that if I use a widget to output information
> > about the midi message, the widget seems to update almost instantly on
> key
> > press/release as does the information written to the console.
> >
>
> Latency is due to the hardware buffer size. In my limited testing, I
> found portaudio to be able to handle low latencies. Try setting the -b
> buffer to 128 and the -B buffer to 256. This should give you
> acceptable latency.


Thank you. That has indeed solved my problem.


>
> What you mention about widgets might be an optical illusion, or might
> be due to Csound sending the values to the software bus on every
> control period, and since ksmps is much lower than the hardware
> latency, the values are displayed faster.
>
> > 2. The option to "run in terminal" doesn't seem to do anything. I've
> checked
> > the path to Terminal.app and it is correct. Nothing seems to happen when
> I
> > try it including that no messages are written to the console.
> >
>
> That's odd... its working here on 10.4. Are you completely sure the
> path is: /Applications/Utilities/Terminal.app?
> (case sensitive)
>

Yes, I've double checked the path. I can get Audacity and QuickTime player
to open as editor and player respectively, but Terminal is not doing
anything. I just did a quick test and substituted the path to Terminal for
the path to the player and Terminal does indeed open when I hit the "Ext.
Player" button.


>
> > 3. The option to graph the csd using graphviz has a problem writing its
> > output file. I get an error dialog that says, "Cannot create temp dot/png
> > file." I'm guessing it is a permissions problem?
> >
>
> I also noticed this. The workaround for now is to put the QuteCsound
> application in another directory, e.g. the desktop, the documents
> directory, etc.
>

Thank you. So far this is mostly a curiosity for me. I have used graphviz in
the past to dump graphs of data structures from c++ code for debugging
purposes. Handy little tool.

Thank you for all your help.

...mathom...

Re: [Qutecsound-users] A few issues

[Andres Cabrera <mantaraya36@gm...>]

Hi,

On Fri, Jan 30, 2009 at 3:30 PM, Matthew Walworth
<matthew.walworth@...> wrote:

> Yes, I've double checked the path. I can get Audacity and QuickTime player
> to open as editor and player respectively, but Terminal is not doing
> anything. I just did a quick test and substituted the path to Terminal for
> the path to the player and Terminal does indeed open when I hit the "Ext.
> Player" button.
>

Please try this:
Delete the file Library/Preferences/com.csound.qutecsound.plist
and try again. If this doesn't help, I can't imagine what it is...

>>
>> > 3. The option to graph the csd using graphviz has a problem writing its
>> > output file. I get an error dialog that says, "Cannot create temp
>> > dot/png
>> > file." I'm guessing it is a permissions problem?
>> >
>>
>> I also noticed this. The workaround for now is to put the QuteCsound
>> application in another directory, e.g. the desktop, the documents
>> directory, etc.
>
> Thank you. So far this is mostly a curiosity for me. I have used graphviz in
> the past to dump graphs of data structures from c++ code for debugging
> purposes. Handy little tool.
>

It's fun to see Csound code as a graph. Bear in mind that you'll need
to give a path like:
/Applications/Graphviz.app/Contents/MacOS/dot

for dot to be found, since it is inside the Graphviz package.

Cheers,
Andrés

Re: [Qutecsound-users] A few issues

[Matthew Walworth <matthew.walworth@gm...>]

On Fri, Jan 30, 2009 at 1:53 PM, Andres Cabrera <mantaraya36@...>wrote:

> >>
> >> > 3. The option to graph the csd using graphviz has a problem writing
> its
> >> > output file. I get an error dialog that says, "Cannot create temp
> >> > dot/png
> >> > file." I'm guessing it is a permissions problem?
> >> >
> >>
> >> I also noticed this. The workaround for now is to put the QuteCsound
> >> application in another directory, e.g. the desktop, the documents
> >> directory, etc.
> >
> > Thank you. So far this is mostly a curiosity for me. I have used graphviz
> in
> > the past to dump graphs of data structures from c++ code for debugging
> > purposes. Handy little tool.
> >
>
> It's fun to see Csound code as a graph. Bear in mind that you'll need
> to give a path like:
> /Applications/Graphviz.app/Contents/MacOS/dot
>
> for dot to be found, since it is inside the Graphviz package.
>

What version of Graphviz are you using? I went out and downloaded the latest
2.2 version since I still had the old 1.whatever on my machine and dot seems
to be having some problems. I wasn't getting an image in the GraphicWindow
so I set a breakpoint in qutecsound::createGraph() and fount that the png
file was empty. The dot file that qtcs is generating is fine as it opens
correctly in Graphviz.app but dot is throwing this error:

dyld: lazy symbol binding failed: Symbol not found:
_pixman_image_create_bits
  Referenced from: /usr/local/lib/graphviz/libgvplugin_pango.5.dylib
  Expected in: flat namespace

So the png doesn't get created. Have you seen this?

...mathom...

Re: [Qutecsound-users] A few issues

[Matthew Walworth <matthew.walworth@gm...>]

On Fri, Jan 30, 2009 at 1:53 PM, Andres Cabrera <mantaraya36@...>wrote:

> Hi,
>
> On Fri, Jan 30, 2009 at 3:30 PM, Matthew Walworth
> <matthew.walworth@...> wrote:
>
> > Yes, I've double checked the path. I can get Audacity and QuickTime
> player
> > to open as editor and player respectively, but Terminal is not doing
> > anything. I just did a quick test and substituted the path to Terminal
> for
> > the path to the player and Terminal does indeed open when I hit the "Ext.
> > Player" button.
> >
>
> Please try this:
> Delete the file Library/Preferences/com.csound.qutecsound.plist
> and try again. If this doesn't help, I can't imagine what it is...
>

This looks like a permissions issue also. I can execute in the terminal as
long as I have write permissions in the folder that qutecsound.app is
sitting in.

Thanks again for your help.

...mathom...

Re: [Qutecsound-users] A few issues

[Andres Cabrera <mantaraya36@gm...>]

Hi

On Fri, Jan 30, 2009 at 5:14 PM, Matthew Walworth
<matthew.walworth@...> wrote:

> This looks like a permissions issue also. I can execute in the terminal as
> long as I have write permissions in the folder that qutecsound.app is
> sitting in.
>

Makes sense, as QuteCsound creates a temporary file and a run script,
so if permissions are wrong, there will be problems here... I'll fix
this.

Cheers,
Andrés