#19 Latency issue

[Mark Bugeja]

Hi I am having latency issues which started after I tried importing other sf2! I cannot revert back to original situation even after uninstalling and re-installing. Imported sf2 do not seem to play well. How can I completely uninstall and reinstall a clean fresh program?

I tried posting on the forum but I am not allowed for some mysterious reason.

I have Windows 7 64x installed on my music system.

[Pedro Lopez-Cabanillas]

Ticket moved from /p/vmpk/bugs/43/

[Pedro Lopez-Cabanillas]

Define what do you mean with 'latency', and what synthesizer settings.

To completely remove all the stored settings after uninstalling VMPK, execute the following command in a cmd.exe shell (as administrator):

reg delete HKEY_CURRENT_USER\Software\vmpk.sourceforge.net

You can use regedit.exe as well to remove the registry data.

[Mark Bugeja]

I removed the registry entry manually before re-installing. Yet I still experience a degree of latency - the time a note sounds after the corresponding key is pressed - and it interferes with the actual playing as the sounds come milliseconds after. It is a small but noticable delay.

[Mark Bugeja]

I will report the settings when I next load the computer but they are the same settings I had set upon first installation of the program. I am using a UMX 61 keyboard to play with default settings except that I cannot used fluidsynth for sound generation as the output is very coarse and crackly.

I have jOrgan (uses fluidsynth or a fluidsynth-portaudio backend developed by Graham Goode) installed and it plays sf2s without any problems but then it does have settings which Virtual Midi Piano does not have ie Audio buffers and size which I usually set to 8 and 512 respectively to get the correct quality of sound and latency something I cannot do with VMP.

Another odd observation is that when trying to import sf2 files, * .ini files are created and stored automatically (no user options allowed). I later discovered that these "files" are saved in the registry.

I hope I have provided enough and correct information to help solve the issues or to help towards improving the program.

[Pedro Lopez-Cabanillas]

I don't understand why do you need a UMX 64 keyboard with VMPK. It is another MIDI controller, just like VMPK.

VMPK is just a MIDI controller. It doesn't produce sound by itself. For users' convenience, it includes a Synthesizer: FluidSynth. And of course there is a dialog box to configure some settings like number of periods, buffer size, and the Soundfont file. See the attached pìcture. These settings are only for FluidSynth, and doesn't affect other synthesizers. Buffer size affects latency and sound stability. If the sound is crackly then you need larger buffers, which means higher latency as well.

The "Microsoft Wave Table Synthesizer" uses big buffers, high latency, and you cannot change that. It doesn't accept alternative soundfonts either. Those parameters cannot be changed from inside VMPK (or by any other way).

A good free alternative to these synths for Windows is "Virtual MIDI Synth" by CoolSoft. http://coolsoft.altervista.org/en/virtualmidisynth

The "import soundfont" function creates the INI file containing the names of the included sounds etc., so they can be controlled from VMPK. It also changes the SF2 setting for FluidSynth as well. You need to match the INI file with the synthesizer settings.

[Mark Bugeja]

I am delighted to report that the latency issue is gone and now the pianio plays as well as ever.

Thank you for pointing out the place where the fluidsynth variables are. I missed that altogether.

Best regards
Mark