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peterrooney

Member

From: PNW

Registered: 2021-09-25

Posts: 7  

[SOLVED] MIDI versus modern technology

I have a question with unclear "appropriate venue", and am wondering what might be the right place, if not here.

On my desktop (16 core ryzen7) a midi file will simply not play smoothly in rosegarden. Most notable are dropouts in the middle of notes.
The same midi file plays just fine on rosegarden running on an ibook (single core g4), a laptop that is over twenty years old. Rosegarden might take a minute to load up, but after that it plays OK without dropouts or stutter.

Things I have tried, in no particular order:
(1) quitting all other applications (yes, including pulseaudio)
(2) disabling unused audio devices - echo 1 > "/sys/devices/pci0000:00/0000:00:08.1/${apropos}/remove"
(3) fuzzing with buffers via qjackctl. this can make the problem worse, but can't fix it.
(4) rebooting with and without #2 above.

So. It's not processing power. It's not conflict with other applications. It's not the fact that there are nowadays four to thirty audio devices on a motherboard to interface with. it's not PA or PW.

What might I be overlooking?

Desktop is running devuan daedelus, with daedalus-updates, daedalus-security, and daedalus-backports. Laptop is running debian unstable, because not much else will install these days.  The midi file is a rendition of Bach's Toccata & Fugue in Dm.

mirrortokyo

Member

Registered: 2021-04-08

Posts: 70  

Re: [SOLVED] MIDI versus modern technology

I can't even get timidity / timidity daemon working from the current packages.

On my other pc there is still old PCI slots that fit the SoundBlaster Audigy II ZS with its wavetable synthesizer.

There don't appear to be any PCI-X sound cards with wavetable synthesizer, so I'd have to get timidity / timidity-daemon or something working on this machine to play MIDI files.

Anyone have a working set-up?

peterrooney

Member

From: PNW

Registered: 2021-09-25

Posts: 7  

Re: [SOLVED] MIDI versus modern technology

I seem to have found a solution, and as usual it's Rui Nuno Capela to the rescue:
sudo apt-get install rtirq-init
The package identifies all kernel threads associated with sound hardware (upon install and every boot), and boosts their priority. I was just able to play a large score without skipping, and I even ran a backgammon match analysis (very cpu-intensive) trying to force it to skip.

Sound processing is all about keeping that buffer filling and emptying on a precise schedule, not CPU power.

Last edited by peterrooney (2025-05-02 23:29:40)