On 7/14/2012 10:04 PM, tim vets wrote:
2012/7/14 Rob Bothof <rbothof@xs4all.nl mailto:rbothof@xs4all.nl>
Dear List, I'm working on a diy midi-controller and running into some latency problems, the controller is a 'scratch disk' with with a pic microcontroller with usb. i've build an absolute encoder for it and i'm sending the data or angle as pitchbend data (for high resolution) the speed with which i'm sending the data is way beyond midi-standards, i know... now when i set up pd to use alsa audio (internal soundcard) and alsa midi, the device works perfect, very smooth.. when i choose jackd as a soundcard, i'm getting getting latency on the midi input..midi input is falling behind, then picking up instantly, falling behind again and so on...like a sawtooth shape.. the settings i choose for jackd have no effect on this..either when i'm using the internal soundcard via jackd -> alsa, or a firewire device via freebob...the latency problem is the same...also with higher audiobuffer settings there is no change in the latency I disabled alsa sequencer support in jack so midi is running straight to pd.. i know i'm working out of midi standards, but any help to where the problem might be, or simular experiences, would be greatly appreciated...I can't be of much help, but I can chime in with a similar/related experience: So far, each time I tried sending midi note messages from pd to something like Qsynth or Qsampler, using alsamidi via jack the timing is unacceptably messy. Inline afbeelding 1 resluts in: Inline afbeelding 2 you can clearly see the irregularity, and yes, it _is_ audible too... ;)
Hi Tim, thank you for the shared blues on midi timing ;) what i find strange is that i do not use jack for midi, i disabled alsa sequencer in jackd so midi should go directly to pd.
only thing i change is the audio card from alsa to jack...i don't see how this would influence the midi, but it does..
greets, Rob
