yes, qtractor does have audio input latency compensation, as far as it's reported by the JACK sub-system.
however, it might not be always perfect or precise, mostly depending on your specific soundcard device (USB is quite notoriously bad in this regard) and on the running JACK settings: as a rule of thumb, you should set JACK buffer-size to a bare minimum: 128 frames/period is good-enough for most purposes and prosumer-graded devices; for USB devices it's also highly recommended you're to set to a 48000 sample-rate, possibly on 3 periods/buffer.
if you can't run or start JACK reliably at that minimum sane specification, then you probably have one ugly and bad cheapo-graded device to begin with.; if you insist though, then abandon all hope on getting any real-time low-latency, precision multi-track recordings of any kind on qtractor... be that audio PCM or even MIDI:)...
when all's set and good(enough) as said above, you may need to adjust a few things and try on:
qjackctl > Setup > Settings > Advanced > Latency I/O: add some systemic input latency (in frames) in the same amount you would possibly need to adjust, on any previously recorded audio clip in qtractor (not audacity);
qtractor > View > Options... > MIDI > Playback > Queue timer (resolution) : make sure you select the high-resolution timer (hrtimer) or one with greater or equal resolution than 1000hz; also, try whether you get any acceptable results on keeping in time while recording MIDI, by enabling the MIDI queue time drift correction (or not).
hi, thanks
yes, qtractor does have audio input latency compensation, as far as it's reported by the JACK sub-system.
however, it might not be always perfect or precise, mostly depending on your specific soundcard device (USB is quite notoriously bad in this regard) and on the running JACK settings: as a rule of thumb, you should set JACK buffer-size to a bare minimum: 128 frames/period is good-enough for most purposes and prosumer-graded devices; for USB devices it's also highly recommended you're to set to a 48000 sample-rate, possibly on 3 periods/buffer.
if you can't run or start JACK reliably at that minimum sane specification, then you probably have one ugly and bad cheapo-graded device to begin with.; if you insist though, then abandon all hope on getting any real-time low-latency, precision multi-track recordings of any kind on qtractor... be that audio PCM or even MIDI:)...
when all's set and good(enough) as said above, you may need to adjust a few things and try on:
hth.
cheers