#45 Transport out of sync in certain condition

[Dr. Manfred Fux]

Unfortunately I found some issues in the new releasd version 1.0.0 of Hydrogen (3rd of august 2020):
I'm using Hydrogen in combination with Ardour (as time master) and Jack transport synchronisation under Ubuntu Studio. Because I'm using live recorded audio files I need bpm speeds with decimal fractions and some speed changes in a song.

1. If there is a speed change with decimal fraction provided by Jack transport, Hydrogen runs slowly out of sync because of a bug in the function "AudioEngine::compute_tick_size". The second parameter (bpm) is defined as "int" type instead of "float". I recompiled the sources with that fix locally on my computer and now decimal fraction speed changes run correct.
2. But there is still an issue concerning moving the playhead. When a song has a speed change then there is a small time offset between Ardour and Hydrogen after the playhead is set to a point behind the speed change. Since I'm not very experienced with Jack sync mechanism and Hydrogen source code I didn't figure out where this problem comes from. It seems to be very tricky to get it work so it needs an expert.
   Don't hesitate to ask me if you need more information how to reproduce the error.

[Sebastian Moors]

Hi!

Thanks for the very detailed bug report! The problem in (1) is my fault, i'm going to fix it also in the 1.0.0 branch so that the next patch version (1.0.1) will include this fix.

Could you create a GitHub (https://github.com/hydrogen-music/hydrogen/issues) Issue for (2)? This old SF bugtracker here is not much used, and the main development takes place on github. This makes it easier to assign it to the jack expert :)