On Sat, 06 Jul 2013 11:14:13 -0400 Owen Williams <owilliams-opwvymzfgylytjvyw6y...@public.gmane.org> wrote: > I'm confused, what are you trying to do? For vinylcontrol absolute > mode, we mostly use the pitch value and then nudge the speed up or down > if it drifts too far from the reported timecode position.For CDs, if > it's more than .1 seconds off then we just seek to that position. I > don't really see the point of having 22 bit resolution.
22-bits is the maximum resolution the CDJ timecode returns for a single-track CD. On a 4-track CD a timestamp is 2.38ms or a worst-case latency of ~5ms. OTOH nudging +/- 0.1 second is 100ms or 20x worse. Dropping seek commands based on acceptable drift is fine on full-resolution incoming timecode at the receiver end, but doing roundtrips and diffs to reach an absolute position makes no sense if the timecode is absolute to begin with. I'd turn the comment around: I don't see the point of truncating bits in the protocol to later try recovering them by chasing the needle :) -- p > On Sat, 2013-07-06 at 11:56 +0200, petah wrote: > > What message should be used to set the absolute position of the virtual > > needle of a loaded track given an absolute time position, f.ex. 2mins > > 34secs 567millisecs? > > > > I went through all the relevant docs (I think), incl. controls and HID > > mappings and didn't find a clear solution. > > > > I need to match an analog CDJ's time display with Mixxx's via a timecode CD > > using absolute timestamps (4 tracks x 15min), i.e. time scale between > > CDJ/Mixxx needs to be 1:1 and clamp, not stretch. > > > > F.ex. "vinylcontrol_mode" is a 3-way switch, one being absolute, but I > > don't see the "set absolute time" message. "playPosition" is scaled over > > the length of the track loaded in mixxx, which won't match a timecode CD's > > track. "scratch2" affects the "absolute speed", hence the relative position. > > > > The absolute time position needs to have at least 22-bit resolution so a > > gentle pitch bend can go through the engine via that cursor position and > > behave as expected, i.e. if any scaling/compression is applied along the > > way it wouldn't chop off the lower bits. > > > > It's just to control track position. Precision is critical but right now > > latency isn't. > > > > thx, > > > > -- p > > > > ------------------------------------------------------------------------------ > > This SF.net email is sponsored by Windows: > > > > Build for Windows Store. > > > > http://p.sf.net/sfu/windows-dev2dev > > _______________________________________________ > > Get Mixxx, the #1 Free MP3 DJ Mixing software Today > > http://mixxx.org > > > > > > Mixxx-devel mailing list > > mixxx-devel-5nwgofrqmnerv+lv9mx5uipxlwaov...@public.gmane.org > > https://lists.sourceforge.net/lists/listinfo/mixxx-devel > > > > > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by Windows: > > Build for Windows Store. > > http://p.sf.net/sfu/windows-dev2dev > _______________________________________________ > Get Mixxx, the #1 Free MP3 DJ Mixing software Today > http://mixxx.org > > > Mixxx-devel mailing list > mixxx-devel-5nwgofrqmnerv+lv9mx5uipxlwaov...@public.gmane.org > https://lists.sourceforge.net/lists/listinfo/mixxx-devel > ------------------------------------------------------------------------------ This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev _______________________________________________ Get Mixxx, the #1 Free MP3 DJ Mixing software Today http://mixxx.org Mixxx-devel mailing list Mixxx-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mixxx-devel
