Clock -ACID Product Family - MAGIX Community Forums Archive

Subject:Clock Posted by: oddboy Date:10/18/2002 10:30:51 PM From the manual "ACID cannot chase MTC or MIDI clock." So if I have word clock on my sound card Acid wont follow it?
Subject:RE: Clock Reply by: pwppch Date:10/19/2002 1:07:52 PM Word clock , MIDI Time Code (MTC), and MIDI Clock are very different things. Word clokc on a sound card is intended to lock two different digtial devices to a common clock. This way the sample rate that multiple devices use will be exactly the same. ACID will 'trigger' to incomming MTC. That is, you can have ACID slave to an external MTC master. This will let ACID 'start' in sync with the master. Chasing means that ACID would continously alter its playback speed to account for any changes in the MTC clock being input. This is problematic and expensive CPU wise. The best solution when triggering to MTC, is to make sure that the MTC master and the sound card used by ACID do have a constant sample clock. This is where the Wordclock can help out. You connect your external MTC Master device to the Word clock connection on your sound card. Set the sound card to use an external word clock. (Make sure that ACID is using the correct sample rate for the word clock being fed to the sound card). What this solves is that once ACID triggers to MTC start, your sound card and your master device will have the same sample rate. While this wont give you sample accurate lock, it will assure that your master and ACID are playing at the exact same sample rate and avoid drifts over time. Peter
Subject:RE: Clock Reply by: oddboy Date:10/19/2002 3:14:21 PM Thanks for the info Im still foggy on MTC and MIDI clock Is midi clock the same as midi beat clock? Is this used to sync software programs and transports? can acid use this with other apps MTC is used to sync only external devices? Is this only for video work?
Subject:RE: Clock Reply by: pwppch Date:10/19/2002 5:43:45 PM MIDI Time Code is a means to lock two or more devices (software is a "device" if you will) to a common clock. MTC is a 'clock on the wall' time format. The master and slaves lock up thier times. 1 MTC min on the master is 1 MTC minute on the slave. MIDI clock is about tempo information as much as it is about sync. MIDI Clock is "temporal" and has not zero or start if you will. Transport control is not part of the MIDI Clock definition. There are other MIDI events that control song position and start/stop. A MIDI Clock mster can tell the slaves to speed up, and slow down, there by affecting the duration of playback. The fundamental difference here is that with MIDI clock, time is relative/proportional to tempo. A song playing at 120 BPM is slower than that same material played at 200 BPM. MTC uses time for absolute postion. MIDI Clock uses musical ticks to communicate position and is indepednent of time. MTC is used to sync hardware/software that has time information that is consitant (or expected to be consistent). MTC is really a translation of SMPTE time code into a MIDI format. MTC cna be used for Audio or video. MIDI Clock is more musical in a sense. It is about transmiting and sync'ing musical information and using musical concepts to achieve sync between a master and its slaves. I have heard MIDI Clock refered to as MIDI beat clock, and this describes what is going on. Peter

Subject:Clock

Posted by: oddboy

Date:10/18/2002 10:30:51 PM

From the manual

"ACID cannot chase MTC or
MIDI clock."

So if I have word clock on my sound card Acid wont follow it?

Subject:RE: Clock

Reply by: pwppch

Date:10/19/2002 1:07:52 PM

Word clock , MIDI Time Code (MTC), and MIDI Clock are very different things.

Word clokc on a sound card is intended to lock two different digtial devices to a common clock. This way the sample rate that multiple devices use will be exactly the same.

ACID will 'trigger' to incomming MTC. That is, you can have ACID slave to an external MTC master. This will let ACID 'start' in sync with the master.

Chasing means that ACID would continously alter its playback speed to account for any changes in the MTC clock being input. This is problematic and expensive CPU wise.

The best solution when triggering to MTC, is to make sure that the MTC master and the sound card used by ACID do have a constant sample clock. This is where the Wordclock can help out. You connect your external MTC Master device to the Word clock connection on your sound card. Set the sound card to use an external word clock. (Make sure that ACID is using the correct sample rate for the word clock being fed to the sound card).

What this solves is that once ACID triggers to MTC start, your sound card and your master device will have the same sample rate. While this wont give you sample accurate lock, it will assure that your master and ACID are playing at the exact same sample rate and avoid drifts over time.

Peter

Subject:RE: Clock

Reply by: oddboy

Date:10/19/2002 3:14:21 PM

Thanks for the info

Im still foggy on MTC and MIDI clock

Is midi clock the same as midi beat clock? Is this used to sync software programs and transports? can acid use this with other apps

MTC is used to sync only external devices? Is this only for video work?

Subject:RE: Clock

Reply by: pwppch

Date:10/19/2002 5:43:45 PM

MIDI Time Code is a means to lock two or more devices (software is a "device" if you will) to a common clock. MTC is a 'clock on the wall' time format. The master and slaves lock up thier times. 1 MTC min on the master is 1 MTC minute on the slave.

MIDI clock is about tempo information as much as it is about sync. MIDI Clock is "temporal" and has not zero or start if you will. Transport control is not part of the MIDI Clock definition. There are other MIDI events that control song position and start/stop. A MIDI Clock mster can tell the slaves to speed up, and slow down, there by affecting the duration of playback. The fundamental difference here is that with MIDI clock, time is relative/proportional to tempo. A song playing at 120 BPM is slower than that same material played at 200 BPM.

MTC uses time for absolute postion. MIDI Clock uses musical ticks to communicate position and is indepednent of time.

MTC is used to sync hardware/software that has time information that is consitant (or expected to be consistent). MTC is really a translation of SMPTE time code into a MIDI format. MTC cna be used for Audio or video.

MIDI Clock is more musical in a sense. It is about transmiting and sync'ing musical information and using musical concepts to achieve sync between a master and its slaves. I have heard MIDI Clock refered to as MIDI beat clock, and this describes what is going on.

Peter