[LAD] interesting blog post about syncing blender and ardour

Ralf Mardorf ralf.mardorf at alice-dsl.net
Tue Sep 22 15:26:04 UTC 2009

Paul Davis wrote:
> On Tue, Sep 22, 2009 at 9:43 AM, Ralf Mardorf
> <ralf.mardorf at alice-dsl.net> wrote:
>> Paul Davis wrote:
>>> i've been told by a company that specializes in timecode and shared
>>> transport control systems that ardour has the fastest and most
>>> accurate MTC sync of any DAW.
>> I noticed too that MTC with Ardour is fine, while MTC for some MIDI
>> equipment can be a PITA. Compliment :).
>> I still wonder that you don't like SMPTE. MTC and SMPTE are related, there
>> isn't a big difference.
> MTC is a different encoding of the same data. SMPTE is an audio signal
> that has be decoded to get time values; MTC is a MIDI event stream
> that has be decoded to get time values. the underlying timeline and
> the resolution of both of them are the same.
> i don't like MTC either as a mechanism to share an audio timeline.
> audio has a resolution of 1 sample. our world has been polluted by
> film and video people who think that 1/30th of a second is accurate
> enough. yeah, ok so they added 1/3000th later (subframes) but who uses
> it?
> i have nothing against MTC or SMPTE for transport synchronization.

Yes, "transport sync" is the right term and that is waht "we" need.

So the rest, my argumentation, is just blah-blah:

Digital audio audio has got a resolution of 1 sample. Maybe audio and 
light waves have got a resolution of a Planck length?
MTC and SMPTE should sync computers to digital or analog audio or video. 
What "we" need is a sync that is  accurate enough to sync to video half 
frames, film frames, sequencer tics etc. in a way that no phases can be 
heard when 2 machines are playing the same audio signals in unison, film 
cut needs to be possible for exactly 1 picture. This is possible by MTC 
and SMPTE. MTC and SMPTE aren't for sync of digital audio IOs, sync of 
video refresh rates etc..
You might be right, times have changed, maybe something "better" is 
needed for the future, but today MTC and SMPTE are still needed because 
a lot of equipment is using this time-codes and they are accurate enough 
if everything is fine. SMPTE between a Yamaha 4 track tape recorder and 
an Atari ST was good enough to play a synth recorded to the audio tape 
and played by the sequencer in unison, without any noticeable delay, 
even simple click signals for sync, used by the C64, were able to do 
this. Something that isn't fine for my actual Linux PC, because of 
jitter. I know that other people don't have noticeable jitter for their 
Linux PCs, but I guess even for those machines sync isn't without jitter.

There's no need for a theoretical perfect accuracy, "we" only need the 
possibility to sync different machines without noticeable delay.

For people who have better luck than I've got MTC can sync different 
machines to Linux good enough, only SMPTE for some applications is 
missing, because video equipment is using SMPTE and not MTC.

If people will sync blender to a tape recorder or external video machine 
JACK transport or MTC aren't a help.

SMPTE is used by people because it's fine ;), it does what it should do :).

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