Emergeny tempo issue

In testing more extreme tempo shift it is clear that the the audio jumps severely.

If it is set to warp then the tempo of the audio bends ways out of proportion.

Obviously when scoring to picture neither of these are remotely workable.

Here is what I think the the issue is, but I don't know how to solve it.

The transport is playing 120bpm at bar 5 we are 8 seconds into the audio clip.

The tempo changes to 240BPM.

Live is now referencing the time it would expect the audio to be at had it been at 240BPM from the start. Live is unaware that the BPM was ever 120BPM because it is given the tempo on the fly. It does not know that from bar 1-4 the tempo is 120.

So at bar 5 we are not 8 seconds into it but 4 seconds. The audio jumps backwards becuase Synfire syncs to the bar not to the time.

I'm scrambling to see If I have a install of my full version of Chaingang. Hopefully it works in Windows 7. If it works, then i can run it on mtc from synfire.

Perhaps Synfire needs a built in video transport if it is going to use rewire and still be a functional scoring tool. Else we are completely dependent on Chaingang which is known to be a little flakey.

If Synfire were to get a video transport, perhaps the audio could be sent to the DAW through the rewire connection.

p.s. I had noticed this in Nuendo before but I didn't understand why. I am sure it is a problem in every sequencer dealing with audio while receiving tempo changes from Synfire with rewire.

Thank you for your prompt reply.

I've switched back to using mtc with ableton and SO FAR it seems to be working well enough. It will get me through this little deadline.

I understand the problem is really on their side, or rather that rewire isn't a very workable solution in the long run.

If the Tempo changes aren't transmitted, then the grid in the daw will not line up with the events, which makes it pretty inconvenient for audio editing. If it has the tempo, I don't see how it can avoid the issue I described.

The only advantage I see to rewire sans tempo is if MTC is not a reliable sync but there aren't many occasions where I need to listen to a single play through of an hour of material. Starting and stopping resets the sync and should work fine. Rewire by in large has been buggy so Im happy not to have to use it.

I don't foresee DAW's getting any more intelligent about their rewire implementation in the near future (by keeping track of what tempo changes happen where and storing them to avoid this problem)

I'm not fond of music at a static tempo, so it seems for the time being Synfire will not be able to work with the DAW audio. I am glad I can at least score to a single audio track now, and potentially record rough bits here and there.

Eventually I would love to lose the DAW altogether but I know that is a tall order and probably far off.

Again thank you for the prompt reply