Random lag playing out of Live Standard 11

Hi! I’m putting together a live show with synced video, and I’m using Videosync to do it. It’s generally working great! Everything has been very plug-and-play … kudos to the Showsync team for a very cool product.

The basic format for the show is that I’m doing the whole thing in Session view. I have a column for backing tracks (audio) (this is an electropop show), and I have a column for video. I put each song’s backing track and backing video in their respective column for each song, I hit play on the scene, the audio goes out through my audio interface, the video goes out via Videosync to the projector … it’s all working great.

The one thing that I can’t seem to figure out is that the videos don’t always start precisely in sync. For certain songs they seem to? And, for certain songs, they seem to come in a few frames late. It’s not bad! But given that the video art is made with the music as a timing input, sometimes it’s a bit noticeable, so I’d like to fix this if possible.

I’m wondering whether any of the Showsync people here, or anyone else who has done this, has best practices for how to do this so that Ableton will reliably play the videos back exactly in sync.

To get a couple of obvious questions out of the way:

  • I am positive that each audio backing track is precisely synced with its respective video. I am aligning the video in Final Cut to the same audio backing track file that I am using in Ableton just to be 1000% sure, and then muting the audio before exporting to Compressor.

  • I have read everything Ableton has to say in their documentation and in their forums about this, and I have tried everything they suggest (try 25fps vs 30, keyframe every frame, h.264, try .mp4 instead of .mov, try different avg streaming rates, etc). None of it makes any difference (i.e., none of it is better or worse; the delay is always exactly the same).

  • I’m doing this on an M1 Air — plenty of power — and the CPU meter is barely moving, aside from a little burst up to ~35% for the first second or so of playback, then back to 1-2%.

  • these are 720p videos, so, not taxing. Also, my rig can play back 4K video flawlessly, so I’m assuming it’s not that type of issue.

I would appreciate any and all ideas! And please let me know if I can clarify anything I’ve written. Thanks — jamie

Welcome to the forum Jamie! Thanks for reporting your issue here.

I did some testing and have determined some unexpected behavior. While the transport is running, any clip that is launched should play perfectly in sync. However, if the transport isn’t running yet, and playback is initiated by launching one or multiple clips, then the videos will appear slightly too late (2 to 10 frames). Videosync will only self-correct this after that clip has looped around once.

Do you stop and start playback regularly during a live performance? Or do you keep the transport running? In case you do stop it regularly, perhaps the issue can be circumvented by either keeping it running, or by starting the transport before starting any video clips.

Let us know if this is helpful, or if you feel none of this applies to your issue. Perhaps you are experiencing a different issue.

Hey Jean-Paul, nice to meet you and thank you for the thoughtful reply!

What you are describing does indeed sound like the same issue I am experiencing.

Our use case is that we are playing a live show, which is a combination of song performances and narrative. Like Pet Shop Boys meets a TED talk. I have our Ableton session set up so that each scene represents a song, or a spoken bit, and firing off the scene triggers every asset that is part of that moment — a musical backing track and/or a video and/or a program change to load the necessary sounds for the softsynths that I am playing live.

Each scene plays through once without looping, and the transport comes to rest at the end of the scene. And then I fire off the next scene manually, after any audience reaction has died down. So, for this reason, unfortunately I am not able to keep the transport running. And also I am not able to start the transport before starting the video clips, as the video and audio fire at the same time and run in visible sync (there are timing cues in the videos that relate in obvious ways to the music).

(I do suppose that I could make a dummy scene preceding each real scene, and link them with follow actions, but I am in no mood to add that extra layer to what is already a fairly complex performance, if you know what I mean!)

It sounds like maybe you will release a patch for this eventually, now that it is on your radar?

In the meantime, I can adjust the start time of the affected video clips in Ableton and visually confirm that they are synced enough to appear correct. There are only 17 scenes, so it doesn’t take that long to check the beginning of each one at soundcheck and tweak any offsets that need it. It’s not a perfect solution, but it will work until the patch comes.

And please let me know if anything I have written gives you any other thoughts!

Thanks again — jamie

Thank you for explaining, that makes your use case very clear.

Indeed, a remedy could be to work with dummy scenes that trigger the next scene with a Follow Action after 1 sixteenth, which would still feel near instantaneous. Or work with negative start times as you suggested. But ultimately of course this shouldn’t be necessary to achieve synchronous playback.

I’ve created a ticket for this internally. Once we’ve investigated this we’ll continue this thread.

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