Receiving MTC and random delays
-
I made a simple testing system with Ableton and Isadora. Ableton outputs MTC (via the LiveMTC add-on) directly to Isadora, which is running a simple set with MTC Movie Locker, Movie Player and a Projector. I've also tested a second version with Ableton outputting LTC, which is then converted to MTC with Lockstep (I'm on a Mac) before Isadora receives it. Ableton also has the same video on a track, so I can compare them both and see how locked they are.
The thing is: I've noticed that there's always some delay between the moment I press play in Ableton and the moment Isadora starts following the timecode. And the worst part: this delay is always a bit different. Sometimes up to three whole frames, sometimes less than one. So there's no way for me to just add an offset. I've checked the FPS and everything matches. What could be causing this? Is that something I have to deal with or are there ways to troubleshoot/fix this? Thanks in advance.
-
@gpeddino Here's a screenshot of the Isadora system:
-
@gpeddino said:
<p>@gpeddino Here's a screenshot of the Isadora system:</p><img src="/assets/uploads/files/1779682232201-screen-shot-2026-05-25-at-01.01.42.png" />
There is naturally some latency in communications, although 3 frames is a lot.
What format is your video? (I only see .mov)
, you want to be using ProRes or Hap
What framerate and cycle rate do you have Isadora set to? 60fps and maxing your cycles rate (may take a little testing) should provide the snappiest response possible. -
@dusx The file format is MP4.
I'll check these settings and try again!
-
Another option is to send a MIDI note to start your Movie Player and see how that works for you.
-
@gpeddino said:
file format is MP4
MP4 is not a good format to use this approach, since the position input of the movie player is being set, this doesn't allow the multi frame decompression used by MP4 to work as expected by the codec.
Try transcoding to HAP, that is the best format for dynamic playback.
-
@dusx I tried converting the file to the HAP codec with Shutter Encoder. The MOV file turned out huge (25 GB) and it won't open in any software, not even Isadora or VLC. I also tried converting to Apple ProRes, the result was the same. Is there anything else I should install?
-
Can you share the .mp4 with me? DM me with a file share link if you can, and I will convert to HAP and test. The file should stream, but yes, it will be very large.
