Discrepancy w/ Odyssey7Q LTC timecode input.

[jshbckr]

I noticed something with the timecode input on the 7Q when working with my buddy who does production sound. He uses a timecode jammer, the MozeGear TIG, and after jamming his Sound Devices 788T, we connected the TIG to my FS700 and ran a BNC cable into the 7Q's LTC in.

Bringing my clips into Premiere, I selected the video clip and the hero audio, then chose Premiere's "Synchronize" option. I chose Timecode as the sync method, but noticed the hero audio clap was nearly 3 frames early.

Then I remembered that the FS700 has a delay out of the SDI/HDMI. So I scrubbed to the slate in my shot and dropped on Premiere's "Timecode" effect, which adds a timecode overlay. Here, you can see that (visually) the timecode jammer was at 15 frames, but by the time it reached the 7Q (thanks to the Sony's delayed SDI output) the timecode LTC in was recording it as frame 18.



Admittedly, I am a complete novice to working with timecode jammers. My dual system sound experience was always done manually before things like PluralEyes came along. Let me know if there is something I'm missing (I tried to look for a frame offset option in the 7Q but didn't find anything). But it looks to me like if I were able to tell the 7Q "Timecode offset: -3" then my burnt-in timecode would perfectly match what my camera is seeing. Because what good is timecode if I'm manually shifting the audio into sync?

 

[nyvz]

I'd guess it wouldn't be too hard for the programmers to put in a TC frame offset depending on what mode the 7Q is in. I imagine there will always be pretty consistent lag in FS700 modes that can be compensated for in the firmware, whereas there is probably no lag in normal HD-SDI recording modes.

 

[jshbckr]

I'd guess it wouldn't be too hard for the programmers to put in a TC frame offset depending on what mode the 7Q is in. I imagine there will always be pretty consistent lag in FS700 modes that can be compensated for in the firmware, whereas there is probably no lag in normal HD-SDI recording modes.

Definitely. Obviously you wouldn't want a system-wide change since other cameras don't have the lag. I hope Mitch can chime in and either school me on timecode or offer up a solution!

 

[Mitch Gross]

We will be adding an audio delay feature for sync. Aside from that, I suggest you reach out to our support line for further assistance.

 

[jshbckr]

We will be adding an audio delay feature for sync. Aside from that, I suggest you reach out to our support line for further assistance.

Now, the audio itself (reference audio coming through the SDI cable into the 7Q) is perfectly in sync. It's just that the timecode that the LTC Input was reading was 3 frames behind by the time the video signal reached the 7Q.

So in the ProRes file off the 7Q, the embedded audio was in sync. The problem arose when I tried to sync the audio from the external recorder using timecode. The file's timecode was three frames behind due to the FS700 SDI output's delay.

I guess I'm assuming an "audio delay" feature would actually shift the audio? All I think this needs is the ability to tell the LTC In to subtract X number of frames from whatever timecode it is burning into the file.

 

[Mitch Gross]

I'm not too sure what is happening here and why, and from a hotel room in Singapore without my gear I can't really do more. Our support team is in a better position to analyze this. They may already know the answer.

 

[Mitch Gross]

Hey Josh, I was talking to our engineers about this. Since the FS700 does not have a timecode input, such delays can occur, as the recorder is syncing to the wrong thing. We are thinking that it might be possible to add a timecode offset function in the future, just as we will be doing for audio for what is essentially the same reason. Can you tell me the mode in which you were shooting (4K RAW, 4K2HD, etc.)?

Moving orward, I would also suggest another solution that would prevent this in the first place. Since the FS700 cannot receive timecode in for jamming, everything else should instead be slaved to it. Audio guys don't like to hear this because they prefer to control the master clock on their own decks, but the fact is that this camera cannot slave to something else, so the camera must become the master timecode generator. This also necessitates shooting in free run all day and I'm sure the sound guy won't trust the camera and insist on a greater number of pauses to run a cable for a timecode jam. But it should work perfectly well and keep all timecode properly in sync.

 

[Pulldownclaw]

I'm shooting a 2 FS700, 2 Odyssey 7Q job later this week, and wondering about TC. I looked in the 7Q manual but didn't see anything about jamming TC, and of course don't have both cams/7Q's in front of me yet.

Can I send TC from one Odyssey to the other, and will that "override" the TC coming from the second cam? Shooting 4k2HD.

Thanks

 

[Mitch Gross]

I believe it will always try to follow the timecode of the camera source. But you can try to go to the timecode menus and do this override.

 

[Essami]

Hi!

Has this been resolved in a later firmware? We have the same problem and are looking into solving this. I'm on a pretty early firmware on my Odyssey since it works great and I don't want to update unless absolutely necessary. I didn't find any notes about timecode offset on Convergent Design site so I assume nothing was done about this?