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Old April 6th, 2006, 10:03 AM   #1
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How to us "Time of Day" function on SD recorders

Could someone with experience describe this process for me. I'm just not getting it. How does the recorder read the clock of the video camera? I've tried going through the SoundDevices manual and it doesn't seem clear. Maybe if I had the recorder in front of me it would make more sense, but I'm just in the process of researching this purchase and the time of day stamp thing sounds really cool. What's the process for matching up the audio in post?
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Old April 6th, 2006, 11:01 AM   #2
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Quote:
Originally Posted by Marco Leavitt
Could someone with experience describe this process for me. I'm just not getting it. How does the recorder read the clock of the video camera? I've tried going through the SoundDevices manual and it doesn't seem clear. Maybe if I had the recorder in front of me it would make more sense, but I'm just in the process of researching this purchase and the time of day stamp thing sounds really cool. What's the process for matching up the audio in post?
what camera do you use , if you like jam the recorder from external tc you need camera which has tc out or use lanc tc converter if its sony dv ( ambient make one)
otherwise you just run time of the day tc or free run and run the same on the camera , you clap evry 2 hourse and later on nle adjust the tc synchronization automatically from clap to clap .
since the cameras use to drift check the actual drift ( you can make snapshots on both display every half hour to see the drift)
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Old April 6th, 2006, 11:14 AM   #3
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Quote:
Originally Posted by Marco Leavitt
Could someone with experience describe this process for me. I'm just not getting it. How does the recorder read the clock of the video camera? I've tried going through the SoundDevices manual and it doesn't seem clear. Maybe if I had the recorder in front of me it would make more sense, but I'm just in the process of researching this purchase and the time of day stamp thing sounds really cool. What's the process for matching up the audio in post?
First of all, does your camera actually output timecode? The SD 744T and the new 702T will jam to external code but it does have to be valid SMPTE timecode, not just video blackburst AFAIK. You connect the TC out of the camera to the TC in on the recorder. With the camera powered up, jam the recorder and it will set itself to the same time value and frame rate the camera is sending. The SD702T manual labels this "audio chasing video." Kind of answers the similar question I posted earlier this morning I guess <g>.

Looked over one of the new 702T's the other day at Trew Audio in Toronto. Amazing little unit, not much bigger than a paperback book! Lightweight but solid as a rock and it exudes build quality from every angle.

When you record in BWF file format, the timecode of the first frame of audio is included in the file header. When you import it into an NLE that understands BWF, it aligns that frame with the corresponding frame in the NLE timeline. If the video is aligned so the code in the video also aligns to the same frame on the timeline, voila! you're in sync. What I'm unclear on is how the video gets lined up to the timeline in the NLE - do any of them drop the video so the its timecode lines up to the timeline automatically or is that a manual process?
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Old April 6th, 2006, 11:25 AM   #4
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No, I won't be using actual time code. But I had been given to understand that these recorders can do some crude kind of sync to prosumer cams using the time of day stamp that gets recorded to tape. I just don't understand the process at all, first how you get the recorder to read the camera's clock, and then how you conform everything in the NLE. The manual has very little to say about it. We would of course clap it and send a feed back to the camera just to be safe.

Yeah, the 702T looks like a cool little dude. That's the recorder I'm looking at. It would be handy if I ever got a job on larger budget movie and they wanted to use real time code.
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Old April 6th, 2006, 11:35 AM   #5
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Quote:
Originally Posted by Marco Leavitt
No, I won't be using actual time code. But I had been given to understand that these recorders can do some crude kind of sync to prosumer cams using the time of day stamp that gets recorded to tape. I just don't understand the process at all, first how you get the recorder to read the camera's clock, and then how you conform everything in the NLE. The manual has very little to say about it. We would of course clap it and send a feed back to the camera just to be safe.

Yeah, the 702T looks like a cool little dude. That's the recorder I'm looking at. It would be handy if I ever got a job on larger budget movie and they wanted to use real time code.
you cant read camera clock if you dont have tc out on camera
if you have , you jam the sd tc to camera or versa
if you dont you run 2 diffrent free run tcods and sync manualy the first take
then you can sync after wile (depend on your camera drift)
on nle you syncronize manually the first take and automaticly adjust the both tcods until the next slate
marco better go to see it in the shop or met someone who have one , it would be much easier :-)
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Old April 6th, 2006, 11:59 AM   #6
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To sync a prosumer camcorder and a 744/702:
1. Choose NDF or DF TC on both devices.
2. Choose "free run" on both devices.
3. Preset the same timecode on both devices. For convenience's sake, this could be time of day, but doesn't have to be. Preset a time that's a minute or two away.
4. Count it down to the preset time, and simultaneously start the TC generators on both devices.

This gives you a sync of better than 15 frames, perhaps lots better. It will probably drift. It's very helpful to record reference audio either with the camera mic or from the 744/722 on the video tape, and then use this for fine sync once in your NLE.

Note that there are issues that are in the process of being resolved related to HDV timecode, it doesn't work properly in some NLEs and some capture programs, or may not translate properly to intermediates or proxies. HDVRack doesn't yet properly record camera timecode from HDV.

However, DV timecode is generally working pretty well in most NLEs.

BWFs, as mentioned, carry a starting timestamp in the file header. They can also be polyphonic, that is, contain more than two channels. Some NLEs (Vegas) can handle BWF, and correctly resolve timestamps, but can't handle polyphonic files. There's a freeware splitter from fostexdvd.net.

My best advice - figure out your post workflow with some tests before you shoot stuff that matters.
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Old April 6th, 2006, 01:50 PM   #7
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Quote:
Originally Posted by Seth Bloombaum
...

Note that there are issues that are in the process of being resolved related to HDV timecode, it doesn't work properly in some NLEs and some capture programs, or may not translate properly to intermediates or proxies. HDVRack doesn't yet properly record camera timecode from HDV.

...

BWFs, as mentioned, carry a starting timestamp in the file header. They can also be polyphonic, that is, contain more than two channels. Some NLEs (Vegas) can handle BWF, and correctly resolve timestamps, but can't handle polyphonic files. There's a freeware splitter from fostexdvd.net.

....
When SMPTE code is recorded to tape and the clips imported into the NLE, does the recorded code influence where the clip is initiallyplaced on the timeline? If I had a clip whose recorded code is at 00;05;00;00 and after capture I import it to the timeline an NLE whose timeline starts at 00;00;00;00, where does the clip end up? Or is it up to me to align the clip start with the appropriate point on the timeline?
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Old April 6th, 2006, 03:21 PM   #8
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Quote:
Originally Posted by Steve House
When SMPTE code is recorded to tape and the clips imported into the NLE, does the recorded code influence where the clip is initiallyplaced on the timeline?... Or is it up to me to align the clip start with the appropriate point on the timeline?
Steve, all I can share is my workflow in Vegas.

1. File | Import | BWF - BWF is now on the timeline at a position corresponding to its timestamp. (note: if polyphonic, bwf would have to have been split before this)

2. Look at the file properties of my video file, note starting timecode stamp. (In Project Media | Detail View)

3. Goto that position on the timeline (Ctrl-G). Drop a marker for future reference (optional). Leave the cursor/play head in that position.

4. Insert my video clip at that position.

Now, I'm ready to do fine sync by playing camera audio against 2nd system audio and listening for echos. Vegas has great numpad shortcuts (4 and 6) that will slip a highlighted clip left or right by an amount relative to your zoom level (on the timeline view).

Couple other neat features with Vegas, if the quantize to frames control is on, slipping will conform to frames, that is, if you're slipping video, you won't inadvertantly cut into a frame. You can also turn it off, and slip the 2nd system audio in sub-frame increments if needed for fine sync.

When I'm synced, I might render an editing clip in DV25 so that I can use the same clip repeatedly from the media pool without additional worry, my sync is locked. Of course this means a downmix to 2-track. This works for me because I'm usually editing event video, with takes averaging maybe 20 minutes. Maybe nesting would be better, and preserve multitrack audio? Haven't tried it.

If I were shooting short takes, I'd probably keep the camera rolling a lot, burning extra tape. Tape is cheap, my time is dear.

Other workflows? One other nice thing about Vegas is the open scripting interface - maybe someone will write us a nice sync routine. Or maybe I'm missing some method to automatically insert a video clip on the timeline in the proper position.
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