Video Assist Setup/No Timecode over T-Bolt

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Dominik777

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Video Assist Setup/No Timecode over T-Bolt

PostMon Mar 31, 2014 3:26 am

Hi Everyone,

I'm trying to get a video assist type workflow working with my BMCC in order to help reviews and organization during shooting. I would like to record the footage on an imac in Prores format while recording Raw on the camera. The easiest way for me do this would be to go SDI out into a BM Extreme card and capture with Media Express. Here is the summary of my problems.

1. SDI out does not show up over the capture card unless I am recording in 25 or 29.97. This does work perfectly but I can't limit myself to those frame rates. Why does the BM Extreme card not see the footage at different rates? I have a JVC monitor which sees the footage just fine.

2. Thunderbolt, the footage comes in just fine, but unfortunately no timecode. I keep seeing rumours here and there that the TC is supposed to come through. Can anyone confirm this?

Any thoughts on these issues or other possible camera assist workflows would be greatly appreciated.

Thanks.
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Chris Hocking

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Re: Video Assist Setup/No Timecode over T-Bolt

PostMon Mar 31, 2014 11:25 pm

Dominik777 wrote:1. SDI out does not show up over the capture card unless I am recording in 25 or 29.97. This does work perfectly but I can't limit myself to those frame rates. Why does the BM Extreme card not see the footage at different rates? I have a JVC monitor which sees the footage just fine.


If you're running the 1.3 firmware or later, the camera only outputs 1920 x 1080i50 or 1920 x 1080i59.94 when overlays are turned off. These are your only options.

Dominik777 wrote:2. Thunderbolt, the footage comes in just fine, but unfortunately no timecode. I keep seeing rumours here and there that the TC is supposed to come through. Can anyone confirm this?


If you're using Media Express - unfortunately timecode from the camera is not read by the software.

Dominik777 wrote:Any thoughts on these issues or other possible camera assist workflows would be greatly appreciated.


Your original plan of using the SDI output of the camera makes the most sense. Timecode is embedded in the SDI feed. If you're shooting 25fps, then the camera will output 1080i50 - otherwise it will output 1080i59.94.
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Dominik777

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Re: Video Assist Setup/No Timecode over T-Bolt

PostMon Mar 31, 2014 11:29 pm

Thanks for the response. The only thing that contradicts what you're saying is that there definitely is a signal at frame rates other than 25 and 60i. I can see a picture when hooked up to a JVC broadcast monitor at 24fps. It's just that I can't capture this signal. What is it about the signal that doesn't allow the BM Extreme card to capture it. Is it a PsF vs P issue?
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Chris Hocking

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Re: Video Assist Setup/No Timecode over T-Bolt

PostTue Apr 01, 2014 9:20 pm

Apologies my last post was incorrect!

The HD-SDI output is always 1920x1080 true progressive and at the same frame rate as the recording format, except if you have selected to record in 25fps or 29.97fps and set the SDI overlays to Off, in which case the SDI output will be set to 1080i50 and 1080i59.94 respectively.

I'm not sure why you're having issues capturing it - but if I get time, I'll try it myself and see what happens.
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Dominik777

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Re: Video Assist Setup/No Timecode over T-Bolt

PostTue Apr 01, 2014 9:23 pm

I have an older blackmagic card. Based on your feedback, my theory is that the older card does not support true progressive. I spoke with support people at BM who tested what I was talking about and confirmed that the new card captures the signal. I've already ordered the HD-SDI card and will share the results with everyone once it comes in.

Thanks.

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