View Full Version : Vertical and Horizontal Blanking in FCP


Jason Coblentz
April 5th, 2007, 06:28 PM
Hello. I have a small problem. I have been asked to edit some footage to end up on an independent television network. I have never done broadcast spec editing before. I am proficient as an editor in FCP, but I need to make sure the footage that I am editing falls within certain specs. I understand what Vertical Blanking and Horizontal blanking intervals are, but is there a way to monitor or measure VBI in FCP so that I can make sure that the video is within specs, or do I need to worry about it when I am completing the master? I also need to find out how to record Horizontal and Vertical synchronizing pulses in the program tape at a level of 40 IRE. I am thankful to any who can help me figure this out.

Nate Weaver
April 5th, 2007, 07:48 PM
The specs you speak of are specifications for an analog signal.

Final Cut only manipulates video after it has been converted to a digital format, so these specs are out of the scope of any editing program. In fact, when working with any digital video or tape format, these specs have no meaning except on the analog outputs of the deck or NLE.

In other words, you only have to worry about these things if you're delivering an analog format like BetaSP or 3/4". And even then chances are if the deck is working correctly, these things won't be a problem.

Does the above make sense?

What format are you delivering?

Jason Coblentz
April 5th, 2007, 08:31 PM
Thanks so much Nate. I understand what you are saying. I appreciate your time. I am delivering the final format in mini DV. So I am to understand this won't be an issue in this format? My other question about recording Horizontal and Vertical synchronizing pulses at a level of 40 IRE, does that apply to the analog signal as well, or do I still need o worry about that? Thank you.

Nate Weaver
April 5th, 2007, 11:04 PM
Everything you mentioned are analog signal specs. Nothing to worry about with those and delivering on MiniDV.

What you DO have to worry about is getting video levels, chroma levels, and audio levels right.

No video levels over 100IRE, no chroma levels over 130IRE (usually), and nominal audio level at -12db. Some places are used to getting MiniDV masters that are all over the place with levels, and just plan on correcting every MiniDV tape that comes through without ever telling you.

Glenn Chan
April 6th, 2007, 01:22 AM
In FCP:

The waveform monitor measures DIGITAL levels, not analog ones. And the WFM is wacky. But anyways...

On the WFM, your levels should read between 0 and 100 (FCP units; they do NOT indicate IRE; IRE is analog).

The waveform monitor will clip everything below 0 (FCP units), so you are sometimes unable to see if there are levels below 0. This shouldn't be an issue with miniDV, because I don't know of any cameras that have levels below 0 unless you explicitly change the pedestal setting. HDV cameras might generate significant levels below 0 (again, FCP units).

The WFM monitor may only monitor the video safe area of the picture, and not stuff on the sides. It also may not monitor every pixel, unless you have the latest version of FCP.

2- If you change the WFM into ""saturation"" mode, it will show you a guess of the composite analog levels.

Your composite analog levels should be between -20 IRE and 115 IRE. The top figure varies from broadcaster to broadcaster. 120 IRE is the limit (by FCC laws in the US, AFAIK), 115 IRE is the practical ceiling (120 IRE is problematic for old receivers), although some broadcasters are more conservative and will set the maximum lower.

You will realize the saturation mode on the WFM isn't useful because it cuts everything off at 110.

Anyways, just use the broadcast safe filter at its 115 or 110 preset (can't remember if it has a 115 preset). Make sure it actually renders; in some versions of FCP it actually doesn't, even though it previews correctly.

3- Yes, FCP's waveform monitor is wacky. This is why facilities use real hardware scopes that are engineered correctly.

4- As Nate pointed out, you don't need to worry about vertical and horizontal blanking interval.

Jason Coblentz
April 6th, 2007, 02:18 AM
Thanks again for the info. It was very helpful. I was given a broadcast spec sheet for the network and I know what levels they want for video, chroma and audio levels. As I mentioned, I never have worked with broadcast video before, so the related technical jargon was beyond me. I have been reading and studying all about DV and HDV aquisition and editing for the last year and a half or so, from this forum and other sources on the internet and in books. I am self taught and I really appreciate the suggestions for FCP solution and the insight on the WFM in FCP. What I am editing is a wrestling exhibition that took place at an outdoor concert event in Las Vegas for I believe the 'Mav Network'. I personally have never heard of the network, but I understand it is a pretty big independent network. Thanks again.

Jason Coblentz