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Video levels peaking in program – Are there any project-wide controls or reports?
We do a weekly Broadcast TV show and just got a report from traffic that our last shows’ video levels peaked. This is rare for us and since we just switched to version 6 we are wondering if some presets may have changed.
We were under the impression that there was a preset that kept any video levels from peaking similar to our razor system. Is this true?
If not is there any way to analyze a program and report any over limit video peaks?
I suppose we can use the broadcast colors plug in to do this manually, but we’d like to have a project wide tool to keep things under control.
any suggestions or techniques others are using?
Thanks so much
Larry
LSW
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4 Replies
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what about scrubbing over the program and looking at
the vector scope or waveform monitor?wouldn’t the broadcast safe plugin only cap the levels
that exceed spec? -
Larry,
There is no automatic video level control applied in Vegas as a default.
As Borjis said, checking with the waveform monitor is the way to go.The Broadcast Levels filter will help, but add quite a bit of rendering time, so it’s best to isolate the problem footage and tweak from there.
Gary
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Larry ~
Two cents, maybe twenty cents worth here. We do weekly programs for broadcast and do the following and have never had a knock back on illegal levels and believe me they are tough on levels down here.
If you have overall high levels on the program you can select the ‘Video Output FX’ plug above the preview window and then select the ‘color corrector’ plugin and use the ‘offset’ and ‘gain’ sliders. Use the waveform monitor for the following adjustments. Make sure all adjustments are done right at the HEAD of the timeline to ensure the adjustment applies to the entire program output from its beginning.
Set ‘black levels’ first.
To ensure that your ‘black’ levels are correct use ‘Media generators’ ‘black’ NOT blank timeline space as this is NOT black and cannot be adjusted. Place some ‘generator black’ at the HEAD of the timeline on a track above your program tracks for this adjustment; this can be deleted after the adjustment is done. Park your cursor at the head of the timeline and adjust the ‘offset’ slider to bring your black level up to ‘0’. You have to do this otherwise you will end up with black levels below ‘blanking’. Vegas ‘generator’ black if used in the program defaults to around minus -7.5 below ‘0’ blanking (on a PAL system at any rate), it may sit at a different low level on NTSC not sure on that but it should be at ‘0’. Once this is done you can delete the ‘black’ sample from the uppermost track. That is program ‘black’ level set.Set ‘gain’ level last.
Now place some ‘media generator’ ‘white’ at the head of the topmost track where you had the ‘black’. Again ensure your cursor is parked at the head of the timeline. You can now adjust the ‘gain’ slider to bring your program peak levels down to ‘100’ i.e. 1 volt peak level. Now delete your ‘white’ sample.These two adjustments will ensure that you program output signal now complies with the ‘1 volt peak to peak’ broadcast requirement.
This is a much better way of setting levels than using the ‘broadcast levels’ plugin only as this will ‘scale’ the video to the 1 volt P-P requirement rather than just ‘clipping’ the black and white signal levels and peaks. You can now check your program blacks and peak levels by dragging the cursor through your timeline while observing the waveform monitor. If you have done this correctly no black levels will go below ‘0’ and no peak levels, usually whites, will go above ‘100’. You now have met the 1-volt P-P broadcast requirement.
An additional thing to watch out for especially if you use solid colors from the media generator is that these reds, blues, greens etc will blow way out past the legal levels on the vector scope. To control these now apply the ‘broadcast levels’ plugin. Check the ‘Studio RGB’ box. Normally you only need to use the ‘conservative’ setting from the dropdown menu to pull these excessive chroma levels back to legal levels. Just check with someone working in NTSC if you have the 7.5 IRE setting on or off. With PAL we don’t use ‘setup’. In NTSC DV I believe it should be unchecked. Don’t quote me on that though!
As a matter of course we use these settings, first using the color corrector ‘offset’ and ‘gain’ sliders to adjust the luminance range and secondly the broadcast levels plugins using the ‘conservative’ setting to control the chroma levels. Using the broadcast levels plugin last will not ‘clip’ your levels as they have already been adjusted with the CC settings. Use this method and I would be surprised if you get another knock back, touch wood!
Of course all of the above can be applied at either clip or track level plugin if so desired.
Chris Young
CYV Productions ‘Google us’
Sydney -
Chris – Thank you. You have “cleared-up” some misunderstandings I’ve needed education on.
PLUS the use of sample WHITES and the RBG option. Thanks! – Grazie
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