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SD Bars for DVCPRO HD Timeline
This may not be such a great idea… but I want some input anyway.
We are mastering most of our material now as HD, but the final product is delivered in SD. We o send the HD timeline through our AJA downconverter to crop and downconvert while going to tape. (It also goes through a Videotek legalizer…) After we get to digibeta, we have to go back to final cut, make a SD sequence with Bars and then insert the SD bars to the digi.
I want to find a way to skip the SD bar insert if possible. Are there any suggestions on how to make pillar boxed NTSC bars encoded for DVCPRO HD without messing up the colors or image in the process? This would let us insert “SD” bars into the HD timeline and edit to tape through the downconvert process.
I’ve tried exporting SD bars as a self contained quicktime and then blowing them up and rendering in the DVCPRO HD timeline. Then rendering as a Self-Contained DVCPRO HD clip. This is no good because too much noise is introduced to the image. It doesn’t hold up under the gammut scope.
Any suggestions?
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3 Replies
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So I take it your are doing a center cut? Can you flip the switch on your AJA downconverter after the bars are done from letterbox to centercut (your bars will be letterboxed)? Bar & Tone your digibeta first in SD, then assemble the down convert? This way, you can bar & tone a bunch of digibeta tapes all at once and just grab them for the masters and assemble on the content.
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Yes we are doing center cut (although I’m protesting this move…) We could switch the dip switch on the AJA box and then the bars (which are now HD bars on the timeline) would not get cut off. However, I don’t think the HD bars in fcp would be appropriate for NTSC. I believe that the 0 vs 7.5 IRE thing and the I and Q bars are different for HD bars vs SD.
Your idea for putting bars and tone first is a good one, however, we are trying to lay back an HD and SD master at the same time. I should have included this in the original post, but thought it would convolute things…
We control the HD deck and put LTC into the digi as external tc and regenerate. The same source video feeding the HD deck is routed through the AJA box or taken from the DC option out of the HD cam.
What I’m getting at is trying to have a DVCPRO HD timeline that has SD and HD bars before program so we can do a simulateous lay back for both masters.
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I wish I could say there was an easy way, but there’s not if you are trying to do the masters at the same time. You might be right about the I & Q (this would be something to check on), but in terms of IRE you have nothing to worry about and I’ll tell you why. FCP natively works with 0 IRE, HD is 0 IRE, digital SD is 0 IRE. As long as you are outputting digitally (SDI to digibeta) you should not be putting setup in your bars since the rest of the program does not have setup. The setup will be added by any analog output that your digibeta tape is played through. Make sense? Your HD & SD masters should have 0 IRE.
Anyone know about downconverting HD bars and what that means to an SD master?
The other way to do this is have both of your HD & SD bars striped on both tapes (pre bar & toned), that way all your doing is assembling the program out of FCP. Still might not the easiest or fastest way, but that way you are only laying off once to both formats.
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