General question: video 'quality'

jtuffen wrote on 3/15/2005, 8:49 AM

This isn't specifically a Movie Studio question, but it's the software I use... so:
I have been making a short film to accompany a piece of music, and am happy with the results so far, I'm now wondering whether there is a (to coin an audio phrase) 'mastering process' to ensure that the resulting video is of sufficient brightness/contrast (whatever). I have a vague recollection of seeing such a thing for film, I'm just wondering about DV/CG.

I guess what I'm after really is some software that will be able to analyse the resulting video and tell me that from a technical point of view it is compliant with some (broadcast?) standard.

Anyone got any ideas?

john..

Comments

IanG wrote on 3/16/2005, 5:16 AM

There are lots of standards for the format of the video and a lot of software to check compliance, but I'm struggling to imagine what criteria could be applied to the content. It might be dark and blurry, but if that was the intention....

Ian G.

jtuffen wrote on 3/16/2005, 6:22 AM

:)

Having googled around a little, it seems that back in the days of analogue video(!) engineers were able to apply a scope (vectorscope?) to the various analogue video signals and by this analysis would be able to tell whether the video signal was acceptable...

I've also found references to 4:1:1 and 4:2:2 video (4:2:2 being 'broadcast quality') and that it is possible to tell the difference ("to the trained eye").

Basically, I don't want to get into a situation where (in the future) I create something and then have it knocked back at me for 'not being broadcast quality'!

cheers,

john..

ScottW wrote on 3/16/2005, 7:45 AM

Vegas (the big brother to VMS) includes vectorscope displays, I don't know whether VMS does, but if it did they would be on the "view" drop down menu. What you're looking at with the vectorscope (amoung other things) is to be sure that the video signal does not exceed certain limits. For example, usage of very intense colors can sometimes bleed over into the audio portion of the bandwidth and cause a buzzing sound on some TV's. This is one of the reasons that Vegas also contains broadcast filters - to limit things and set appropriate levels.

Broadcast quality seems to be a very subjective term (at least to me). The 4:2:2 color space is indeed used for broadcast, where as DV uses 4:1:1 - so looking only at color space you can make the claim that DV isn't broadcast quality and technically you'd be right. However, in practice well shot DV with correct lighting and a decent camera, most people are not going to be able to tell the difference between DV and "broadcast quality" material.

So, does that mean you can never take DV to broadcast? Certainly not. People do it all the time, especially in advertising. While a lot of TV stations won't accept MiniDV tape, there's nothing to stop you from dubbing the DV footage over to BetaSP tape and sending them that. I've got a client where we do exactly that - he hands me the finished 30 second ad, usually in uncompressed AVI form. I check it for any problems and correct if necessary, dump it to MiniDV, take it to a duplication house nearby (since I can't justify the $5k needed for a BetaSP deck yet), they dub it to BetaSP and then I ship things off. It's a little easier with Comcast here in Denver because they happlily accept material on MiniDV.

--Scott