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Opinion wanted: Downconvert or native m2t when output target is DVD?
Hi
I regularly shoot long concerts and events and deliver the final product to the customer on DVD. I typically shoot, capture and edit in HDV, and then output to DVD. This gives me about 75-79 minutes on a standard DVD before compression is required, which I try to avoid at all costs.
I also do just camera work for someone else, but his workflow is shoot in HDV, then downconvert in camera to DV and then capture/edit in AVI. He does not deliver in bluray, only DVD, and is able to get 120 minutes of footage on disc. His logic is that downcoverted footage is of higher quality to begin with, and if the customer is getting just a DVD end product, they will not notice the difference.
I am about to embark on my own project which may well go into 2 hours, and the client has got quotes from other companies claiming that they can deliver 140 minutes on a single DVD (not dual layer), and have requested the same from me. The only way I think this is possible is shoot HDV and downconvert to AVI then edit.
So the question is: Is there a genuine quality difference in the final product (DVD) with HDV m2t versus downconverted AVI footage?
Intel i920, 12GB RAM, ASUS P6T, Vegas Pro 9 (X64), Vista x64 Ultimate, Vegas Production Assistant 1.0, VASST Ultimate S 4.1
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5 Replies
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The biggest advantage to editing with native m2t footage is that you can zoom in if you want to.
If you downconvert in camera, you lose this ability.As far as a 140 min. DVD, yes, it can be done.
Should you do it?
That depends entirely on your camera.
If it’s a consumer camcorder with no on-scene lighting, it’s going to look pretty bad.
If it’s a decent camera with a good lens and all scenes are well lit, then yes, it is possible.
Keep in mind that the average bitrate will only be 4,000,000 and, IMO, that’s the borderline quality margin.
I shot a play this spring that was over 2 hr. long and the resulting DVD looked OK to me and everyone else.
It was shot with a 3 CCD camera with 1/2″ CCDs and a good lens combined with a properly lit stage with few extremes in lighting. -
Mike
I use a Z1P and an FX1 and we might also have an NX5 in the mix. It’s a Flamenco dance concert with stage lighting, so I am expecting that lighting will be good.
I have done a concert with zooming as you described to crop the image of a remote cam, but there was noticeable strobing on fast movements. Perhaps I cropped a bit too much.
So, are you saying that down-converting is a path worth considering? Was you spring play edited from downconverted HDV?
Intel i920, 12GB RAM, ASUS P6T, Vegas Pro 9 (X64), Vista x64 Ultimate, Vegas Production Assistant 1.0, VASST Ultimate S 4.1
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“I use a Z1P and an FX1 and we might also have an NX5 in the mix.”
The Z1 and FX1 are excellent cameras but I don’t know anything about the NX5.
“It’s a Flamenco dance concert with stage lighting, so I am expecting that lighting will be good.”
I’ve never seen a concert of this type so I strongly encourage you to attend a rehearsal as the lighting may not be what you expect.
By that, I mean a lot of different colours with spotlights or dark and moody.“…there was noticeable strobing on fast movements. Perhaps I cropped a bit too much.”
Did you shoot it in 24p?
This shooting mode doesn’t like fast pans.“So, are you saying that down-converting is a path worth considering?”
If there’s a possibility that you’ll be zooming in on the video afterward, then I’d keep HDV on the timeline.
“Was you spring play edited from downconverted HDV?”
Nope. It was plain old standard def miniDV.
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Your footage on disc has absolutely nothing to do with the editing format, only that last render. Use a bitrate calculator… you can precisely figure out the average bit rate needed to deliver X minutes on a DVD5 or DVD9, for any senario.
As for editing.. I would always edit in HD if I shot in HD, even if I’m only delivering in SD. For one, you can zoom without effective quality loss. But also, if you’re shooting NTSC, there’s a very specific mismatch between DV and DVD.
As with most consumer formats, DV and DVD both do color subsampling. You have 720×480 pixels in each case, but only 360×240 color samples. This makes sense… as humans, we have about 120 million luma sensors per eye (eg, we see resolution very well), but only 6 million color sensors per eye (eg, we’re only so-so on color). The problem is that NTSC DV does 4:1:1 color subsampling, DVD (and PAL DV, and HDV, and AVCHD) so 4:2:0 color subsampling.
So just based on that, your DVD will look better from HDV than from HDV converted on-camera to DV. But there’s also the recompression and everything. Always edit in your best quality format if possible, and you’ll get the best result. Editing in the same resolution as the deliver format, you’ll get more recompression effects, etc.
-Dave
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Thanks Guys
Agree with everything you say and appreciate your advice.
The NX5 shoots in NXCAM, the next generation of Sony AVCHD.
I forgot to mention I live in PAL land, and am not shooting in 24p.
I have done long projects in HDV and output to DV, but I had to either compress in DVD architect or reduce the bit-rate in Vegas. I was unsure if the latter would introduce strange artefacts, and will bring out the bit-rate calculator.
Thanks
Intel i920, 12GB RAM, ASUS P6T, Vegas Pro 9 (X64), Vista x64 Ultimate, Vegas Production Assistant 1.0, VASST Ultimate S 4.1
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