working in the wild compressed world of DV

Hello.

What is the best way to acchieve the best possible quality with DV footage when using a lot of effects ?? I always thought DV stays the same once in the computer but have learned that once you apply any type of effect that portion of the video needs to be re-rendered which results in quality loss. To maintain the highest standard of quality would it be neccessary to capture your footage as DV, lay down a rough cut with no effects or transistions, then use the media manager to spit out a copy of all your clips using UNCOMPRESSED 10bit video ? Then could you take this uncompressed video and apply all your effects without quality loss, finsih the movie and spit back out either as a quicktime or mpeg2?

thanks

oh yeah, im using the panasonic ag-dvx100a

I believe that's it. The only timeline that doesn't require multiple recompressions is uncompressed.

A good way to reduce your show to garbage is to do multiple effects and corrections on a DV timeline.

Best is to start out uncompressed, but you should be able to convert to uncompressed and the quality should stay the same from that point on.

Koz

you could also do the same by simply making a copy of your final sequnce,
changing the sequnce settings to 10bit uncompressed,
and rendering.

FCP always renders in the highest possible colour space, then converts back down to your sequence settting

Graeme Natress recomends a sequnce setting of PhotoJpeg at 100%

but if you are just going back to your DV deck, it's all pointless, and you should stay in DV all the way.

nick

Thats Koz!

Question, after coverting into uncompressed video, do I have to change my timeline settings as well?

Also, according to what Im doing in DV would it matter to go from 8bit to 10bit ?

thanks

Yes but if I did a lot of effects and kept everything in DV then went back out to DV tape, wouldnt the quality be lessened if I just had edited in uncompressed and spit it back out to DV?

Capture DV - timeline uncompressed 10bit - Output DV

as opposed to

Capture DV - timeline DV - Output DV

no.
FCP is kind of doing that anyway, you see, at least for the rendering.

if you add to many conversions to the chain, you would even make the uneffected images slightly worse.

for making an MPG file for DVD, perhaps you would get some improvemnts.

also when adding extra FX, etc, FCP always refers back to the source files, and re-builds the renders from scratch.
it never uses a render file as a source when doing another effect.
the exception would be if you exported a shot with an effect, brought it back into FCP and edded an extra effect.
or indeed if you imported an actual render file and started using that in your timeline.

cheers,
nck

Thanks Nick. Thats what I always thought, that FCP goes to the source files for renders. I heard through the internet though that whenever there is an effect applied, FCP has to render that effect and in doing so applies the miniDV codec to that portion of the clip. So this anonymous piece of information I stumbled accross was basically saying, all of your clips remain just how you shot them if you do not apply effects to the clips. Those clips with effects applied would be of a slightly lesser quality. Just based on my eyeballs though I cant see a difference.

You said I would benefit from using uncompressed video while going to mpeg2, how so ?

thanks nick !

it's true, you do get your footage recompressed when you aply an effect.

but the eyeball thing counts for a lot, i reckon.
thres no way i can see a pop, or any change at all when some text comes on. or a fade out starts.

where i HAVE seen the bad side of DV is on gradients, where you can get visible banding of the colours.
not just gradients you'd aply yourself, either.
in one show i was using a photographic image with a studio backdrop sublty falling off from grey to black.
that looked pretty bad in DV
and any chromakey work is trickier to pull off, (not that ive ever done any)

the benfits going to MPeg can be seen if you plot out the compression path:

DV > effects rendered as DV(possible banding etc) > Mpeg

DV > effects rendered as Uncompressed or JPeg100% > Mpeg

but as i say, if you are going back to DV tape, then keep a clean DV path.

cheers,
nick

thanks again nick