Rendering in FCP and Quality of Final Output

[JackoFluent]

[I posted this in another forum (Editing) but it's been pointed out that this is quite a specific Apple/FCP question, so I apologise if I'm breaking house rules by posting twice ...]

Nevertheless:

I'm trying to burn the highest quality 30 min DVDs (so no issue on disk space) using Final Cut Pro (recently converted from Windows and loving it) and DVD Studio, and the results I get are reasonably good (wildlife documentary/travel stuff).

However, I'm trying to squeeze the very highest quality output from the uncompressed DV tapes I've captured, and I've now run into a brain teaser.

Basically I'm confused about the difference between RENDERING during the editing process to see my edits and effects in real time during the editing process, and how that may or may not affect my final output files during the ENCODING process.

Are these totally separate functions, and my final quality only rests on the encoding settings, which should convert my edited uncompressed AVI/DV to MPEG-2 files, OR can I mess up the quality of the uncompressed DV by rendering filters/transitions/titles etc etc during editing??

I have burned a few minutes of DVD footage to test, and it seems that clips that have had a high degree of filters and effects applied (and then rendered during editing to see results) are of a poorer quality after encoding than the un'effected' raw footage. I'm using the highest bitrates available under the DVD Studio encoder (after exporting through Apple's Compressor) - so that is a constant for both types of clip (ones that basically were unrendered vs ones that were rendered several times)

Anyone have an insight into this i.e. does rendering during editing in FCP affect output quality regardless of encoding?

Many thanks, Nick

[terryj]

First of all, welcome to our Corner of the world!

Second, you should never convert to MPEG-2 to edit.
Always edit in DV, period. FCP will allow you to render
clips and effects to give you a preview of what
might happen, but when it sends the files to Compressor,
it goes back to the original DV file and then creates
NEW the effect and edits to the FCP reference movie.
UNTIL COMPRESSOR DOES ITS WORK, the original
DV source is basically untouched. What you see in
your renders are copies of the DV file and effects
rendered for Preview only, and these copies are
stored in your Batch folders on your Scratch Disc.

Third, but you sound as if your are compressing TWICE,
once through Compressor, then again through
DVD Studio Pro.

You should only compress ONCE, and that is through Compressor,
to MPEG-2 and AIFF audio (or AC3 audio)
and then import these ready made assetts into DVD
Studio Pro. Things will then go much faster, as
DVD Studio PRO will NOT have to render anything,
and will just create the structure and burn.

I would also suggest you invest in getting a Bit Rate Budget Calaculator
to help you on using
Compressor. This handy tool will enable you to figure out
how high you need to set up your Compressor encoding
parameters for your MPEG-2 setting, to get the best
possible Quality out of the encoding process.

[JackoFluent]

This is great input terryj, many thanks.

I am already working in 'raw' DV within FCP rather than MPEG, so I'm half way there, but your advice on not re-compressing through DVD Studio is very relevant. I'll make sure I only encode once through Compressor in the future. I'm away from my Mac at the moment, but I am assuming that 16:9 handling is not affected as this is a flag created when the VOB files are created by DVD Studio (is that right?) - I earlier thought I needed to encode in DVD Studio because of it's superior 16:9 handling (vs iMovie and iDVD combo) - but I guess that is at the stage AFTER encoding....

I'll also follow up on the Bit Rate Calculator, thanks.

BTW - do you have any advice on filters and effects used in FCP that will reduce image quality after rendering and subsequent encoding? I have vaguely assumed that the BOLD selection items (that do not require rendering for preview in FCP) are lest destructive than the other effects wich require rendering to view - but maybe I'm barking up the wrong tree on this.

I've burnt a few DVD-RW test sequences with and without filters, and with different 'intensities' +1+2+3 etc, and it certainly seems that I loose image quality with many filters, especially at the higher levels. Is there any guide available to help me on this, or is experimentation (the long winded way!) the only path?

Any input appreciated. Cheers, Nick

[SERBIAN]

As terryj said welcome to our little world...And regarding your questions - check LAFCP User Group site...You'll find all the answers you need there...

[JackoFluent]

Thanks for the warm welcome guys!

I just started browsing the LA FCP UG site after being directed there by Ken Stone - seems like a very rich and informative FCP resource. Ken also has an excellent site as I'm sure you know.

I'll report back if I get any guidance on filter usage that is worth sharing.

Meanwhile - any more responses to this specific question most welcome

Cheers, Nick