"Export using Compressor" vs. "Export a Quicktime Reference Movie"

I agree, that is poorly written.

Compressor sees my DVCPRO HD footage as 960 x 720, but if I export as a Quicktime reference, it recognizes it as 1280 x 720 file.<</div>

What does the VIDEO FORMAT in the Compressor Inspector window say after you choose your setting for export? If you make it 720p does that give you the proper size?

rh

The only difference as far as I can tell is that by exporting a reference or non self contained movie from FCP first, (very quick procedure) you can open Compressor outside of FCP and start encoding. This allows you to continue working in FCP while the encode takes place.

You could do the same by exporting a self contained movie, but it would take longer to export. Regardless, that's the route I'd go as I've never had luck using reference movies for anything.

As far as generation loss, I can't see how it would make that much difference. As far as I know, exporting using current project settings should give you a file identical to the quality you have in your timeline. The only loss might be where you've used effects and filters but I think that would be minor if any.

As for the options available in Compressor for the two methods, I'm with you... as far as I know, they are the same.

Wish I had another guess for you on the "size" issue. I'm sure you'll get some more suggestions from others tomorrow on that.


Manually Confused in Toronto

rh

Can someone explain this to me? From what I can tell, I get the same set of options from Compressor when exporting using either method. What is the difference?

The major difference - and this isn't something that many people take advantage of - is that if you Export Using Compressor, you don't have to render your timeline because Compressor will process all renderable material (effects, transitions, composites, etc) directly into the MPEG-2 file. This takes up to 2-3x longer than compressing a reference movie, but if you've got heavy color correction, filtering or composite work, it really does make a difference.

Outside of that, what the manual is really trying to say is that exporting directly to Compressor processes frame-by-frame, which takes longer, but also produces better quality (though the difference is usually minimal with rendered timelines).

The thing that is concerning to me is that if I select "export using Compressor," Compressor sees my DVCPRO HD footage as 960 x 720, but if I export as a Quicktime reference, it recognizes it as 1280 x 720 file. What gives?

When exporting directly to Compressor, Compressor uses the frame size from FCP's sequence settings (which, in the case of DVCProHD is 960x720) but when you export a reference movie, Compressor (and it's Preview window) reads and displays the QT codec (which translates that 960x720 frame size into 1280x720).

But the input is the same, the two methods simply prefer different line items, if you will, so your output files would be the same frame size.

A famous guru once told me that if you export using compressor, and tie up FCP in the process, you end up with a better MPEG stream, rendered timeline or not... I can't confirm this (because I've never bothered to check it out, so I simply use the command every time), but have had many an experienced editor tell me they see a difference. The manual even points at this... "if quality and transcoding controls are important to your project..." Apparently, Compressor uses some code or information from FCP during the process which results in a better encode. It does take a lot longer to do things this way, so I suspect that there's truth in the quoted statement.

Jerry

No, you'll have to trash your render files. There are lots of ways to do so but my favorite is - with the sequence open in the Timeline - to select all (Command-A) then to toggle Clip Enable/Disable (that is, press Control-B twice).

Good information Han. I've often wondered about the "in's and out's" of Compressor.

I'm curious, is there a reason you don't use Render manager to trash the renders? I know that you can undo the trash using your method (good because you can get them back if you want after compressing) so I assume that it simply breaks the connection to the renders, but does Compressor know that?

rh

This allows you to continue working in FCP while the encode takes place

I always thought that when you were doing processor heavy tasks that you should not try to multitask, as it may affect the render or export. Any ideas on that? Meaning that when I do those exports I usually try to step away from the computer, do them at night etc.

I'm curious, is there a reason you don't use Render manager to trash the renders?

It's just a question of speed, in most cases. And because I prefer to use the keyboard. But, yes, Compressor knows that you've "unrendered."

But you bring up a good caveat - if you're using nested sequences in a specific way, it's preferable to use Render Manager (to trash everything associated with the project) since the Clip Enable/Disable trick won't always work. If you assemble and render sequences in their own timeline, then nest them in a parent sequence, those renders won't get cleared using Control-B in the parent sequence. If you simply assemble a sequence in its own timeline, but render it out in the parent sequence, then Control-B will work.

I find that when going out to DVD - usually because of the need to place chapter markers specifically - few folks make use of nests in the first way (I notice most folks just copy and paste clips over).

But thanks for triggering that Randy, it is a key caveat.