Editing with intermediate files

arty tribe

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I was following the discussion on using intermediate files when editing, in another thread and gave it a try. Either I am doing it wrong, or it is just a pain or both.

I used Green Valley HQX AVI, but I can't get it to convert multiple files at once (in excess of 3 or 4) without an error message 'Conversion has failed. (Codec cannot be used)'. The 'failed' files can be converted on a second attempt, but no more than two or three at a time.

My clips are not particularly long, and a typical edit will involve around 200. Not an unusual situation I would have thought, but a slow conversion at 2-3 at a time.

As has been said it is a very slow process anyway, but it wouldn't be so bad if all the files could be selected and it could be left to get on with it, without rejecting more than it converts.

I did persevere with one project but couldn't see any real differences, the panning and zoom were no better in edit and the finished film rendered to an AVCHD file, and also burned to a DVD, didn't appear any better than normal results.

I am using an i 7 processor with 8gb of memory on a newish machine, so it is possible that it doesn't need intermediate files and copes with the normal editing workload anyway, but that doesn't feel right, it certainly seems to be working hard.

So is there a workaround to select all files at once for conversion, and is the advantage in using intermediate files just in the editing process or also in the finished product?
 
If you're using the Grass Valley AVCHD2HQ converter utility, and don't have an Edius NLE installation, then not all the functions will work (You can for example convert to the HQX codec - but not to HQ).
For those functions that won't work, you will get the error you describe. Sounds like batch conversion is one of them? (Haven't tried it myself yet).
EDIT: I can confirm that on my old machine - which does have Edius installed - the batch conversion works OK. On the new machine, which has no Edius installation, it doesn't work..

I did persevere with one project but couldn't see any real differences, the panning and zoom were no better in edit and the finished film rendered to an AVCHD file, and also burned to a DVD, didn't appear any better than normal results.

That's excellent news....an HQX conversion (or indeed any conversion) can't add anything to the quality of your original clip, but as you can't see any difference, it looks as if it hasn't taken much away either.....Which is what it's designed to do...

Where HQX is useful is for frame accurate editing, better cuts, dissolves and transitions with fewer colour space conversion errors (which can be a real pain with so called 'smart rendering'.)
It's often much easier to work with on the timeline than AVCHD (or any other long GOP format). It's also better for 'smooth' previews etc...
But the newer versions of some consumer editors - when used with a powerful computer - can make working with original clips much easier than it used to be...

Because HQX functions as a VFW codec, you could use a freebie like Virtualdub to do your batch conversions. That certainly works... so you simply let that run automatically with as many files as you need.
Depends on what your main aim in using an intermediate codec is?.....
 
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Hi rogs, thanks for the feedback, my aim in using an intermediate file conversion was just to see if there were any improvements, you guys seemed to rate it so I gave it a try. Interesting experience if a little disappointing.
 
The use of intermediates is very useful in some cases, and probably unnecessary in others. Intermediates can handle several sequential editing procedures without any noticeable quality loss. (Try adding several procedures - cropping - dissolves - colour correction - brightness and contrast changes - resizing - PIP - etc, etc and long GOP files will quickly lose quality)

They're also very much less demanding of CPU power , which can make timeline work much easier - especially on less powerful computers.
We often get complaints here about 'stuttering' previews and playback, with some editors which use the original long GOP files to work with. Converting to an intermediate will usually cure that.

But of course intermediates can't actually add any quality.... they can merely help prevent too much loss of quality where heavy editing is involved ...
 
I accept that you can't add quality, and was just hoping to limit the losses, but couldn't see any discernible difference, and without batch conversion its too much work.
 

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