Assembling VOBs and m2ts files

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Dave Watterson
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Assembling VOBs and m2ts files

Post by Dave Watterson »

BIAFF 2012 assembled each programme for the mini-cinemas and each section of the Awards Show on Blu-Ray discs. Session trailer and caption cards were built-in too. Careful preparation ensured that videos were shown in the correct aspect ratios.

The system made for the slickest presentation I have seen at any non-commercial film festival, anywhere.


The problem appears to be that in order to prepare such compilation discs, separate entries on DVD or Blu-Ray had to be decoded and then recoded with a small resulting loss of quality. In one case where a problem had arisen the original Blu-Ray entry was screened and never has that format looked better. The image outclassed everything else in that session.

Is there a way / program / work-around that would allow the "film files" from DVDs and Blu-Rays to be placed onto a Blu-Ray without recoding?

Dave
Michael Slowe
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Re: Assembling VOBs and m2ts files

Post by Michael Slowe »

Dave, more and more festivals (and broadcast companies) are asking that films be submitted as files rather than video. The transmission of these files can be a problem, although eventually, this will be done over the ether. Last year I took a drive down to a London festival where they downloaded my file there and then since I was reluctant to part with the drive. Other ways of doing this include burning the file (not the video) on to a DVD or BD. However, for instance, my file for my film Painter (running time 30 minutes) is 41 GB's in size. This is because it is HD in the ProRes 422 HQ codec, which is my editing codec. This would not fit on to anything other than a double layer BD. So, in order to fit it on to a disc I would have to further compress it by converting to another codec. This would still be preferable to the method employed at this year's BIAFF where I was horrified to learn that they were transferring off the discs submitted.

With the demise of tape files will (have already) become the professional currency. Cheaper small drives will be the best bet if we can't send files over the internet. I agree that the shows were very slickly presented and, to be honest, looked very good indeed. I think that files will be the answer but will have to be fitted on to a disc (DVD max 4.75 GB's, BD 25 GB's?). Work therefore for HD 'shooters' to encode to a suitable codec.
col lamb
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Re: Assembling VOBs and m2ts files

Post by col lamb »

Dave

A simple answer is no, but also yes.

DVD's if the movie is a single VOB file can be ripped off the disc and its VOB extension renamed to .mpg, no re-coding (as long as the disc creation software that the compilor is using sees the file encoding as being OK). For Blu-ray it is not that simple and ripping software is used.

At the end of the day it all depends upon the quality of the original encoding.

Solid state is the way forward to accept files for compilation use.

For full HD from AVCHD and derivatives I suggest advising MPG2 or MP4 as the file formats, these will offer the best quality against file size with a 1/2 movie being about 6Gb.

Totally avoid accepting ProRes or Cannopus HQ and similar, yes they have the quality but at the cost of a very large file sizes which will take an age to load into a PC. They are after all intermediate file formats, we have had this discussion on ProRes before but it still remains not the format to use for distribution.
Col Lamb
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Michael Slowe
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Re: Assembling VOBs and m2ts files

Post by Michael Slowe »

Col, I know you're not keen on ProRes as a codec but post houses and broadcasters are very happy with it. The file sizes are way down on uncompressed HD and I save huge amounts of storage space using it, with very little loss of quality. I can bring a 40 GB file back into my edit system (MacPro 2.5 GHz Intel Core 2 Duo computer) quite quickly although I confess I haven't timed it. I just think that it would be nice to avoid the compression of MPEG 2.

Where were you at the week end? Some of the forum fans met up but obviously not all.
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Dave Watterson
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Re: Assembling VOBs and m2ts files

Post by Dave Watterson »

Col - the problem, of course, is that we have little control over what competition entrants send us so we have to work with what arrives.

I have often used the rename *.VOB as *.mpg trick to put DVD movies onto a timeline, but whenever I burn a new disc from them, the software re-encodes it. What software do you know that might simply assemble them?

On a more general note ... it ought to be possible to edit the *.inf file on a DVD to accept additional VOBs, though it might be tricky. Getting those files onto a Blu-Ray disc along with native Blu-Ray movies poses a whole new set of problems.

I take your point that playback from a good hard-disc system is usually the best practical method, but there would still be problems assembling the necessary files, would there not?

Dave
col lamb
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Re: Assembling VOBs and m2ts files

Post by col lamb »

Dave

There are too many variables to always avoid re-encoding, best to rip and re-encode with a quality piece of software

You need Edius, with it you can import disc files into the editing software and do with them what you want

As I have advised entrants could also supply movies as MP4 or HD MPG2 burned on a data disc, easily copied to PC/MAC for compilation, this is by far the best practical way forward until web based streaming at full HD becomes the norm.

If movies are to be shown via compilations on DVD/Blu-ray then using Playlists within Encore would make life so much easier. All the movies included in the playlist would be played one after the other (perhaps with a short IAC logo video between them?)

Solid state players generally do not have Playlist functions, but on the editing timeline all the movies with suitable inserts can be put one after the other (same format SD, HD etc) and after normalizing the sound an MP4 file is generated. At the event press play and all the movies will be seen one after the other, no disc/tape changing, no fidling with the sound.

Mike

We could go round in even more circle on ProRes, yes it does produce great quality images but for projection at events like BIAFF supplying a ProRes file is not the way to go due to the very large file size. MP4 or HD MPG2 is the best format with a video data rate of up to 35mbps the image quality on screen will be as good as you can get from most reasonably priced projectors.

Also my Wife works Saturday's hence weekend events are no-go's

I will be at the AGM later in the year at Grange Over Sands in Cumbria but not staying as I only live an hour away.
Col Lamb
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Michael Slowe
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Re: Assembling VOBs and m2ts files

Post by Michael Slowe »

Col, I have been convinced that you're right as far as transmission of files for festivals are concerned. Ripping already encoded DVD's though does seem ridiculous. As you say, doubtless web based streaming in full HD will soon be with us and that will solve that problem.

My wife does not reckon on amateur films so won't attend festivals, surely the fact that yours can't make it gives you the freedom to do your thing?
We missed you.
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Dave Watterson
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Re: Assembling VOBs and m2ts files

Post by Dave Watterson »

I'll echo that: we missed you, Col.

You are right about the way to present BIAFF shows. I am sure other regions will follow SoCo's lead in putting complete shows onto Blu-Ray. They did indeed have them as (in effect) a single film with caption cards between each one. All the projectionist had to do was press the pause button on each caption, when necessary.

The catch is that on the one occasion when a film maker's two entries were shown: one from his own Blu-Ray entry and the other from the compilation disc - the quality difference was obvious.

Hey-ho - the standard of picture and sound was better than ever before, so we are talking about minor improvements.

Dave
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