[vdr] Re: Suggestion: High speed cutting

[Ari Huttunen <Ari.Huttunen@f-secure.com>]

I'd like to comment that I never found the cutting speed any problem, but at the 
moment I just don't cut at all as USB hard drive space is pretty cheap.

If there's something changed there I would like more accurate cutting, but this 
would require video encoding stuff. I'd need to do this prior to MPEG4 
conversion, and I couldn't find any other software that was as easy to use for 
cutting video than VDR. (I've not tried MPEG4 for a year or so. As I said it's 
just easier to buy USB hard drives.)

Ari Huttunen

Udo Richter wrote:

> Hi list,
>
> I've been thinking about video cutting strategies, and I think its 
> possible to speed up the cutting process noticeable, with some 
> modifications to VDR. Here's what I think of:
>
> 1. Reduce file fragment size noticeable (I'd suggest 20mb instead 2000mb)
>
> 2. Change cutting strategy: If the source recording switches from one 
> file fragment to the next, start a new file fragment on the destination 
> too.
>
> Now each file fragment that has no cut mark in it will be copied to 
> destination 1:1, without changes. By that, we can:
>
> 3. If a source fragment has no cut mark in it, do a hard link from 
> source folder to destination folder instead of copying the whole file 
> frame by frame.
>
> Now the only stuff that needs to be copied are the few blocks that have 
> cut marks in it, plus index/marks/summary.
>
> Pro/Con's:
> ----------
> (+) A typical movie with three breaks would require ~80mb to be copied, 
> not 3-4Gb.
>
> (+) Should be done in 5-10 seconds.
>
> (+) Dont need much disk space to do the cutting.
>
> (+) No precautions needed if source gets deleted. Hard link will 
> automatically turn into regular file.
>
> (+) Compatibility: Set 2000mb fragment size and disable advanced 
> strategies, and everything is as before.
>
> (-) Needs true Unix file system. Fallback for FAT file system: plain old 
> copy.
>
> (-) VDR is limited to 255 fragments. This needs to be increased. 65535 
> sounds good.
>
> (-) Change file names to 5 digits. (maybe only for fragments >999?)
>
> (-) index.vdr slightly changes, to support more fragments. Use reserved 
> byte for that. (backwards compatible if <256 files)
>
> (-) File system has to handle more small files. Typically 200-300.
>
> (-) No modification inside recordings allowed. (does not happen, or?)
>
>
> What do you think? Worth implementing it? Too much trouble? A must-have? 
> Anything else that may break?
>
> Cheers,
>
> Udo
--
E Mare Libertas
          <Sealand's national motto>

Ari Huttunen                   phone: +358 9 2520 0700
Software Architect             fax  : +358 9 2520 5001

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