Looking for best way to compress dvd backups

[Wolfsrudel]

Hi,

my nas is at its limits, so i have to think of converting my mpeg2+ac3 dvd backups to a more efficient codec.
do you have some good hints on how to compress them? Which program? Which codec? What settings (bitrate...)?

Important to me:
- There should be no loss in video/audio quality.
- The new file has to be playable with popcornhour (www.popcornhour.com) and pc.
- The conversion should be rather easy to do
- Possibility to make use of subtitles

Thanks a lot for your help.
Chris

[mats.hogberg]

Can't be done - Not without a/v quality loss.

/Mats

[Wolfsrudel]

Hi Mats,

H264 and so on can not produce the quality of good old mpeg2+ac3?
That really surprises me.

As a Newbi, i thought that the huge hype about H264 was because of better quality + reduced size.

- Chris

[mats.hogberg]

H264 and so on can not produce the quality of good old mpeg2+ac3?

Yes it can and will if you start from the same source:
Hi def source (100%) -> H264 (95%)=95%
Hi def source (100%) -> mpg2 DVD (75%)=75%

However this is not the case, as what you'll have to do is:
Hi def source (100%) -> mpg2 DVD (75%) -> H264 (95%) = 71%

The quality percentages are just for educational purpose

/Mats

[Wolfsrudel]

Ok. Thanks.

So in order to still have DVD-quality, i have to stick with mpeg2+ac3 for my dvd backups.
And it makes (keeping dvd quality in mind) no sense to convert my mpeg2 to h.264 i.e.

Correct?

Thanks for your help, Mats.

[mats.hogberg]

Well, the quality loss may be small enough to be acceptable (or even invisible/inaudible) to you. I'd try AutoGK with regular XviD (+ original audio) - Use quantizer mode and pick an acceptable quality and see what you think. I'm sure you'll be able to at least halve the space requirements without too much degradation of video q.

/Mats

[GrayStrickland]

my nas is at its limits, so i have to think of converting my mpeg2+ac3 dvd backups to a more efficient codec.

With 1tb drives available for <$300, isn't it easier just to add more storage? I'm not trying to be a smarta~~, but even if you had an ultra fast multi-core pc solely dedicated to the conversion process, it would still take a longdamntime to convert a sizeable library.

Meanwhile, my search for an inexpensive NAS enclosure capable of holding 6 or 8 SATA drives continues. There're many for <$100 (excl. cost of drives) which will hold one drive or two. I want an encl. which will hold 6 or 8. I'll start with just one 1tb drive, then add as needed. Something like... this... but cheaper.

[Krispy Kritter]

Any conversion will cause a loss in quality. However, since you are planning to convert the files anyway to reduce size, the question becomes which codec/format will provide the best quality while reducing the size. In which case you are likely looking at h.264 or Divx/Xvid.

You should create some sample clips using various codecs (from the same source) and see which meet your expectations and perform properly.

[Wolfsrudel]

A new NAS with more space sems to be the best solution, since i really don´t want to loose any quality.

I just thought that converting the dvd-like mpeg2/ac3 files to h.264/mpeg4 wouldn´t result in lesser quality - no matter what settings i use.

Thanks for your help.
Chris