Is the compression algorithm multi-pass

[kelson]

I've looked through the guide documentation and tried searching but I can't find the answer to this. When one copies the main movie only and asks for compression to a DVD-5, is the transcoding algorithm a simple single pass or is it a more sophisticated multi-pass transcoding to maximize quality.

[maineman]

I've looked through the guide documentation and tried searching but I can't find the answer to this. When one copies the main movie only and asks for compression to a DVD-5, is the transcoding algorithm a simple single pass or is it a more sophisticated multi-pass transcoding to maximize quality.

Hi kelson and welcome,

Single pass. With DVD to DVD, I haven't noted an improvement in quality with single pass as opposed to something like dvd shrink, deep analysis or similarly with nero recode. To be honest, I haven't tried in qiute some time....and maybe it's just my 60 year-old eyes...

Where I believe you'll find difference is with the DVD to Mobile conversions.
Here you have the option to do 1 or 2-pass.
Requires a lot from your cpu though, so the more robust your cpu, the better.

[kelson]

Thank you for the reply. The difference between single and multi-pass transcoding becomes more evident the larger and sharper ones display is.

[signals]

Thank you for the reply. The difference between single and multi-pass transcoding becomes more evident the larger and sharper ones display is.

The bitrate of the original content also plays a major role in the effectiveness of (and necessity for) 2-pass in DVD to DVD modes.

[stonemiser]

maineman, I use DVDShrink and have used the DVD5. Both give about the same result. With DVDShrink though you can adjust the main movie portion for better quality. It will take some from the Trailers and such. Usually my Trailers portion will skip around, but the movie will play fine.

[maineman]

Thank you for the reply. The difference between single and multi-pass transcoding becomes more evident the larger and sharper ones display is.

Yes, quite true. As signals mentioned, there are multiple factors related to video quality...and then you have all the subjective input from the viewer as well.

Like I said, on a 42 HD TV, I never noticed much of a difference in dvd to dvd...when uncompressed, whether 1 or 2 pass. Even when reasonably compressed, there is little loss in quality...to my eyes anyway.

I know some folks that swear by strict encoding software like dvd rebuilder.
Myself, I could never be bothered .

Like they say..."to each his own".

[maineman]

maineman, I use DVDShrink and have used the DVD5. Both give about the same result. With DVDShrink though you can adjust the main movie portion for better quality. It will take some from the Trailers and such. Usually my Trailers portion will skip around, but the movie will play fine.

Yeah, shrink has always been a solid piece of software. I hardly ever use it anymore, but I keep it installed. It's like an old friend.
Fab is just so easy...1-click for SL bkups and the "ever-so labor intensive" 2-click process for DLs (2 clicks because I use Img and have to set the LB)...

We have had the title compression function on the wish list for Fab for a few years now. It'd sure be nice.
Maybe it's time to give the F-man another jingle.

[kelson]

The bitrate of the original content also plays a major role in the effectiveness of (and necessity for) 2-pass in DVD to DVD modes.

I agree with you completely. I have a 50" 1080p plasma and with my eyes I start to see a noticeable lessening of PQ if I transcode the main title to less than 90% of original size using the 2-pass encoder of Shrink. I make it a policy not to go below 90%. Given that quality +DL media has become more affordable, if I have to transcode below 90% to fit it on SD media, I just leave it at 100% and put it on +DL.