Video quality at higher levels of compression in DVDshrink

[poopyhead]

it seems that some ppl have mentioned obvious degradations in video quality if letting dvdshrink transcode anything beyond lvl 2...maybe lvl 4,5 max.....even ppl with regular, non-hdtv or plasma have mentioned this...

i personally have a regular 32" TV....i've had to transcode certain movies as much as the max allowable (lvl10, 50%...still images don't count)....i frankly don't see any difference w/ the main movie...i do see artifacts with extra features transcoded at lvl10, but not the main movie...even when i TRY to look for them (i.e. in dark scenes, high action, etc...) am i missing something here???

could it be dvd player differences...because some dvd players produce better video playback (at least with commercial DVDs) than others....those cheap Apex, etc..... players don't seem to have very good video playback quality, as more trustworthy brands, i.e. pioneer...could that be another variable that may worsen any loss in quality from transcoding...cuz my pioneer dv333 shows no artifacts when played on my 32" regular TV (not comparing to HDTVs)

[vance43211]

i really wish people stop them hdtv comments

i have a 46in and a 52in TV (everything is plug in with composite in, not the s-video or component in

and a 19in and a 21in moniter

i see obvious sign of of quality with different programs


but

on my step mom tv (27in)

i couldn't see the obvious difference (even my burns with neodvd look good on her tv and they look horrible at my house)

i can tell difference between cheap and expensive dvd players at my house too. and there is a difference

i then realize why so many people actually argue over what was obvious difference to me on the forum, because they couldn't tell on their tvs

that being said

if it look good to u don't worry about it

p.s. if u want better quality from dvd shrink

shrink it twice at lower levels i.e. level 3 or 4 twice instead of level 8 once

[ddlooping]

Hi all

poopyhead, I do believe compression above 35/40% will show degradation.
How much degradation depends on the movie you're backing-up, and the quality of your viewing equipment (TV, DVD player, connections, etc etc).

As I'm using a very good EIZO 17" LCD monitor as reference, I'm fairly confident in the quality of my backups.

I made a test DVD containing movie clips from DVD Shrink, DVD2One and DVD2DVD-R backups, and then took it to local shops to view it on the latest Pioneer, Bang & Olufsen plasma screens, and Sony Wega TVs.
Only the plasma screens showed the same level of "accuracy" as my LCD.

When watching this test DVD on my 32" widescreen Hitachi, using a DV626-D Pioneer set-top, the perceived degradation was decreased noticeably (sometimes to the extent of disappearing completely).

My conclusion:
If you do not see any difference in quality between an original and a backup compressed at 35% or more, it's probably due to your viewing equipment.
It's all good if you don't intend to upgrade it.
But what if (when) plasma screens get more affordable?
If you then decide to get one, you might have some bad surprises.

P.S: that's why I use DVD2DVD-R/CCE instead of DVD Shrink when backing up very long movies.

[SVCDummy]

Geting back to your original post...

Yes problems occur in higher compression ranges.
Yes it is VERY dependent on the DVD player being used.
Yes you seem to be shielded from much of the degradation but I'd bet that if you started taking your DVD backups to several friends houses that had lower quality components, you'd see the same problems described here.

A good rule of thumb... ANY video length greater that 1hr 45min will have serious degradation when compressed with DVDShrink (based on 'movie only' transcoding).

This is from experience of transcoding 75 movies and viewing them through 6 different set top DVD players ranging from the lowest APEX to the best SONY all tied to standard 27" tv's and ALL done with DVDShrink.

[vance43211]

that 1 hr 45min

just about translate to the 6.5 ( roughly 110 min of uncompress movie) gig limit i had talked about which is basically the limit that dvd shrink will gives u good quality

i use ic7 for longer movies,

but the quality do look better if u shrink it twice at lower levels , instead once at a higher level

[theanimala]

Not sure if you guys are actually saying that the quality is acceptable or not. I am a HUGE fan of backing up my movies at the higest picture quality. I always drop the extra's, and extra sound tracks to have the highest quality picture possible.

However, I had to backup a couple of movies at a higher compression level (Like Red Dragon) even after dropping all the extra's and sound tracks. Hell, I'll get rid of nearly every credit as well to keep the quality.

You know what I noticed? Hardly any difference at all. I have a 47" Widescreen HDTV with a progressive scan dvd player. I also had my set professionally ISF calibarated 4 months ago (for a pretty penny as well). I only sit 7' away, and watching as hard as I cood, WANTING to see flaws, and I couldn't. A couple of very dark scenes had what might be notices as a bit less detail and some more noise when compared next to the original (which I did, many times). When I say a couple, and also when I say might be noticed, I am not lying. The quality was just that good.

This is coming from someone who hardly ever listens to MP3's because of the loss of quality as compared to the original file. I would rather watch a DVD compressed with DVD Shrink then listen to an MP3.

Now I am not saying I would watch a movie at level 8 compression. I have not had to do it, and I doubt I would. But if someone were to tell the quality was pretty good, I would tend to believe them.

[adam]

Though transcoding and encoding work very differently, they both do the same thing; compress by throwing out data. If a movie is encoded in a very high bitrate, higher than what it probably needed, than throwing out some of this data may not result in any noticable quality loss. However, for something like an extra feature which is encoded in a lower bitrate, compressing this even a little may result in noticable quality loss. So in my opinion, alot of this variation is due to the movie itself. Some DVDs use ridiculously low bitrates so that they can cram more extra's onto the disk. Some movies are just not very compressible. If you try to transcode these movies by very much, the quality may turn out piss poor while everyone else argues how they can't see any noticable difference even on level 10 in DVD Shrink.

My 2 cents... On an average movie you may be able to get away with compressing the movie, through transcoding, by about 30%-40% without seeing any difference in quality, but any more than this just produces very noticable macroblocking on all players and tv's I have tested. So for those people who do movie only backups, transcoding is probably sufficient. However, on the average DVD9, if you choose to keep the extra's you are going to have to compress your movie by at least 50%, which is just unacceptable to my eyes unless you do a full re-encode. In this instance, transcoding just doesn't cut it for me by a long shot.

I don't consider my eyes or my equipment special by any means. However high compression levels using the latest versions of DVD Shrink, DVD2ONE and IC do result in quality loss which is noticable enough to me that it becomes obtrusive.