Question About Loss of Quality

This may seem like a stupid question, but when you copy a DVD with lesser quality, due to the capacity of DVD-5, where will you see this loss of quality?

Is there anyway to compress a movie so that there is no visual loss of quality, but rather all lost in the audio portion?

Another question…

I have burned a full disc with 100% quality to a blank DVD+R DL. My computer can read it, but my DVD player cannot. Any ideas why? If my DVD player is not able to read DL discs I have burned to, then why would it be able to read the DL manufactured version? Different DL formats?

I’m a pretty big noob when it comes to this stuff, so any help would be greatly appreciated.

Welcome to the forum :slight_smile:

[QUOTE=SketchyNS;1955334]This may seem like a stupid question, but when you copy a DVD with lesser quality, due to the capacity of DVD-5, where will you see this loss of quality?

Is there anyway to compress a movie so that there is no visual loss of quality, but rather all lost in the audio portion?[/quote]
For the most the quality loss is in the video part, and most of times it can be noticed only watching the compressed movie on a large screen.

However, bear in mind that the resulting quality is related also on the original movie quality: as a general rule, the higher is the bitrate of the original, the better is the quality of compressed video.

Moreover, there is a large subjectivity in the video quality evaluation. Some people are able to see artifacts also in the original movie.

Probably it’s possible to compress the audio part, but I don’t know how to do it.

[QUOTE=SketchyNS;1955334]I have burned a full disc with 100% quality to a blank DVD+R DL. My computer can read it, but my DVD player cannot. Any ideas why? If my DVD player is not able to read DL discs I have burned to, then why would it be able to read the DL manufactured version? Different DL formats?[/QUOTE]

Most of times this is due to a low quality disc or to a bad burned disc. I suggest to try again with a Verbatim +R-DL disc (most of times -R DL discs have a very low compatibility with standalone players).

Also updating the burner firmware can improve writing quality :slight_smile:

Thanks alot.
Answered all my questions, and in less than 10 minutes from the time I posted :slight_smile:

From personal experience, would you, or anyone else for that matter, be able to tell me at what % quality you start to notice the loss?

Thanks again, glad I can be a part of this forum.

You’re welcome :slight_smile:

As I said it is related to the screen dimensions (I think that above 30 inch the difference can be easier to notice), but also on the source movie. If the original has a low quality, also the compressed movie will show a low quality.

To reduce as much as possible the artifacts, the best way is to use a mpeg encoder (i.e. the method used by DVDrebuilder) and not a transcoder (like dvd shrink or clonedvd). The advantage is a lower amount of artifacts, but the drawback is that a mpeg encoding requires a powerful CPU and a lot of time. If you have a quadcore CPU, however, it is possible to compress an entire DVD disc in few hours :slight_smile:

Another thing you can do is some tests. For example,you can use dvd shrink to extract a single part of a movie and compress it in different %, and then burn the different movies on a rewritable disc (to not waste media). Watching by yourself the test on your television is the better test :slight_smile:

As a thumb rule, I can say that compressing more than 75% gives easily noticeable artifacts.

Hi Sketchy. I will assume that since this is the DVDFab forum, you are asking about how these matters relate to DVDFab. What Geno said about re-encoders is true but they are painfully slow. DVDFab produces good output on my HDTV down to as low as 75% on some movies. To me, even original DVDs don’t look all that good when you get used to real hi def pictures. Fengtao of DVDFab has said that the software is suitable for screen sizes up to (I think) 60 inches. The problem you are having playing burned DLs is most likely, as Geno said, the burn/media quality. Try reducing the burn speed. It could also be that the backups are not set for DVD-ROM booktype. Some players do not work well withoiut this. Unfortunately, not all burners support this feature.

Unless the audio track is LPCM (WAV) it usually isn’t that big a file that you’d gain much more than a few MegaBytes by compressing it. LPCM as the only audio track isn’t real likely, so if you have LPCM you can usually just not use it to save some space.

[QUOTE=SketchyNS;1955352]Thanks alot.
Answered all my questions, and in less than 10 minutes from the time I posted :slight_smile:

From personal experience, would you, or anyone else for that matter, be able to tell me at what % quality you start to notice the loss?

Thanks again, glad I can be a part of this forum.[/QUOTE]

For most movies less than 2 hours, using the “Movie-Only” mode, results are more than acceptable on up to 60" screens when compared with original source.

This method cuts out all the extraneous crap that studios seem to fill the disks up with and the movie is only compressed enough to ensure that it fits on the disk.

Of course, if you want to retain everything, burn to a dual layer disk and there will be no compression.