disc image or volume

[schempsey]

I've always been creating volumes before burning to a DVD. I just a read a few things that makes me wonder if I should be creating a disc image. I tried one and it played but thje file size is much greater with the disc image. Can someone tell me what is the best way and if it is to use a disc image, why is the file size so much larger than the volume files I create?

Many Thanks!

[redwudz]

I use a disc image for two purposes, to make an exact copy of a file without the burning program modifying or changing it and to make multiple, exact copies of a file.

In the case of DVDShrink, making an image and using it to control the burning process may make a more compatible disc. I've really seen no difference between the image burned or using Nero to burn the video folders as DVD Video. But I have no problems with either burned disc. If I did, I would probably use the image method.

If you don't want to buy or can't afford Nero or a similar program, you can use the freeware DVDDecrypter to burn DVD images for no software costs.

These are just my reasons.

[schempsey]

Thanks. I do have Nero but I've been using Record Now (ver.7). I'm still curious, when I copied a Video_TS folder, the Disc image was much larger than the original, did I do something wrong or is that suppose to happen?

Thanks Again.
P.S. I just read elsewhere on this forum about adjusting my settings and adding back an Audio_TS folder which my authoring program doesn't create any longer. This apparently will help elminate playback problems in some players. I didn't have the TAO closed and I didn't select UDF as part of the file system. Any feedback on this would be great too . I've had a horrible year with numerous playback issues which resulted in re-doing jobs and they still weren't perfect. I'm hoping that these changes will be what I'm looking for.

[rogun]

Here's my belated take:

I think images are larger because they contain additional data. I'm not sure if I can explain this very well, because I'm no expert on the topic, but some of the additional information is in the form of telling the burner how well to burn each of a particular segment of the disc. I forgot what these "segments" are called (weak and strong bits I think) and this isn't the correct way to put it, but I'm just trying to convey the idea here. As an example, I think that some copyright protection schemes use a method where particular segments have to be burned to a particular "quality" (not necessarily the best) in order for the disc to work.

Something relevant to this discussion that's worth mentioning is that when you create a direct disc image of the source disc, you're actually creating an image of how your drive reads the disc. So you're likely creating an image with both weak and strong bits, depending on how the disc was originally recorded and, I think, on the condition of the disc. The reason this is important is because a disc image may have more weak bits than the original disc and I think that even more are introduced when the image is burned to a disc. Thus, in this respect, it's better to create volumes than disc images because you'll get a better quality copy that doesn't include all the weak bits.

I'm not sure if that made any sense, and I hope someone will correct any mistakes I made, but I thought that I'd give it a try. I can tell you that I've run across disc images before that my burner could not create a working disc with, but I could get around this by extracting the data from the image and then burning to disc.

[redwudz]

rogun don't be afraid to post your 'take'. If others know better, then they can correct the info, and all of us are better for it. I know very little about why the size of disc images increase over the size of the original video.

[rogun]

Thanks redwudz. That's exactly the way I work, in hope that others will correct my mistakes and hopefully not criticize them.

To add to my previous comment, I think that a disc image will contain any errors that the drive used to create the image had while attempting to read the disc. Thus, scuff marks and scratches may have an affect on the quality of the image. I mention this because my previous comment was sort of murky.

Copying the volume to a hard drive first and then creating an image, however, will prevent any loss in quality. Of course there's probably no reason to create an image once the data is copied to a hard drive, unless you don't have the tools needed to burn the raw data in the desired disc format (e.g. DVD-Video.)

This is how I remember it working, but I do hope that someone will correct me if I'm wrong.