Bluray shrink/compress to 23GB?? not real 25GB

[Little fruit fly]

Hi Developers, it has been a while I bug you again. :-)

I notice that there is some space at the outer tracks after burn the bluray disc, close to a few GB, even though I select 25GB as the destination size. What I afraid is that even though it says 25GB like SSD out there that is selling for 480GB but it is really 443GB capacity.

Is there an option to do real 25GB from DVDFAB? So we don't have to waste disc space and compress too much.


Your comrade from MW. :-)

[LaciBacsi]

The disparity comes from converting from decimal to binary, or visa-versa. For example, 1 kilobit decimal is actually 1,024 kilobits in binary. With that said, I believe DVDFab is trying to be conservative and create a total file/folder size that would not burn to the very edge of the writeable area of the disc as a default, since this area is most prone to even minor damage (nicks, scratches, etc.) and thus possible future read errors. The default output size of 23,000 MB may be conservative, but is a safe estimate. You can, however, change this manually yourself, up to the max size of 26,252 MB, under "Common Settings>Drives>Blu-ray Write". Depending on the quality of your media and/or burner and/or standalone player, it may or may not work well for you; but honestly, I would use caution and stick with the default size.

[Little fruit fly]

Thanks, I think DVDFab is conservative. So if I change the setting under "Common Settings>Drives>Blu-ray Write", DVDFab would create the iso or folder size specified?

[LaciBacsi]

Or close to it. You will not likely hit the exact size due to the fact that, as in DVD GOP's (Group Of Pictures), I assume Blu-ray has similar groupings that fall on specific boundaries and thus exact selected target size may likely not be achieved. There have been a few occasions where for some odd reason or another, the resulting size was much smaller than what I anticipated (like 88% capacity of a BD-R, rather than the usual 95-96% when using the default output size) and had to experiment around by increasing target size until I got around the 23,000 MB default output size.

I believe in part this also has to do with how the original combined video/audio stream is encoded as well as DVDFab's compression algorithm.

Honestly, you will likely not see a difference in video quality (at least I didn't) by increasing output size to the MAX size from default size, but risk creating an output size that will write very close, or up to the outer capacity boundary, which is not recommended for the reasons stated above. If you do decide to do that, I would recommend using a slower write speed than is recommended for you particular burner/media combination and be sure you have verify turned on. In my own experimentation I have found that the media quality at the very edge of the disc may not be optimal on all discs, even across the same brand and model. Best thing to do is experiment around like I did until you find a combination that works best for your current setup. Worse case, you may end up with a nice set of coasters you can set out when entertaining special company, lol. Staying with default might also help to future-proof your backups since not all players are the same, and some have problems reading at the very edge of a disk, as I have learned first-hand, and you may likely be changing payers at some point in the future. This is even more apparent with dual layer media, but I wont even begin to get into that here . Remember too that DVDFab is likely trying to fit a variably different combination of media, burners and players, so conservative is probably the best way to go for them. Users can then experiment on their own if they want to deviate. Good luck!