Reported media free space discrepancies under varying conditions

[discuser]

I very recently attempted to prepare a disc layout for a BD-RE-TL 100GB disc and was attempting to squeeze as many files as possible into the available formatted free space of approximately 94 GB (which may vary up or down slightly depending on whether spare sector areas are enabled and what size spare sectors were specified during disc formatting). It was noticed that there are discrepancies reported in different areas of Imgburn under varying conditions, as follows:

1. When there was NO formatted BD-RE media inserted, and the disc layout editor was used to produce a draft disc layout and the disc space consumption bar was monitored (disc type next to disc space consumption bar was manually set to BD-RE-TL in this case in the disc layout editor) when files were dropped into the layout, I added files so that it was within 1% to 2% of maximum disc space, i.e. disc consumption was 98% to 99%. After closing disc layout editor, and returning to the INFORMATION tab of Imgburn, clicking the CALCULATOR button resulted in a disc consumption result of 99% (which was correctly rounded up from 98%+ shown in the disc layout editor).

2. However, when the BD-RE-TL media was inserted into the BD writer and the relevant BD writer drive was selected in Imgburn, and the INFORMATION tab CALCULATOR button was clicked again, the INFORMATION tab now showed that the disc space consumption was BEYOND actual available free disc space on the blank but formatted media (with spare sectors enabled in preferred mode) and the information tab showed the consumption at 102% and free disc space was NEGATIVE 2 GB, both figures highlighted in red.


At first I thought these discrepancies might be a bug, but then realized that the probable reason this occured is that after formatted blank media with enabled spare sectors was inserted, the effective free disc space was reduced from the initial calculation due to disc space reservation / consumption by spare sectors areas.

Is this what is happening?

This is the only immediately obvious logical explanation I could surmise. If this is correct, then I would need to remove some files from the disc layout to meet the reduced free space available on disc. If this is not the reason for the reduction in available free disc space calculation, then this may be a bug or due to other factors.

If the reason for the available disc space discrepancy is as surmised, then I would suggest that the disc layout editor's DISC SPACE CONSUMPTION BAR PERCENTAGE also take into account the same factors that affect available free disc space. Because currently, I have observed that while the INFORMATION tab calculation takes into account actual available disc space after formatted media is inserted, the disc layout editor available free space percentage does not re-adjust to reflect this and thus there's a major discrepancy between the free space percentage reported in the disc space editor and the information tab calculation, by as much as 4%. In the above example, the disc layout editor's disc space consumption bar is a little over 98% but the information tab reports it as 102%. Thus a free disc space discrepancy of nearly 4% in this particular example.

I also noticed that when the AUTO box is ticked in the INFORMATION tab, and another ODD is selected which may not have any media inserted, the disc space consumption is not updated to reflect this, even though I do understand that the AUTO box is for auto updates of disc space consumption after disc layout editor is closed rather than when the selected ODD drive is changed, but this may be a point of enhancement worth considering for a future release to maintain constantly correct calculation relative to the currently selected drive and whether it has writable media inserted where the effective available free disc space could be determined by Imgburn that could be used to update disc space consumption / free space available values.
 

Edited May 27, 2018 by discuser

[LIGHTNING UK!]

The % usage in the DLE window is an approx value based on file sizes alone and it doesn't look at the drive or media in it at all. It's based on hard-coded disc sizes, none of which include adjustments for the inclusion of spare areas - which of course are variable.

 

The 'Calculate' feature back on the main window is the accurate one - taking into account all of the options, file system overhead, padding etc. It'll use the available/free space from the inserted disc when it can, but will not (as you've noticed yourself) update the calculated value if you eject/reinsert discs or change drives (even with the 'auto' option ticked).

[discuser]

Thanks for confirmation of program behaviour. Your description confirms my suspicion, that the disc layout editor is just using a generic media capacity value based on the currently selected media type on the pull down menu to the right of the disc space consumption bar. I was hoping the disc consumption calculation in the disc layout editor would reflect the actual remaining free space based on media inserted, as this would now mean that when I try to pack a disc as close to maximum capacity as possible, I will have to go into the layout editor, play with adding or deleting a number of files and each time changing the file layout slightly, to go back outside to the calculator panel on the information tab to recalculate. But at least I know for sure this is the expected behaviour of the software at this time.

Otherwise, my very long write and verify session to the BD-RE-TL media worked normally and in general Imgburn works very well with this media even though this BD-RE capacity wasn't readily available for testing back at the time this version of the software was released. The write-with-verify session took about 6 3/4 hours and the separate verify against source file portion took around 2 1/2 to 3 hours, which means a full 90 GB (formatted capacity with spare sectors enabled) packed BD-RE-TL disc can take nearly 10 hours to fully complete write and verification.

I noticed there's an AUTOMATIC TARGET MEDIA tick box next to the layout editor's disc space consumption bar's media type menu. When that box is ticked, does this mean that the software will detect the type of disc inserted and at least select the correct media type, even if not taking into account the actual effective available space on the particular media inserted? Or does this just mean the media type required to accommodate the disc space consumption will be automatically adjusted by the software so to inform the user what media type / capacity to use?
 

[Ch3vr0n]

It can reflect actual free space. You just need to do the opposite of what you're doing. You're adding files first, then insert a blank. Insert a blank FIRST and THEN add your files. That way the auto calculate will use the proper free space provided by the inserted disc

 

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[discuser]

It can reflect actual free space. You just need to do the opposite of what you're doing. You're adding files first, then insert a blank. Insert a blank FIRST and THEN add your files. That way the auto calculate will use the proper free space provided by the inserted disc

 

Yes, I do normally insert blank formatted media first before using the disc layout editor. But as L-UK says, the disc layout editor (DLE) calculation is only an approximation even with inserted media, whereas the information panel calculation is the exact correct value. So if I'm using the DLE then I still have to flip back to the information tab to get the exact updated result. I don't always have the information tab AUTO box ticked because the auto calculation can generates one or more prompts depending on the files added to the DLE. So I'm currently using the information tab calculator only manually. As for my reply above, I was asking L-UK about the AUTO box in the DLE (to the right of the disc consumption bar).

[LIGHTNING UK!]

The checkbox in the DLE window just adjusts the value of the drop down box based on the total size of the files you've added. It is not related to the media that may or may not be inserted at the time.