Emulator

The way you worded it, it sounds like you're meaning that you're putting an ACTUAL Wii/Gamecube disc in your drive and trying to boot it. Dolphin doesn't work that way.

Is this what you're trying to do?

About disk - yes...
But what then option "Boot from DVD drive" does?

And what about starting *.dol?

You can only boot games off of backup discs in a DVD drive due to how the Wii/GC can't be read in conventional disc drives. So that part of the issue report is just invalid.

I'm not sure about the *.dol, but the "Boot from DVD drive", as far as I understand, is for booting a disc image that has been burnt to a DVD.

What is backups? Is this some special format or simple iso burned to DVD?

By the way, the screen I showed is from attempt to load *.dol

A backup disc is simply an ISO image burned to a DVD-R. You have to use a "burn image" option in DVD burning software for this, instead of just placing the ISO as a file on the disc.

As for the DOL files, are you trying to load software that typically is distributed as DOL (some sort of homebrew), or are you extracting a .dol file from a commercial game?

Just tested burning ISO to DVD disk.
The ISO itself working (it's Skies of Arcadia Legends CG game), but when burned to DVD disk with use of ImgBurn, Dolphin can't load it. I really burn ISO, instead of placing ISO file on the disk.

About *.dol.
Again, let's say Skies of Arcadia legends. I extracted all files from the disk with use of Gamecube Rebuilder v1.0. I pointing Dolphin to load start.dol from the folder, where the disk extracted, but it hangs after rendering first frame.

Just for test, I also tried to load main.dol of extracted Fatal Frame 2 Wii Edition game.
Again hang after first frame.

I don't think Dolphin supports using a folder as a disc image. The game's code will be able to start, but Dolphin acts as if no disc is inserted, so the game can't load any of its data. You could probably get it to work if you set the game's ISO as the Default ISO, but there's not much point in booting from a DOL when you have to keep the ISO around anyway. Dolphin's option for loading DOL files is probably just intended for running homebrew.

I'm not sure what the problem is with reading from a DVD.

Ugh, this is very bad that Dolphin can't run extracted games.
I am translating the game and must rebuild it every time I want to test something.
That's why I though it can run dol directly, so I no need to rebuild it.

Okay, I took a look at the code, and there's a file called VolumeDirectory that looks like it might be intended for this purpose. (I don't know why it's a Volume instead of a BlobReader, though.) It looks like this code isn't being called from anywhere, and it doesn't even support necessary functionality like raw reads... Does any of the devs know what's up with this?

Can you make a new issue report that is a feature request for folders as disc images? It would be good to keep it separated from the issue with reading physical DVDs.

Ehm, I can do that, but are you sure this is different issues?
I just though it is same kind of issue, since Dolphin hangs in a same way with folders and physical dvds.

Apologies, the VolumeDirectory code is actually in use. Try going into Config > Paths and setting DVD Root to the folder you're using, then load the DOL.

Umm, same hang.
I think you can test it by yourself, or no?
Dolphin can extract files from ISO.

Okay, I've tried it now. I have to say that this feature kinda sucks in user-friendliness, but it does work. I managed to view the intro of Zelda: Twilight Princess (GC). After extracting an ISO using GameCube Rebuilder, set Dolphin's DVD Root to the root folder, set Dolphin's Apploader to the AppLoader.ldr file in &&systemdata, then finally run the DOL (I did it by dragging it into the Dolphin window). And once again, sorry for not looking this up before trying to give instructions.

I found some weird behavior when trying to load a 0 bytes large DOL, but that's not really related to this issue.

I believe you can boot from a retail GC/Wii disc ONLY on certain DVD drives (it has to do with the drive having extra instructions to read the raw data off the disc or something like that). There should be a forum discussion with a list of working drives.

JosJuice, thank you, now I can test the game that I translating much faster :P

This really started to work..., and this really not easy to guess.
I don't even know why this made in so weird way.

Maybe worth to remake this feature or if it used for something, then make another menu item like "Start game from folder" and then it automagically determines all needed files to run the game.

Regarding DVD booting, I still don't understand. Developers say that I can boot only backups, other ppls say that retail disks on certain DVD drives.
Well, anyway I can't boot backups.

To clarify, you can play retail discs (I'm not sure about backups) or dump them with one of these drives: http://bit.ly/1wSIkb8.

I don't think Dolphin can run retail discs even if you have a drive like that.

Under the "File" menu, there's an option that says "Boot from DVD Drive" with a dropdown to pick a drive to boot from. Is that for something other than booting with a supported drive?

Yes, it's for booting backups using any DVD drive.

sirwinstoncat5: the feature is only for backups, retail discs can not be played directly from ANY drive

Kinda weird I must say. I tried to start the game from virtual DVD drive with loaded ISO and it's worked.
It were exactly same ISO that I burned to DVD-R and Dolphin were unable to start the game from that real disk.
But if think that image were incorrectly burned... - no. I created another ISO from that real DVD-R disk and Dolphin were able to run it.

Maybe we should just remove the feature? I remember people testing it a few months ago and it still working with backups.

Why would we want to remove this feature?

I have a few reasons.

1: We don't know if it works.
2: It only works from backup discs.
3: Many games crash/stutter due to how Dolphin isn't designed to load from an actual disc drive

1: Then we should check if it works, and fix it if necessary.
2: So what? Some people use backup discs to play games, even on real consoles.
3: It's true that there are performance problems. I'm planning on addressing those by moving disc reads off of the CPU thread, but that's very unlikely to be done before 5.0. I don't know anything about there being crashes.

No one has DVD-RW and spare disk to check this?

it does work. it just is pitifully slow with the current master.

it used to be a slow initial start and then ok after that.

metafalica@gmx.com you are either not waiting long enough, or burning the disc wrong, although at this point I wouldn't suggest bothering with it unless it gets much faster

I waited for 3 minutes in the very first attempt to load game from dvd and considered is as hang.
Later I always waited for around 10 seconds.
Should I wait more?

Well, I didn't use Boot from DVD drive feature for a while but I can confirm it worked without any major issues (despite being a little slow) in 3.0-xxx era. All backup discs I had worked normally...

Can you test it with newest versions?
How do you burn the ISO? I used ImgBurn for that.

Both ImgBurn and Windows 7 built-in image burner worked fine. I'll test with a DVD-RW I have and report soon...

Did a quick test and Boot from DVD drive still works the same way as I remember in 3.0-xxx era. I used a DVD+RW disc and tested with Donkey Kong Country Returns and Zelda Wind Waker, burned DKCR with ImgBurn and ZWW with Windows 8 built-in ISO burner utility and it worked fine in 4.0-4980 (clean build, except for the save files that I imported).

The differences I noticed between booting from disc drive and booting directly from ISO was a little long boot time (around 5-10 seconds more), a little long loading time (when transitioning between rooms or approaching into islands in ZWW and in the loading screens between the levels in DKCR) and some random stutters here and there, mostly in loading screens or when starting cutscenes.

Sometimes the disc drive stops spinning and when the game tries to load something while the drive is stopped it'll freeze for about 5-10 seconds (it varies, generally until the drive starts spinning again) but after that the game unfreezes and continue working fine.

In fact, I feel the performance improved at least a little when compared to 3.0-xxx era, where random crashes were common while running games from disc drive...

Thank you for testing this.
Meh, I don't know what's up. For me Dolphin simply enters into infinite loading.
The green diode on the drive flashes like reading still happens, but after some time disk stops spinning (sound of spinning gone), but the diode still stays green forever.

I have Optiarc DVR RW AD-5260S

Tested with a Lite-On DH-20A4P and with a hp BD CMB UJ160 (which is just a rebranded Matshita UJ160), both worked fine (although I felt the loading times longer in the Matshita drive)...

This may be useful for JosJuice: loading games from Folder structure is broken since 4.0-4901 (when https://github.com/dolphin-emu/dolphin/pull/1776 got merged). In 4.0-4898 and older, I could successfully boot most games from a folder by extracting all files and .dol and then correctly pointing to DVD Root and App Loader in Config => Path. Then, opening boot.dol would start the game from the extracted files and it worked with most of them (unless if their folder structure had paths that didn't comply with 8.3 format -- Luigi's Mansion, for example)

In 4.0-4901 and newer, Dolphin instantly crashes when you load boot.dol while using DVD Root feature ("Dolphin has stopped working)...

Does the .dol crash happen with GC games, Wii games, or both?

Both

Thanks. This PR fixes it: https://github.com/dolphin-emu/dolphin/pull/1860