Edit: This post (not necessarily the topic) is now out of date. Update to the latest beta build of ScummVM (or ScummVM v3.0 when it releases) to enjoy various work-arounds to bugs within the original game.

The DVD version of the game (including the version currently provided by GOG) currently has problems playing correctly in ScummVM v2.0. It is recommended that you play the CD-ROM version of the game with ScummVM v2.0 until the DVD compatibility issues have been sorted out with ScummVM.

I'm going to help the ScummVM teams identify compatibility issues with the DVD version (specifically the version provided by GOG) and report them on their bug tracker website. There's already been a confirmed DVD compatibility issue early in to the game.

Edit:

It seems like this may be caused by a conflict between the CD-ROM and DVD versions of the game or a conflict between ScummVM and ZEngine files.

When GOG upgraded the game from the CD-ROM version which used ZEngine, to the DVD version that was bundled with ScummVM... the ZEngine files (and whatever other redundant files) aren't removed from the installation directory. The files that were made redundant seemingly aren't removed from the installation directory when performing a uninstall via GOG Galaxy, too.

I updated the game from the CD-ROM version to the DVD version via GOG Galaxy.

Uninstalling the game, manually deleting the installation folder and then installing the game again has seemingly fixed the soft-lock issue.

I Tried the gog version with the scummvm bundled version and there are no apparent problems found. the game runs fine

I tried the game with the nightly build version from scummvm and it runs fine as well. what I do not know is if the dvd mpeg movies are active or not with this version.

There are some scripting bugs that have been mentioned in other threads. The nightly version of ScummVM has some additional workarounds, compared to the stable version (which is what I guess GOG uses), but I wouldn't be surprised if there are other such bugs lurking around. (I assume that means they happened with the original interpreter as well.)

The nightly version can support the DVD movies, but it depends on an external library for sound decoding. I don't know if the nightly versions include that. I'm using Linux myself, which makes it a bit hard to test. The sound volume for them is still a bit low, but other than that they seem to work pretty well. I have to tell ScummVM to either stretch the rest of the game to the higher resolution, or add black borders to it. Both options have pros and cons...

I have noticed that the mpeg option on/off can be enabled in game but The movies look the same apparently, so I have doubts about the functioning, and I guessed that the movies revert back to CD even with mpeg enabled because the sound does work and the movies do play. but I have no idea.

Is the external library needed to be added in folder? If so, where can it be downloaded?

Greetings

No, it's a compile-time option rather than a run-time option. Though I was under the impression that at least tthe Windows "Daily Build" included support for it. It says on the ScummVM downloads page that "They are generated by our buildbot", and looking at the log files from the configuration stage for them, both the 32- and 64-bit versions have these lines:

Checking for libmpeg2 >= 0.4.0... yes
Checking for liba52... yes

Which I think is all that should be needed for the video playback. (The video decoding is done by libmpeg2, and the audio decoding by liba52.)

ScummVM should display a list of compile-time features (MP3, FreeType2, etc.) as part of the "About..." credits. But I forgot to add one for A/52 until a few minutes ago. In future builds, you should be able to check for both "MPEG2" and "A/52" in the "Features compiled in" section near the top.

I am pretty sureit is like you are saying.
Probably the mpeg movies are working fine and It is only a matter of choosing the ideal resolution or renderer from my side to have the game good looking.

Thanks for the info an greetings.

I'm not sure sure now, actually. I downloaded the GOG versinn of the game, and replaced scummvm.exe with one from the nightly build. Then I ran it in Wine (since I use Linux, not Windows), and I didn't get the high-resolution movies. If I used the Linux version of ScummVM that I've compiled myself, I did get high-resolution movies with GOG's data files.

So I guess something is missing from the nightly build after all?

One way to tell if it's playing the high-resolution movies is that instead of one logo animation before the game's main menu screen, there are three: One for Dolby Digital, one for Activision (similar to the standard resolution version), and one for Enterprise.

Ok Then, no mpeg movies at all because no dolby logo plays at launch. Running Windows version of ScummVM.

EDIT: The folder structure I use is the GOG one. Maybe the movies should be in a different folder or name?

The nightly build does not seem to include the A/52 library. I am using the win32 version.

I downloaded the latest build and had to edit "create_project.cpp" to enable Mpeg2 and I also had to add an entry for the "A/52" library:
{ "mpeg2", "USE_MPEG2", "libmpeg2", true, "MPEG-2 support" },
{ "a52", "USE_A52", "liba52", true, "A52 decoding support" },

Since the "liba52" library is not available in the SCUMMVM_LIBS, I grabbed it from KODI. They seem to be using a slightly different version so I had to edit "ac3.cpp" to pass the correct parameters.

I complied ScummVM and now it shows the "A/52" feature. I ran ZGI and I was able to enable MPEG movies from the in-game Prefs. The game now plays the .vob (DVD) files fine.

Do you know where to get the proper windows "A/52" library from?

FYI: If you don't see both MPEG2 and A/52 in compiled features (About ScummVM) then the DVD files will not play in ZGI.

I'm afraid I don't. The Linux library was already packaged for the distribution I use, and all I know apart from that is that the project home page is apparently at http://liba52.sourceforge.net/

By the way, the reply I got when I asked around if the Windows daily build of ScummVM supports the high-resolution movies was that "looks like the daily builds (from buildbot) have liba52, but the daily snapshots (from kirben) don't".

Thank you for adding "A/52" to the About features display!

I just checked the Windows (32 bit) "development build" (from the ScummVM Buildbot nightly builds) and it does include the "A/52" library. The Windows (32 bit) "stable build" does not.

The "development build" plays the ZGI DVD .vobs fine. If someone is still having issues then they should check if they have "Use high resolution MPEG video" checked on the ScummVM Edit Game->Engine tab and the MPEG switch set to on in the ZGI Preferences.

How do you play the GOG version with a newer version of ScummVM? I tried just replacing GOG's ScummVM files with the latest dev build, and it didn't work (I would've been surprised if it did).

EDIT: I figured out how to add it in the latest dev build, but ScummVM just crashes when trying to open it.

Bit of a late reply, but I finally figured this out: you need the Windows (32 bit) version. The 64-bit version crashes on startup.

Note that you can just download the "Windows 32-bit latest development build" from this page and take scummvm.exe from inside that, and drop it into the Zork Grand Inquisitor/scummvm directory (making a backup of scummvm.exe that's already there), and then it will run fine, even if you launch from GOG Galaxy.

Also, unfortunately it seems all the MPEG videos in ZGI are interlaced so they actually look quite awful in-game. If you play them in VLC, it automatically applies a deinterlace filter which looks quite nice. It would be great if ScummVM applied the same filter, but I don't think the library they are using (libmpeg) supports that.

I wrote a lengthy post about the details of getting this working over on the ScummVM forums. For people above talking about compiling from source and liba52, I figured out how to build that too (instructions are in the post). Took a bloody long time.

Hopefully some day soon, GOG will include an updated version of SVM with ZGI so this "just works". (Though there haven't been any stable builds made since this all got working -- the latest stable build was from January 2019 and the latest release build is from 2017. If I were GOG, I'd at least wait until a new stable build comes along.)

Hi there,

Recently, a few ScummVM developers looked into the cause of this bug for the 64bit ScummVM version.

The bug was caused by the mpeg2 decoding library, (libmpeg2) which we statically link into the ScummVM binary. It was mainly due to the original source code for that library being... well old and needing some minor touches to prevent the segmentation fault / crash.

Newer ScummVM developer Windows builds (2.3.0git) should no longer have this issue.

The fix will be part of the next stable ScummVM release (2.3.0) -- although there is no ETA for that as of yet.