When I try to view these files, the viewer starts but either switches to some form of HEX view or finally DOpus will GPF. I believe it's a plug-in problem or quicktime install problem, but I have tried re-installing QT various versions. Stuck, any ideas?
You need to make sure that Windows Media Player is able to play the files. Once that is working then Opus should also be able to play them in almost all cases.
I believe the FFDShow codec can decode MPEG4 movies within Windows Media Player and Opus, and without the need for QuickTime. (Installing both should also be fine, which is what I've done, and I'm able to play a .mp4 video in the Opus viewer without problems.)
Oh yeah, in terms of QuickTime .mov files, they work in Opus for some people but not for others. We haven't worked out a definitive way to get them to work but it is possible and it works for some people (inc. me) without doing anything special.
If you do a forum search on "mov" you'll find 3 other threads on mov playback which have some ideas. If you find anything useful please add it here or to one of the threads and if we get a definitive answer we'll write it up as a FAQ.
The long and the short of it is you have to get mov playback working in Windows Media Player. It might be worth asking for help on one of the forums dedicated to video encoding/playback/conversion where people know more than anyone here is likely to as we're just guessing really 
. If you find some good info let us know!
I've just had a look at which DLLs are loaded by dopus.exe when I play a QuickTime .mov file and one caught my eye:
QuickTime(tm) Decoder Wrapper from Nero AG
It's possible that Nero installs this wrapper to enable it (and Windows Media Player and Opus and other programs which use DirectShow) to decode QuickTime files.
This isn't definitely the answer since there are a lot of other DLLs loaded, including all the QuickTime components (some of which were optional installs), FFDShow and some other video codecs, but it's definitely worth checking out...
Is anyone with Nero installed not able to play QuickTime files in the Opus viewer pane?
I've got Nero 6 for what that's worth.
I've attached the complete list of DLLs loaded as a result of playing the movie.
(It's a shame Apple couldn't just write a video codec for Windows instead of inflicting their awful player/GUI on us and making it difficult to display QT in other programs... Sigh.)
opus-quicktime-dlls.zip (986 Bytes)
[quote="nudel"]...Is anyone with Nero installed not able to play QuickTime files in the Opus viewer pane?...(It's a shame Apple couldn't just write a video codec for Windows instead of inflicting their awful player/GUI on us and making it difficult to display QT in other programs... Sigh.)[/quote]Hello Leo...
For what it's worth, I do NOT have Nero loaded, I am using QuickTime Alternative instead of the genuine QuickTime, and I DO have ffdshow installed. I CANNOT play either .MOV or .MP4 in either the Dopus viewer or the Windows Media Player.
Both work flawlessly, however, in Media Player Classic, the freebie which comes with QT Alternative. I needed to install ffdshow to get MP4s working.
I'd like to be able to use DOpus viewer for them, but I am not prepared to pay the price of loading the genuine QuickTime, which I suspect may somehow be the reason for your success. I have compared your list of QT DLLs with those on my hard drive, and the QT specific ones are all there, courtesy of QT Alternative.
I am not sure if any of the above contributes anything to solving the puzzle.
Odd that the FFDShow stuff isn't working in the Opus viewer pane. Has the Movie plugin become disabled or something? Maybe it doesn't support .mp4 or something else is trying (but failing) to handle it because Opus is trying codecs in a different order... I don't really know enough about how movie playback works to say but it is strange for something to work in MPC but not in Opus. (I have seen it happen a couple of times, though, so there are (small?) differences for sure but I don't know what they are.)
It'd be so cool if Media Player Classic were available as a DLL to plug into other programs. It's a great media player.
If you add the .mp4 extension to the ActiveX plugin you may get Windows Media Player to play MP4 movies in the viewer pane. Not as nice as the Opus movie plugin but better than nothing, if it works.
What price? 
You've already got a copy of most of QuickTime installed via QTA. The only price is having to configure a couple of things (turn off the tray icon, maybe change some filetype or MIME associations back) after installing the official QuickTime. But then you don't have to worry about not having the latest version or having something broken by whatever corners QTA cuts, or not being able to install iTunes (okay that's probably not a bad thing unless you've got an iPod ). Plus you're then not running an unlicenced version of QuickTime Pro.
(Although Apple are gits for asking people to pay money for such amazing features as Save-As and full-screen movie playback and for not making their stupid movie format a codec so that we can choose which application we view it in rather than be forced, by the people who encode the video we want to watch, to use the diabolical app that is QuickTime for Windows... QuickTime Pro == WinRAR.)
Anyway, I'm off on a rant tangent here! 
I've got no love for QuickTime but I think QTA is vastly overrated.
All of that said , QTA may not be the cause of your problems. I don't like it because it claims to be an alternative when it's not (QTA is the QuickTime DLLs plus a directshow filter), not because it's ever caused a problem that I'm aware of.
(I think the 
emoticon 8) police may be knocking on my door after that post.)
Hello Leo...
So far QT Alternative has worked without a hitch for me, over a prolonged period, although now for the first time, I suspect your use of the genuine QT may be the reason why you can view .MOV and .MP4 movies in DOpus.
All other movie formats work fine in the DOpus movie viewer.
As you say, MPC is a small gem, although my use of it has diminished somewhat, since I added buttons for DOpus PLAY and SHOW to my main toolbar. It was the latter that alerted me to my inability to view the .MOV and .MP4 files using the SHOW command.
That said, movie playing has been a hit-and-miss arcane art, rather than a science for me. 
I shall experiment with adding the.MP4 extension to the ActiveX plugin and let you know how it goes.
[quote="bspeight"]As you say, MPC is a small gem, although my use of it has diminished somewhat, since I added buttons for DOpus PLAY and SHOW to my main toolbar. It was the latter that alerted me to my inability to view the .MOV and .MP4 files using the SHOW command.
That said, movie playing has been a hit-and-miss arcane art, rather than a science for me. I shall experiment with adding the.MP4 extension to the ActiveX plugin and let you know how it goes.[/quote]Hello Leo...
Just a quick note to say I did experiment with the ActiveX plugin with no joy.
Curiously, I tried both extensions on another PC, and DOpus SHOW worked fine for .MOV, but not for .MP4. QT Alternative and ffdshow in use there too. I think, for now, I shall just accept that this is one of life's little mysteries, which I am not meant to understand, and move on. 
MPC can fill the void for me.
Thanks for your suggestions.