Thanks John, but none of those around to confuse matters.

(I wrote a longish reply, describing several other odd symptoms, including the inability to delete MapCircleDkGrnLrg.wmv without the "computer's administrator's permission"! But my post has vanished and I really must get on and do some productive work!)

I think all of this stems from the fact that Overwrite doesn't work in MEPP 2016, or works inconsistently. After using it (with no rendering apparent) the file remains in File Explorer, but cannot be accessed. If MEP is closed, the file disappears, showing that it was deleted insted of over-written.

Hopefully this doesn't arise in MEPP 2017?

Hi Terry

MEP (all versions), and many other programs, normal behaviour is to lock a loaded file, for exclusive use, against possible changes if opened in more than one program.

There are exceptions, eg Paintshop Pro, which loads a copy of the file and does not lock the original.

I have had no issues with over writing exports, which are not loaded in MEP

HTH

John EB

Hi John,

I'm not sure I follow. Surely you don't mean that it's normal for MEP's export Overwrite to give the result I described?

Hi Terry

. . . . I think all of this stems from the fact that Overwrite doesn't work in MEPP 2016, or works inconsistently. After using it (with no rendering apparent) the file remains in File Explorer, but cannot be accessed. If MEP is closed, the file disappears, showing that it was deleted insted of over-written. . . . .

Having re-read this several times I am not so sure as to the sequence of events you are describing - I interpreted it as you exported a video, viewed the video, in for example Windows Media Player, and found an error, went back to MEP and corrected the error and then tried to export again.

Is this correct and did you close Windows Media player before going back to MEP?

John EB

Hi John,

MXV or AVI files
1. Open any MXV file in MEP 2016. It plays OK on timeline. Edit it.
2. Export with same name. Message asks Overwite? Confirm.
3. Message "Cannot delete the file. Please check whether the file is still in use or enter a different file name."
4. Cannot proceed without saving a second file with a new name.

WMV files
1. Open any WMV file in MEP 2016. It plays OK on timeline. Edit it.
2. Export with same name. Message asks Overwite? Confirm.
3. No message. No activity or progress bar.
4. In File Explorer try to play the WMV in any player, such as MPC HC. Message 'No file found'. Or in WMP 'Windows Media Player cannot access the file...'.
5. In MEP, the file now plays a black screen.
6. Not surprising, because after MEP is closed the file is no longer in its folder. (Have to restore from backup.)

MPG files
1. Open any MPG file in MEP 2016. It plays OK on timeline. Edit it.
2. Export with same name. No message about file already existing!
3. But exports the edit correctly, giving it a new name, not overwriting.

MP4 files
1. Open any MP4 file in MEP 2016. It plays OK on timeline. Edit it.
2. Export with same name. Message asks Overwite? Confirm.
3. Exports correctly. (The only one that behaves exactly as I'd expect from an 'overwrite'.)

'Overwite' plainly doesn't work consistently or reliably here! Yet OK for you?

Terry, East Grinstead, UK

Hi Terry

MXV/AVI - I get the 'File exists' and 'Cannot delete file' messages

WMV files

I get the same as you (and in MEP 2017) - this would appear to be a bug - could be a timing issue where on shut down it releases the file, then completes the delete action, instead of showing the cannot delete file dialog as soon as it attempts to render.

MPG files - I get the 'File exists' and 'Cannot delete file' messages

MP4 files - I get the 'File exists' and 'Cannot delete file' messages

With the exception of the WMV file, the behaviour I get for the formats listed is the correct behaviour - MEP has already locked the appropriate file, so it cannot be overwritten.

HTH

John EB

Hi John,

Thanks for taking the time to test those.

Are your results all for MEP 2016? If so then it's very puzzling that you get such different behaviour to me for MPG and MP4.

For MXV and AVI (and WMV if that was bug-free) I still don't agree that it can be 'correct' for MEP to offer to overwrite files if it is incapable of doing so. IMO all those file types (and others we've not tested) should behave like they do for me with MP4. Namely, overwrite the file!

That's how resaving and overwriting is handled in all my major applications. You get a warning that a file of that name already exists and if you agree to overwrite it that's what happens.

Hi Terry

Results are for MEP 2016 and MEP 2017.

It is possible that the 'Cannot delete' dialog is hidden for MPG and MP4 - try Alt + Tab to cycle through the active applications to see if it is there.

. . . .That's how resaving and overwriting is handled in all my major applications.. . . . .

That is true for programs such as Word, Excel, PSP etc. However the difference is these programs are loading a copy of the file into memory.

MEP and many other video editing programs, do not load the video into memory, the object on the timeline is a reference object to that file, and contains many 'hooks' into different locations within that file so you can jump/scrub from one section to the other quickly - without this you would have to move through the displayed file linearly starting from the beginning of that video or audio file every time.

The means the file must be locked to prevent changes that make those reference 'hooks' are invalid. Sometime you get a message stating that the references are invalid/different when loading some files.

. . . . I still don't agree that it can be 'correct' for MEP to offer to overwrite files if it is incapable of doing so. . . .

That is because Windows actually handles all the file container creation/renaming/deleting not MEP and is how Windows handles saving files - the MEP / Windows conversation would be something like this:

MEP - I want to save this file, here is the file name.

Windows - that file exists, what do you want to do?

MEP - I will ask the user if they want to overwrite it.

MEP - the user wants to overwrite the file.

Windows - I cannot delete that file it is locked.

MEP - OK I will tell the user.

Apologies if this seems a little simplistic or childish, however it is the best way to demonstrate a very complex set of transactions between a program and Windows.

HTH

John EB

Hi John,

Thanks, understood!

Just re-tested the other two.

MPG: No hidden messages, but I found the reason. My original was a randomly chosen 15 s clip called crab1.mpeg. I didn't notice the extension - the only one of about 50 in that \Misc MP4s folder! The exported file (edited by simply reducing its duration to 4 s) was mpg. My bad! With an mpg extension I get same as you: the rather frustrating but now understood behaviour due to the locking you describe.

MP4: I couldn't reproduce my result of last night. But I suspect it may be somehow connected to a combination of these factors (with the target export the only object present):
- Whether 'Export selected range only' is enabled
- Whether a (blue) range is over the object
- Whether square brackets are displayed, and their poosition. (First time I've focused on this and realised I don't know their purpose!)
IOW I think perhaps the edit I made (a simple trim) was not recognised by MEP, due to one or more of those settings, and so the file was regarded as unchanged. But I couldn't find a combination that gave me that result again. And Saturday husbandly chores now intervene...

Anyway, an interesting exercise. Thanks for your patience in exploring it with me. Looks like it kept you up late last night, for which my apologies!

Have a good weekend 😉

Terry, East Grinstead, UK