Is there any way to select a custom filename for TMPGEnc4XP's output files, apart from the automatically generated name. Like "Save As" in other programs, where you simply type in the name you want

Yes, just type it in in the Encode stage where it says "Output file name". It's right below the preview area. You can also click on the "Browse..." button to select an output directory.

Ah, you must be talking about multiple file output. No, you can't set a file name for that; it'll be based on the clip name. There are some options for the naming if you go the preferences-->Output folder/file settings.

>Yes, just type it in in the Encode stage where it says "Output file name". It's right below the preview area. You can also click on the "Browse..." button to select an output directory.

It says "Output folder name" (not "Output file name").

So if the folder in the field is already say C:\XYZ and I amend it to
C:\XYZ\test.avi as test.avi is what I want the output filename to be, then when I press the Encode button it says:

"The file below will be outputted: C:XYZ\test.avi\[source name-of-file].avi

i.e. it takes test.avi to be a folder name

Too bad as I thought your answer met my requirement.

>Yes, just type it in in the Encode stage where it says "Output file name". It's right below the preview area. You can also click on the "Browse..." button to select an output directory.

Ah, I found you are correct if I changed Format, File output mode to "Output all clips into one file (or one set of files)" rather than what I had previously "Output each clip in a separate file (or separate set of files)"

I used the latter because I was always worried file would be overwritten, but I see that if "Output all clips into one file (or one set of files)" is used, a warning is issued to avoid this.