List MP4 by " file '*.mp4' " to a .txt

I'm not sure I understand the goal right, but if you want every line to read

file '/full/path/to/filename.mp4'

I suggest to use find this way:

find ~+ -type f -name "*.mp4" -printf "file\t'%p'\n"

This searches the current working directory (~+ is expanded to the full path by bash's Tilde Expansion) for files whose name matches *.mp4 and prints them in the specified format: "file" followed by a tab and the filename enclosed in single quotes followed by a newline character – if you want a space instead of the tab, simply substitute \t by a space. If you want to store the output in a file files.txt, just add >files.txt to the command line. Note that this will silently overwrite any existing files.txt, if you want to append to the file use >>files.txt instead.

Example output

$ find ~+ -type f -name "*.mp4" -printf "file\t'%p'\n"
file    '/home/dessert/test/a.mp4'
file    '/home/dessert/test/b.mp4'
$ find ~+ -type f -name "*.mp4" -printf "file\t'%p'\n" >files.txt
$ cat files.txt 
file    '/home/dessert/test/a.mp4'
file    '/home/dessert/test/b.mp4'

If you however want files.txt to contain the output of file 'some.mp4', you can use file directly:

file *.mp4 >files.txt     # with relative paths
file ~+/*.mp4 >files.txt  # with absolute paths

You can use:

for i in ./*.mp4; do echo "file" \'$(realpath ${i#*\/})\' >> files.txt; done

If you don't need file in front of each filename, you can use:

ls path/to/files/*.mp4 > files.txt

Result from first command:

file '/home/george/Documents/askubuntu/disk_use.txt'
file '/home/george/Documents/askubuntu/efi_info.txt'
file '/home/george/Documents/askubuntu/empty.txt'
file '/home/george/Documents/askubuntu/fam.txt'

Note:

• I used .txt files, yours will .mp4.
• This is run from the folder of interest, if you need to target another please change the line for i in ./*.mp4 tp for i in /path/to/files/*.mp4`.