Changing output file name in a batch file

Question

Sorry, the title isn't very descriptive, but I couldn't think of a better one.

I use this script to drag and drop video + audio file, and combine them with ffmpeg.

ffmpeg -i "%~1" -i "%~2" -c copy "C:\New Folder\%~n1".mp4

It works great, but the input, and subsequently output files have ".raw" ending before the extension. Is there an easy way remove the last 4 characters of %~n1 or replace ".raw" with ""? I want to manipulate the string before assigning it as file name with ffmpeg, I don't want to output the file with .raw.mp4 ending, and then rename it.

Answer 1

Is there an easy way remove the last 4 characters of %~n1?

You need to use the substring operator. Try the following cmd script:

@echo off
rem avoid polluting global environment space
setlocal
set "_file=%~n1"
rem strip last 4 characters from _file
set "_name=%_file~0,-4%"
rem run ffmpeg with new name
ffmpeg -i "%~1" -i "%~2" -c copy "C:\New Folder\%_name%".mp4
endlocal

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Further Reading

• An A-Z Index of the Windows CMD command line | SS64.com
• Windows CMD Commands (categorized) - Windows CMD - SS64.com
• Endlocal - Local environment variables - Windows CMD - SS64.com
• Setlocal - Local variables - Windows CMD - SS64.com
• variable substring - Windows CMD - SS64.com

Answer 2

Here's the answer that works

set filename=%~n1
set filename=%filename:.raw=%
ffmpeg -i "%~1" -i "%~2" -c copy "%filename%.mp4"
pause