"-tmp" parameter of MP4Box needs 2 backslashes

Question

I'm on Windows 7 Ultimate SP1 x64, running MP4Box - GPAC version 0.7.2-DEV-rev357-g7115eeb8-master.

I've created a BAT file like this :

mp4box -add %1#trackID=1:name= -add %2#trackID=1:name= -tmp "%~dp1\" -new "%~n1_new.mp4"

which works fine, but before adding \ to %~dp1\ it gave the error :

Error - 2 input names specified, please check usage

Why does it need 2 backslashes to work ?

If it's important I just drag&drop the video and audio on the BAT file.

BTW, is %1#trackID=1:name= OK or I should change it to this "%~1#trackID=1:name=" ?

Answer 1

To fix this you can use batch variable substrings to replace the single back slash characters \ in the string value of the first argument with two backslash characters \\ in that string value instead. You can set another variable to have the new value and use it accordingly.

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Batch Script

@ECHO OFF
SET a=%~1
SET a=%a:\=\\%
SET dp=%~dp1
SET dp=%dp:\=\\%

mp4box -add %a%#trackID=1:name= -add %2#trackID=1:name= -tmp "%dp%" -new "%~n1_new.mp4"
::::mp4box -add %1#trackID=1:name= -add %2#trackID=1:name= -tmp "%dp%" -new "%~n1_new.mp4"

Note: The issue is likely the mp4box app expects full paths to use either double backslashes \\ or single forward slashes / due to the backslash character being an escape character it uses otherwise internally and thus using a single backslash it does not see the backslash literally.

You may be able to use to test if it also uses forward slashes as well as double backslashes.

SET a=%~1
SET a=%a:\=/%
SET dp=%~dp1
SET dp=%dp:\=/%

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Further Resources

• Variable Substrings
• Set
• Escape Character