I have a directory of .mxf files that I'm batch transcoding to .mp4. Some of the mxf's already have mp4 versions within the directory.

I want to check in bash that the mp4 version does not exist so the batch process will skip files that already have an mp4 version.

Psuedo code example:

for file.mxf in folder: do
  if file.mp4 != exist
    $ffmpeg_command
  fi
done

CodePudding user response：

Would you please try the following:

#!/bin/bash

for fin in folder/*.mxf; do                     # loop over mxf files in "folder"
    fout=${fin%.mxf}.mp4                        # filename of the paired mp4
    if [[ ! -f $fout ]]; then                   # if the mp4 file doesn't exist
        echo ffmeg -i "$fin" [options] "$fout"  # then transcode
    fi
done

• Put appropriate options such as codec and bitrate as [option].
• If the printed commands look okay, drop echo and run.

CodePudding user response：

#!/bin/bash

while IFS= read -r filename; do  
   # if ${filename}.mp4 not exist 
   if [ ! -f "${filename}.mp4" ]; then 
        # do some with ${filename}.xmf
        echo "ffmpeg_command for ${filename}.mxf" 
   fi 
done < <(find . -iname "*.mxf"|sed 's/\.mxf$//')

• find . -iname "*.mxf" find *.mxf files
• sed 's/\.mxf$//' remove extension from file