ffmpeg shell script with spaces in path

Question

I have a quick shell script that is taking a list of input and output names line by line and providing them to ffmpeg for conversion. Some of the output paths have spaces in them, and I receive one of two errors, no matter how I escape or double quote the path with spaces.

Input File

file1.avi "output path"/file1.mp4
file1.avi "output\ path"/file1.mp4
file1.avi "output path/file1.mp4"
file1.avi output\ path/file1.mp4

convert.sh

while read -r file1 file2; do ffmpeg -i "$file1" -c copy -bsf:a aac_adtstoasc $file2; done <list

One error that I receive is:

"output path"/file1.mp4: No such file or directory

The other error that I receive is:

Unable to find a suitable output format for '"output'

The variations in the input file lines are there to show the things that I have tried in order to escape the space. I have also tried the same with adding double quotes around file2 in the shell script.

Answer 1

Provided your filenames do not contain literal backslash characters, then if you use backslash escapes (but not quotes) in the list file

file1.avi output\ path/file1.mp4

then you may omit the -r so that read does interpret the escape sequences (as spaces) rather than as the literal character sequence \ . Then you can simply double-quote the expansions in the usual way:

while read file1 file2; do 
  ffmpeg -i "$file1" -c copy -bsf:a aac_adtstoasc "$file2"
done <list

To illustrate:

$ cat list
file1.avi output\ path/file1.mp4

then

$ while read file1 file2; do 
    printf '==%s==\n==%s==\n' "$file1" "$file2"
  done <list
==file1.avi==
==output path/file1.mp4==