sox merge two files of different length

Question

I have two audio files A of length X and other B of length Y (X > Y). Now I want to replace the last Y part of file A with the file B.

For e.g. file A is of length 60s and file B is of length 43s. I need to replace the last 43s of file A with file B.

I hope it is clear.

Is it possible to do this using sox? How, do I need to merge them? If so then how to merge them?

Also is there any way to automate? Like I don't have to manually determine the length of both etc.

Answer 1

You could concatenate both files, then remove the part that you don't need:

sox A B O trim 0 17 43

In a bash shell, this can be fully automated like so:

sox A B O trim 0 $(( $(soxi -s A) - $(soxi -s B) ))s $(soxi -s B)s

Here, soxi -s file is used to determine the file length in samples. Another possibility, using a second sox instance in a pipe special input file:

sox "| sox A -p trim 0 -$(soxi -s B)s" B O