When very large files are ingested, the segmented file list can be a
very long list. This list of files are passed to ffmpeg commands which
will may fail with a 'command: arg list too long' error (linux error and
not ffmpeg error). This happens because the arg length exceeds the
MAX_ARG limit which varies from kernel to kernel. To workaround this
issue, we break down the list into smaller chunks and then concat those
chunks to get the final concatenated file.