javicle/bin/jconcat

#!/bin/bash
#
# Concatenate media files
#
# Usage:
#
#    jconcat [-n|--no-exec] out-file in-file-1 [in-file-2 ...]
#
# -n or --no-exec : if set, do not execute ffmpeg but print what would have run
# out-file        : output file
# in-file-N       : input files
#
# BEWARE SHELL WILDCARDS!
# Shell wildcards will match files in non-deterministic order, meaning that
# your combined file will be assembled out of order.
#
# If you are combining files that were split with `jvc` (or `jsplit`), then
# sorting them by time (oldest first) is sufficient.
#
# For example, do this:
#
#    jconcat combined-file.mp4 $(ls -1tr path/to/parts*.mp4)
#
# NOT THIS:
#
#    jconcat combined-file.mp4 path/to/parts*.mp4  # args not ordered!
#
SCRIPT="${0}"
SCRIPT_DIR="$(cd "$(dirname "${SCRIPT}")" && pwd)"
. "${SCRIPT_DIR}"/jvc_common

OUT_FILE="${1?no out-file provided}"
shift

IN_FILE="${1?no in-file(s) provided}"
echo "
{
  \"assets\": [
$(
F_INDEX=0
for path in "$@" ; do
  if [[ ${F_INDEX} -gt 0 ]] ; then
    echo ","
  fi
  F_INDEX=$((F_INDEX + 1))
  echo -n "    { \"name\": \"input_${F_INDEX}\", \"path\": \"${path}\" }"
  shift
done)
  ],
  \"operations\": [
    {
      \"operation\": \"concat\",
      \"creates\": {
        \"name\": \"combined\",
        \"dest\": \"${OUT_FILE}\"
      },
      \"sources\": [$(END=$#
for ((i=1;i<=END;i++)); do
  if [[ ${i} -gt 1 ]] ; then echo -n "," ; fi
  echo -n "
          \"input_${i}\""
done)
      ]
    }
  ]
}
" | "${SCRIPT_DIR}"/jvc -z ${JVC_OPTIONS}