Bash Scripts for Audio-Visual Preservation

It is easier to port a shell than a shell script.
~ Larry Wall

Bash AVpres is a set of Bash scripts for audio-visual preservation, used on a daily base at our conservation and restoration lab, AV Preservation by reto.ch. These small programs are designed for both to be used individually and to be chained each other as needed. The scripts are released under a 3-Clause BSD License and provided “as is” without warranty or support of any kind. Bug reports are very welcome, as usual.

Elements of the Set

Checksums

make_manifest – make a checksum manifest
verify_manifest – verify a checksum manifest
name_hash – add, verify or remove a checksum as filename’s suffix
make_framemd5 – make a frame MD5 checksum manifest
verify_framemd5 – verify a frame MD5 checksum manifest

Files

make_ffv1 – make a Matroska/FFV1 file
verify_ffv1 – verify a Matroska/FFV1 file
make_h264 – make a MP4/H.264 file
make_prores – make a ProRes file
missing_files – find missing files in a folder of sequentially numbered files

BagIt

make_bagit – make a BagIt archive
verify_bagit – verify a BagIt archive
undo_bagit – undo a BagIt archive

FFmpeg

ffengine_presets – list, install, delete or print FFCommand Engine presets (macOS and Windows)
ffmpeg_head – install, patch or delete FFmpeg HEAD

Documentation

All the scripts come with a short embedded help message and a manual page (“man”). Running bash_avpres shows the list of the installed commands:

$ bash_avpres
Bash AVpres 2021-05-08 provides the following commands:
  make_bagit                verify_bagit              bash_avpres
  make_ffv1                 verify_ffv1               ffengine_presets
  make_framemd5             verify_framemd5           ffmpeg_head
  make_h264                 verify_manifest           missing_files
  make_manifest                                       name_hash
  make_prores               undo_bagit                nano_config
$

Installation

The scripts can be run from everywhere, without any specific installation. Of course, they have to be executable; if they aren’t, run for example chmod +x bash_avpres or, when administrator privileges are requested, sudo chmod +x bash_avpres.

In addition, two possibilities are provided for a regular installation at the root: via a Homebrew formula and via a Makefile. And we advise to use either one of these.

Homebrew

The installation via Homebrew works fine not only on Linux and Mac, but also on Windows running Terminal or Subsystem for Linux. Run the following command in the Terminal:

brew install avpres/formulae/bash-avpres

Makefile

As usual, directions are recalled in the README.txt file. Run the following three classic commands in the Terminal:

cd bash-avpres-YYYY-MM-DD ./configure make install

Compatibility

The Bash AVpres scripts have been used successfully on various modern x86_64 and ARM64 architectures running under the following operating systems:

Linux: Debian 10.9 and 9.13; Ubuntu 20.04.2 LTS, 18.04.5 LTS and 16.04.7 LTS; Slackware 15.0 Beta and 14.2; Qubes OS 4.0.4
Mac: macOS 11.3 (Intel and Apple M1), 10.15.7 and 10.14.6
Windows 10: version 20H2, 2004 and 1909, running Terminal or Subsystem for Linux

The scripts have been programmed to run also on the old Bash version 3.2 (released on 2006-10-11), which sadly still comes with the Apple computers. However, we strongly advise to install the current Bash version 5.1 (released on 2020-12-07) also on computers running under macOS.

Source Code

The source code of the Bash AVpres package is available on our website as a “.tar.gz” file, a TAR archive which was compressed with gzip. Of course, it includes a Change Log file.

2021-05-08