dano

dano is a wrapper for ffmpeg that checksums the internal file streams of ffmpeg compatible media files, and stores them in a format which can be used to verify such checksums later. This is handy, because, should you choose to change metadata tags, or change file names, the media checksums should remain the same.

Features

• Non-media path filtering (which can be disabled)
• Highly concurrent hashing (select # of threads)
• Several useful modes: WRITE, TEST, COMPARE, PRINT or DUMP
• Select from multiple checksum algorithms (default: murmur3, MD5, adler32, CRC32, SHA160, SHA256, SHA512)
• Option to decode the stream before executing hash function
• Write to xattrs or to hash file (and always read back and operate on both)

Why dano? Because FLAC is really clever

To me, first class checksums are one thing that sets the FLAC music format apart. FLAC supports the writing and checking of the streams held within its container. When I ask whether the FLAC audio stream has the same checksum as the stream I originally wrote to disk, the flac command tells me whether the checksum matches:

bash % flac -t 'Link Wray - Rumble! The Best of Link Wray - 01-01 - 02 - The Swag.flac' Link Wray - Rumble! The Best of Link Wray - 01-01 - 02 - The Swag.flac: ok

Why can't I do that everywhere?

The question is -- why don't we have this functionality for video and other media streams? The answer is, of course, we do, (because ffmpeg is incredible!) we just never use it. dano aims to make what ffmpeg provides easier to use.

So -- when I ask whether a media stream has the same checksum as when I originally wrote it to disk, dano tells me whether the checksum matches:

```bash % dano -w 'Sample.mkv' murmur3=2f23cebfe8969a8e11cd3919ce9c9067 : "Sample.mkv" % dano -t 'Sample.mkv' "Sample": OK

Now change our file's name and our checksum still verifies,

because the checksum is stored in a xattr

% mv 'Sample.mkv' 'test1.mkv' % dano -t 'test2.mkv' "test1.mkv": OK

Now change our file's metadata and *write a new file in a

new container* and our checksum is the same

% ffmpeg -i 'test1.mkv' -metadata author="Kimono" 'test2.mp4' % dano -w 'test2.mp4' murmur3=2f23cebfe8969a8e11cd3919ce9c9067 : "test2.mkv" ```

Can I use dano with my FLAC files?

Of course you can. dano will even import your FLAC file's checksums directly:

```bash

Import dano checksum from FLAC and write to an xattr

% dano --import-flac 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac' MD5=fed8052012fb6d0523ef3980a0f6f7bd : "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac" Writing dano hash for: "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac" No old file data to overwrite.

Verify checksum is the same as the checksum embedded in the FLAC container

% metaflac --show-md5sum 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac' fed8052012fb6d0523ef3980a0f6f7bd

Verify the decoded FLAC audio stream is the same as the xattr checksum

% dano -t 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac' "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac": OK ```

Ugh, why can't ALAC be more like FLAC?

ALAC, like most formats, misses integrated checksums and verification, which make ALAC less suitable for the long term storage of lossless audio.

You, of course, could checksum the file yourself (md5 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a'), but, if you change the ALAC file's metadata, or, significantly, its album art, then the checksum changes. For serious collectors, if you can't verify your checksums later when you change the album art, what use is a checksum?

dano allows you have to store a stable checksum, and verify it later, just like FLAC:

```bash

To test, this we will create an ALAC copy of a FLAC file

ffmpeg -i 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac' -acodec alac 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a'

Write dano checksum to an xattr

% dano -w --only=audio --decode --hash-algo=md5 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a' MD5=fed8052012fb6d0523ef3980a0f6f7bd : "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a" Writing dano hash for: "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a" No old file data to overwrite.

Verify checksum is the same as the decoded FLAC audio stream

% metaflac --show-md5sum "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.flac" fed8052012fb6d0523ef3980a0f6f7bd

Verify the decoded ALAC audio stream is the same as the xattr checksum

% dano -t "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a" "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a": OK ```

Because MD5 is generally overkill for a file checksum, dano also supports faster algorithms, like murmur3, thus verifying all your checksums can be faster using dano.

bash % dano -w --only=audio --decode --hash-algo=murmur3 'Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a' murmur3=f863a834f4d8504944b6121eee3d1993 : "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a" Writing dano hash for: "Pavement - Wowee Zowee_ Sordid Sentinels Edition - 02-02 - 50 - We Dance.m4a" No old file data to overwrite.

Shout outs! Yo, yo, yo!

Inspired by hashdeep, md5tree, flac, and, of course, ffmpeg.

Install via Native Packages

For Debian-based and Redhat-based Linux distributions (like, Ubuntu or Fedora, etc.), check the tagged releases for native packages for your distribution.

You may also create and install your own native package from the latest sources, like so:

```bash curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh cargo install cargo-deb git clone https://github.com/kimono-koans/dano.git cd ./dano/; cargo deb

to install on a Debian/Ubuntu-based system

dpkg -i ./target/debian/dano_*.deb

or convert to RPM

alien -r ./target/debian/dano_*.deb

and install on a Redhat-based system

rpm -i --replacefiles ./dano*.rpm ```

Installation from Source

For now, dano depends on ffmpeg.

dano is only tested on MacOS and Linux, and will probably only compile and run on Unix-y Rust supported platforms, but a Windows is version is likely to compile with only minor changes. My further thoughts on a Windows version can be found in this linked issue.

Note: In addition to what your package manager or OS may provide, there are several alternative methods for installing the rustc compiler and cargo besides the method described below.

bash curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh cargo install --git https://github.com/kimono-koans/dano.git