# mkvdump
[](https://codecov.io/gh/cadubentzen/mkvdump)
[](https://github.com/cadubentzen/mkvdump/blob/main/.github/workflows/test.yml)
[](https://crates.io/crates/mkvdump)
A command-line tool for debugging Matroska/WebM files. It displays all internal elements of a Matroska file as JSON or YAML.
Sample YAML output
```yaml
- id: EBML
header_size: 5
size: 36
children:
- id: EBMLVersion
header_size: 3
size: 4
value: 1
- id: EBMLReadVersion
header_size: 3
size: 4
value: 1
- id: EBMLMaxIDLength
header_size: 3
size: 4
value: 4
- id: EBMLMaxSizeLength
header_size: 3
size: 4
value: 8
- id: DocType
header_size: 3
size: 7
value: webm
- id: DocTypeVersion
header_size: 3
size: 4
value: 2
- id: DocTypeReadVersion
header_size: 3
size: 4
value: 2
- id: Segment
header_size: 12
size: Unknown
children:
- id: Void
header_size: 9
size: 229
value: null
- id: Info
header_size: 5
size: 44
children:
- id: TimestampScale
header_size: 4
size: 7
value: 1000000
- id: MuxingApp
header_size: 3
size: 16
value: Lavf58.29.100
- id: WritingApp
header_size: 3
size: 16
value: Lavf58.29.100
- id: Tracks
header_size: 5
size: 101
children:
- id: TrackEntry
header_size: 9
size: 96
children:
- id: TrackNumber
header_size: 2
size: 3
value: 1
- id: TrackUID
header_size: 3
size: 4
value: 1
- id: FlagLacing
header_size: 2
size: 3
value: 0
- id: Language
header_size: 4
size: 7
value: und
- id: CodecID
header_size: 2
size: 7
value: V_AV1
- id: TrackType
header_size: 2
size: 3
value: video
- id: DefaultDuration
header_size: 4
size: 8
value: 41708333
- id: Video
header_size: 9
size: 32
children:
- id: PixelWidth
header_size: 2
size: 4
value: 1280
- id: PixelHeight
header_size: 2
size: 4
value: 720
- id: Colour
header_size: 3
size: 15
children:
- id: Range
header_size: 3
size: 4
value: broadcast range
- id: ChromaSitingHorz
header_size: 3
size: 4
value: left collocated
- id: ChromaSitingVert
header_size: 3
size: 4
value: half
- id: CodecPrivate
header_size: 3
size: 20
value: '[81 05 0c 00 0a 0b 00 00 00 2d 4c ff b3 df ff 98 04]'
- id: Tags
header_size: 5
size: 61
children:
- id: Tag
header_size: 10
size: 56
children:
- id: Targets
header_size: 10
size: 10
children: []
- id: SimpleTag
header_size: 10
size: 36
children:
- id: TagName
header_size: 3
size: 10
value: ENCODER
- id: TagString
header_size: 3
size: 16
value: Lavf58.29.100
- id: Cluster
header_size: 6
size: 2679
children:
- id: Timestamp
header_size: 2
size: 3
value: 0
- id: SimpleBlock
header_size: 2
size: 45
value:
track_number: 1
timestamp: 0
keyframe: true
- id: SimpleBlock
header_size: 2
size: 59
value:
track_number: 1
timestamp: 42
- id: SimpleBlock
header_size: 2
size: 32
value:
track_number: 1
timestamp: 83
# ...
```
## What's it useful for?
This tool is similar to [mp4dump](https://www.bento4.com/documentation/mp4dump/), but for Matroska files. It may be useful for:
- **snapshot testing:** you can save mkvdump's output for a produced Matroska asset and use that in a human-readable snapshot test.
- **learning about EBML/Matroska/WebM:** with this tool you can see how a Matroska file is structured. I also learned by writing the tool 😊
## Getting mkvdump
### Debian package
Ubuntu users (>= 20.04) can install mkvdump via the DEB package available in the [releases page](https://github.com/cadubentzen/mkvdump/releases).
### Homebrew
Linux and macOS users on x86_64 devices can install mkvdump via the [Homebrew tap](https://github.com/cadubentzen/homebrew-mkvdump):
```bash
$ brew install cadubentzen/mkvdump/mkvdump
```
macOS users on M1 or M2 devices need to use
```bash
$ brew install --build-from-source cadubentzen/mkvdump/mkvdump
```
### Cargo
If you have [cargo-binstall](https://github.com/cargo-bins/cargo-binstall) installed, you can install mkvdump with
```bash
$ cargo binstall mkvdump
```
Else, you can install by building it from source with:
```bash
$ cargo install mkvdump
```
### Docker
To pull latest mkvdump from [Docker Hub](https://hub.docker.com/r/cadubentzen/mkvdump):
```bash
$ docker pull cadubentzen/mkvdump
```
A [GitHub package](https://github.com/cadubentzen/mkvdump/pkgs/container/mkvdump) is also available via
```bash
$ docker pull ghcr.io/cadubentzen/mkvdump
```
Images are multi-arch with support for `linux/amd64`, `linux/386`, `linux/arm64`, `linux/arm/v7` and `linux/arm/v6`.
#### Running the container
Asssuming a Mastroska file in the host located at `/host-path/sample.mkv`. You can run mkvdump on it with the following command, by mounting a volume:
```bash
$ docker run -v /host-path:/media cadubentzen/mkvdump /media/sample.mkv
```
### Prebuilt binaries
Download prebuilt binaries from the [release page](https://github.com/cadubentzen/mkvdump/releases). There are binaries for the following targets:
- Linux
- statically linked with musl: `x86_64`, `x86`, `aarch64`, `armv7l` and `armv6l`
- with GNU libc: `x86_64` and `x86` (built on Ubuntu 20.04)
- macOS
- `x86_64` and `aarch64` (>= macOS 11 Big Sur)
- Windows
- `x86_64` and `x86` with MSVC and MinGW
## License
© 2022 Carlos Bentzen .
This project is licensed under either of
- [Apache License, Version 2.0](https://www.apache.org/licenses/LICENSE-2.0) ([`LICENSE-APACHE`](LICENSE-APACHE))
- [MIT license](https://opensource.org/licenses/MIT) ([`LICENSE-MIT`](LICENSE-MIT))
at your option.
The [SPDX](https://spdx.dev) license identifier for this project is `MIT OR Apache-2.0`.