---
title: "Inspect a video file from the command line"
url: https://recursiveai.org/onemedia/cookbook/inspect-video-cli/
description: "Inspect an MP4, MOV, MKV or WebM file from the command line with the onemedia .NET tool: tracks, RFC 6381 codec strings, tags, capture time, location and rotation, as text or JSON."
version: "0.1.0-preview.1"
---

# Inspect a video file from the command line

`onemedia info <file>` prints a video file’s format, duration, tracks with their codec strings, tags and capture facts. Add `--json` for the same as JSON, with every candidate for each fact. It is a .NET tool, so it needs the .NET 10 SDK or runtime. The files are MDN’s CC0 flower clip and the iPhone-style test file from the OneMedia repository (synthetic picture, invented tags).

```shell
dotnet tool install --global RecursiveAI.OneMedia.Tool --version 0.1.0-preview.1
curl -L -o flower.mp4 https://interactive-examples.mdn.mozilla.net/media/cc0-videos/flower.mp4
curl -L -o iphone-style.mov https://raw.githubusercontent.com/recursive-ai-oss/onemedia-csharp/v0.1.0-preview.1/testdata/metadata/tags_keys.mov
onemedia --version
```

```text
0.1.0-preview.1
```

## Text

```shell
onemedia info flower.mp4
```

```text
format: isobmff
duration: 00:00:05.0550000
track 0: video h264 (avc1.64001F) [avc1] 960x540 30000/1001 fps lang=und disposition=Default
track 1: audio aac (mp4a.40.2) [mp4a] 48000 Hz 2 ch lang=und disposition=Default
captureTime: 2018-03-07T15:21:21Z (mvhd, 1 candidate(s))
rotation: 0 (tkhd.matrix, 1 candidate(s))
```

Each track line is: index, kind, codec, the RFC 6381 string in parentheses, the container’s codec tag in brackets, then size, rotation (`rotate 90` when there is one) and frame rate for video, or rate and channels for audio, then language and flags. A file with tags and device facts prints more lines:

```shell
onemedia info iphone-style.mov
```

```text
format: isobmff
duration: 00:00:01
track 0: video h264 (avc1.64000B) [avc1] 160x120 25/1 fps lang=und disposition=Default
track 1: audio aac (mp4a.40.2) [mp4a] 44100 Hz 1 ch lang=und disposition=Default
tag Title: Keyed_Title
tag Author: Pat_Doe
tag Comment: Keyed_comment
tag Encoder: Lavf61.1.100
captureTime: 2023-04-05T10:11:12+02:00 (mdta:com.apple.quicktime.creationdate, 1 candidate(s))
location: 37.7749,-122.4194,12.5 (mdta:com.apple.quicktime.location.ISO6709, 1 candidate(s))
make: Contoso (mdta:com.apple.quicktime.make, 1 candidate(s))
model: Camera_X1 (mdta:com.apple.quicktime.model, 1 candidate(s))
software: 17.1 (mdta:com.apple.quicktime.software, 1 candidate(s))
rotation: 0 (tkhd.matrix, 1 candidate(s))
```

Each fact line shows the value, where it came from, and how many candidates the file holds. Damage the reader found prints as `defect:` lines.

## JSON

```shell
onemedia info iphone-style.mov --json
```

The object has `format`, the durations as exact ticks and timescales, `tracks` (with `rfc6381`, size, rotation, rate and channels), `tags`, `facts` and `defects`. Each fact lists every candidate:

```text
"location": {
  "value": "37.7749,-122.4194,12.5",
  "candidates": [
    {
      "value": "37.7749,-122.4194,12.5",
      "source": "mdta:com.apple.quicktime.location.ISO6709",
      "raw": "\u002B37.7749-122.4194\u002B012.500/",
      "interpretation": "ISO 6709 latitude, longitude and optional altitude",
      "timezone": "Unknown"
    }
  ]
}
```

The JSON escapes `+` as `\u002B`; any JSON parser reads it back as `+`.

## Exit codes

`0` when the file was read, `1` when it couldn’t be (not found, or not a format OneMedia reads: `unsupported: The data is not in any registered format.` on standard error), and `2` with a usage message for anything but `info <file> [--json]` or `--version`.

## Limits

- **One command.** 0.1 has `info` and `--version` only. It doesn’t convert, extract, trim or edit anything.
- **Formats.** MP4, MOV, 3GP, M4A/M4V, fragmented MP4, MKV and WebM, as for the library.
- **Text output** shows the best candidate of each fact and the number of candidates; use `--json` to see them all. It doesn’t print track names; `--json` doesn’t either, so use the library for those (see [List the tracks of a video](https://recursiveai.org/onemedia/cookbook/list-video-tracks/)).
- **Matroska frame rates** print as the container’s fraction of nanoseconds, such as `200000000/8333333 fps` for 24 fps.

The same information from C#: [Get video duration, resolution and codec](https://recursiveai.org/onemedia/cookbook/get-video-duration-resolution-codec/).