# Music and video formats

> Play and make MP3, AAC, H.264, HEVC and AC3 files, and get the common fonts, with one click in the installer or the Store. Never added without you.

Source: https://wolos.org/manual/media-formats

## What it is

A *format* (or *codec*) is the way a song or a video is packed into a file. Most music, phone videos and films use a handful of them: MP3, AAC, H.264, HEVC and AC3 (Dolby Digital). WolOS adds all of them, plus the fonts most documents and web pages expect, in one step called **Media Codecs**. It is a *Kit*: a set of extras the Store adds together. You find it in two places: the installer's page **Music and Video Formats**, and the Store's **Kits**.

## Why

Some of these formats are patented in some countries, so whether to add them is your choice, not ours. WolOS never adds them on its own, and it never hides them behind a search either: one switch, a line for each format that says what it is for, and a sentence about the patents. Then your files just open.

## How

### While you install WolOS

1. **On the page "Music and Video Formats", turn on Add Media Formats.**
   You see what each format is for (*MP3: Music files and podcasts*, *H.264: Most videos on the web and from cameras*, and so on) and the sentence *Some of these formats are patented in some countries. You choose whether to add them.*

   ![The installer page Music and Video Formats with Add Media Formats switched on, a list of MP3, AAC, H.264, HEVC (H.265), AC3 (Dolby Digital) and Fonts with what each is for, and the patent sentence.](/img/manual/installer-extras-on-1280.png)
2. **Continue.** The formats download while WolOS installs. Without the internet, the summary says they will be added "at first start with a network", and the Store's Kits page has them too.

### On a WolOS that is already installed

1. **Open the Store and choose Kits** in the sidebar.
   You see **Media Codecs** (*Play and make MP3, AAC, H.264, HEVC and more*) with a **Get** button, and what each format is for.

   ![The Store's Kits page: 1 Kits in the sidebar, 2 the Get button of Media Codecs; under it the six parts (MP3, AAC, H.264, HEVC, AC3, Fonts) and the patent sentence.](/img/manual/store-kits-wide-annotated.png)
2. **Click Get.**
   You see a password sheet: adding packages for every account needs an administrator. Type your password and click **Allow**.
3. **Wait for Added.**
   You see the button change to **Added**. Files that did not open before now open in the music and video apps, the browser and the creative apps.

   ![The same Kits page after the install: the Media Codecs button now reads Added.](/img/manual/store-kits-added-wide.png)

### What each part is for

| Part | You need it for |
|---|---|
| MP3 | Music files and podcasts |
| AAC | Music from stores, phone videos and streams |
| H.264 | Most videos on the web and from cameras |
| HEVC (H.265) | Videos from newer phones and 4K files |
| AC3 (Dolby Digital) | Sound on DVDs and many films |
| Fonts | Documents and web pages look as their authors meant |

## A worked example

Alice's phone video opens with sound but no picture. She opens the Store, chooses Kits and clicks **Get** on Media Codecs. She types her password, clicks **Allow** and waits for the button to read **Added**. The same video now plays, and so do the MP3s her sister sent.

## If something goes wrong

| What you see | What to do |
|---|---|
| A video opens with sound but no picture, or does not open | The Kit is not added yet. Open the Store > Kits and check that Media Codecs says **Added**. |
| Settings > Modules lists *AAC, H.264, HEVC (H.265), AC3 (Dolby Digital)* under **Could Not Be Added** | You ticked the formats in the installer, but they could not be downloaded after several tries. Check that you're online and click **Retry**. |
| **Get** does nothing offline | The Kit downloads its parts. Connect to a network and try again. |
| A file still will not play after the Kit is added | Some files use rarer formats. Try another player from the Store's **Play** page, such as VLC or mpv. |

## Related

[Creative apps in one step](/manual/creative-module) · [Store](/manual/store) · [Installing WolOS](/manual/install) · [Modules](/manual/modules)