# `FrameRate`

Frames a second, as an exact fraction: `25/1`, or `30000/1001` for 29.97.

Use it for video. Video rates aren't round numbers, which is why this is a fraction. For anything else per second, use [`Frequency`](/docs/types/type-frequency.md).

## Shape

| Field | Type | Required? |
|---|---|---|
| `numerator` | `Int` | Yes |
| `denominator` | `Int` | Yes |

## Example

```jadpo
FrameRate { numerator: 25 denominator: 1 }
```

`text.parse(raw, as: FrameRate)` reads one from text that comes from outside. Text that isn't one at all fails `malformed`, such as `29.97`, `30` or `0/1`.

## Good to know

- `29.97` is refused. Write the fraction.
- `==` tells you whether two are the same. `<` and `list.sort_by` don't take it, so sort by one of its parts instead.

## In JSON

A string, in a request, a response or `json.write`:

```json
"24/1"
"25/1"
"24000/1001"
```

## Details

<details>
<summary>Text form, storage, how it is shown, and operations</summary>

`FrameRate` is in the group Media and visual, and has been in Jadpo since 0.1.0.

### Text form

`text.from` writes one standard text form, the same form `text.parse` reads back: `24/1`, `25/1` and `24000/1001`.

### How it is stored

It is stored in 2 columns, each named for the field, `_` and its suffix. This is `24000/1001`:

| Column | Type | Holds |
|---|---|---|
| `<field>_numerator` | `integer` | `24000` |
| `<field>_denominator` | `integer` | `1001` |

### How it is shown to people

`text.format(value, locale:)` shows it to people in their locale.

With `locale: Locale.en_gb`:

| Value | Shown |
|---|---|
| `24/1` | `24/1` |
| `25/1` | `25/1` |
| `24000/1001` | `24000/1001` |
| `30000/1001` | `30000/1001` |
| `60000/1001` | `60000/1001` |

### Operations

It also takes `text.parse`, `text.from`, `text.format`, `json.read`, `json.write` and `==`. [How every standard type behaves](/docs/every-standard-type-meets-one-contract.md) says how they work.

</details>