---
title: Functions
description: Public API reference for the HLS extension
---

## Extension Entry Points

| Function | Description |
|---|---|
| `NewExtension(opts ...ConfigOption) forge.Extension` | Create the HLS extension with functional options |
| `NewExtensionWithConfig(config Config) forge.Extension` | Create the HLS extension with a complete config |
| `DefaultConfig() Config` | Returns the default configuration |

## HLS Interface -- Stream Management

| Method | Description |
|---|---|
| `CreateStream(ctx, options) (*Stream, error)` | Create a new stream (live, VOD, or event) |
| `GetStream(ctx, streamID) (*Stream, error)` | Get stream information |
| `DeleteStream(ctx, streamID) error` | Delete a stream and its segments |
| `ListStreams(ctx) ([]*Stream, error)` | List all streams |
| `StartStream(ctx, streamID) error` | Start a live stream |
| `StopStream(ctx, streamID) error` | Stop a live stream |

## HLS Interface -- Segment Operations

| Method | Description |
|---|---|
| `IngestSegment(ctx, streamID, variantID, data) error` | Push a media segment |
| `GetSegment(ctx, streamID, variantID, segmentNum) (io.ReadCloser, error)` | Retrieve a segment |

## HLS Interface -- Playlists

| Method | Description |
|---|---|
| `GetMasterPlaylist(ctx, streamID) (string, error)` | Generate the master playlist (m3u8) |
| `GetMediaPlaylist(ctx, streamID, variantID) (string, error)` | Generate a media playlist |

## HLS Interface -- Stats

| Method | Description |
|---|---|
| `GetStreamStats(ctx, streamID) (*StreamStats, error)` | Get stream statistics |

## Playlist Generator

| Function | Description |
|---|---|
| `NewPlaylistGenerator(baseURL) *PlaylistGenerator` | Create a playlist generator |
| `GenerateMasterPlaylist(stream) string` | Generate a master m3u8 playlist |
| `GenerateMediaPlaylist(stream, variantID) string` | Generate a media m3u8 playlist |

## Utility Functions

| Function | Description |
|---|---|
| `DefaultProfiles() []TranscodeProfile` | Get default transcode profiles (360p to 4K) |
| `FormatResolution(width, height) string` | Format a resolution string |
| `ParseResolution(resolution) (width, height, error)` | Parse a resolution string |
| `GenerateCodecsString(profile) string` | Generate HLS codecs attribute string |

## Key Types

### `StreamOptions`

| Field | Type | Purpose |
|---|---|---|
| `Name` | `string` | Stream display name |
| `Type` | `StreamType` | `live`, `vod`, or `event` |
| `Profiles` | `[]TranscodeProfile` | Quality profiles to generate |

### `TranscodeProfile`

| Field | Type | Purpose |
|---|---|---|
| `Name` | `string` | Profile name (e.g. `"720p"`) |
| `Width` | `int` | Output width |
| `Height` | `int` | Output height |
| `VideoBitrate` | `int` | Video bitrate (kbps) |
| `AudioBitrate` | `int` | Audio bitrate (kbps) |
| `VideoCodec` | `string` | Video codec (e.g. `"h264"`) |
| `AudioCodec` | `string` | Audio codec (e.g. `"aac"`) |