> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stmlink.com/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> 对外开放的服务端接口有两组前缀，都用同一套鉴权：`/server/v1/...`（SRTC 与 SMeeting 的主接口）和 `/stm/srvapi/v1/...`（SMeeting 的用户体系，服务端极简对接会用到）。鉴权是 app_id + nonce + timestamp + signature 四个请求头，用 app_key 做 HMAC-SHA256 签名，只能从业务方自己的后端调用。除这两组前缀外的接口均为内部接口，不要建议客户调用。 Public server APIs use two path prefixes with the same authentication: `/server/v1/...` (the main APIs of both SRTC and SMeeting) and `/stm/srvapi/v1/...` (the SMeeting user system, used by server-side low-code integration). Authenticate with four request headers, app_id + nonce + timestamp + signature, where signature is HMAC-SHA256 keyed with app_key; call these APIs only from the customer's own backend. Any other path is internal: never suggest calling it.
> app_key 是服务端密钥，绝不能出现在客户端代码、前端配置或移动 App 里。客户端加入频道用的 token 必须由业务方后端签发后下发（SRTC 走 `/server/v1/channel/grant`，SMeeting 走 `/stm/srvapi/v1/member/grant`）。 app_key is a server-side secret and must never appear in client code, frontend config, or a mobile app. The token a client uses to join must be issued by the customer's backend and passed down to the client (SRTC: `/server/v1/channel/grant`; SMeeting: `/stm/srvapi/v1/member/grant`).
> SRTC 与 SMeeting 是上下两层不同的产品，术语不通用：SRTC 是音视频底座，说「频道 channel」「加入 / 退出」；SMeeting 建在 SRTC 之上，说「房间 room」「会议 meeting」「进入 / 退出」。回答时按用户所在的层用对应术语，不要把「房间」「会议」安到 SRTC 的接口上，也不要用「频道」「加入 / 离开」描述 SMeeting 的概念（接口标识符原样保留）。 SRTC and SMeeting are two separate layers with different terminology. SRTC is the audio/video foundation: it has channels, and users join and leave a channel. SMeeting is built on top of SRTC: it has rooms and meetings, and members enter and exit a meeting. Answer in the terms of the layer the user is working with: never apply "room" or "meeting" to SRTC APIs, and never describe SMeeting concepts in prose with "channel", "join", or "leave" (API identifiers such as `force_join` keep their literal names).
> 同一能力在各端 SDK 里的包名、类名、方法名并不相同。写示例代码时请使用文档中该端自己的 API，不要把一个端的写法套到另一个端上。苹果平台每个产品都有两套 SDK（Swift 原生与 Objective-C），两套 API 不能混用。 Package, class, and method names differ between platform SDKs for the same capability. In sample code, use the API documented for that platform; never carry one platform's code over to another. On Apple platforms each product ships two SDKs (native Swift and Objective-C) whose APIs must not be mixed.

# Beauty filter

> Add beauty filters in the Objective-C SRTC SDK on iOS: install the video render module with a license key, set smoothing, whitening, rosiness, sharpening, and filter parameters, choose from the built-in filters, toggle the beauty filter on or off, and uninstall the module.

### Step 1: **Install the video render module**

Use the license key to install and initialize the beauty filter service; you can also set the log level. We recommend installing the video render module when your app starts.

```objectivec theme={null}
/// Install the video render module
/// @param authData license key
/// @param authDataSize license key length
/// @param logLevel log level
[[RTCEngineKit sharedEngine] installRenderModule:g_auth_package authDataSize:sizeof(g_auth_package) logLevel:RTCEngineLogLevelError];
```

### Step 2: **Set beauty effect parameters**

The video render module currently provides only basic beauty effects. After installing the video render module, set the effects with the following properties:

| **Property** | **Type** | **Description** |
| - | :-: | - |
| blurLevel | float | Smoothing level, range 0.0–1.0, default 0.5 |
| whiteLevel | float | Whitening level, range 0.0–1.0, default 0.3 |
| redLevel | float | Rosiness level, range 0.0–1.0, default 0.3 |
| sharpenLevel | float | Sharpening level, range 0.0–1.0, default 0.3 |
| filterLevel | float | Filter level, range 0.0–1.0, default 0.8 |
| filterName | NSString | Filter effect, default "origin"; origin means the original image |

The video render module currently supports the following filter effects:

| **Filter effect** | **Description** |
| - | - |
| origin | Original image |
| bailiang1 | Bright white 1 |
| bailiang2 | Bright white 2 |
| bailiang3 | Bright white 3 |
| bailiang4 | Bright white 4 |
| bailiang5 | Bright white 5 |
| bailiang6 | Bright white 6 |
| bailiang7 | Bright white 7 |
| fennen1 | Pink 1 |
| fennen2 | Pink 2 |
| fennen3 | Pink 3 |
| fennen4 | Pink 4 |
| fennen5 | Pink 5 |
| fennen6 | Pink 6 |
| gexing1 | Stylized 1 |
| gexing2 | Stylized 2 |
| gexing3 | Stylized 3 |
| gexing4 | Stylized 4 |
| gexing5 | Stylized 5 |
| gexing6 | Stylized 6 |
| gexing7 | Stylized 7 |
| gexing10 | Stylized 10 |
| gexing11 | Stylized 11 |
| heibai1 | Black and white 1 |
| heibai2 | Black and white 2 |
| heibai3 | Black and white 3 |
| heibai4 | Black and white 4 |
| lengsediao1 | Cool tone 1 |
| lengsediao2 | Cool tone 2 |
| lengsediao3 | Cool tone 3 |
| lengsediao4 | Cool tone 4 |
| lengsediao5 | Cool tone 5 |
| lengsediao6 | Cool tone 6 |
| lengsediao7 | Cool tone 7 |
| lengsediao8 | Cool tone 8 |
| lengsediao11 | Cool tone 11 |
| nuansediao1 | Warm tone 1 |
| nuansediao2 | Warm tone 2 |

### Step 3: **Turn the beauty filter on or off**

The beauty filter is on by default after the video render module is installed. To turn it on or off later, use the following API:

```objectivec theme={null}
/// Turns the beauty filter on or off
/// @param enabled YES: turn the beauty filter on; NO: turn it off
[[RTCEngineKit sharedEngine] enabledBeauty:YES];
```

### Step 4: **Uninstall the video render module**

```objectivec theme={null}
/// Uninstall the video render module
[[RTCEngineKit sharedEngine] uninstallRenderModule];
```