# 查询频道直播截图

### 接口描述

```
1、截图功能，查询当前频道正在直播的截图（截图五分钟更新一次）
2、接口URL中的{channelId}为频道号
3、接口支持https协议
```

### 接口URL

```
http://api.polyv.net/live/v2/stream/{channelId}/capture
```

[在线API调用](https://git.polyv.net/help-center/document-center/-/blob/master/req.html?api=http:/api.polyv.net/live/v2/stream/%7BchannelId%7D/capture/README.md)

### 请求方式

```
POST
```

### 接口约束

1、接口同时支持HTTP 、HTTPS ，建议使用HTTPS 确保接口安全，接口调用有频率限制，[详细请查看](https://git.polyv.net/help-center/document-center/-/blob/master/live/api/limit/README.md)

### 请求参数描述

| 参数名       | 必选   | 类型     | 说明                                                                                                                                                                                                        |
| --------- | ---- | ------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| appId     | true | String | 账号appId【详见[获取密钥](https://git.polyv.net/help-center/document-center/-/blob/master/live/api/getSecretKey/README.md)】                                                                                        |
| timestamp | true | Long   | 当前13位毫秒级时间戳，3分钟内有效                                                                                                                                                                                        |
| sign      | true | String | 签名，为32位大写的MD5值,`生成签名的appSecret密钥作为通信数据安全的关键信息，严禁保存在客户端直接使用，所有API都必须通过客户自己服务器中转调用POLYV服务器获取响应数据`【详见[签名生成规则](https://git.polyv.net/help-center/document-center/-/blob/master/live/api/buildSign/README.md)】 |

### 示例

```requestUrl
http://api.polyv.net/live/v2/stream/1965681/capture
```

表单参数：

```requestUrl
appId=frlr1zazn3&sign=56CB347C3D71093F0D8EFBE59AF7CDA0&timestamp=1621842995655
```

### 响应参数描述

| 参数名     | 类型      | 说明                                                                                                                               |
| ------- | ------- | -------------------------------------------------------------------------------------------------------------------------------- |
| code    | Integer | 响应状态码，200为成功返回，非200为失败【详见[全局错误说明](https://git.polyv.net/help-center/document-center/-/blob/master/live/api/errorInfo/README.md)】 |
| status  | String  | 响应状态文本信息                                                                                                                         |
| message | String  | 响应描述信息，当code为400或者500的时候，辅助描述错误原因                                                                                                |
| data    | String  | 请求成功时为截图地址，请求错误时为空                                                                                                               |

### Java请求示例

快速接入基础代码请下载相关依赖源码， [点击下载源代码](https://git.polyv.net/help-center/document-center/-/blob/master/third_res/util.zip) ,下载后加入到自己的源码工程中即可。测试用例中的**HttpUtil.java 和 LiveSignUtil.java** 都包含在下载文件中。

> 强烈建议您使用[直播Java SDK](https://git.polyv.net/help-center/document-center/-/blob/master/live/java/README.md)完成API的功能对接，直播Java SDK 对API调用逻辑、异常处理、数据签名、HTTP请求线程池进行了统一封装和优化。

```java
private static final Logger log = LoggerFactory.getLogger(ChannelOperateTest.class);
/**
 * 查询频道直播截图
 * @throws IOException
 * @throws NoSuchAlgorithmException
 */
@Test
public void testGetCaptureImage() throws IOException, NoSuchAlgorithmException {
    //公共参数,填写自己的实际参数
    String appId = super.appId;
    String appSecret = super.appSecret;
    String userId = super.userId;
    String timestamp = String.valueOf(System.currentTimeMillis());
    //业务参数
    String url = "http://api.polyv.net/live/v2/stream/%s/capture";
    String channelId = "1965681";
    
    url = String.format(url, channelId);
    Map<String, String> requestMap = new HashMap<>();
    requestMap.put("appId", appId);
    requestMap.put("timestamp", timestamp);
    requestMap.put("sign", LiveSignUtil.getSign(requestMap, appSecret));
    String response = HttpUtil.postFormBody(url, requestMap);
    log.info("测试查询频道直播截图，返回值：{}", response);
    //do somethings
    
}
```

### 响应示例

系统全局错误说明详见[全局错误说明](https://git.polyv.net/help-center/document-center/-/blob/master/live/api/errorInfo/README.md)

成功示例

```json
{
    "code": 200,
    "status": "success",
    "message": "",
    "data": "//liveimages.videocc.net/uploaded/images/2021/03/fx0p8ouo04.jpg"
}
```

异常示例

```json
{
    "code": 400,
    "status": "error",
    "message": "invalid signature.",
    "data": ""
}
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://polyv.gitbook.io/document/docs/live/api/channel/operate/get_capture_image.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.