tencent cloud

Use Cases

Quick playback file generation

Live stream playback can increase the value and reduce the production costs of high-quality resources to boost the profits. The panoramic recording feature can record the class content from user's perspective in real time, quickly transcode the content based on the massive serverless computing power pool after a class ends, and generate the recording file for playback instantly.

Highlight collection

Parents seldom have time to watch entire class videos of their children. The highlight collection feature renders the moments of children's excellent performance during the class to parents to improve their perception and recognition of the class. You can clip highlights from class recording files on the HTML5 platform, use panoramic recording to generate MP4 files, create a collection of highlight moments of children in class, and quickly distribute them through CDN.

File composition

General file composition requires transcoding, which consumes a lot of computing power. With SCF + TRTC, you can compose videos, audios, images, etc. on the same frontend page, adjust the layout, perform panoramic recording, decode multiple streams, and encode all of them into one stream to quickly generate video files, giving full play to computing power resources.

How It Works

Tencent Cloud's proprietary panoramic recording feature allows you to record videos in a WYSIWYG way. You only need to provide an accessible public network URL, and the feature can use Chrome for page rendering and recording, perform FFmpeg transcoding, and directly upload videos to COS to generate recording files in real time. Together with other Tencent Cloud products such as CSS, VOD, and TRTC, this offers a one-stop solution for education, gaming, and interactive entertainment scenarios.

Application Strengths

• Lower costs
  Panoramic recording uses Chrome for multi-stream decoding and one-stream encoding, which reduces computing power consumption and lowers the cost by over 60% compared with traditional recording solutions.
• High fidelity
  Panoramic recording can capture all external information such as special effects in class on the client, fully retaining the in-person class experience.
• Free switch
  During panoramic recording, you can flexibly adjust the browser layout and switch between teacher and student views.
• Ultra high concurrency
  SCF computing instances can be quickly started to stably sustain high concurrency and handle business traffic spikes with ease.
• Instant output
  Panoramic recording allows you to directly get the recording file for playback once the live stream ends, with no need to perform complex composition, which is time-saving and efficient.

Application Resources

After panoramic recording is deployed, the following resources will be created:

• SCF function: it gets the external link data and uses panoramic recording to record videos in real time.
• CLS log: it stores video processing logs and may incur fees. For more information, see CLS Billing Rules.
• API Gateway: you can use an API Gateway trigger to trigger events.

Prerequisites

1. Configure and deploy account permissions as detailed in Account and Permission Configuration.
2. Configure execution role permissions.
3. Panoramic recording needs to be used together with other services, so you must add the following policies: QcloudRedisFullAccess, QcloudVPCFullAccess, QcloudCFSFullAcces, QcloudSCFFullAccess, QcloudCOSFullAccess, and QcloudAccessForScfRole. For more information, see Policy.

Directions

Creating dependency resources

The following components are required as dependencies during function creation and must be created in advance: VPC, CFS file system or COS bucket, and TencentDB for Redis instance. For detailed directions on how to create them, see Building up an IPv4 VPC, Creating File Systems and Mount Targets, Getting Started with the Console, and Creating TencentDB for Redis Instances respectively.

Creating panoramic recording application

1. Log in to the Serverless console and select Serverless Application on the left sidebar.
2. On the Serverless Application page, click Create Application.
3. On the Create Application page, configure as prompted.
   • Creation method: select Template.
   • Fuzzy search: enter "panoramic", search, and select Panoramic recording .
     Click Learn More in the template to view relevant information in the Template Details pop-up window, which can be downloaded.
4. Click Next and configure the related information .
   • Application Name: enter a name such as "record-app".
   • Region: select a region such as "Shanghai".
   • Intermediate Result Storage: select the storage position of temporary files during recording. You can select COS or CFS as needed.
   • Target Storage: select the final storage position of recording results. You can select VOD or COS as needed.
   • File System: select as needed.
   • Redis: select as needed.
5. Click Complete.
   If you want to modify function configuration based on your business scenario, do so in Serverless Application > Resource List > Function Details as shown below:
   

   Note

   • If the recording application needs to rely on the prolonged function execution capability, configure as instructed in Async Execution.
   • To avoid request timeout, we recommend you set the backend timeout period of the API Gateway trigger to a large value or use the default value. For more information, see Provisioned Concurrency.

API use instructions

Prerequisites

• Prepare a webpage that can be visited through a URL and is compatible with Chrome as the recording content source.
• You should handle the possible login status or authentication on the page to be recorded by yourself.
• If multimedia needs to be played back on the page to be recorded, you should handle multimedia operations such as playback, redirect, and stop by yourself.
• The page to be recorded must display the complete content within the specified width and height with no scrollbars, as web panoramic recording can record only the visible area of the browser window but cannot record the content outside this area.

API request path

Recording start API

This API is used to start panoramic recording. Parameters such as recording URL, resolution, and result callback address need to be specified in API parameters.

{
    "Action": "Start",
    "Data": {
        "RecordURL": "https://web-record-12596******.cos.ap-chengdu.myqcloud.com/test/ponyo.mp4", 
        "Width": 1280,
        "Height": 720,
        "CallbackURL": "http://xxx/webrecord/callback",
        "MaxDurationLimit": 21600,
        "Output":{
            "Cos":{
                "Domain":"abc.xxx.com", 
                "Bucket":"webrecord-xxx", 
                 "Region":"ap-shanghai", 
                "TargetDir":"11234/", 
                "TargetName":"record-file-name.mp4"  
        },
         "Vod": {
          "MediaInfo": {
                "MediaName": "test",
                "ExpireTime": "2023-10-01T10:00:00Z",
                "StorageRegion": "ap-shanghai",
                "ClassId": 1
                },
        "ProcedureInfo": {
                "Procedure": "",
                "SessionContext": ""
                },
        "SubAppId": 1500007120
            },
     "Video": {
        "Muxer": "hls",
            "EncryptKey": "21834cca41778803e1afba3f41e70c90",
            "AuthUrl": "https://hls-web-record-1253970226.cos.ap-shanghai.myqcloud.com/m3u8-encrypt/enc.key"
            }
         }
        }
}

// Response upon request success
{
    "TaskID": "d1806f20-25b8-4c30-8176-c0832b**",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

// Response upon request failure
{
    "ErrorCode": "InvalidParam",
    "ErrorMessage": "RecordURL missing",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

Recording pause API

This API is used to pause a running recording task.

{
    "Action": "Pause", 
    "Data": {
        "TaskID": "0f7d9522-a1a3-4517-b5ad-7a6eca**" 
    }
}

// Response\supon\srequest\ssuccess
{
    "TaskID": "d1806f20-25b8-4c30-8176-c0832b**",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

// Response upon request failure
{
    "ErrorCode": "InvalidParam",
    "ErrorMessage": "TaskID missing",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

Recording resumption API

This API is used to resume a paused recording task. The video content after resumption will be directly added to the content before pause without generating new video segments.

{
    "Action": "Resume", 
    "Data": {
        "TaskID": "0f7d9522-a1a3-4517-b5ad-7a6eca**" 
    }
}

// Response upon request success
{
    "TaskID": "d1806f20-25b8-4c30-8176-c0832b**",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

// Response upon request failure
{
    "ErrorCode": "InvalidParam",
    "ErrorMessage": "TaskID missing",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

Recording page refresh API

This API is used to initiate a request to refresh the page to be recorded.

{
    "Action": "Refresh", 
    "Data": {
        "TaskID": "0f7d9522-a1a3-4517-b5ad-7a6eca**" 
    }
}

// Response upon request success
{
    "TaskID": "d1806f20-25b8-4c30-8176-c0832b**",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

// Response upon request failure
{
    "ErrorCode": "InvalidParam",
    "ErrorMessage": "TaskID missing",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

Recording stop API

This API is used to initiate a recording stop request.

{
    "Action": "Stop", 
    "Data": {
        "TaskID": "0f7d9522-a1a3-4517-b5ad-7a6eca**" 
    }
}

// Response upon request success
{
    "TaskID": "d1806f20-25b8-4c30-8176-c0832b**",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

// Response upon request failure
{
    "ErrorCode": "InvalidParam",
    "ErrorMessage": "TaskID missing",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

Recording task information query API

This API is used to initiate a request to query the recording task information.

{
    "Action": "Describe", 
    "Data": {
        "TaskID": "0f7d9522-a1a3-4517-b5ad-7a6ec**"
    }
}

// Response upon request success
{
    "TaskID": "7a035551-d9d6-494e-b604-fa787b**",
    "RequestID": "95941e2c85898384a95b81c2a5**",
    "CreateTime": 1620982173,
    "Status": "finished",
    "StartTime": 1620982177,
    "CancelTime": 1620982203,
    "StopTime": 1620982203,
    "FinishTime": 1620982210,
    "Result": {
        "Videos": [
            {
                "Filename": "1621406865789.mp4",
                "FileSize": 169780,
           "FileDuration": 9,
            "FileId": 31235664578998,
                "FileURL": "http://web-record-125******.cos.ap-chengdu.myqcloud.com/4d0f336d-4de4-4fc8-b505-d1f790974909/162140******.mp4"
            }
        ]
    }
}

// Response upon request error
{
    "ErrorCode": "InvalidParam",
    "ErrorMessage": "TaskID missing",
    "RequestID": "95941e2c85898384a95b81c2a5**"
}

// Response upon recording task error
{
    "TaskID": "7a035551-d9d6-494e-b604-fa787b**",
    "RequestID": "95941e2c85898384a95b81c2a5**",
    "CreateTime": 1620982173,
    "Status": "finished",
    "StartTime": 1620982177,
    "CancelTime": 1620982203,
    "StopTime": 1620982203,
    "FinishTime": 1620982210,
    "Result": {
        "ErrorCode": "CallbackFailed",
        "ErrorMessage": "Callback failed even all tries. last error message:ECONNABORTED:timeout of 2000ms exceeded"
    }
}