:StartLiveMPUTask (new)

By default, you can create up to 200 single-stream relay tasks and up to 40 mixed-stream relay tasks for an application. To increase the quota, submit a ticket.

Request parameters

Layout and volume SEI

If a single streamer is streaming, the SEI message that viewers receive contains information about only one participant. If co-streaming or a battle occurs, the SEI message that viewers receive contains information about multiple participants.

For example, when the streamer whose user ID is 111 is streaming, an SEI frame in the following format is sent to the viewer side:

When the streamer whose user ID is 111 is co-streaming with a co-streamer whose user ID is 222, an SEI frame in the following format is sent to the viewer side:

Viewers can determine whether a streaming layout changes based on the number of stream arrays. If only one stream array exists, a single streamer is streaming. If more than one stream array exists, co-streaming or a battle occurs. The layout information of the participants can indicate the position of each participant in the mixed stream.

SEI pass-through

• To configure custom SEI, call the StartLiveMPUTask operation to start a mixed-stream relay task and specify the PayloadContent parameter under the PassThrough parameter, or call the UpdateLiveMPUTask operation to update a mixed-stream relay task and specify the PayloadContent parameter under the PassThrough parameter.
• Custom SEI can be sent periodically. You can use the Interval parameter under the PassThrough parameter to specify the interval in milliseconds.
• Custom SEI can also be sent with keyframes by specifying the FollowIdr parameter under the PassThrough parameter.
  • You can configure settings to periodically send the custom SEI and send the custom SEI with keyframes at the same time. For example, you can set the Interval parameter to 1000 and the FollowIdr parameter to 1 to send the custom SEI every 1,000 milliseconds and include the custom SEI in keyframes.
  • If you do not specify the Interval parameter and the FollowIdr parameter, the custom SEI is sent only once when you call the operation.

For example, the streamer whose user ID is 111 ingests a stream and calls the UpdateLiveMPUTask operation to specify periodic SEI. In the operation, the Interval parameter is set to 1000, the FollowIdr parameter is set to 0, and the PayloadContent parameter is set to "hello world". In this case, the custom SEI is sent every 1,000 milliseconds. The SEI frame received on the viewer side is in the following format:

Mixed-stream relay across channels

If you want to mix streams from multiple streamers across multiple channels and relay the mixed stream to ApsaraVideo Live, you must specify the user ID and channel ID of the streamer who initiates the cross-channel call and the user IDs of other streamers as input parameters to create a mixed-stream relay task. Example:

In a battle scenario, Streamer A in Channel A initiates a cross-channel battle with Streamer B in Channel B by using the client interface and relays the mixed stream to viewers in Channel A. In this example, the following parameters are specified:

• ChannelID: channelA
• UserId under UserInfos: userA and userB

Response parameters

Examples

Sample requests

http(s)://live.aliyuncs.com/?Action=StartLiveMPUTask
&AppId=yourAppId
&ChannelId=yourChannelId
&TaskId=yourTaskId
&MixMode=0
&StreamURL=rtmp://example.com/live/stream
&MultiStreamURL=[{"URL":"rtmp://example.com/live/stream****"}]
&Region=CN-Shanghai
&SingleSubParams={"SourceType":"camera","StreamType":"0","UserId":"yourSubUserId"}
&TranscodeParams={"Background":{"RenderMode":"1","URL":"yourImageUrl"},"EncodeParams":{"AudioOnly":"false","AudioBitrate":"128","AudioChannels":"2","AudioSampleRate":"44100","VideoCodec":"H.264","VideoBitrate":"3500","VideoFramerate":"25","VideoGop":"20","VideoHeight":"1000","VideoWidth":"1920","EnhancedParam":"{\"profile\": \"high\", \"preset\": \"veryfast\"}"},"Layout":{"UserPanes":[{"UserInfo":{"SourceType":"camera","ChannelId":"yourChannelId","UserId":"yourSubUserId"},"Height":"0.2632","Width":"0.3564","X":"0.2456","Y":"0.3789","ZOrder":"0","BackgroundImageUrl":"yourImageUrl","RenderMode":"1"}]},"UserInfos":[{"SourceType":"camera","StreamType":"0","ChannelId":"yourChannelId","UserId":"yourSubUserId"}]}
&SeiParams={"LayoutVolume":{"FollowIdr":"0","Interval":"1000"},"PassThrough":{"FollowIdr":"0","Interval":"1000","PayloadContent":"yourPayloadContent","PayloadContentKey":"yourPayloadContentKey"},"PayloadType":"100"}
&<Common request parameters>

Sample success responses

XML format

HTTP/1.1 200 OK
Content-Type:application/xml

<StartLiveMPUTaskResponse>
    <RequestId>0F72851F-5DC1-1979-9B2C-450040316C3E</RequestId>
</StartLiveMPUTaskResponse>

JSON format

HTTP/1.1 200 OK
Content-Type:application/json

{
  "RequestId" : "0F72851F-5DC1-1979-9B2C-450040316C3E"
}

Error codes

For a list of error codes, see Service error codes.