Creates a mixed-stream relay task.
Usage notes
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.
QPS limit
You can call this operation up to 500 times per second per account. Requests that exceed this limit are dropped and you will experience service interruptions. We recommend that you take note of this limit when you call this operation. For more information, see QPS limits.
Debugging
Request parameters
Parameter | Type | Required | Example | Description |
Action | String | Yes | StartLiveMPUTask | The operation that you want to perform. Set the value to StartLiveMPUTask. |
AppId | String | Yes | yourAppId | The application ID. You can specify only one application ID. The ID can be up to 64 characters in length and can contain letters, digits, underscores (_), and hyphens (-). |
ChannelId | String | Yes | yourChannelId | The channel ID. You can specify only one channel ID. The ID can be up to 64 characters in length and can contain letters, digits, underscores (_), and hyphens (-). |
TaskId | String | Yes | yourTaskId | The task ID. You can specify only one task ID. The ID can be up to 55 characters in length and can contain letters, digits, underscores (_), and hyphens (-). The ID must be unique. |
MixMode | String | Yes | 0 | The stream mixing mode. Valid values:
|
StreamURL | String | Yes | rtmp://example.com/live/stream | The ingest URL. You can specify only one URL. For information about the generation rules of ingest URLs, see Ingest and streaming URLs. Note
|
Region | String | No | CN-Shanghai | The region in which the streams are mixed. Valid values:
|
SingleSubParams | Object | No | The single-stream relay parameters. These parameters are required if you set MixMode to 0. Leave these parameters empty in the mixed-stream relay mode. | |
UserId | String | Yes | yourSubUserId | The user ID. In the single-stream relay mode, you can relay only one stream in a request. |
StreamType | String | No | 0 | The type of the stream that you want to relay. Valid values:
|
SourceType | String | No | camera | The type of the video source. This parameter is valid only when you set StreamType to 2. Valid values:
|
TranscodeParams | Object | No | The mixed-stream relay parameters. These parameters are required if you set MixMode to 1. Leave these parameters empty in the single-stream relay mode. | |
UserInfos | Array | No | The information about the user. If you leave this parameter empty, streams from all users are mixed. | |
UserId | String | Yes | yourSubUserId | The user ID. |
StreamType | String | No | 0 | The type of the stream that you want to relay. Valid values:
|
SourceType | String | No | camera | The type of the video source. This parameter is valid only when you set StreamType to 2. Valid values:
|
EncodeParams | Object | No | The encoding parameters for the output stream. | |
AudioOnly | String | No | false | Specifies whether the output stream is an audio-only stream. Valid values:
|
VideoWidth | String | No | 1920 | The width of the video. Valid values: [0,1920]. Unit: pixels. |
VideoHeight | String | No | 1000 | The height of the video. Valid values: [0,1920]. Unit: pixels. |
VideoFramerate | String | No | 25 | The frame rate of the video. Valid values: [1,60]. Unit: frames per second (FPS). |
VideoBitrate | String | No | 3500 | The bitrate of the video. Valid values: [1,10000]. Unit: Kbit/s. |
VideoGop | String | No | 20 | The group of pictures (GOP) size of the video. Valid values: [1,60]. |
AudioSampleRate | String | No | 44100 | The audio sampling rate. Valid values: 8000, 16000, 32000, 44100, and 48000. Unit: Hz. |
AudioBitrate | String | No | 128 | The bitrate of the audio. Valid values: [8,500]. Unit: Kbit/s. |
AudioChannels | String | No. | 2 | The number of sound channels. Valid values: 1 and 2. |
Layout | Object | No | The video layout information. Note You must specify this parameter for audio and video transcoding. Leave this parameter empty if the stream is an audio-only stream. | |
UserPanes | Array | No | The information about the pane. | |
UserInfo | Object | No | The information about the user whose stream is played in the pane. If you leave this parameter empty, the system automatically sets this parameter based on the order in which streamers join the channel. This parameter is valid only when you set StreamType to 0 or 2. | |
UserId | String | No | yourSubUserId | The user ID. |
SourceType | String | No | camera | The type of the video source. This parameter is valid only when you set StreamType to 2. Valid values:
|
X | String | No | 0.2456 | The x-coordinate of the pane. The value is normalized. |
Y | String | No | 0.3789 | The y-coordinate of the pane. The value is normalized. |
Width | String | No | 0.3564 | The width of the pane. The value is normalized. |
Height | String | No | 0.2632 | The height of the pane. The value is normalized. |
ZOrder | String | No | 0 | The layer in which the pane resides. A value of 0 indicates the bottom layer. A value of 1 indicates the upper layer of the bottom layer. By analogy, you can obtain the specific layer indicated by a specific value. |
BackgroundImageUrl | String | No | yourImageUrl | The URL of the background image of the pane. This image is displayed if the user disables the camera or has not joined the channel. |
RenderMode | String | No | 1 | The display mode of the pane. Valid values:
|
Background | Object | No | The global background image. | |
URL | String | No | yourImageUrl | The URL of the global background image. |
RenderMode | String | No | 1 | The display mode of the global background image.
|
SeiParams | Object | No | The supplemental enhancement information (SEI) parameters. | |
PayloadType | String | No | 100 | The custom payload_type of the SEI. Valid values: 100 to 254. If you do not specify this parameter, the default value 5 is used. |
LayoutVolume | Object | No | The layout and volume SEI. If you leave this parameter empty, the default layout and volume SEI is used. | |
FollowIdr | String | No | 0 | Specifies whether to include the SEI in an Instantaneous Decoder Refresh (IDR) frame. Valid values:
|
Interval | String | No | 1000 | The interval at which the SEI is sent. Valid values: [1000,5000]. Unit: milliseconds. |
PassThrough | Object | No | Specifies whether to pass through the SEI. | |
PayloadContentKey | String | No | yourPayloadContentKey | The key of the payload content of the SEI. If you do not specify this parameter, the default value udd is used. |
PayloadContent | String | No | yourPayloadContent | The payload content of the SEI. |
FollowIdr | String | No | 0 | Specifies whether to include the SEI in an IDR frame. Valid values:
|
Interval | String | No | 1000 | The interval at which the SEI is sent. Valid values: [1000,5000]. Unit: milliseconds. |
Layout and volume SEI
Parameter | Description |
canvas | The information about the canvas. The following fields are included:
|
stream | The information about the video stream. The following fields are included:
|
ts | The operating system timestamp when the SEI is generated. Unit: milliseconds. |
ver | The version of the SEI. For example, the current version is 1.0.0.20220915. |
udd | The custom scenario-based event that is sent by using the PassThrough parameter. The content of the event is specified by the PayloadContent parameter. |
The following example shows a co-streaming scenario:
If a single streamer is streaming, the SEI message that viewers receive contains information about only one participant. If co-streaming or 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:
{"canvas":{"w":1920,"h":1080,"bgnd":0},"stream":[{"uid":"111","paneid":-1,"zorder":0,"x":0,"y":0,"w":0,"h":0,"type":0,"status":1,"muted":0,"vol":0,"vad":0}],"ver":"1.0.0.20220915","ts":1697696105170}
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:
{"canvas":{"w":1920,"h":1080,"bgnd":0},"stream":[{"uid":"111","paneid":0,"zorder":1,"x":0,"y":0.25,"w":0.5,"h":0.5,"type":0,"status":1,"muted":0,"vol":1,"vad":119},{"uid":"222","paneid":1,"zorder":1,"x":0.5018382,"y":0.25,"w":0.5,"h":0.5,"type":0,"status":1,"muted":0,"vol":60,"vad":123}],"ver":"1.0.0.20220915","ts":1697696106230}
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 battle occurs. The layout information of the participants can indicate the position of each participant in the mixed stream.
Pass through the SEI
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:
{"canvas":{"w":1920,"h":1080,"bgnd":0},"stream":[{"uid":"111","paneid":-1,"zorder":0,"x":0,"y":0,"w":0,"h":0,"type":0,"status":1,"muted":0,"vol":0,"vad":0}],"ver":"1.0.0.20220915","ts":1697696109876,"udd":"hello world"}
Response parameters
Parameter | Type | Example | Description |
RequestId | String | 0F72851F-5DC1-1979-9B2C-450040316C3E | The request ID. |
Examples
Sample requests
http(s)://live.aliyuncs.com/?Action=StartLiveMPUTask
&AppId=yourAppId
&ChannelId=yourChannelId
&TaskId=yourTaskId
&MixMode=0
&StreamURL=rtmp://example.com/live/stream
&Region=CN-Shanghai
&SingleSubParams={"UserId":"yourSubUserId","StreamType":"0","SourceType":"camera"}
&TranscodeParams={"UserInfos":[{"UserId":"yourSubUserId","StreamType":"0","SourceType":"camera"}],"EncodeParams":{"AudioOnly":"false","VideoWidth":"1920","VIdeoHeight":"1080","VideoFramerate":"25","VideoBitrate":"3500","VideoGop":"20","AudioSampleRate":"44100","AudioBitrate":"128","AudioChannels":"2"},"Layout":{"UserPanes":[{"UserInfo":{"UserId":"yourSubUserId","SourceType":"camera"},"X":"0.2456","Y":"0.3789","Width":"0.3564","Height":"0.2632","ZOrder":"0","BackgroundImageUrl":"yourImageUrl","RenderMode":"1"}]},"Background":{"URL":"yourImageUrl","RenderMode":"1"}}
&SeiParams={"PayloadType":"100","LayoutVolume":{"FollowIdr":"0","Interval":"1000"},"PassThrough":{"PayloadContentKey":"yourPayloadContentKey","PayloadContent":"yourPayloadContent","FollowIdr":"0","Interval":"1000"}}
&<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.