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    Intelligent Media Services:Manage channels

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    Intelligent Media Services:Manage channels

    Last Updated:Jun 11, 2025

    MediaLive uses channels to configure and control the workflows of live streams, including obtaining input sources, configuring encoding settings, and specifying output destinations. This enables real-time transmission and distribution of high-quality content. This topic describes how to manage channels.

    What is MediaLive channel?

    A MediaLive channel ingests and transcodes source content from the inputs attached to that channel, and packages the new content into outputs. You configure and control the channel to implement your business workflow.

    Note

    You can add multiple inputs and up to 20 output groups to a channel.

    Configure inputs

    1. Log on to the Intelligent Media Services (IMS) console. In the top left corner, select a region based on your business requirements.

    2. In the left-side navigation pane, choose MediaLive > Channels. On the Channels page, click Create Channel.image

    3. Enter a custom name in the Channel Name field. Click Add in the Added Inputs section.image

    4. In the Add Input panel, enter an input ID or name in the search box and click the input that you want to add. Then, click OK.

      Note

      If no inputs are available, you can create one directly in the panel. For information about input configurations, see Step 4 in Manage inputs.

      image

    5. The Edit Input Settings panel shows the Input ID, Input Name, and Input Type. You can configure the audio selectors.image

      Note

      The audio selectors are optional. If the input protocol is Real-Time Messaging Protocol (RTMP), you can configure only one audio selector.

      Audio selector parameters:

      Parameter

      Description

      Audio Selector Name

      The name of the audio selector, which is generated by the system by default.

      For RTMP inputs:

      Language Name

      Enter a custom language name. It will be referenced in the output.

      For SRT and MediaConnect inputs:

      Selector Settings

      Valid values:

      • Audio language selection

      • Audio pid selection

      • Audio track selection

      Language code

      If Selector Settings is set to audio language selection, enter an ISO 639-2 language code.

      PID

      If Selector Settings is set to audio pid selection, enter a PID.

      Track

      If Selector Settings is set to audio track selection, enter one or more track IDs.

    6. Click OK to add the input. You can click Modify to modify the input settings.image

      Note

      The basic information section displays the input status. Online indicates that audio and video data are being received. Offline indicates no data input.

    7. To delete an added input, click the Delete icon next to the input.image

    Configure output groups

    Note

    • Outputs in an output group must use the same protocol. Currently, MediaLive supports outputs to MediaPackage only.

    • You can configure an active output and a standby output in an output group.

    • You can configure specific audio and video parameters for each output.

    1. Click Add in the Added Output Groups section. Configure the parameters of the output group. image

      Output group parameters:

      Parameter

      Description

      Output Group Name

      Enter a custom name. The name can be up to 64 characters in length and can contain digits, letters, underscores (_), and hyphens (-).

      Output Group Type

      Only MediaPackage is supported.

      MediaPackage Destination

      GroupName: the name of the channel group in the Live Package module.

      ChannelName: the name of the channel in the Live Package module.

      The stream in pushed to the specified MediaPackage channel under the same account.

      Output Name

      Enter a custom name.

      Manifest Name Modifier

      The child manifests include this modifier in their file names. This is used to distinguish between different outputs.

      Manifest Audio Group ID

      Enter a custom manifest audio group ID.

      SCTE-35 Processing

      Specify whether to pass-through SCTE-35 ad markers.

      • Pass-through (default): SCTE-35 messages from the input are passed through and included in the TS segments of output. The SCTE-35 markers are also written to the manifest file.

      • Do Not Pass: SCTE-35 messages from the input are removed for the TS segments of output.

      Note

      • The SCTE-35 standard specifies the format and methods for inserting cue messages into video streams. The signals defined by the standard are typically embedded in MPEG-2 transport streams to indicate the positions of advertising insertion points.

      • This setting is only available for SRT inputs, including SRT streams from MediaConnect.

      SCTE-35 PID

      The parameter is available when SCTE-35 Processing is set to Pass-through.

      If your input contains multiple SCTE-35 PIDs, you can select one to pass through to the output. By default, MediaLive will select the first PID present on the input. If the PID value specified is not present in the input, no PID will be passed.

      Media Type

      Select the type of output encode. Valid values:

      • Audio and Video

      • Audio

      • Video

      Video Output Name

      Enter a custom name.

      Video Transcoding Template

      Valid values:

      • Regular transcoding: supports up to 4K resolution.

      • Narrowband HD™ transcoding: supports up to 1080P resolution.

      Note

      • Both templates support H.264 and H.265 codecs.

      • Narrowband HD™ transcoding is a transcoding solution developed by Alibaba Cloud. Compared to regular transcoding, it ensures high image quality while reducing bandwidth usage through advanced encoding and smart optimization. This helps provide a clearer, smoother viewing experience at the same bandwidth.

      Video Codec

      Select a video codec. After you specify this parameter, you can configure the specific video encoding parameters.

      Audio Output Name

      Enter a custom name.

      Audio Encoder

      Valid values:

      • aac

      • libfdk_aac

      After you specify this parameter, configure the specific audio encoding parameters.

      Audio Selector

      Select an audio selector. The available audio selectors are determined by the input settings. If not specified, the source specification is used by default.

      Language Code

      Enter a 3-character ISO 639-2 language code. If not specified, the source specification is used by default.

      Language Name

      Enter a language name. If not specified, the source specification is used by default.

      Note

      The name can contain letters in various languages, digits, spaces, underscores (_), and hyphens (-), with up to 32 UTF-8 characters in length. It cannot start or end with a space.

      Video codec settings:

      Parameter

      Description

      Resolution

      Enter the width and height of a custom resolution.

      Note

      • If the width and height are not specified or set to 0, the output uses the source specifications. If one of them is specified, the other automatically adapts to maintain the original aspect ratio.

      • For regular transcoding, the maximum resultion is 4K (long edge ≤ 3840 and short edge ≤ 2160).

      • For Narrowband HD™ transcoding, the maximum resolution is 1080P (long edge ≤ 1920 and short edge ≤ 1080).

      Video Bitrate

      Enter a custom video bitrate. If not specified, the source specification is used by default. Valid values: 50 to 6000 kbps.

      Bitrate Control Mode

      Select one of the following modes. If not specified, the source specification is used by default.

      • ABR

      • CBR

      • VBR

      Max Bitrate

      Enter a custom maximum video bitrate. If not specified, the source specification is used by default. Valid values: 100 to 6000 kbps.

      Buffer Size

      Enter a custom video buffer size. If not specified, the source specification is used by default. Unit: kbps.

      Frame Rate Mode

      Select one of the following modes. If not specified, the source specification is used by default.

      • Custom

      • Use Source Specification

      Frame Rate

      Enter a custom frame rate numerator and frame rate denominator. The max frame rate supported is 60 FPS.

      GOP Size Unit

      Select one of the following units. If not specified, the source specification is used by default.

      • SECONDS

      • FRAMES

      GOP

      Enter a GOP value. If not specified, the source specification is used by default.

      Number of B Frames

      Enter a custom number of B-frames. If not specified, the source specification is used by default.

      H.264 Profile

      Select one of the following profiles. If not specified, the source specification is used by default.

      • BASELINE

      • MAIN

      • HIGH

      Audio codec settings:

      Parameter

      Description

      Profile

      Different audio encoders support different audio profiles.

      • If Audio Encoder is set to aac, the following profiles are available:

        • AAC-LOW

        • AAC-MAIN

      • If Audio Encoder is set to libfdk_aac, the following profiles are available:

        • AAC-LOW

        • AAC-HE

        • AAC-HEV2

      Audio Bitrate

      Enter a custom audio bitrate. If not specified, the source specification is used by default.

      Sample Rate

      Enter a custom audio sample rate. If not specified, the source specification is used by default.

    2. Click OK. The output group is added to the channel. You can click Modify to modify the settings of the output group.image

    3. To delete an output group, click the Delete icon next to the output group.image

    4. After all inputs and output groups are configured, click Start or Stop in the Channel Status section to start or stop the channel. You can also view the basic information of the channel or modify the channel name in the Basic Information section.image

    View channels

    • On the Channels page, channels are displayed in descending order based on creation time.

    • The channel list includes the following columns: Channel ID/Name, Status, Last Started, Running Time, Inputs, Output Groups, and Actions. For more information, see View channels.

    • You can click the refresh button on the right of the Channels page to display the latest channel information. Up to 10 channels can be displayed per page.

    References

    For more information about how to start and stop a channel, see Control channel state.