MediaLive ingests external video sources, converts streaming protocols, transcodes video, and composes audio tracks for live-stream outputs.
Overview
MediaLive provides four core features: input association, protocol conversion, video transcoding, and audio track composition.
-
Input association: Add multiple external video sources to MediaLive for processing, such as obtaining a video stream, filtering audio streams, and merging video and audio streams for channel output.
-
Protocol conversion: Configure multiple output groups that use different streaming protocols for a channel. The output group converts the protocol of the video and audio streams merged in the previous step to the required protocol.
-
Video transcoding: Configure the transcoding format for an output. For example, you can convert an original video stream from 1080P to 720P.
-
Audio track composition: Configure audio tracks for an output. The audio tracks are combined with the video track transcoded and packaged in the specified format to form an output to MediaPackage.
An output group consists of one or more outputs. Each output contains a specific combination of video and audio tracks.
Input association
Associate a configured input with a channel. You can configure an audio selector to extract specific audio tracks from the input so that only those tracks are used in the output.
-
The audio selector is optional. An RTMP input supports only one audio selector, while an SRT input supports multiple selectors.
-
For more information, see Audio selector parameters.
A channel supports only one video stream and multiple audio streams. By default, the video stream of the first input is used.
Protocol conversion
Converts the streaming protocol of the source video to the required protocol. For more information, see Output group parameters.
MediaLive supports delivering content to MediaPackage only over the HLS protocol.
Video transcoding
Modifies the encoding parameters of the original video. Advanced configurations include ad marker passthrough, transcoding templates, and 4K transcoding.
-
Ad marker passthrough: Passes through specified SCTE-35 messages from the input source to the output.
-
Transcoding templates: Supports two types of video transcoding templates
-
Regular transcoding: Supports up to 4K resolution.
-
Narrowband HD™ transcoding: Uses Alibaba Cloud's proprietary algorithm to achieve lower data usage with the same image quality or higher definition video with the same bandwidth. Supports up to 1080P resolution.
-
-
4K transcoding: Provides real-time encoding for 2K and 4K high-resolution content.
For more information, see Output group parameters.
Audio track composition
Extracts audio tracks from inputs by using the audio selector and combines them with other audio and video streams for outputs.
When associating an input with a channel, configure the audio selectors for the required audio tracks. Then, select the appropriate configured audio selectors for an output.