Single Stream Transcoding
Feature Overview
Single stream transcoding refers to converting a single original stream into transcoded streams with different encoding formats and resolutions in the cloud. In scenarios such as live streaming, audiences can choose streams of different resolutions to watch based on network quality, terminal devices, etc., to ensure smooth playback.
Application Scenarios
- When developers provide video streams of multiple resolutions for users to watch on demand, they need to convert the original stream into transcoded streams of different definitions. At this time, the single stream transcoding feature can be used.
- When converting original video streams to different video encoding formats, the single stream transcoding feature can be used. For example, when some devices cannot decode H.265 due to performance issues, they need to be transcoded to H.264.
Prerequisites
The single stream transcoding feature is currently in beta testing. If you need to access it, please contact ZEGO business personnel or ZEGOCLOUD Technical Support.
Before using the single stream transcoding feature, please ensure:
-
You have created a project in the ZEGOCLOUD Console and applied for a valid AppID and AppSign. For details, please refer to Console - Project Information.
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You have integrated the ZEGO Express SDK in your project and implemented basic audio and video streaming functionality. For details, please refer to Quick Start - Integration and Quick Start - Implementation.
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You need to use L3 playing stream, Relay to CDN playing stream (playing stream by streamID), or RTC playing stream, and have not used the stream mixing feature.
For scenarios that already use the stream mixing feature, you can directly implement outputting multiple streams with different resolutions based on the stream mixing interface without triggering single stream transcoding.
Implementation Process
The main process of single stream transcoding is as follows:
- Add transcoding template.
- Create engine and login room.
- Pull transcoded streams on demand, choose the playing method as L3 playing stream, Relay to CDN playing stream (playing stream by streamID), or RTC as needed, and pass in the transcoding template ID to trigger transcoding.
1 Add transcoding template
Please contact ZEGOCLOUD Technical Support to add a transcoding template and obtain the corresponding transcoding template ID.
Currently supported transcoding parameters are: template ID, resolution, bitrate, frame rate, and video encoding format.
- Currently only supports configuring video-related parameters.
- An AppID supports adding up to 5 transcoding templates. If you need to set more templates, please contact ZEGOCLOUD Technical Support.
| Parameter | Description |
|---|---|
| Template ID | Integer greater than 100, ID must be unique. Recommended to name according to output resolution, for example, the template ID for transcoding output resolution of 360P can be named 360. If the transcoding output resolution is less than 100P, you can name it yourself. |
| Resolution |
|
| Bitrate | Value must be greater than 0, unit is bps. |
| Frame Rate | Supported range: [1, 20], unit fps. If you need to output a higher frame rate, please contact ZEGOCLOUD Technical Support for configuration. |
| Video Encoding Format | Supports the following video encoding formats:
|
2 Create engine and login room
For specific process, please refer to the Create Engine and Login Room sections in the "Implementing Video Call" document.
Before implementing single stream transcoding, there must be an existing stream in the Room.
3 Play transcoded stream
Configure the codecTemplateID attribute of ZegoPlayerConfig, fill in the transcoding template ID obtained in Step 1 Add Transcoding Configuration Template, and start playing stream.
ZegoPlayerConfig playerConfig = new ZegoPlayerConfig();
// Configure according to actual business situation
playerConfig.resourceMode = ZegoStreamResourceMode.DEFAULT;
// 101 is the configured template ID, refer to Step 1 Add Transcoding Configuration Template
playerConfig.codecTemplateID = 101;
ZegoCanvas playCanvas = new ZegoCanvas(playView);
// engine is the ZegoExpressEngine object created when creating the engine
engine.startPlayingStream("playStreamID", playCanvas, playerConfig);FAQ
What is the difference between stream mixing and single stream transcoding?
- Stream mixing is generally used to merge multiple input streams into one, while supporting defining encoding format, resolution, and other parameters for multiple output streams. Stream mixing transcoding requires developers to additionally call client or server interfaces to trigger.
- Single stream transcoding is used to implement transcoding functionality for a single stream, and does not require developers to additionally call client or server interfaces to trigger. It only needs to be triggered by carrying template parameters when playing stream.