Single Stream Transcoding

Feature Introduction

Single stream transcoding refers to converting a single original stream into transcoded streams with different encoding formats and resolutions on the cloud. In scenarios such as live streaming, viewers can choose streams of different resolutions to watch based on network quality, terminal devices, etc., to ensure playback smoothness.

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 clarity. 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

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.

• You have integrated the ZEGO Express SDK in the project and implemented basic audio and video publishing and playing functions. For details, please refer to Quick Start - Integration and Quick Start - Implementation Flow.

• You need to use L3 Playing Stream, Forward-to-CDN Playing Stream (playing by streamID), or RTC playing stream, and have not used the stream mixing feature.

Implementation Flow

The main flow of single stream transcoding is as follows:

1. Add transcoding template.
2. Create engine and log in to room.
3. Pull transcoded stream as needed, choose the playing stream method as L3 Playing Stream, Forward-to-CDN Playing Stream (playing by streamID) or RTC as needed, and pass in the transcoding template ID to trigger transcoding.

1 Add transcoding template

Please contact ZEGO 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.

2 Create engine and log in to room

For the specific flow, please refer to the Create Engine and Login Room sections of the "Implementing Video Call" document.

3 Play transcoded stream

Configure the codecTemplateID property of ZegoPlayerConfig, fill in the transcoding template ID obtained in Step 1 Add Transcoding Configuration Template, and start playing stream.

ZegoPlayerConfig *playerConfig = [[ZegoPlayerConfig alloc] init];
// Configure according to actual business conditions
playerConfig.resourceMode = ZegoStreamResourceModeOnlyL3;
// 101 is the configured template ID, refer to Step 1 Add Transcoding Configuration Template
playerConfig.codecTemplateID = 101;

ZegoCanvas *playCanvas = [ZegoCanvas canvasWithView:self.playView];

// engine is the ZegoExpressEngine object created when creating the engine
[[ZegoExpressEngine sharedEngine] startPlayingStream:@"streamID" canvas:playCanvas config:playerConfig];

ZegoPlayerConfig *playerConfig = [[ZegoPlayerConfig alloc] init];
// Configure according to actual business conditions
playerConfig.resourceMode = ZegoStreamResourceModeOnlyL3;
// 101 is the configured template ID, refer to Step 1 Add Transcoding Configuration Template
playerConfig.codecTemplateID = 101;

ZegoCanvas *playCanvas = [ZegoCanvas canvasWithView:self.playView];

// engine is the ZegoExpressEngine object created when creating the engine
[[ZegoExpressEngine sharedEngine] startPlayingStream:@"streamID" canvas:playCanvas config:playerConfig];

FAQ