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 definitions. In this case, the single stream transcoding function can be used.
• When converting original video streams into different video encoding formats, the single stream transcoding function can be used. For example, when some devices cannot decode H.265 due to performance issues, they need to transcode to H.264.

Prerequisites

Before using the single stream transcoding function, ensure that:

• 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 ZEGO Express SDK into your project and implemented basic audio and video stream publishing and playing functionality. For details, please refer to Quick Start - Integration and Quick Start - Implementation.

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

Implementation Flow

The main flow of single stream transcoding is as follows:

1. Add transcoding template.
2. Create engine and login to room.
3. Play transcoded streams on demand, choose stream playing method as L3 Stream Playing, Relay to CDN Stream Playing (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 transcoding templates 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 Login to Room

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

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 config;
// Configure according to actual business situation
config.resourceMode = ZEGO_STREAM_RESOURCE_MODE_DEFAULT;
// 101 is the configured template ID, refer to Step 1 Add Transcoding Configuration Template
config.codecTemplateID = 101;

ZegoCanvas canvas(ZegoUtilHelper::GetView(ui->frame_Play));
canvas.viewMode = static_cast<ZegoViewMode>(ui->comboBox_ViewModePlay->currentIndex());
// engine is the IZegoExpressEngine object created when creating the engine
engine->startPlayingStream("streamid", &canvas, config);

ZegoPlayerConfig config;
// Configure according to actual business situation
config.resourceMode = ZEGO_STREAM_RESOURCE_MODE_DEFAULT;
// 101 is the configured template ID, refer to Step 1 Add Transcoding Configuration Template
config.codecTemplateID = 101;

ZegoCanvas canvas(ZegoUtilHelper::GetView(ui->frame_Play));
canvas.viewMode = static_cast<ZegoViewMode>(ui->comboBox_ViewModePlay->currentIndex());
// engine is the IZegoExpressEngine object created when creating the engine
engine->startPlayingStream("streamid", &canvas, config);

FAQ