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Overview

Open Broadcaster Software (OBS) is a third-party open-source tool for live streaming. It’s easy to use and free of charge, and it supports OS X, Windows, and Linux. OBS can be used in a wide range of scenarios to meet most live streaming needs without requiring additional plugins. You can download its latest version at the OBS website.

Prerequisites

• You have installed OBS Studio.
• You have activated CSS and added a playback domain with an ICP filing number in the console (for push, you can use the default domain we provide or add your own).

Getting a Push URL

1. Log in to the CSS console, click Address Generator in the left sidebar, and follow the steps below:
   1. Select *Push Domain** for Domain Type.
   2. Select the domain name you have added in Domain Management.
   3. Enter an application name (AppName), which is used to distinguish applications under the same domain. The default value is live.
   4. Enter a custom stream name (StreamName), such as live.
   5. Select the expiration time of the address, such as 2020-06-09 23:59:59.
2. Click Generate Address to get an OBS push URL.

Configuring OBS for Push

Step 1. Configure the push URL

1. Open OBS and click Controls > Settings at the bottom to enter the settings page.
   
2. Click Stream and select Custom for Service.
3. Fill in the Server and Stream Key fields with the information obtained in Getting a Push URL.
   • Server: Enter the OBS push address (rtmp://domain/AppName/).
   • Stream key: Enter the OBS push name (StreamName?txSecret=xxxxx&txTime=5C1E5F7F).
     
4. Click OK to save the information.

Step 2. Configure the source

Note：

For bitrate, recording, and other settings, click Tools > Auto-Configuration Wizard in the top menu bar, and follow the instructions provided by OBS to complete the settings.

1. Find Sources in the menu bar at the bottom.
   
2. Click + and select a source that fits your needs, for example, Display Capture.
   

Common live streaming sources

Step 3. Use the studio mode

In studio mode, you can edit your current live stream in real time and configure transitions for scene swapping, minimizing the impact on user experience.

1. Click Controls > Studio Mode in the menu bar at the bottom.
2. After editing, click Transition to swap the edit and live views.
   

Step 4. Start streaming

1. Find Controls in the menu bar at the bottom.
2. Click Start Streaming to push your video to the configured push URL.
   

Note：

• If you see at the bottom, the push is successful.
• To stop streaming, click Stop Streaming.

Other Push Settings

Streaming latency

1. Go to Controls > Settings > Output.
2. Select Advanced for Output Mode to set parameters including Keyframe Interval.
   
3. Click Advanced in the left sidebar to set Stream Delay:
   

Local live recording

To record live streams to your local storage, follow the steps below:

1. Go to Controls > Settings > Output.
2. Complete the settings under Recording and click OK.
   
3. Click Video in the left sidebar to set the resolution and frame rate.

   Note：

   Resolution determines the clarity of video shown to viewers. The higher the resolution, the clearer the video. Frame rate (frames per second) determines playback smoothness. Typical frame rate falls in the range of 24 fps to 30 fps. Playback may stutter if frame rate is lower than 16 fps. Video games require higher frame rate and tend to stutter at a frame rate lower than 30 fps.

Transcoding

To change the video bitrate during streaming, follow the steps below:

1. Click Controls > Settings in the menu bar at the bottom.
2. Click Output in the left sidebar and select Simple for Output Mode.
3. Enter the bitrate you want to use and click OK.
   

More

Audio-only push

According to OBS Forums, OBS Studio 23.2.1 and earlier versions do not support audio-only streaming.
You can follow the steps below to implement a similar feature. The method uses a static canvas (blank screen or image) for video content. This means there will still be video data in the live stream. To reduce bandwidth usage, you can set the video frame rate and bitrate to the minimum values.

1. As instructed in Configure the source, select Audio Input Capture as the source. Do not use a video or image source.

2. Go to Controls > Settings > Video.

3. Set Base (Canvas) Resolution and Common FPS Values to the minimum values and click OK.
   

4. Click Output in the left sidebar, configure the output as shown below (set Bitrate to the minimum value), and click OK.
   

5. Start streaming as instructed in Configuring OBS for Push. The audience will hear audio, while the video will be a blank screen or an image. Because the video bitrate is set to the minimum value, the bandwidth usage is significantly lower than that of video push.

Video looping

• Loop a single file
  1. Click + in Sources and select Media Source. In the pop-up window, choose a local file to stream, select Loop, and click OK.
     
  2. Set the Server and Stream Key as instructed in Configure the push URL.

You can use the following methods to check whether the push is successful:

• PC: Use VLC to play the stream.
• Mobile: Use the MLVB SDK to play the stream.

  Note：

  Mobile Live Video Broadcasting (MLVB) extends the services of CSS to mobile devices. It offers not only an RTMP SDK that allows quick integration, but also a one-stop, multi-cloud solution that integrates Tencent Cloud services including LVB, LEB, VOD, IM, and COS.
  Live Event Broadcasting (LEB) is the ultra-low-latency version of LVB. It delivers superior playback experience with millisecond latency and is suitable for scenarios with high requirements on latency, such as online education, sports streaming, and online quizzes.