Configure video encoding

Customer satisfaction with your Video Calling integrated app depends on the quality of video and audio it provides. The sharpness, smoothness, and overall quality of the video is directly linked to the frame rate, bitrate, and other video encoder settings. Choosing improper settings can result in poor video quality. Conversely, if the settings are too demanding, the available bandwidth quickly gets choked, leading to a suboptimal experience for your users.

This page guides you on configuring the video encoder settings to ensure optimal video quality in your Broadcast Streaming app.

In Video SDK you can set the video dimensions, framerate, bitrate, orientation mode, and mirror mode by specifying a video profile. You can also set the degradation preference to specify how video quality is degraded under suboptimal network conditions.

• Resolution: Defines the video encoding resolution in pixels. The default value is 960 × 540. Higher resolutions generally result in better video clarity. Note that this parameter does not determine the final video orientation. Refer to Video orientation for setting the video output orientation.

• Frame rate: Represents the number of frames encoded per second (FPS). The default value is 15 FPS. A higher frame rate contributes to smoother video playback. For scenarios demanding high video smoothness, consider setting this parameter to 20 or 25. It is advised not to exceed a frame rate of 30.

• Bitrate: Indicates the video encoding bitrate in Kbps. The default mode is set to Standard Bitrate. In this mode, the Video SDK dynamically sets an appropriate bitrate based on the channel profile, resolution, and frame rate.

To find a suitable bitrate for a given combination of dimensions and framerate, refer to the Video profiles table.

To achieve high video quality, it's crucial to maintain a balanced relationship between resolution, bitrate, and frame rate. Higher resolutions necessitate a higher bitrate. If the bitrate is fixed, an excessively high frame rate can reduce the resolution.

The configured parameter settings represent maximum values under ideal conditions. In cases where video quality cannot reach the set maximum values due to network constraints or other factors, the actual values are adjusted to match the specified maximum resolution, frame rate, or bitrate as closely as possible.

Note

Video encoder configuration settings may affect billing. If settings are lowered due to adaptation, billing is based on the video resolution actually subscribed to by the user. For details, see Pricing.

The recommended video settings vary by scenario. For example, in a one-to-one online class, the video windows of the teacher and student are both large, which calls for higher resolution, frame rate, and bitrate. However, in a one-to-many online class, the video windows are smaller. You can set lower resolution, frame rate, and bitrate to accommodate bandwidth limitations.

Use the following as a guide when configuring video settings for these scenarios:

• One-to-one video call:

  • Resolution: 320 x 240; Frame rate: 15 fps; Bitrate: 200 Kbps.
  • Resolution: 640 x 360; Frame rate: 15 fps; Bitrate: 400 Kbps.

• One-to-many video call:

  • Resolution: 160 x 120; Frame rate: 15 fps; Bitrate: 65 Kbps.
  • Resolution: 320 x 180; Frame rate: 15 fps; Bitrate: 140 Kbps.
  • Resolution: 320 x 240; Frame rate: 15 fps; Bitrate: 200 Kbps.

The way video is displayed on the playing device depends on orientationMode used on the encoding device, orientation of the capturing device, orientation of the playing device, and whether screen rotation is enabled on the playing device. On the capturing device, you can set the orientationMode to:

• Adaptive

  In the this mode, the direction of the video output is consistent with the direction of the captured video. The receiving end rotates the video based on the received video rotation information. This mode is suitable for scenarios where the receiving end can adjust the video direction. No matter which mode you choose, Video SDK ensures that the relative position of the video and the status bar is always consistent at the capturing end and playback end.

• Fixed Portrait

  In this mode, the output video is always in landscape mode relative to the Status Bar. If the captured video is in portrait mode, the video encoder crops it. This method is suitable for situations where the receiving end cannot process the rotation information.

• Fixed Landscape

  In this mode, the output video is always in portrait mode relative to the Status Bar. If the captured video is in landscape mode, the video encoder crops it. This method is suitable for situations where the receiving end cannot process the rotation information.

The following images illustrate different combinations.

• Screen rotation: Disabled

• Capturing device orientation: Landscape

• Screen rotation: Disabled

• Capturing device orientation: Portrait

• Screen rotation: Enabled

• Capturing device orientation: Landscape

• Screen rotation: Enabled

• Capturing device orientation: Portrait

• Capturing device orientation: Landscape

• Capturing device orientation: Portrait

• Capturing device orientation: Portrait

• Capturing device orientation: Landscape

To enhance the video experience for users in low-bandwidth conditions, the Video SDK offers the degradationPreference parameter. This parameter allows you to set your preference for video encoding downgrade when bandwidth is limited.

By default, Video SDK does not mirror the video during encoding. You use the mirrorMode parameter to decide whether to mirror the video that remote users see.

For specific requirements related to video quality or transmission frame rate, adjust the minimum encoding frame rate parameter minBitrate. It sets the minimum video encoding bitrate in Kbps. The Video SDK performs bitrate adaptation based on network conditions. Increasing this parameter beyond the default value compels the video encoder to produce high-quality images, but it may lead to increased packet loss, affecting video playback smoothness.

Caution

The default value of minBitrate meets the requirements of most real-time scenarios. For general scenarios, Agora suggests not changing the default value.

Ensure that you have implemented the SDK quickstart in your project.

Use the setVideoEncoderConfiguration method to configure video encoding parameters. Best practice is to call this method before calling enableVideo to speed up the time required for the first frame to appear. Alternatively, call this method within the channel to flexibly adjust video encoding properties.

To set video encoder configuration, refer to the following code:

_18

// Set the video encoding resolution, frame rate, bit rate and horizontal and vertical screen orientation mode according to the user's selection in the interface

_18

VideoEncoderConfiguration.VideoDimensions value = VD_640x360;

_18

try {

_18

Field tmp = VideoEncoderConfiguration.class.getDeclaredField(dimension.getSelectedItem().toString());

_18

tmp.setAccessible(true);

_18

value = (VideoEncoderConfiguration.VideoDimensions) tmp.get(null);

_18

} catch (NoSuchFieldException e) {

_18

Log.e("Field", "Can not find field " + dimension.getSelectedItem().toString());

_18

} catch (IllegalAccessException e) {

_18

Log.e("Field", "Could not access field " + dimension.getSelectedItem().toString());

_18

}

_18

_18

engine.setVideoEncoderConfiguration(new VideoEncoderConfiguration(

_18

value,

_18

VideoEncoderConfiguration.FRAME_RATE.valueOf(framerate.getSelectedItem().toString()),

_18

Integer.valueOf(et_bitrate.getText().toString()),

_18

VideoEncoderConfiguration.ORIENTATION_MODE.valueOf(orientation.getSelectedItem().toString())

_18

));

This section contains content that completes the information on this page, or points you to documentation that explains other aspects to this product.

Video SDK provides a selection of video dimensions and frame rates to choose from. You can also customize the values according to the following table:

Resolution (width × height)	Frame rate (fps)
160 × 120	15
120 × 120	15
320 × 180	15
180 × 180	15
240 × 180	15
320 × 240	15
240 × 240	15
424 × 240	15
640 × 360	15
360 × 360	15
640 × 360	30
360 × 360	30
480 × 360	15
480 × 360	30
640 × 480	15
480 × 480	15
640 × 480	30
480 × 480	30
848 × 480	15
848 × 480	30
640 × 480	10
960 × 540	15
960 × 540	30
1280 × 720	15
1280 × 720	30
960 × 720	15
960 × 720	30
1920 × 1080	15
1920 × 1080	30
1920 × 1080	60
2560 × 1440	30
2560 × 1440	60
3840 × 2160	30
3840 × 2160	60

Note

After you set the resolution and frame rate, the SDK automatically sets the corresponding bitrate. Agora does not recommend that you modify the bitrate manually.

Agora provides open source sample projects for your reference. Download or view the JoinChannelVideo source code for a more detailed example.

• setVideoEncoderConfiguration