Agora Developer Portal - FAQ


Why does the cellphone freeze when joining two desktops, and is irresponsive when pressing the Home button?

In a video session participated by Safari, Google Chrome, and a cellphone, the cellphone may freeze. This is caused by the H.264 video code from Google Chrome. For more information, see:

Why can’t I connect with the Safari browser when using Google Chrome for Android?

Safari uses the H.264 video codec for video streaming and all users in the Safari session must support this codec. Currently, Google Chrome for Android prevents the device from streaming H.264 video to other users, causing a black screen on Android devices. This issue will be fixed in a later version of Google Chrome. For more information, see:

You may encounter another issue on Google Chrome for Android where you will receive only voice, but no video. The H.264 codec support was added to Google Chrome for Android in version 57. Only Qualcomm (Kitcat and later) and Samsung Exynos (Lollipop and later) chipsets support the H.264 video codec. For more information, see:!msg/discuss-webrtc/xXjeKbW_JYI/LIXzVrKWCwAJ

When I resume a web call after a QQ call, I cannot send any voice communication?

If a third-party application, such as QQ, takes over the audio device during a web call, your device may fail to send out any voice communication once you return to your web session. Agora recommends that you start a new session.

When Safari joins a session in the audio-only mode, why would a user fail to hear the other’s voice?

Currently, Safari does not support initiating an audio-only call session to one another. This will be fixed in a later version of Safari.

Two participants both use the Chrome browser on a macOS device and a Windows device, if the Windows device switches to another Wi-Fi, image on the macOS device freezes?

In a session joined by a Chrome on a macOS and a Windows decice, if the Windows device switches its Wi-Fi, the Mac screen may freeze till you refresh the page. This issue will be fixed in the next two weeks.

During an audio/video talk or live broadcast, if I enable dualStream on the iOS 11 Safari, the iOS window blacks out and the remote cannot receive video from the iOS Safari?

The iOS Safari is currently not fully compatible with the dual-stream mode. This is caused by the restrictions of Safari itself. We will keep track on this issue.

The parameters of joinChannel has changed, and I cannot join the channel. There is also an websocket error and ddos-like attacks?

In the Web SDK later than Version 1.12, join() the attributes of the ChannelKey has been added:

Web SDK before 1.12 has no such attribute:

So notice this change when you are integrating.

In the h264_interop mode, if Firefox is the publisher, the receiver cannot switch to the low stream?

The setting of stream is affected by the browser, resolution and codec type. Generally browsers have an internal algorithm to adjust the stream, therefore chances are that the stream is not in absolute accordance with your settings.

During a live-broadcast, in the AgoraRTC.createClient({mode:’interop’}) mode, if the host does not set transcoding stream, there will be no video?

In the AgoraRTC.createClient({mode:’interop’}) mode, the host (if he/she is the only host in the channel) needs to transcode before publishing the stream, or there will be no video.

If you hope to push stream directly, you can switch to the AgoraRTC.createClient({mode:’h264_interop’}) mode.

Possible impacts: Transcoding charges extra fee.

If the Safari browser plays third-party audio content during live broadcast, the audio is affected after Safari switches back to the broadcast?

During a live broadcast, if the Safari browser plays music with a third-party application, and then resumes audio and video talk, the audio and video talk is compromised. After technical analysis, we find that this is caused by the recent updates of Safari. We will keep track on this issue. For more information on the subject, see:

Setting video profile on the Firefox does not work?

When using the Firefox browser, we find that some device may fail to set the video profile. This is caused by the incompatibility between your computer and the browser. So far we have detected this issue on the following devices:

  • Macbook Pro(13-inch, 2016, Two Thunderbolt 3 ports)
  • Windows 10 (MI)

We will keep track of this issue and update the list of abnormal devices. If you encounter such problem during your usage, please contact Agora’s technical support.

Calling getAudioLevel to get the volume level on the iOS does not work?

After technical analysis, we find that on the iOS Safari browser, one cannot get the volume level by calling getAudioLevel. This is caused by the browser and we will keep track of this issue.

What resolutions does Safari support?

Safari supports the following resolutions and corresponding frame rates:

Resolution (Width x Height) Frame Rate
3840 x 2160 30 fps
3840 x 2160 60 fps
2560 x 1440 30 fps
2560 x 1440 60 fps
1920 x 1080 15 fps
1920 x 1080 30 fps
1920 x 1080 60 fps
1280 x 720 15 fps
1280 x 720 30 fps
640 x 480 15 fps
640 x 480 30 fps
320 x 240 15 fps