Agora Developer Portal - FAQ

Web SDK FAQ

In the H264 mode, when joining a session with the Firefox Browser on a macOS device, setting the low stream does not work?

On the macOS device, if you join a session in the H264 mode with the Firefox Browser, you may fail to set the low stream parameter, and the resolution is the same as that of the high stream. In the VP8 mode, however, there is no such problem. We will keep track of this issue and keep you informed of any updates.

When joining a session with the latest Firefox (v59.01) on a macOS device, I cannot see the remote video?

On the macOS device, when you join a session with the Firefox Browser v59.01, you can only see the local video but not the remote video. This problem has been fixed on Web SDK 2.1 Hotfix.

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:

http://bugs.webkit.org/show_bug.cgi?id=176439

http://bugs.webkit.org/show_bug.cgi?id=178357

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:

https://bugs.chromium.org/p/chromium/issues/detail?id=761336

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:

https://groups.google.com/forum/#!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: https://docs.agora.io/en/2.0/product/Video/API%20Reference/web_API_video?platform=Web

Web SDK before 1.12 has no such attribute: https://docs.agora.io/cn/1.8/user_guide/API/webrtc_api.html

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:

https://bugs.webkit.org/show_bug.cgi?id=179964

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:

Video Profile Resolution (widthxheight) Frame Rate Bitrate
4K 3840 x 2160 30 fps 8910
4K_1 3840 x 2160 30 fps 8910
4K_3 3840 x 2160 60 fps 13500
1440P 2560 x 1440 30 fps 4850
1440P_1 2560 x 1440 30 fps 4850
1440P_2 2560 x 1440 60 fps 7350
1080P 1920 x 1080 15 fps 2080
1080P_1 1920 x 1080 15 fps 2080
1080P_2 1920 x 1080 30 fps 3000
1080P_3 1920 x 1080 30 fps 3150
1080_5 1920 x 1080 60 fps 4780
720P 1280 x 720 15 fps 1130
720P_1 1280 x 720 15 fps 1130
720P_2 1280 x 720 15 fps 2080
720P_3 1280 x 720 30 fps 1710
480P 640 x 480 15 fps 500
480P_1 640 x 480 15 fps 500
480P_4 640 x 480 30 fps 750
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