...

webrtc_sdp_h264_exclude_profiles=

Content type management while publishing from Chromium based browser

In some cases, most browsers based on Chromium 91 agressively assess a publishing channel quality and drop publishing resolution lower than set in constraints, even if channel is enough to publish 720p or 1080p stream. To workaround this behaviour, since WebSDK build  2.0.180 videoContentHint option was added:

    session.createStream({
        name: streamName,
        display: localVideo,
        cacheLocalResources: true,
        receiveVideo: false,
        receiveAudio: false,
        videoContentHint: "detail"
        ...
    }).publish();

By default, this option is set to detail and forces browsers to keep the publishing resolution as set in constraints. However, browser can drop FPS in this case when publishing stream from som USB web cameras. If FPS should be kept mo matter to resolution, the option should be set to motion

    session.createStream({
        name: streamName,
        display: localVideo,
        cacheLocalResources: true,
        receiveVideo: false,
        receiveAudio: false,
        videoContentHint: "motion"
        ...
    }).publish();

Known issues

1. If the web app is inside an iframe element, publishing of the video stream may fail.

...

Solution: update MacOS to build 11.3.1, Safari to build 14.1 (16611.1.21.161.6), in this build the Webkit bug seems to be fixed, the problem is not reproducing

16. When publishing from Google Pixel 3/3XL, the picture is strongly distorted in some resolutions

Symptoms: a local video is displaying normally, but is playing with a strong distortion (transverse stripes)

Solution: avoid the following resolutions while publishing stream from Google Pixel 3/3XL:

• 160x120
• 1920x1080