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Since WCS build 5.2.1504 a stream can be played from server via WebRTC in a number of video qualities like HLS ABR. A browser will play a first available quality track, then playing client can switch between quailities if necessary.qualities if necessary.
Since builds WCS 5.2.1663 and SFU SDK 2.0.231 player may switch between available ABR qualities automatically when playback channel state is changing. Automatic quality switching is based on WebRTC playback statistics data.
Supported platforms and browsers
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If there are two profiles with the same name in the setup, an undefined behavior occurs. To resolve it, server will use only the last profile with the same name.
Force transcoding of a maximum ABR quality only if there are B-frames in a source stream
To reduce a server load while video encoding, since WCS build 5.2.1840 it is possible to transcode a maximum ABR quality (which is usually the original stream resolution and bitrate) only if there are B-frames in a source stream. The feature may be enabled by the following parameter
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h264_b_frames_force_transcoding=true |
In this case the server will detect B-frames in a stream analizing a certain frames count (10 by default)
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frame_cnt_to_determine_their_type=10 |
If there are B-frames in the stream, the maximum ABR quality will be transcoded and will be available for playback.
If there are no B-frames in the stream, the maximum ABR quality will not be transcoded. The original quality should be requested separately from a playing client.
Quick manual on testing
1. For test we use:
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