The video encoder settings in <Compression>.
optional
channelId: number
Zero-based channel, 0 to 63.
optional
isNoTranslateFrame: number
0 or 1; meaning not recovered beyond the name.
optional
mainStream: CompressionStream
Main (high resolution) stream.
optional
subStream: CompressionStream
Sub (low resolution) stream.
optional
thirdStream: CompressionStream
Third stream; the camera never writes gop here.