The totalDecodeTime property of the RTCInboundRtpStreamStats dictionary indicates the total time spend decoding frames for this media source/stream, in seconds.
The time it takes to decode one frame is the time passed between feeding the decoder a frame and the decoder returning decoded data for that frame.
The number of decoded frames is given in framesDecoded, and the average decode time is totalDecodeTime / framesDecoded.
Note: The property is undefined for audio streams.
A positive number, in seconds.