Browser not able to decode frames


sorry for asking this here but I’m really inexperienced with WebRTC and I’m always having a hard time analysing issues when something doesn’t work.

For me it really often happens that the browser can’t decode the frames at all despite receiving all the packages. When I look into this with chrome://webrtc-internals/ I can see that the browsers selected decoderImplementation is unknown. I really can’t figure out what the issue with these streams is?

If the browser can decode the frames there is usally a decoderImplementation like ffmpeg or ExternalDecoder.

Could someone give me a hint and point me into the right direction?