Fix 357

[penguinol]

This PR tried to fix #357

We should deal with reference timestamp wrapping.

Refer to:
https://chromium.googlesource.com/external/webrtc/+/refs/heads/main/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc#383

[ibc]

Will check tomorrow. Thanks!

[jmillan]

Thanks @penguinol!

Do you think you could write some test for the changes in `mediasoup_helpers.h ?

The affected methods (GetBaseDeltaUs and GetBaseTimeUs) are only mediasoup dependant, so they could reside in mediasoup code base, indeed in the same RTCP packet class. Testing them should be fairly easy.

[jmillan]

@penguinol it seems that is the FeedbackRtpTransportPacket::GetReferenceTimestamp() the correct place to fix it.

IMHO those changes should be there instead.

EDIT:

GetBaseDeltaUs is not part of mediasoup and should stay in worker/deps/libwebrtc/libwebrtc/mediasoup_helpers.h

[sarumjanuch]

Hello @penguinol, it is happened that we were looking at the same issue, without knowing each other. I wrote tests to ensure that mediasoup is parsing transport-cc RTCP packets the same way as libwebrtc does, currently there is a discrepancy in how mediasoup and libwebrtc looks at reference_time timestamp #899. I just want to ask you permission, to take your PR and combine it with the one that i prepared for tests to be passing. And also I am going to write tests for GetBaseDelta.

[penguinol]

@sarumjanuch Great! Combine it to your test!

[penguinol]

Mereged with #899. So close this PR.