Video is blurred when using H.264 with Chrome 80

mediasoup libraries
1

Hi, Team
I’m using Mediasoup 3.5.5, and i found the receiving video is blurred when using H264 with Chrome 80.0.3987.149.
I catched the packet and found the video will blurred even only one packet is dropped, and rtx is working fine.
But there is no such issues with Chrome 79.
I don’t know whether it is a compatibility bug of mediasoup or a bug of Chrome 80.

It’s easy to reproduce, what you need is two PC installed Chrome 80, and a tool such as clumsy which can drop some packets.

test
test1083×728 120 KB

2

Confirmed that it happens using Chrome M80 with H264 (decoderImplementation: "FFmpeg (fallback from: ExternalDecoder)") by introducing downlink packet loss.

  • It does not happen using VP8.
  • It does not happen using Canary 83.0.4095.0.

So it may be a temporal regression in libwebrtc or Chrome. No idea. RTX is working fine so there is little we can do. Please investigate/report the issue in libwebrtc tracker and let’s know.

1 Like
3

This happens on Chrome 90.04430.93 also in my router configuration I have
{
kind: “video”,
mimeType: “video/h264”,
clockRate: 90000,
parameters: {
“packetization-mode”: 1,
“profile-level-id”: “4d0032”,
“level-asymmetry-allowed”: 1,
“x-google-start-bitrate”: 1000,
},
},
{
kind: “video”,
mimeType: “video/h264”,
clockRate: 90000,
parameters: {
“packetization-mode”: 1,
“profile-level-id”: “42e01f”,
“level-asymmetry-allowed”: 1,
“x-google-start-bitrate”: 1000,
},
on the browser I see 4d001f

image
image1692×87 16.5 KB
.
I was referring to this article where the conclusion was that 4d001f was not doing simulcast. Should we stay away from h264 for video?