H264 video can't decode in High BitRate

kohzo tomita

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Jun 14, 2021, 9:18:56 PM6/14/21

to meetecho-janus

In Streaming of Low bitrate (e.g. 1Mbps) video can decode and display on Chrome browser.

However, in Streaming of High bitrate (e.g. 10Mbps) video can not decode and display.

The video has 30fps and 30GOP.

I notice that the transfer time of the keyframe in low bitrate is under 33msec.

And, in high bitrate, the transfer time is over 40 msec.

I think that as 30fps, a transfer time of 1 frame is desirable under 33msec (=1000msec/30 ).

I want to know the setting that video can display in this situation.

Alessandro Toppi

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Jun 17, 2021, 3:20:58 AM6/17/21

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Sounds like a media source problem

Streaming plugin just acts just as a relayer and does not have control over the source bistream.
As of the numbers you mentioned, I'm not sure about the meaning of those, but 33-40ms for keyframe interarrival time is an overkill in realtime video. You're basically "wasting" the bandwidth and the user experience might not be ideal.

Lorenzo Miniero

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Jun 17, 2021, 3:37:44 AM6/17/21

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The keyframe interval is dictated by 30GOP, which IIRC means "a keyframe every 30 frames". At 30fps, this means a keyframe every second, which is an awful waste of bandwidth, and very suboptimal in WebRTC (it means it' much more likely a packet loss will impact an important frame, a keyframe, which will cause freezes). Keyframes should be sent much more sparingly, every 5 seconds being the lowest tradeoff IMO.

L.

kohzo tomita

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Jun 17, 2021, 8:18:13 PM6/17/21

to meetecho-janus

I could not tell my situation well.

As I frame size is too big, the transfer time take long time.

So, the packet in 30GOP period on the receiving PC looks like the followings.

I think I-frame arrival time is delayed from the master clock, it is not displayed.

when I frame transfer time is 20 msec, it is displayed correctly

thanks.

------------------------------------------------------------

I frame transfer time 100 msec

#1 P frame transfer time 2 msec

#2 P frame transfer time 2 msec

blank 5 msec

#3 P frame transfer time 2 msec

blank 31 msec

#4 P frame transfer time 2 msec

blank 31 msec

#5 P frame transfer time 2 msec

blank 31 msec

#6 P frame transfer time 2 msec

blank 31 msec

#7 P frame transfer time 2 msec

blank 31 msec

#8 P frame transfer time 2 msec

blank 31 msec

#9 P frame transfer time 2 msec

blank 31 msec

#10 P frame transfer time 2 msec

blank 31 msec

#11 P frame transfer time 2 msec

blank 31 msec

#12 P frame transfer time 2 msec

blank 31 msec

#13 P frame transfer time 2 msec

blank 31 msec

#14 P frame transfer time 2 msec

blank 31 msec

#15 P frame transfer time 2 msec

blank 31 msec

#16 P frame transfer time 2 msec

blank 31 msec

#17 P frame transfer time 2 msec

blank 31 msec

#18 P frame transfer time 2 msec

blank 31 msec

#19 P frame transfer time 2 msec

blank 31 msec

#20 P frame transfer time 2 msec

blank 31 msec

#21 P frame transfer time 2 msec

blank 31 msec

#22 P frame transfer time 2 msec

blank 31 msec

#23 P frame transfer time 2 msec

blank 31 msec

#24 P frame transfer time 2 msec

blank 31 msec

#25 P frame transfer time 2 msec

blank 31 msec

#26 P frame transfer time 2 msec

blank 31 msec

#27 P frame transfer time 2 msec

blank 31 msec

#28 P frame transfer time 2 msec

blank 31 msec

#29 P frame transfer time 2 msec

blank 31 msec

-----------------------------------

1000 msec(= 1sec)

2021年6月17日木曜日 16:37:44 UTC+9 lmin...@gmail.com:

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