Unacceptable latency

RVMedia support and discussion (components for displaying and controlling IP cameras, webcams, video conferencing, video chats, recording audio and video files)
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jimhawkins2
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Unacceptable latency

Post by jimhawkins2 »

After many tests I have reluctantly come to the conclusion that RVMedia is not adequate for a professional environment. We have found it impossible to get latency below about 4 seconds in LAN or WAN tests. IN my area - interpreting - latency must be as low as possible. Below one second would be acceptable provided it worked with a multiple-client server model.

Can we expect an update that will focus on streaming efficiency in a reasonable time-frame?
Sergey Tkachenko
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Re: Unacceptable latency

Post by Sergey Tkachenko »

I recently investigated the reasons of this latency, and found that it is because of the sender's buffering (if it receives frames faster than it can send them, it accumulates frames to send).
I'll try to fix it in the next update (but no guaranties, sorry).
jimhawkins2
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Re: Unacceptable latency

Post by jimhawkins2 »

Thanks, Sergey. Really video should drop frames if overloaded. Audio should be a higher priority, surely?
Sergey Tkachenko
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Re: Unacceptable latency

Post by Sergey Tkachenko »

Some intermediate results...

The sender buffering does not add too much time to the total latency, as well as the receiver buffering (except for a fixed delay added by TRVCamReceiver.VideoLatency).

The main delay is caused by TRVCamera.Latency.
This property has a different effect than other latency properties, so probably it will be renamed.
It allows accumulates frames if they are received faster than they can be processed. It can make sense if the source of video is a network, and frames may be received sometimes faster, sometimes slower. Only frames that are older than the specified Latency (default = 1 second) are discarded.
Assign Latency = 0 to disable this feature.
Also, TRVCamera draw accumulated frames using the same speed as they were received. I think a good idea to draw them faster.

Another good news, low-level sending and receiving procedure can be made faster by sending and receiving using larger chunks of data.
Sergey Tkachenko
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Re: Unacceptable latency

Post by Sergey Tkachenko »

Please test RVMedia 7.5
And assign RVCamera.Latency = 0.
jimhawkins2
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Re: Unacceptable latency

Post by jimhawkins2 »

I would love to test it, but I can't locate it anywhere!
Sergey Tkachenko
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Re: Unacceptable latency

Post by Sergey Tkachenko »

I restored access to protected RVMedia forums for your account. You can find the links in the protected "RVMedia" forum.
Also, you can always re-run the old Setup, it can check for updates and download them.
jimhawkins2
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Re: Unacceptable latency

Post by jimhawkins2 »

Thank you - Got installers and will test!

Jim
jimhawkins2
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Re: Unacceptable latency

Post by jimhawkins2 »

It's much improved. Client/Server is about 1.5 seconds latency, which is acceptable for chat.

Well done, Sergey!
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