Weird data in onnewBitrate

[sw-orjan]

Hi.

I'm trying to make sure my app is working well in bad network conditions. I'm using a BitrateAdapter connected in onNewBitrate, like the example (calling adapter.adaptBitrate from onNewBitrate).

I'm using an XCode tool from Apple, called Network Link Conditioner, where I can simulate different types of connections. When switching to a "bad network" profile that limits to 1mbit/s and 10% packetloss, webbrowsing becomes really slow and switching to a "100% loss" profile it stops completely. But in both those situations, onNewBitrate keeps reporting a "good" bitrate and doesn't seem to care that the network is bad.

The backend I'm connecting to does stop receiving packets when the limiting profiles are active, so the limiter is working, it just doesn't seem like BitrateChecker actually detects the lack of throughput. I also get no dropped packets reported from the streamer.

I'm thinking perhaps I'm missing something in the setup, but since onNewBitrate reports the "wrong" values, I don't really know what I could do differently.

[pedroSG94]

Hello,

Maybe the problem is related with the cache. You only will have packets drops after the cache is filled

[sw-orjan]

I don't think so. I added log entries for cache size in StreamBlockingQueue.trySend and the cache is never even used, cacheTime is always 0. The queue-size seems to fluctuate between around 0 and 4, pretty much what I would expect if the network was running as it should.

I had a look at the queue handling of sending, and I don't really understand how it's meant to work. BaseSender.trySend puts the frame in the queue (assuming no cache enabled), and RtmpSender.onRun takes from the queue, processes it and then calls CommandsManager.sendVideoPacket. But at no point are failed packets put back on the queue, or any sending error handled other than with logging a send error and disconnecting. So as long as RtmpSender.onRun keeps running, the queue will most likely never fill up and trySend will never fail.

I also tried enabling the cache, but it stayed completely stable at 22 entries regardless of network status.

I've tried the example app as well, the one with rotation support. At the top it writes the current "throughput", I'm guessing taken from the value in each onNewBitrate call. It also doesn't change when the available network throughput changes.

[sw-orjan]

@pedroSG94 can you test the demo application and see if it properly detects network problems for you?

Useful conditioner applications for different platforms in case you need it:
Windows - Clumsy - https://jagt.github.io/clumsy/
OSX - Network Link Conditioner - part of Apple's XCode Extra Developer Tools
Linux - NetEm - usually available in the package repository

[pedroSG94]

Hello,

I used NetEm to limit the network and all is working fine. The cache is correctly filled as expected using 1mb of network speed with 25% packet loss

[sw-orjan]

When you do that, does the bitrate reported in onNewBitrate go down below 1mb like it should? Because when I throttle the network, the reported bitrate stays at 1.7mb/s, which should be impossible.

[pedroSG94]

Yes, can you try to do a speed test in your device used to test this case?
Maybe the limitation is not working as you expected in the device.
If you are using an emulator. Android studio sometimes create a network for emulator so maybe the cap used by the program is not correct in your case.