LLHLS Playlist does not contain AVERAGE-BANDWIDTH

[ruirodrigues-eyenov]

Hello all

Why isn't AVERAGE-BANDWIDTH being written into LLHLS?
It is being written on HLS.
I have a multi quality audio only LLHLS stream and I can't get AVPlayer to upgrade its bitrate once it goes to the lowest due to network conditions.
With HLS AVPlayer goes up and down.

[getroot]

We did not expect that providing AVERAGE-BANDWIDTH in addition to BANDWIDTH would affect player behavior.
Could this be related to the low-latency characteristics of LL-HLS?

Could you try creating a separate master playlist that includes AVERAGE-BANDWIDTH and check whether the issue is resolved?

[naanlizard]

Tangential, but it would be convenient to programmatically know if average bandwidth for a stream is significantly lower than the configured bandwidth. We encourage our users to use VBR and there's no other way to detect that I don't think

[ruirodrigues-eyenov]

How can I create a separate master playlist with AVERAGE-BANDWIDTH?

[getroot]

To calculate average bandwidth, it's best to actually measure it. However, in CBR mode, BANDWIDTH and AVERAGE-BANDWIDTH will actually be nearly identical.

Also, (LL-)HLS players download the master playlist only once and never update it again. Therefore, even if the average bandwidth is updated in the master playlist, the player already playing it won't notice.

Based on these two facts, I don't think the AVERAGE-BANDWIDTH value will significantly affect ABR playback in live broadcasts.

I'll test this further later when I have time. One way to test this yourself is to download the master m3u8 file, add the AVERAGE-BANDWIDTH attribute, host it with something like nginx, and play it with a player. Since AVERAGE-BANDWIDTH will be nearly identical in CBR, you can set it to the same value. However, setting it to a value about 10% lower would also be a good idea.

[ruirodrigues-eyenov]

Thanks, I'll do that.

[ruirodrigues-eyenov]

I have tried adding AVERAGE-BANDWIDTH with values 10% lower and I don't see a bug difference, seems that AVPlayer does not goes up once the network restrictions are removed (I was using network link conditioner to simulate bad network connection).
This might be because it is a audio only stream and audio chunks are small.