Fix miscalculation when increasing layer

[penguinol]

We should subtract the whole bitrate of provisional layer when increasing to a higher spatial layer.

[ibc]

Please run npm run lint (there will be errors) and then npm run worker:format to fix them.

Also, could you please detail the rationale of this change? I fail to see it.

[penguinol]

When we increse to a higher spatial layer, we need to know how mush additional bitrate is needed.
But GetLayerBitrate only return the bitrate of one temporal layer.
For example, we have a S2T2 stream.
When we are sending S1T2, means we are both sending packets of S1T1 and S1T2
Then we tried to increase to S2T1, so the addtional bitrate = bitrate of S2T1 - (bitrate of S1T1 + bitrate of S1T2)
And GetBirate(0,1) = GetLayerBitrate(0, 0) + GetLayerBitrate(0, 1), so here should be GetBitrate

[ibc]

You are 100% right. Thanks. Merging.

[ibc]

releasing a new version in a few minutes.

[jmillan]

👍