Instead, caclulating average bandwidth by dividing the sum of the
sizes of every segment by the sum of the durations of every segment.
This aligns with the requirement in HLS spec:
https://tools.ietf.org/html/draft-pantos-http-live-streaming-23 4.1.
BandwidthEstimator is also simplified to handle all blocks only.
Fixes#361
Change-Id: I89e7d415a841f4d4048f199de8dae7ffa250467b
iframe playlists will be given a name based on the output name of
the main stream. This is done to ensure unique filenames between
different video output streams.
Change-Id: Id0de9c5834599e9d896243e30569c55f34e7cd68
KongQun Yang
Aaron Vaage