Apple spec talks about having average bandwidth and peak bandwidth in master playlist as below -
'You should include the average bit rate as well as the peak bit rate. This is especially important if your peak is more than 20% different from your average. Specifying the average allows the client to make more intelligent decisions about which variant to play.'
Ref -
https://tools.ietf.org/html/draft-pantos-http-live-streaming-23#page-28
https://developer.apple.com/library/content/technotes/tn2224/_index.html#//apple_ref/doc/uid/DTS40009745-CH1-BITRATERECOMMENDATIONS

Exoplayer seems to be expecting only average Bandwidth in the master playlist as the regex in HLSplaylistParser is "BANDWIDTH=(\d+)\b".

For supporting VBR we need a) regex fix to extract average bitrate and peak bitrate, b) data holder in Format object for peak bitrate

Sample snippet from a master .m3u8 file -
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=2095000,SUBTITLES="subs",AVERAGE-BANDWIDTH=1945000,RESOLUTION=1280x720

I am looking at Exo v2.3.1.
Thanks, _jue