WSS initialization for HLS streams

[AlexAplin]

WebSockets are now used for Niconama streams.

[AlexAplin]

wss_url = ["site"]["relive"]["webSocketUrl"] broadcast_id =["site"]["program"]["broadcastId"]

GET wss_url 101 Upgrade

Initialization:

CLIENT: {"type":"watch","body":{"command":"playerversion","params":["leo"]}}
CLIENT: {"type":"watch","body":{"command":"getpermit","requirement":{"broadcastId":broadcast_id,"route":"","stream":{"protocol":"hls","requireNewStream":true,"priorStreamQuality":"abr","isLowLatency":true,"isChasePlay":false},"room":{"isCommentable":true,"protocol":"webSocket"}}}}
SERVER: {"type":"watch","body":{"command":"statistics","params":["66864","41957","0","0"]}}
SERVER: {"type":"watch","body":{"command":"servertime","params":["1562491996809"]}}
SERVER: {"type":"watch","body":{"command":"permit","params":["12100564943432"]}}
CLIENT: {"type":"watch","body":{"command":"getakashic","requirement":{"isChasePlay": false}}}
SERVER: {"type":"watch","body":{"currentStream":{"uri":"https://pb085cb3ae2.dmc.nico/hlslive/ht2_nicolive/nicolive-production-pg12100564943432_87ca7412ec2223150e41e5ed71b9effc1e20b5a246168df9ee14632c4a8237ef/master.m3u8?ht2_nicolive=anonymous-user-0114ad22-44d0-4fc2-b518-4794fffac627.kru1if_pu9mjg_2ssy8uydxz3ja","name":null,"quality":"abr","qualityTypes":["abr","super_high","high","normal","low","super_low"],"mediaServerType":"dmc","mediaServerAuth":null,"streamingProtocol":"hls"},"command":"currentstream"}}

Ping check with server:

SERVER: {"type":"ping","body":{}}
CLIENT: {"type":"pong","body":{}}

Every thirty seconds after first message:

CLIENT: {"type":"watch","body":{"command":"watching","params":[broadcast_id,"-1","0"]}}

[AlexAplin]

Streams seem to be stable when played in an external player and do not seem to change URL. As long as we communicate the watching command and pong back, these should work without any issue.

[AlexAplin]

The client initialization can be reduced to:

{"type":"watch","body":{"command":"getpermit","params":[broadcast_id,"","true","hls",""]}}

playerversion can be ommited.

[AlexAplin]

A fully qualified getpermit is required to get all qualities. The stream stutters in MPC and VLC, even when adjusting buffers. It's stable in mpv/streamlink, so I'm guessing like most HLS/DASH streams it needs an aggressive cache and threading.