Files
pytchat-fork/pytchat/paramgen/arcparam_mining.py
2020-02-22 17:10:40 +09:00

134 lines
3.0 KiB
Python

from base64 import urlsafe_b64encode as b64enc
from functools import reduce
import math
import random
import urllib.parse
'''
Generate continuation parameter of youtube replay chat.
Author: taizan-hokuto (2019) @taizan205
ver 0.0.1 2019.10.05
'''
def _gen_vid_long(video_id):
"""generate video_id parameter.
Parameter
---------
video_id : str
Return
---------
byte[] : base64 encoded video_id parameter.
"""
header_magic = b'\x0A\x0F\x1A\x0D\x0A'
header_id = video_id.encode()
header_sep_1 = b'\x1A\x13\xEA\xA8\xDD\xB9\x01\x0D\x0A\x0B'
header_terminator = b'\x20\x01'
item = [
header_magic,
_nval(len(header_id)),
header_id,
header_sep_1,
header_id,
header_terminator
]
return urllib.parse.quote(
b64enc(reduce(lambda x, y: x+y, item)).decode()
).encode()
def _gen_vid(video_id):
"""generate video_id parameter.
Parameter
---------
video_id : str
Return
---------
bytes : base64 encoded video_id parameter.
"""
header_magic = b'\x0A\x0F\x1A\x0D\x0A'
header_id = video_id.encode()
header_terminator = b'\x20\x01'
item = [
header_magic,
_nval(len(header_id)),
header_id,
header_terminator
]
return urllib.parse.quote(
b64enc(reduce(lambda x, y: x+y, item)).decode()
).encode()
def _nval(val):
"""convert value to byte array"""
if val<0: raise ValueError
buf = b''
while val >> 7:
m = val & 0xFF | 0x80
buf += m.to_bytes(1,'big')
val >>= 7
buf += val.to_bytes(1,'big')
return buf
def _build(video_id, seektime, topchat_only):
switch_01 = b'\x04' if topchat_only else b'\x01'
if seektime < 0:
raise ValueError("seektime must be greater than or equal to zero.")
if seektime == 0:
times = b''
else:
times =_nval(int(seektime*1000))
if seektime > 0:
_len_time = ( b'\x5A'
+ (len(times)+1).to_bytes(1,'big')
+ b'\x10')
else:
_len_time = b''
header_magic = b'\xA2\x9D\xB0\xD3\x04'
sep_0 = b'\x1A'
vid = _gen_vid(video_id)
_tag = b'\x40\x01'
timestamp1 = times
sep_1 = b'\x60\x04\x72\x02\x08'
terminator = b'\x78\x01'
body = [
sep_0,
_nval(len(vid)),
vid,
_tag,
_len_time,
timestamp1,
sep_1,
switch_01,
terminator
]
body = reduce(lambda x, y: x+y, body)
return urllib.parse.quote(
b64enc( header_magic +
_nval(len(body)) +
body
).decode()
)
def getparam(video_id, seektime = 0.0, topchat_only = False):
'''
Parameter
---------
seektime : int
unit:seconds
start position of fetching chat data.
topchat_only : bool
if True, fetch only 'top chat'
'''
return _build(video_id, seektime, topchat_only)