# -*- coding: utf-8 -*-
# cython: language_level=3
# Copyright (c) 2021-present VincentRPS
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE
"""Implementation of Opus."""
# based off the implementation of discord.py and disco.
import array
import ctypes
import ctypes.util
import os
import struct
import sys
import threading
from enum import Enum
from typing import List
from ..internal.exceptions import DiscordError
__all__: List[str] = ['Encoder']
# structs
class EncoderStruct(ctypes.Structure): # noqa: ignore
pass
# if your curious, the 'decoder' handles, voice recv.
class DecoderStuct(ctypes.Structure): # noqa: ignore
pass
# pointers
c_int_ptr = ctypes.POINTER(ctypes.c_int)
c_int16_ptr = ctypes.POINTER(ctypes.c_int16)
c_float_ptr = ctypes.POINTER(ctypes.c_float)
EncoderStructPtr = ctypes.POINTER(EncoderStruct)
DecoderStructPtr = ctypes.POINTER(DecoderStuct)
opus_loaded: threading.Event = threading.Event()
# options
default_options = {
# generic stuff
'opus_get_version_string': (None, ctypes.c_char_p, None),
'opus_strerror': ([ctypes.c_int], ctypes.c_char_p, None),
# packets
'opus_packet_get_bandwidth': ([ctypes.c_char_p], ctypes.c_int),
'opus_packet_get_nb_channels': ([ctypes.c_char_p], ctypes.c_int),
'opus_packet_get_nb_frames': ([ctypes.c_char_p, ctypes.c_int], ctypes.c_int),
'opus_packet_get_samples_per_frame': (
[ctypes.c_char_p, ctypes.c_int],
ctypes.c_int,
),
}
# Enums
class AppEnum(Enum):
AUDIO = 2049
VOIP = 2048
LOWDELAY = 2051
class CntrlEnum(Enum):
SET_BITRATE = 4002
SET_BANDWIDTH = 4008
SET_FEC = 4012
SET_PLP = 4014
# Errors
class OpusError(DiscordError):
pass
# loader
def loader(name: str):
opus = ctypes.cdll.LoadLibrary(name)
return opus
def load_opus() -> bool:
global lib
try:
if sys.platform == 'win32':
basedir = os.path.dirname(os.path.abspath(__file__))
bitness = struct.calcsize('P') * 8
target = 'x64' if bitness > 32 else 'x86'
filename = os.path.join(basedir, 'bin', f'opus-{target}.dll')
lib = loader(filename)
opus_loaded.set()
else:
lib = loader(ctypes.util.find_library('opus'))
opus_loaded.set()
except Exception as exc:
lib = None
raise OpusError from exc
return lib is not None
def check_load():
if opus_loaded.is_set() is not True:
return load_opus()
else:
return lib
class Opus:
EXP = {}
def __init__(self):
self.lib = check_load()
meths = {}
meths.update(default_options)
meths.update(self.EXP)
for name, option in meths.items(): # type: ignore # noqa: ignore
func = getattr(loader, name)
try:
if option[1]:
func.argtypes = option[0]
func.restype = option[1]
setattr(self, name, func)
except KeyError:
pass
# encoder
[docs]class Encoder(Opus):
"""A class used to encode `.pcm` data into opus data for the discord voice gateway"""
EXP = {
'opus_encoder_get_size': ([ctypes.c_int], ctypes.c_int, None),
'opus_encoder_create': (
[ctypes.c_int, ctypes.c_int, ctypes.c_int, c_int_ptr],
EncoderStructPtr,
),
'opus_encode': (
[
EncoderStructPtr,
c_int16_ptr,
ctypes.c_int,
ctypes.c_char_p,
ctypes.c_int32,
],
ctypes.c_int32,
),
'opus_encode_float': (
[
EncoderStructPtr,
c_float_ptr,
ctypes.c_int,
ctypes.c_char_p,
ctypes.c_int32,
],
ctypes.c_int32,
),
'opus_encoder_ctl': (None, ctypes.c_int32),
'opus_encoder_destroy': ([EncoderStructPtr], None, None),
}
def __init__(self):
self._inst = None
@property
def inst(self):
if not self._inst:
self._inst = self.create()
self.set_bitrate(128)
self.set_fec(True)
self.set_expected_plp(0.15)
return self._inst
def set_bitrate(self, kbps):
kbps = min(128, max(16, int(kbps)))
ret = self.opus_encoder_ctl(
self.inst, int(CntrlEnum.SET_BITRATE.value), kbps * 1024
)
if ret < 0:
raise RuntimeError('Failed to set bitrate, %s: %s', kbps, ret)
def set_fec(self, value):
ret = self.opus_encoder_ctl(self.inst, int(CntrlEnum.SET_FEC.value), int(value))
if ret < 0:
raise RuntimeError('Failed to set bitrate, %s: %s', value, ret)
def set_expected_plp(self, perc):
ret = self.opus_encoder_ctl(
self.inst, int(CntrlEnum.SET_PLP.value), min(100, max(0, int(perc * 100)))
)
if ret < 0:
raise RuntimeError('Failed to set bitrate, %s: %s', perc, ret)
def create(self):
ret = ctypes.c_int()
result = self.opus_encoder_create(
self.sampling_rate, self.channels, self.application.value, ctypes.byref(ret)
)
if ret.value != 0:
raise RuntimeError
return result
def __del__(self):
if hasattr(self, '_inst') and self._inst:
self.opus_encoder_destroy(self._inst)
self._inst = None
def encode(self, pcm, frame_size):
m_data_bytes = len(pcm)
pcm = ctypes.cast(pcm, c_int16_ptr)
data = (ctypes.c_char * m_data_bytes)()
ret = self.opus_encode(self.inst, pcm, frame_size, data, m_data_bytes)
if ret < 0:
raise RuntimeError
return array.array('b', data[:ret].tobytes())