Python 进程 TypeError: no default __reduce__ due to non-trivial __cinit__

Posted 2023-02-16

【中文标题】Python 进程 TypeError: no default __reduce__ due to non-trivial __cinit__

【英文标题】：Python process TypeError: no default __reduce__ due to non-trivial __cinit__

【发布时间】：2021-11-01 02:07:12

【问题描述】：

from aiohttp import web
from aiortc.mediastreams import MediaStreamTrack
from aiortc import RTCPeerConnection, RTCSessionDescription
from aiortc.contrib.media import MediaPlayer
from pydub import Audiosegment
import av
from aiohttp import web
from aiortc.mediastreams import MediaStreamTrack
from aiortc import RTCPeerConnection, RTCSessionDescription
from aiortc.contrib.media import MediaPlayer
from pydub import AudioSegment
import av
import pyaudio
import asyncio
import json
import os
from multiprocessing import Process, freeze_support, Queue
import sys
import threading
from time import sleep
import fractions
import time

class RadioServer(Process):
    def __init__(self,q):
        super().__init__()
        self.q = q
        self.ROOT = os.path.dirname(__file__)
        self.pcs = []
        self.channels = []
        self.stream_offers = []
    
    def run(self):
        self.app = web.Application()
        self.app.on_shutdown.append(self.on_shutdown)
        self.app.router.add_get("/", self.index)
        self.app.router.add_get("/telephone_calls.js", self.javascript)
        self.app.router.add_get("/jquery-3.5.1.min.js", self.jquery)
        self.app.router.add_post("/offer", self.offer)
        
        threading.Thread(target=self.fill_the_queues).start()
        web.run_app(self.app, access_log=None, host="192.168.1.20", port="8080", ssl_context=None)

    def fill_the_queues(self):
        while(True):
            frame = self.q.get()
            for stream_offer in self.stream_offers:
                stream_offer.q.put(frame)

    async def index(self,request):
        content = open(os.path.join(self.ROOT, "index.html"), encoding="utf8").read()
        return web.Response(content_type="text/html", text=content)


    async def javascript(self,request):
        content = open(os.path.join(self.ROOT, "telephone_calls.js"), encoding="utf8").read()
        return web.Response(content_type="application/javascript", text=content)

    async def jquery(self,request):
        content = open(os.path.join(self.ROOT, "jquery-3.5.1.min.js"), encoding="utf8").read()
        return web.Response(content_type="application/javascript", text=content)

    async def offer(self,request):  
        params = await request.json()
        offer = RTCSessionDescription(sdp=params["sdp"], type=params["type"])

        pc = RTCPeerConnection()
        self.pcs.append(pc)

        # prepare epalxeis media
        self.stream_offers.append(CustomRadioStream())
        pc.addTrack(self.stream_offers[-1])

        #player = MediaPlayer(os.path.join(self.ROOT, "ΑΓΙΑ ΚΥΡΙΑΚΗ.mp3"))
        #pc.addTrack(player.audio)

        @pc.on("datachannel")
        def on_datachannel(channel):
            self.channels.append(channel)
            self.send_channel_message(str(len(self.pcs)))


        @pc.on("iceconnectionstatechange")
        async def on_iceconnectionstatechange():
            if pc.iceConnectionState == "failed":
                self.pcs.remove(pc)
                print("Current peer connections:"+str(len(self.pcs)))
            

        # handle offer
        await pc.setRemoteDescription(offer)

        # send answer
        answer = await pc.createAnswer()
        await pc.setLocalDescription(answer)
        
            

        return web.Response(content_type="application/json",text=json.dumps("sdp": pc.localDescription.sdp, "type": pc.localDescription.type))

    async def on_shutdown(self,app):
        # close peer connections
        if self.pcs:
            coros = [pc.close() for pc in self.pcs]
            await asyncio.gather(*coros)
            self.pcs = []
            self.channels = []
            self.stream_offers = []
            
    def send_channel_message(self,message):
        for channel in self.channels:
            channel.send(message)
            

class CustomRadioStream(MediaStreamTrack):
    kind = "audio"
    
    def __init__(self):
        super().__init__()  # don't forget this!
        
        self.q = Queue()
        self._start = None
        
    async def recv(self):
        frame = self.q.get()
        frame_time = frame.time
        if self._start is None:
            self._start = time.time() - frame_time
        else:
            wait = self._start + frame_time - time.time()
            await asyncio.sleep(wait)
        return frame

class RadioOutputStream:
    def __init__(self,q):
        self.sample_rate = 44800
        self.AUDIO_PTIME = 0.744
        self.samples = int(self.AUDIO_PTIME * self.sample_rate)
        self.packet_time = 20

        self.FORMAT = pyaudio.paInt16
        self.CHANNELS = 2
        self.RATE = self.sample_rate
        self.CHUNK = int(44100*0.744)

        
        self.files_directory = os.path.abspath(r"C:\Users\Χρήστος\Music\Αναστάσιμα τροπάρια ή άλλα τροπάρια Δεσποτικών, Θεομητορικών ή άλλων εορτών Αγίων")
        self.files_paths = os.listdir(self.files_directory)
        self.files_info = []
        for song_file in self.files_paths:
            if ".mp3" in song_file.lower():
                file_segment = AudioSegment.from_file(os.path.join(self.files_directory, song_file)).set_frame_rate(self.sample_rate)
                duration_milliseconds = len(file_segment)
                self.files_info.append("file_segment":file_segment,"duration_milliseconds":duration_milliseconds)
        self.total_files = len(self.files_info)
        self.current_file = 0
        self.chunk_number = 0

        self.silence = AudioSegment.silent(duration=self.packet_time)

        self.q = q

        self.codec = av.CodecContext.create('pcm_s16le', 'r')
        self.codec.sample_rate = 44800
        self.codec.channels = 2

        self.audio_samples = 0
        
    def run_stream(self):
        while(True):
            if((self.chunk_number+1)*(self.packet_time)<=self.files_info[self.current_file]["duration_milliseconds"]):
                final_slice = self.files_info[self.current_file]["file_segment"][self.chunk_number*self.packet_time:(self.chunk_number+1)*self.packet_time]
                #final_slice = final_slice + 100
                self.chunk_number += 1

                packet = av.Packet(final_slice.raw_data)
                frame = self.codec.decode(packet)[0]
                frame.pts = self.audio_samples
                frame.time_base = fractions.Fraction(1, self.codec.sample_rate)
                self.audio_samples += frame.samples
                self.q.put(frame)
            else:
                if(self.chunk_number*self.packet_time<self.files_info[self.current_file]["duration_milliseconds"]):
                    final_slice = self.files_info[self.current_file]["file_segment"][self.chunk_number*self.packet_time:]
                    final_slice = final_slice + self.silence
                    #final_slice = final_slice + 100
                    self.chunk_number += 1


                    packet = av.Packet(final_slice.raw_data)
                    frame = self.codec.decode(packet)[0]
                    frame.pts = self.audio_samples
                    frame.time_base = fractions.Fraction(1, self.codec.sample_rate)
                    self.audio_samples += frame.samples
                    self.q.put(frame)
                else:
                    #start song from begin
                    self.chunk_number=0
                    if self.current_file==self.total_files-1:
                        self.current_file = 0
                    else:
                        self.current_file += 1
                    
            sleep(0.01)

if __name__ == "__main__":
    freeze_support()

    q = Queue()
    radio_stream = RadioOutputStream(q)
    threading.Thread(target=radio_stream.run_stream).start()

    custom_server_child_process = RadioServer(q)
    custom_server_child_process.start()
    print("Thread and process started sucessfully.")

错误：

Traceback (most recent call last):
  File "C:\Python\lib\multiprocessing\queues.py", line 245, in _feed
    obj = _ForkingPickler.dumps(obj)
  File "C:\Python\lib\multiprocessing\reduction.py", line 51, in dumps
    cls(buf, protocol).dump(obj)
  File "stringsource", line 2, in av.audio.frame.AudioFrame.__reduce_cython__
TypeError: no default __reduce__ due to non-trivial __cinit__

上面的错误重复了很多次。

我做错了什么？

【问题讨论】：

看来av包中的某些类是用Cython编写的，并使用__cinit__（Cython类中的一种特殊方法，用于在纯（C）ython代码中初始化某些类的实例结构） .在这种情况下，Cython 不提供默认的 __reduce__ 方法，因为它无法推断应如何从较低级别的代码重构类的实例。该课程的作者必须提供他们自己的__reduce__。但是，当您将这些对象传递给 multiprocessing.Queue 时，它们必须被腌制，因此会出现错误。

您可能会做的是将AudioFrame 类中的数据转储为一些中间表示，然后重构它（本质上，提供您自己的可以腌制的包装器），但我不熟悉pyav 足以立即提供解决方案。

【参考方案1】：

我找到了！

from aiohttp import web
from aiortc.mediastreams import MediaStreamTrack
from aiortc import RTCPeerConnection, RTCSessionDescription
from aiortc.contrib.media import MediaPlayer
from pydub import AudioSegment
import av
from aiohttp import web
from aiortc.mediastreams import MediaStreamTrack
from aiortc import RTCPeerConnection, RTCSessionDescription
from aiortc.contrib.media import MediaPlayer
from pydub import AudioSegment
import av
import pyaudio
import asyncio
import json
import os
from multiprocessing import Process, freeze_support, Queue
import sys
import threading
from time import sleep
import fractions
import time
import queue

class RadioServer(Process):
    def __init__(self,q):
        super().__init__()
        self.q = q
        self.ROOT = os.path.dirname(__file__)
        self.pcs = []
        self.channels = []
        self.stream_offers = []

    
    def run(self):
        self.codec = av.CodecContext.create('pcm_s16le', 'r')
        self.codec.sample_rate = 44800
        self.codec.channels = 2

        self.audio_samples = 0
    
        self.app = web.Application()
        self.app.on_shutdown.append(self.on_shutdown)
        self.app.router.add_get("/", self.index)
        self.app.router.add_get("/radio.js", self.javascript)
        self.app.router.add_get("/jquery-3.5.1.min.js", self.jquery)
        self.app.router.add_post("/offer", self.offer)

        threading.Thread(target=self.fill_the_queues).start()
        web.run_app(self.app, access_log=None, host="192.168.1.20", port="8080", ssl_context=None)

    def fill_the_queues(self):
        while(True):
            data = self.q.get()
            packet = av.Packet(data)
            frame = self.codec.decode(packet)[0]
            frame.pts = self.audio_samples
            frame.time_base = fractions.Fraction(1, self.codec.sample_rate)
            self.audio_samples += frame.samples
            for stream_offer in self.stream_offers:
                stream_offer.q.put(frame)

    async def index(self,request):
        content = open(os.path.join(self.ROOT, "index.html"), encoding="utf8").read()
        return web.Response(content_type="text/html", text=content)


    async def javascript(self,request):
        content = open(os.path.join(self.ROOT, "radio.js"), encoding="utf8").read()
        return web.Response(content_type="application/javascript", text=content)

    async def jquery(self,request):
        content = open(os.path.join(self.ROOT, "jquery-3.5.1.min.js"), encoding="utf8").read()
        return web.Response(content_type="application/javascript", text=content)

    async def offer(self,request):  
        params = await request.json()
        offer = RTCSessionDescription(sdp=params["sdp"], type=params["type"])

        pc = RTCPeerConnection()
        self.pcs.append(pc)

        # prepare epalxeis media
        self.stream_offers.append(CustomRadioStream())
        pc.addTrack(self.stream_offers[-1])

        #player = MediaPlayer(os.path.join(self.ROOT, "ΑΓΙΑ ΚΥΡΙΑΚΗ.mp3"))
        #pc.addTrack(player.audio)

        @pc.on("datachannel")
        def on_datachannel(channel):
            self.channels.append(channel)
            self.send_channel_message(str(len(self.pcs)))


        @pc.on("iceconnectionstatechange")
        async def on_iceconnectionstatechange():
            if pc.iceConnectionState == "failed":
                self.pcs.remove(pc)
                print("Current peer connections:"+str(len(self.pcs)))
            

        # handle offer
        await pc.setRemoteDescription(offer)

        # send answer
        answer = await pc.createAnswer()
        await pc.setLocalDescription(answer)



        return web.Response(content_type="application/json",text=json.dumps("sdp": pc.localDescription.sdp, "type": pc.localDescription.type))

    async def on_shutdown(self,app):
        # close peer connections
        if self.pcs:
            coros = [pc.close() for pc in self.pcs]
            await asyncio.gather(*coros)
            self.pcs = []
            self.channels = []
            self.stream_offers = []
            
    def send_channel_message(self,message):
        for channel in self.channels:
            channel.send(message)
            
class CustomRadioStream(MediaStreamTrack):
    kind = "audio"
    
    def __init__(self):
        super().__init__()  # don't forget this!
        
        self.q = queue.Queue()
        self._start = None
        
    async def recv(self):
        frame = self.q.get()
        frame_time = frame.time
        if self._start is None:
            self._start = time.time() - frame_time
        else:
            wait = self._start + frame_time - time.time()
            await asyncio.sleep(wait)
        return frame

class RadioOutputStream:
    def __init__(self,q):
        self.sample_rate = 44800
        self.AUDIO_PTIME = 0.744
        self.samples = int(self.AUDIO_PTIME * self.sample_rate)
        self.packet_time = 20

        self.FORMAT = pyaudio.paInt16
        self.CHANNELS = 2
        self.RATE = self.sample_rate
        self.CHUNK = int(44100*0.744)

        
        self.files_directory = os.path.abspath(r"C:\Users\Χρήστος\Music\Αναστάσιμα τροπάρια ή άλλα τροπάρια Δεσποτικών, Θεομητορικών ή άλλων εορτών Αγίων")
        self.files_paths = os.listdir(self.files_directory)
        self.files_info = []
        for song_file in self.files_paths:
            if ".mp3" in song_file.lower():
                file_segment = AudioSegment.from_file(os.path.join(self.files_directory, song_file)).set_frame_rate(self.sample_rate)
                duration_milliseconds = len(file_segment)
                self.files_info.append("file_segment":file_segment,"duration_milliseconds":duration_milliseconds)
        self.total_files = len(self.files_info)
        self.current_file = 0
        self.chunk_number = 0

        self.silence = AudioSegment.silent(duration=self.packet_time)

        self.q = q
        
    def run_stream(self):
        while(True):
            if((self.chunk_number+1)*(self.packet_time)<=self.files_info[self.current_file]["duration_milliseconds"]):
                final_slice = self.files_info[self.current_file]["file_segment"][self.chunk_number*self.packet_time:(self.chunk_number+1)*self.packet_time]
                #final_slice = final_slice + 100
                self.chunk_number += 1
                self.q.put(final_slice.raw_data)
            else:
                if(self.chunk_number*self.packet_time<self.files_info[self.current_file]["duration_milliseconds"]):
                    final_slice = self.files_info[self.current_file]["file_segment"][self.chunk_number*self.packet_time:]
                    final_slice = final_slice + self.silence
                    #final_slice = final_slice + 100
                    self.chunk_number += 1


                    self.q.put(final_slice.raw_data)
                else:
                    #start song from begin
                    self.chunk_number=0
                    if self.current_file==self.total_files-1:
                        self.current_file = 0
                    else:
                        self.current_file += 1
                    
            sleep(0.01)

if __name__ == "__main__":
    freeze_support()

    q = Queue()
    radio_stream = RadioOutputStream(q)
    threading.Thread(target=radio_stream.run_stream).start()

    custom_server_child_process = RadioServer(q)
    custom_server_child_process.start()
    print("Thread and process started sucessfully.")

我将数据包编码“传输”到处理，并将编码器定义放在 run 方法中。

无论如何，谢谢大家的帮助。

【讨论】：

这看起来像是你可以做到的另一种方式。

【参考方案2】：

因为我从来没有使用过 PyAV 并且没有安装它，所以只是一个狂野的刺伤，但是从 my comments 和 PyAV documentation 开始，AudioFrame 类有 from_ndarray 和 @987654327 @ 方法。

因此，当您可以做的不是直接通过队列发送 AudioFrame 实例时，您可以发送：

frame_data = (frame.to_ndarray(), frame.format, frame.layout)

（假设AudioFormat 和AudioLayout 类可以被腌制；如果不是，你必须做进一步的解构）。

然后通过队列发送这些：

self.q.put(frame_data)

当在队列的另一端（例如在CustomRadioStream.recv() 中）您需要重构AudioFrame 对象时：

frame_data = self.q.get()
frame = AudioFrame.from_ndarray(frame_data[0], format=frame_data[1], layout=frame_data[2])

您还可以使用namedtuple 来表示frame_data 或包装类以使调试更容易一些。