Recherche avancée

Sur d’autres sites (12084)

• ffmpeg : How to set AVFormatContext from NSData

  21 janvier 2014, par SUKIYAKI

  I'm using FFmpeg library in Objective-C.

  I want to set AVFormatContext from NSData which contain imagedata.
  I know I can set AVFormatContext with av_open_input_file().
  so writing contents of NSData to a temporary file, I can do it like this.

  [data writeToFile:@"./temp.mov" atomically:YES];
  
  av_open_input_file(&pFormatCtx, "./temp.mov", NULL, 0, NULL);
  
  
  
  .
  
  .
  
  .
  
  
  
  NSFileManager *fm = [NSFileManager defaultManager];
  
  [fm removeFileAtPath:@"./temp.mov" handler:nil];

  but, I don't want to use temporary file.

  Does anyone know smart way ?

  sorry my poor English.

  Thanks

• Using PyAV to encode mono audio to file, params match docs, but still causes Errno 22

  20 février 2023, par andrew8088

  While trying to use PyAV to encode live mono audio from a microphone to a compressed audio stream (using mp2 or flac as encoder), the program kept raising an exception ValueError: [Errno 22] Invalid argument.

  


  To remove the live microphone source as a cause of the problem, and to make the problematic code easier for others to run/test, I have removed the mic source and now just generate a pure tone as a sequence of input buffers.

  


  All attempts to figure out the missing or mismatched or incorrect argument have just resulted in seeing documentation and examples that are the same as my code.

  


  I would like to know from someone who has used PyAV successfully for mono audio what the correct method and parameters are for encoding mono frames into the mono stream.

  


  The package used is av 10.0.0 installed with
pip3 install av --no-binary av
so it uses my package-manager provided ffmpeg library, which is version 4.2.7.

  


  The problematic python code is :

  


  #!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Recreating an error 22 when encoding sound with PyAV.

Created on Sun Feb 19 08:10:29 2023
@author: andrewm
"""
import typing
import sys
import math
import fractions

import av
from av import AudioFrame

""" Ensure some PyAudio constants are still defined without changing 
    the PyAudio recording callback function and without depending 
    on PyAudio simply for reproducing the PyAV bug [Errno 22] thrown in 
    File "av/filter/context.pyx", line 89, in av.filter.context.FilterContext.push
"""
class PA_Stub():
    paContinue = True
    paComplete= False

pyaudio = PA_Stub()


"""Generate pure tone at given frequency with amplitude 0...1.0 at 
   sampling frewuency fs and beginning at phase offset 'phase'.
   Returns the new phase after the sinusoid has cycled over the 
   sampling window length.
"""
def generate_tone(
        freq:int, phase:float, amp:float, fs, samp_fmt, buffer:bytearray
) -> float:
    assert samp_fmt == "s16", "Only s16 supported atm"
    samp_size_bytes = 2
    n_samples = int(len(buffer)/samp_size_bytes)
    window = [int(0) for i in range(n_samples)]
    theta = phase
    phase_inc = 2*math.pi * freq / fs
    for i in range(n_samples):
        v = amp * math.sin(theta)
        theta += phase_inc
        s = int((2**15-1)*v)
        window[i] = s
    for sample_i in range(len(window)):
        byte_i = sample_i * samp_size_bytes
        enc = window[sample_i].to_bytes(
                2, byteorder=sys.byteorder, signed=True
        )
        buffer[byte_i] = enc[0]
        buffer[byte_i+1] = enc[1]
    return theta


channels = 1
fs = 44100  # Record at 44100 samples per second
fft_size_samps = 256
chunk_samps = fft_size_samps * 10  # Record in chunks that are multiples of fft windows.

# print(f"fft_size_samps={fft_size_samps}\nchunk_samps={chunk_samps}")

seconds = 3.0
out_filename = "testoutput.wav"

# Store data in chunks for 3 seconds
sample_limit = int(fs * seconds)
sample_len = 0
frames = []  # Initialize array to store frames

ffmpeg_codec_name = 'mp2'  # flac, mp3, or libvorbis make same error.

sample_size_bytes = 2
buffer = bytearray(int(chunk_samps*sample_size_bytes))
chunkperiod = chunk_samps / fs
total_chunks = int(math.ceil(seconds / chunkperiod))
phase = 0.0

### uncomment if you want to see the synthetic data being used as a mic input.
# with open("test.raw","wb") as raw_out:
#     for ci in range(total_chunks):
#         phase = generate_tone(2600, phase, 0.8, fs, "s16", buffer)
#         raw_out.write(buffer)
# print("finished gen test")
# sys.exit(0)
# #---- 

# Using mp2 or mkv as the container format gets the same error.
with av.open(out_filename+'.mp2', "w", format="mp2") as output_con:
    output_con.metadata["title"] = "My title"
    output_con.metadata["key"] = "value"
    channel_layout = "mono"
    sample_fmt = "s16p"

    ostream = output_con.add_stream(ffmpeg_codec_name, fs, layout=channel_layout)
    assert ostream is not None, "No stream!"
    cctx = ostream.codec_context
    cctx.sample_rate = fs
    cctx.time_base = fractions.Fraction(numerator=1,denominator=fs)
    cctx.format = sample_fmt
    cctx.channels = channels
    cctx.layout = channel_layout
    print(cctx, f"layout#{cctx.channel_layout}")
    
    # Define PyAudio-style callback for recording plus PyAV transcoding.
    def rec_callback(in_data, frame_count, time_info, status):
        global sample_len
        global ostream
        frames.append(in_data)
        nsamples = int(len(in_data) / (channels*sample_size_bytes))
        
        frame = AudioFrame(format=sample_fmt, layout=channel_layout, samples=nsamples)
        frame.sample_rate = fs
        frame.time_base = fractions.Fraction(numerator=1,denominator=fs)
        frame.pts = sample_len
        frame.planes[0].update(in_data)
        print(frame, len(in_data))
        
        for out_packet in ostream.encode(frame):
            output_con.mux(out_packet)
        for out_packet in ostream.encode(None):
            output_con.mux(out_packet)
        
        sample_len += nsamples
        retflag = pyaudio.paContinue if sample_lencode>

  


  If you uncomment the RAW output part you will find the generated data can be imported as PCM s16 Mono 44100Hz into Audacity and plays the expected tone, so the generated audio data does not seem to be the problem.

  


  The normal program console output up until the exception is :

  


  mp2 at 0x7f8e38202cf0> layout#4
Beginning
 5120
. 5120


  


  The stack trace is :

  


  Traceback (most recent call last):&#xA;&#xA;  File "Dev/multichan_recording/av_encode.py", line 147, in <module>&#xA;    ret_data, ret_flag = rec_callback(buffer, ci, {}, 1)&#xA;&#xA;  File "Dev/multichan_recording/av_encode.py", line 121, in rec_callback&#xA;    for out_packet in ostream.encode(frame):&#xA;&#xA;  File "av/stream.pyx", line 153, in av.stream.Stream.encode&#xA;&#xA;  File "av/codec/context.pyx", line 484, in av.codec.context.CodecContext.encode&#xA;&#xA;  File "av/audio/codeccontext.pyx", line 42, in av.audio.codeccontext.AudioCodecContext._prepare_frames_for_encode&#xA;&#xA;  File "av/audio/resampler.pyx", line 101, in av.audio.resampler.AudioResampler.resample&#xA;&#xA;  File "av/filter/graph.pyx", line 211, in av.filter.graph.Graph.push&#xA;&#xA;  File "av/filter/context.pyx", line 89, in av.filter.context.FilterContext.push&#xA;&#xA;  File "av/error.pyx", line 336, in av.error.err_check&#xA;&#xA;ValueError: [Errno 22] Invalid argument&#xA;&#xA;</module>

  


  edit : It's interesting that the error happens on the 2nd AudioFrame, as apparently the first one was encoded okay, because they are given the same attribute values aside from the Presentation Time Stamp (pts), but leaving this out and letting PyAV/ffmpeg generate the PTS by itself does not fix the error, so an incorrect PTS does not seem the cause.

  


  After a brief glance in av/filter/context.pyx the exception must come from a bad return value from res = lib.av_buffersrc_write_frame(self.ptr, frame.ptr)
  
Trying to dig into av_buffersrc_write_frame from the ffmpeg source it is not clear what could be causing this error. The only obvious one is a mismatch between channel layouts, but my code is setting the layout the same in the Stream and the Frame. That problem had been found by an old question pyav - cannot save stream as mono and their answer (that one parameter required is undocumented) is the only reason the code now has the layout='mono' argument when making the stream.

  


  The program output shows layout #4 is being used, and from https://github.com/FFmpeg/FFmpeg/blob/release/4.2/libavutil/channel_layout.h you can see this is the value for symbol AV_CH_FRONT_CENTER which is the only channel in the MONO layout.

  


  The mismatch is surely some other object property or an undocumented parameter requirement.

  


  How do you encode mono audio to a compressed stream with PyAV ?

  


• FFmpegAudio object has no attribute _process

  28 janvier 2023, par Benjamin Tsoumagas

  I'm trying to make a Discord music bot that is remotely hosted and to do that I need ffmpeg to work. I was able to add it using my Dockerfile but upon trying to play music with the bot I get the following errors. For context, I am hosting on Fly.io and using python with the Nextcord library. Below is my relevant code and the error message. Please let me know if any more information is required.

  


  import nextcord, os, json, re, youtube_dl
from nextcord import Interaction, application_checks
from nextcord.ext import commands

youtube_dl.utils.bug_reports_message = lambda: ''

ytdl_format_options = {
    "format": "bestaudio/best",
    'outtmpl': '%(extractor)s-%(id)s-%(title)s.%(ext)s',
    'restrictfilenames': True,
    'noplaylist': True,
    'nocheckcertificate': True,
    'ignoreerrors': False,
    'logtostderr': False,
    'quiet': True,
    'no_warnings': True,
    'default_search': 'auto',
    'source_address': '0.0.0.0',
}

ffmpeg_options = {"options": "-vn"}

ytdl = youtube_dl.YoutubeDL(ytdl_format_options)

class YTDLSource(nextcord.PCMVolumeTransformer):
    def __init__(self, source, *, data, volume=0.5):
        super().__init__(source, volume)
        self.data = data
        self.title = data.get("title")
        self.url = data.get("url")

    @classmethod
    async def from_url(cls, url, *, loop=None, stream=False):
        loop = loop or asyncio.get_event_loop()
        data = await loop.run_in_executor(None, lambda: ytdl.extract_info(url, download=not stream))

        if "entries" in data:
            data = data["entries"][0]
        
        filename = data["url"] if stream else ytdl.prepare_filename(data)
        return cls(nextcord.FFmpegAudio(filename, *ffmpeg_options), data=data)

async def ensure_voice(interaction: Interaction):
    if interaction.guild.voice_client is None:
        if interaction.user.voice:
            await interaction.user.voice.channel.connect()
        else:
            await interaction.send("You are not connected to a voice channel.")
            raise commands.CommandError("Author not connected to a voice channel.")
    elif interaction.guild.voice_client.is_playing():
        interaction.guild.voice_client.stop()

class Music(commands.Cog, name="Music"):
    """Commands for playing music in voice channels"""

    COG_EMOJI = "🎵"

    def __init__(self, bot):
        self.bot = bot
    
    @application_checks.application_command_before_invoke(ensure_voice)
    @nextcord.slash_command()
    async def play(self, interaction: Interaction, *, query):
        """Plays a file from the local filesystem"""

        source = nextcord.PCMVolumeTransformer(nextcord.FFmpegPCMAudio(query))
        interaction.guild.voice_client.play(source, after=lambda e: print(f"Player error: {e}") if e else None)

        await interaction.send(f"Now playing: {query}")

    @application_checks.application_command_before_invoke(ensure_voice)
    @nextcord.slash_command()
    async def yt(self, interaction: Interaction, *, url):
        """Plays from a URL (almost anything youtube_dl supports)"""

        async with interaction.channel.typing():
            player = await YTDLSource.from_url(url, loop=self.bot.loop)
            interaction.guild.voice_client.play(
                player, after=lambda e: print(f"Player error: {e}") if e else None
            )

        await interaction.send(f"Now playing: {player.title}")

    @application_checks.application_command_before_invoke(ensure_voice)
    @nextcord.slash_command()
    async def stream(self, interaction: Interaction, *, url):
        """Streams from a URL (same as yt, but doesn't predownload)"""

        async with interaction.channel.typing():
            player = await YTDLSource.from_url(url, loop=self.bot.loop, stream=True)
            interaction.voice_client.play(
                player, after=lambda e: print(f"Player error: {e}") if e else None
            )

        await interaction.send(f"Now playing: {player.title}")

def setup(bot):
    bot.add_cog(Music(bot))


  


  2023-01-28T23:16:15Z app[7d3b734a] yyz [info]Exception ignored in: <function at="at" 0x7fa78ea61fc0="0x7fa78ea61fc0">&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]Traceback (most recent call last):&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/player.py", line 116, in __del__&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]    self.cleanup()&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/player.py", line 235, in cleanup&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]    self._kill_process()&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/player.py", line 191, in _kill_process&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]AttributeError: &#x27;FFmpegA&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]AttributeError: &#x27;FFmpegA&#xA;dio&#x27; object has no attribute &#x27;_process&#x27;&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]Ignoring exception in command :&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]Traceback (most recent call last):&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/application_command.py", line 863, in invoke_callback_with_hooks&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]    await self(interaction, *args, **kwargs)&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]  File "/main/cogs/music.py", line 153, in yt&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]    player = await YTDLSource.from_url(url, loop=self.bot.loop)&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]  File "/main/cogs/music.py", line 71, in from_url    &#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]    return cls(nextcord.FFmpegAudio(filename, *ffmpeg_options), data=data)&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]&#xA;The above exception was the direct cause of the following exception:&#xA;&#xA;re given&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]The above exception was the direct cause of the following exception:&#xA;2023-01-28T23:16:15Z app[7d3b734a] yyz [info]nextcord.errors.ApplicationInvokeError: Command raised an exception: TypeError: FFmpegAudio.__init__() takes 2 positional arguments but 3 were given     &#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]Exception ignored in: <function at="at" 0x7fa78ea61fc0="0x7fa78ea61fc0">&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]Traceback (most recent call last):&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/player.py", line 116, in __del__&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]    self.cleanup()&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/player.py", line 235, in cleanup&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]    self._kill_process()&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/player.py", line 191, in _kill_process&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]    proc = self._process&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]AttributeError: &#x27;FFmpegAudio&#x27; object has no attribute &#xA;&#x27;_process&#x27;&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]Ignoring exception in command :&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]Traceback (most recent call last):&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]  File "/usr/local/lib/python3.10/site-packages/nextcord/application_command.py", line 863, in invoke_callback_with_hooks&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]    await self(interaction, *args, **kwargs)&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]  File "/main/cogs/music.py", line 153, in yt&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]    player = await YTDLSource.from_url(url, loop=self.bot.loop)&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]  File "/main/cogs/music.py", line 71, in from_url    &#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]    return cls(nextcord.FFmpegAudio(filename, *ffmpeg_options), data=data)&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]TypeError: FFmpegAudio.__init__() takes 2 positional arguments but 3 were given&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]The above exception was the direct cause of the following exception:&#xA;2023-01-28T23:16:19Z app[7d3b734a] yyz [info]nextcord.errors.ApplicationInvokeError: Command raised an exception: TypeError: FFmpegAudio.__init__() takes 2 positional arguments but 3 were given&#xA;</function></function>

  


  Similar posts have been made but their issues were typos in changing 'option' : '-vn' to 'options' : '-vn'. I've combed through for any other errors but I can't find any. I was hoping to see I made a similar mistake, but this is the template I was following from the Nextcord developers and I had no luck :