Ошибка FFMpeg при преобразовании из MP4 в MP3 в Python

Мы можем использовать полный путь, чтобы FFmpeg мог найти файлы. Мы можем объединить downloadDirectory с videoTitle для создания полного пути:

def MP3():
        ...
        videoTitle = video.title

        videoTitle = os.path.join(downloadDirectory, videoTitle)

        new_filename = videoTitle + '.mp3'
        ...

Полный пример кода:

from pytube import Playlist
import ffmpy
from ffmpy import FFmpeg
import os

playlistLink = 'https://www.youtube.com/playlist?list=PLS1QulWo1RIaJECMeUT4LFwJ-ghgoSH6n' #input("Introduz o link da Playlist: ")
playlist = Playlist(playlistLink)   

diretório = 'E'
while diretório != 'M' and diretório != 'V':
    diretório = 'M' #input("Vais baixar música ou vídeos? (M/V)")
    if diretório == 'M':
        downloadDirectory = "C:/Users/fonti/Documents/Projetos Python/Youtube/Músicas"
    elif diretório == 'V':
        downloadDirectory = "C:/Users/fonti/Documents/Projetos Python/Youtube/Vídeos"

print("Número total de vídeos a baixar: ", len(playlist.video_urls))    

print("\n\n Links dos vídeos:\n")

for url in playlist.video_urls:
    print(url) 

def MP3():
    for video in playlist.videos:

        audio = video.streams.get_audio_only()
    
        audio.download(downloadDirectory)

        videoTitle = video.title

        videoTitle = os.path.join(downloadDirectory, videoTitle)  # Concatenate the directory and the file name
    
        new_filename = videoTitle + '.mp3'
        default_filename = videoTitle + '.mp4'        
    
        print(default_filename+'\n\n'+new_filename)

        ff = ffmpy.FFmpeg(
            executable = 'C:/ffmpeg/bin/ffmpeg.exe',
            inputs = {default_filename : None},
            outputs = {new_filename : None}
        )
        ff.run()


def MP4():
    for video in playlist.videos:
        print('Downloading : {} with url : {}'.format(video.title, video.watch_url))
        video.streams.\
            filter(type='video', progressive=True, file_extension='mp4').\
            order_by('resolution').\
            desc().\
            first().\
            download(downloadDirectory)

escolha = 'E'
while escolha != 'V' and escolha != 'A':
    escolha = 'A' #input("Queres formato de vídeo ou áudio (V/A)? ")
    if escolha == 'V':
        MP4()
    elif escolha == 'A':
        MP3()
    else:
        print("Escolha inválida")

Более надежное решение — поиск файла .mp4 в папке и удаление его после преобразования в mp3:

from pytube import Playlist
import ffmpy
from ffmpy import FFmpeg
import os
import glob

playlistLink = 'https://www.youtube.com/playlist?list=PLS1QulWo1RIaJECMeUT4LFwJ-ghgoSH6n' #input("Introduz o link da Playlist: ")
playlist = Playlist(playlistLink)   

diretório = 'E'
while diretório != 'M' and diretório != 'V':
    diretório = 'M' #input("Vais baixar música ou vídeos? (M/V)")
    if diretório == 'M':
        downloadDirectory = "C:/Users/fonti/Documents/Projetos Python/Youtube/Músicas"
    elif diretório == 'V':
        downloadDirectory = "C:/Users/fonti/Documents/Projetos Python/Youtube/Vídeos"

print("Número total de vídeos a baixar: ", len(playlist.video_urls))    

print("\n\n Links dos vídeos:\n")

for url in playlist.video_urls:
    print(url) 

def MP3():
    # Delete all mp4 files in Músicas folder
    mp4_files = glob.glob(os.path.join(downloadDirectory, '*.mp4'))  # dir C:/Users/fonti/Documents/Projetos Python/Youtube/Músicas/*.mp4
    for f in mp4_files:
        os.remove(f)

    for video in playlist.videos:

        audio = video.streams.get_audio_only()
    
        audio.download(downloadDirectory)

        videoTitle = video.title
        videoTitle = videoTitle.strip() # use the strip() method to remove trailing and leading spaces https://stackoverflow.com/a/10443548/4926757
       
        # List all mp4 files in the directory.
        videoTitle = glob.glob(os.path.join(downloadDirectory, '*.mp4'))  # dir C:/Users/fonti/Documents/Projetos Python/Youtube/Músicas/*.mp4
        
        #videoTitle = os.path.join(downloadDirectory, videoTitle)  # Concatenate the directory and the file name
    
        #new_filename = videoTitle + '.mp3'
        #default_filename = videoTitle + '.mp4'

        default_filename = videoTitle[0]  # Suppused to be only one mp4 file in the folder.
        new_filename = default_filename.replace('.mp4', '.mp3')  # Remplace .mp4 with .mp3
    
        print(default_filename+'\n\n'+new_filename)

        ff = ffmpy.FFmpeg(
            executable = 'C:/ffmpeg/bin/ffmpeg.exe',
            inputs = {default_filename : None},
            outputs = {new_filename : None}
        )
        ff.run()

        os.remove(default_filename)  # Delete the mp4 file


def MP4():
    for video in playlist.videos:
        print('Downloading : {} with url : {}'.format(video.title, video.watch_url))
        video.streams.\
            filter(type='video', progressive=True, file_extension='mp4').\
            order_by('resolution').\
            desc().\
            first().\
            download(downloadDirectory)

escolha = 'E'
while escolha != 'V' and escolha != 'A':
    escolha = 'A' #input("Queres formato de vídeo ou áudio (V/A)? ")
    if escolha == 'V':
        MP4()
    elif escolha == 'A':
        MP3()
    else:
        print("Escolha inválida")