使用Python调用FFmpeg给MKV添加字幕时路径报错求助

错误原因分析 #

从报错信息里的Unable to parse option value "UsersclaraDocumentsProyectosSubtitulossubtitulos..." as image size可以看出：Windows路径的反斜杠被转义后消失，导致路径变成无分隔符的连续字符串，FFmpeg误将其识别为subtitles滤镜的original_size参数值，从而触发参数无效的错误。

解决方案 #

方案1：修正路径转义问题 #

将Windows路径的反斜杠替换为正斜杠，同时避免在滤镜字符串中使用单引号包裹路径：

import os
from fuzzywuzzy import fuzz
import ffmpeg

for video_file, (video, subtitle) in video_subtitle_mapping.items():
    print(f"Video: {video_file}, Subtitle: {subtitle}")

    # 构建字幕、视频和输出路径
    subtitulo_file = os.path.join(r"C:\Users\clara\Documents\Proyectos\Subtitulos\subtitulos", subtitle)
    video_path = os.path.join(r"C:\Users\clara\Documents\Proyectos\Subtitulos\videos", video_file)
    output_video_file = os.path.join(r"C:\Users\clara\Documents\Proyectos\Subtitulos\videos_con_subtitulos", video_file)

    # 将Windows反斜杠替换为正斜杠，避免转义问题
    subtitulo_file = subtitulo_file.replace("\\", "/")
    video_path = video_path.replace("\\", "/")

    try:
        # 直接传递路径，无需额外单引号包裹
        ffmpeg.input(video_path).output(output_video_file, vf=f"subtitles={subtitulo_file}").run()
    except ffmpeg.Error as e:
        # 解码stderr输出为可读字符串
        print(f"Error processing video {video_file}: {e.stderr.decode('utf-8')}")

方案2：使用FFmpeg-Python的filter方法（推荐） #

直接调用filter()方法传递字幕参数，完全避免字符串转义问题：

import os
from fuzzywuzzy import fuzz
import ffmpeg

for video_file, (video, subtitle) in video_subtitle_mapping.items():
    print(f"Video: {video_file}, Subtitle: {subtitle}")

    # 构建路径
    subtitulo_file = os.path.join(r"C:\Users\clara\Documents\Proyectos\Subtitulos\subtitulos", subtitle)
    video_path = os.path.join(r"C:\Users\clara\Documents\Proyectos\Subtitulos\videos", video_file)
    output_video_file = os.path.join(r"C:\Users\clara\Documents\Proyectos\Subtitulos\videos_con_subtitulos", video_file)

    try:
        # 使用filter方法配置字幕滤镜，无需手动处理字符串转义
        stream = ffmpeg.input(video_path)
        stream = ffmpeg.filter(stream, 'subtitles', filename=subtitulo_file)
        ffmpeg.output(stream, output_video_file).run()
    except ffmpeg.Error as e:
        print(f"Error processing video {video_file}: {e.stderr.decode('utf-8')}")

额外提示 #

• 如果输出文件已存在，FFmpeg默认会报错，可以在output()方法中添加overwrite_output=True参数覆盖已有文件：ffmpeg.output(stream, output_video_file, overwrite_output=True).run()
• 确保FFmpeg已正确添加到系统环境变量中，或者在代码中指定FFmpeg的路径：ffmpeg.input(video_path, cmd=r"C:\path\to\ffmpeg.exe")

内容的提问来源于stack exchange，提问作者Clara Ogalla