python
# 格式转化文件，包含多种文件的互相转化，主要与视频相关
from pathlib import Path
import subprocess
import random
import os
import re
class Utils(object):
@staticmethod
def get_decimal_part(x: float) -> float:
s = format(x, '.15f') # 格式化为15位小数字符串
if '.' in s:
_, decimal_part = s.split('.')
decimal_str = decimal_part.rstrip('0') # 移除末尾多余的0
if not decimal_str: # 如果小数部分全为0
return 0.0
result = float("0." + decimal_str)
return -result if x < 0 else result # 处理负数
return 0.0
@staticmethod
def file_path_processor(*file_paths: str) -> str | list[str]:
if len(file_paths) == 1:
return file_paths[0].replace("\\", "\\\\")
return [file_path.replace("\\", "\\\\") for file_path in file_paths]
class TimeConverter(object):
def time_analysis(self, time_str, offset: float = 0.0) -> tuple[int, int, int, int]:
pattern = r'^(\d{1,2})\D(\d{1,2})\D(\d{1,2})[.,](\d{1,3})$'
match: re.Match = re.match(pattern, time_str)
if not match:
raise ValueError(f"无法解析的时间格式: {time_str}")
results = list(match.groups())
results[-1] = f"{results[-1]:0<3}"
hours, minutes, seconds, milliseconds = map(int, results)
if offset != 0:
milliseconds += int(Utils.get_decimal_part(offset) * 1000)
offset = int(offset)
hours += (offset // 3600)
minutes += (offset // 60)
seconds += (offset % 60)
# 注意进位
seconds += milliseconds // 1000
minutes += seconds // 60
hours += minutes // 60
seconds %= 60
milliseconds %= 1000
minutes %= 60
return hours, minutes, seconds, milliseconds
def format_number(self, input_str: str, length: int) -> str:
if not input_str.isdigit():
raise ValueError("输入必须是数字字符串")
if not isinstance(length, int) or length <= 0:
raise ValueError("长度必须是正整数")
if len(input_str) > length:
return input_str[:length] # 截断超长部分
else:
return '0' * (length - len(input_str)) + input_str
def format_copy(self, ref_time):
match: re.Match = re.match("^(\d+)(\D)(\d+)(\D)(\d+)(\D)(\d+)$", ref_time)
if not match:
raise ValueError(f"无法复制的时间格式: {ref_time}")
(h_str, sep1, m_str, sep2, s_str, sep3, ms_str) = match.groups()
h_len, m_len, s_len, ms_len = map(len, (h_str, m_str, s_str, ms_str))
def time_formater(hours: int, minutes: int, seconds: int, milliseconds: int) -> str:
return (
f"{self.format_number(str(hours), h_len)}{sep1}"
f"{self.format_number(str(minutes), m_len)}{sep2}"
f"{self.format_number(str(seconds), s_len)}{sep3}"
f"{self.format_number(str(milliseconds), ms_len)}"
)
return time_formater
class SubtitleConverter(object):
def ass_analyser(self, ass_file) -> list[dict]:
ass_object = []
with open(ass_file, "r", encoding="utf-8") as f:
start_record = False
record_fields = False
for i in f:
if i.strip() == "[Events]":
record_fields = True
continue
if re.match("\[.*?\]$", i.strip()):
start_record = False
continue
if record_fields:
record_fields = False
start_record = True
fields = [j.strip() for j in i.split(",")]
continue
if start_record:
row = map(lambda j: j.strip(), i.split(",", maxsplit=len(fields) - 1))
ass_object.append({k: v for k, v in zip(fields, row)})
return ass_object
def ass2srt(self, ass_file: str, srt_file: str, offset: float) -> None:
if not ass_file.endswith(".ass"):
return
time_analyser = TimeConverter()
formatter = time_analyser.format_copy("00:00:00,000")
srt_file_obj = open(srt_file, "w", encoding="utf-8")
count = 1
for row in self.ass_analyser(ass_file):
if not re.match("标准", row["Style"]):
continue
start_time = formatter(*time_analyser.time_analysis(row["Start"], offset))
end_time = formatter(*time_analyser.time_analysis(row["End"], offset))
subtitle = row["Text"]
srt_file_obj.write(
f"{count}\n{start_time} --> {end_time}\n{subtitle}\n\n"
)
count += 1
srt_file_obj.close()
def ass2ass_eng(self, ass_file: str, output_file: str, remove_style='标准-Chi') -> None:
"""
这个方法是纯AI写的，与ass_analyser脱节。
其作用是处理ass文件中的样式，去除其中的描边设置，同时移除掉指定字幕。
字幕文件下载自网站：http://154.17.3.217:8888/sub/new, 原生字幕可能中英夹杂，但有时
我们出于学习目的，可能只想要英文字幕；或纯粹出于娱乐目的，只想保留中文字幕等；
"""
with open(ass_file, 'r', encoding='utf-8-sig') as f:
lines = f.readlines()
output = []
current_section = None
for line in lines:
line = line.rstrip('\r\n')
stripped = line.strip()
if stripped.startswith('[') and stripped.endswith(']'):
current_section = stripped
output.append(line)
continue
if current_section == '[V4+ Styles]':
if line.startswith('Style:'):
parts = line[len('Style:'):].split(',')
if len(parts) >= 17:
parts[16] = '0'
output.append('Style:' + ','.join(parts))
else:
output.append(line)
else:
output.append(line)
elif current_section == '[Events]' and line.startswith('Dialogue:'):
content = line[len('Dialogue:'):].strip()
fields = content.split(',', 9)
if len(fields) >= 4 and fields[3].strip() == remove_style:
continue
output.append(line)
else:
output.append(line)
with open(output_file, 'w', encoding='utf-8') as f:
f.write('\n'.join(output))
def ass2ass_offset(self, ass_file1, ass_file2, offset: float) -> None:
time_analyser = TimeConverter()
ref_time = "0:00:00.00"
time_formatter = time_analyser.format_copy(ref_time)
ass_object = self.ass_analyser(ass_file1)
for row in ass_object:
offset_start = time_analyser.time_analysis(row["Start"], offset)
offset_end = time_analyser.time_analysis(row["End"], offset)
row["Start"] = time_formatter(*offset_start)
row["End"] = time_formatter(*offset_end)
fields = ",".join(ass_object[0].keys())
rows = "\n".join(",".join(row[k] for k in ass_object[0]) for row in ass_object)
rows = rows.replace("\\", "\\\\")
new_body = f"[Events]\n{fields}\n{rows}"
pattern = r'\[Events\]\nFormat:.*(?:\nDialogue:.*)*'
with open(ass_file1, "r", encoding="utf-8") as f:
content = f.read()
new_content = re.sub(pattern, new_body, content, re.MULTILINE)
with open(ass_file2, "w", encoding="utf-8") as f:
f.write(new_content)
def srt2srt_offset(self, srt_file1, srt_file2, offset: float) -> None:
time_analyser = TimeConverter()
ref_time = "00:00:00,000"
time_formatter = time_analyser.format_copy(ref_time)
with open(srt_file1, "r", encoding="utf-8") as f1:
f2 = open(srt_file2, "w", encoding="utf-8")
for i in f1:
res = re.match("^(.*?) --> (.*)$", i.strip())
if res:
start_time, end_time = res.groups()
offset_start = time_analyser.time_analysis(start_time, offset)
offset_end = time_analyser.time_analysis(end_time, offset)
start_time = time_formatter(*offset_start)
end_time = time_formatter(*offset_end)
i = f"{start_time} --> {end_time}\n"
f2.write(i)
f2.close()
class VedioConverter(object):
def mkv2mp4(self, mkv_file: str, mp4_file: str) -> None:
mkv_file, mp4_file = Utils.file_path_processor(mkv_file, mp4_file)
command = [
ffmpeg_file_path,
'-i', Utils.file_path_processor(mkv_file),
'-c:v', 'copy',
'-c:a', 'copy',
'-y',
Utils.file_path_processor(mp4_file)
]
subprocess.run(command, check=True)
def ass_embed_mp4(self, mp4_file: str, ass_file: str, output_file: str, itsoffset: float = 0.0) -> None:
mp4_file, ass_file, output_file = Utils.file_path_processor(
mp4_file, ass_file, output_file
)
converter = SubtitleConverter()
random_name = f"{random.randint(0, 1000000)}.ass"
converter.ass2ass_offset(ass_file, random_name, itsoffset)
command = [
ffmpeg_file_path,
'-i', mp4_file,
'-vf', f"subtitles={random_name}",
'-c:v', 'libx264',
'-profile:v', 'high',
'-pix_fmt', 'yuv420p',
'-preset', 'fast',
'-b:a', '192k',
'-c:a', 'aac',
'-movflags', '+faststart',
'-y',
output_file
]
subprocess.run(command, check=True)
os.remove(random_name)
def ass_embed_mkv(self, mkv_file: str, ass_file: str, output_file: str, itsoffset) -> None:
mkv_file, ass_file, output_file = Utils.file_path_processor(
mkv_file, ass_file, output_file
)
command = [
ffmpeg_file_path,
'-i', mkv_file,
'-itsoffset', str(itsoffset),
'-i', ass_file,
'-map', '0',
'-map', '-0:s',
'-map', '1',
'-c', 'copy',
'-metadata:s:s:0', 'language=eng',
'-y',
output_file
]
subprocess.run(command, check=True)
ffmpeg_file_path = r"ffmpeg.exe"
vedio_converter = VedioConverter()
# 加入硬字幕(mp4)
vedio_converter.ass_embed_mp4(
r"your_input_mp4_file.mp4",
r"your_ass_subtitle_file.ass",
r"your_output_mp4_file.mp4",
itsoffset=6.3 # 指定的字幕偏移时间，让字幕对齐音频
)为了方便字幕的视频嵌入，上述代码实现了一些较为重要的功能，部分如下：
①ass文件转srt文件，见SubtitleConverter的ass2srt方法；
②根据srt文件和ass文件的时间偏移指定时间生成新的srt文件和ass文件的方法，见SubtitleConverter的ass2ass_offset和srt2srt_offset
③ass字幕文件嵌入mp4视频的方法（可指定时间偏移），见VedioConverter的ass_embed_mp4方法，注意是硬字幕嵌入，相对耗时。
这些方法的实现都不是很难，不过并不能保证没有Bug；经过简单而基本测试，暂时没有出现问题
在使用之前，请确保找到你的ffmpeg路径。如果已经添加到环境变量，可以直接使用；否则请自行修改里面ffmpeg的路径为绝对路径。此处提供ffmpeg的下载路径：
FFmpeg 最新 Windows 64 位 GPL 版本下载
关于为什么mp4视频嵌入硬字幕，而mkv视频却是嵌入软字幕（在代码中），其实是有原因的：
mp4被更加广泛的兼容，几乎所有视频播放器都可以正确播放。但如果是嵌入软字幕，mp4视频的字幕则不一定能被播放器支持。硬字幕嵌入能保证字幕一定显示，更凸显mp4兼容的优势。缺陷就是硬字幕不能选择隐藏，同时需要重新编码，比较耗时；
mkv视频的支持性就明显要差不少，如手机上很多视频播放器就对mkv视频的支持不好，或视频变形，或音频丢失；但是软字幕的显示往往不是问题，这得益于mkv视频是字幕的天然容器，所以只要能找到合适的mkv视频播放器，几乎就能正常的显示软字幕。