Python 3 使用subprocess调用FFmpeg进行转码，通过控制台输出日志中的时间来计算转换进度
注意事项：
FFmpeg日志中的时间进度是在stderr(标准错误)中输出，所以需要将stderr(标准错误)和stdout(标准输出)两个输出流进行合并，才能获取进度相关日志。
使用subprocess.Popen调用cmd命令行，不同操作系统的换行符不统一，windows:\r\n mac:\r linux:\n，所以需要使用text = True来调整换行符（或者Universal_newlines = True）。Changed in version 3.7: Added the text parameter, as a more understandable alias of universal_newlines.（在3.7版中的改变：添加了text参数，作为Universal_newlines的更易理解的别名。）
对于cmd命令行中有中文字符参数，还应该添加encoding = "utf-8"参数。
完整代码
import re
import subprocess
# 将日志输出的时间类型转换成秒
def get_seconds(time):
h = int(time[0:2])
# print("时：" + str(h))
m = int(time[3:5])
# print("分：" + str(m))
s = int(time[6:8])
# print("秒：" + str(s))
ms = int(time[9:12])
# print("毫秒：" + str(ms))
ts = (h * 60 * 60) + (m * 60) + s + (ms / 1000)
return ts
# size= 25189kB time=00:04:28.67 bitrate= 768.0kbits/s speed= 748x
# video:0kB audio:25189kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.000302%
cmd = ['ffmpeg.exe', '-i', 'D:\\test.mp3', '-ar', '48000', '-ac',
'1', '-acodec', 'pcm_s16le', '-hide_banner', 'D:\\out.wav']
process = subprocess.Popen(cmd, shell=False, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, encoding="utf-8",
text=True)
for line in process.stdout:
# print(line)
duration_res = re.search(r'\sDuration: (?P<duration>\S+)', line)
if duration_res is not None:
duration = duration_res.groupdict()['duration']
duration = re.sub(r',', '', duration)
result = re.search(r'\stime=(?P<time>\S+)', line)
if result is not None:
elapsed_time = result.groupdict()['time']
# 此处可能会出现进度超过100%，未对数值进行纠正
progress = (get_seconds(elapsed_time) / get_seconds(duration)) * 100
print(elapsed_time)
print(progress)
print("进度:%3.2f" % progress + "%")
process.wait()
if process.poll() == 0:
print("success:", process)
else:
print("error:", process)
原文地址:https://blog.csdn.net/qq_41730930/article/details/103815613
