Python3.10中ffprobe的困難

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所以這個 getLength 函式將在 python 2.7 中運行良好，但我無法讓它在 3.10 中運行。想知道是否有人可以建議可能需要更改的內容，因為我不知所措。當我嘗試列印退貨時，那里什么都沒有。我 95% 確定問題出在 result = subprocess.Popen() 行，但為了完整起見，我包含了整個函式

#function... 回傳視頻檔案的持續時間 HH:MM:SS

def getLength(filename):

   #uses ffprobe to get info about the video file

   result = subprocess.Popen(["ffprobe", filename],

   stdout = subprocess.PIPE, stderr = subprocess.STDOUT)


   #finds the info that has the word "Duration"

   y = [x for x in result.stdout.readlines() if "Duration: " in x]

   #get the location of the "Duration: " phrase

   loc = y[0].find("Duration: ")

   #assuming we find the location of that phrase..

   if loc != -1:

   #cut out everything before and everything more than 10 characters later

   print ( y[0][loc 10:loc 18] )

   return y[0][loc 10:loc 18]

   else:

   #if we don't find anything then set it to be 2 seconds of nothing...

   print ( y[0][loc 10:loc 18] )

   return '00:00:02' 

uj5u.com熱心網友回復：

在 Python 3 中，字串是Unicode 格式，stdout輸出是位元組陣列。

我們可以使用以下方法將位元組陣列轉換為字串x.decode("utf-8")：

決議串列可能如下所示：

y = [x.decode("utf-8") for x in result.stdout.readlines() if "Duration: " in x.decode("utf-8")]

完整的代碼示例（使用stderr代替stdout）：

import subprocess

def get_length(filename):
    # Uses FFprobe to get info about the video file
    result = subprocess.Popen(["ffprobe", filename], stderr=subprocess.PIPE)

    # Finds the info that has the word "Duration"
    # Convert bytes array to strings using decode("utf-8")
    y = [x.decode("utf-8") for x in result.stderr.readlines() if "Duration: " in x.decode("utf-8")]

    # Get the location of the "Duration: " phrase
    loc = y[0].find("Duration: ")

    # Assuming we find the location of that phrase..
    if loc != -1:
        # Cut out everything before and everything more than 10 characters later
        print(y[0][loc 10:loc 18])
        return y[0][loc 10:loc 18]
    else:
        # If we don't find anything then set it to be 2 seconds of nothing...
        print(y[0][loc 10:loc 18])
        return '00:00:02' 


res = get_length('BBB.ogv')
print(res)

為了獲取 OVG（或 MP4）檔案的視頻時長，我們可以選擇 JSON 格式：

import subprocess as sp
import json

# https://superuser.com/questions/650291/how-to-get-video-duration-in-seconds
data = sp.run(["ffprobe", '-v', 'error', '-select_streams', 'v', '-of', 'default=noprint_wrappers=1:nokey=1', '-show_entries', 'stream=duration', '-of', 'json', 'BBB.ogv'], stdout=sp.PIPE).stdout

dict = json.loads(data)

print(dict['streams'][0]['duration'])

uj5u.com熱心網友回復：

我很確定python3中的輸出是位元組流而不是str。
嘗試這個：

import subprocess
media = "/home/rolf/BBB.ogv"
try:
    comm = subprocess.Popen(['ffprobe', '-hide_banner', '-show_entries', 'format=size, duration',\
                       '-i', media], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, universal_newlines=True)
except Exception as e:
    pass
try:
    with comm.stdout:
        for i in iter(comm.stdout.readline, b''):
            if i != '':
                print(i)
            else:
                break
except Exception as e:
    print("Error: ", str(e))

輸出：

python probe.py
Input #0, ogg, from '/home/rolf/BBB.ogv':

  Duration: 00:01:00.14, start: 0.000000, bitrate: 264 kb/s

  Stream #0:0(eng): Video: theora, yuv420p, 640x360 [SAR 1:1 DAR 16:9], 24 fps, 24.04 tbr, 24.04 tbn

    Metadata:

      creation_time   : 2011-03-16 10:41:52

      handler_name    : Apple Video Media Handler

      encoder         : Lavc56.60.100 libtheora

      major_brand     : mp42

      minor_version   : 1

      compatible_brands: mp42avc1

  Stream #0:1(eng): Audio: vorbis, 44100 Hz, mono, fltp, 80 kb/s

    Metadata:

      creation_time   : 2011-03-16 10:41:53

      handler_name    : Apple Sound Media Handler

      encoder         : Lavc56.60.100 libvorbis

      major_brand     : mp42

      minor_version   : 1

      compatible_brands: mp42avc1

[FORMAT]

duration=60.139683

size=1992112

[/FORMAT]
    

uj5u.com熱心網友回復：

如果您對以秒為單位的持續時間（不在HH:MM:SS符號中）感到滿意，我更喜歡使用該-of json選項，以便我可以使用json包來決議 ffprobe 輸出：

import subprocess as sp
import json
from pprint import pprint

out = sp.run(['ffprobe','-hide_banner','-of','json',
                        '-show_entries','format:stream', f'"{filename}"'], 
             stdout=sp.PIPE, universal_newlines=True)
results = json.loads(out.stdout)

pprint(results) # to see the full details

format_duration = float(results['formats']['duration']) # in seconds
stream_durations = [float(st['duration']) for st in results['streams']] # in seconds

注意：您必須指定-show_entries選項，否則它將回傳空 JSON

只需插入我的庫 ( pip install fmpegio-core)，您可以交替運行：

import ffmpegio

file_duration = ffmpegio.probe.format_basic(filename)['duration']

標籤：python-3.x python-2.7 ffmpeg ffprobe python-3.10

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