Using ffmpeg to obtain video durations in python

Question

I've installed ffprobe using the pip ffprobe command on my PC, and installed ffmpeg from here.

However, I'm still having trouble running the code listed here.

I try to use the following code unsuccessfully.

SyntaxError: Non-ASCII character '\xe2' in file GetVideoDurations.py
on line 12, but no encoding declared; see
http://python.org/dev/peps/pep-0263/ for details

Does anyone know what's wrong? Am I not referencing the directories correctly? Do I need to make sure the .py and video files are in a specific location?

import subprocess

def getLength(filename):
    result = subprocess.Popen(["ffprobe", "filename"],
    stdout = subprocess.PIPE, stderr = subprocess.STDOUT)
    return [x for x in result.stdout.readlines() if "Duration" in x]

fileToWorkWith = ‪'C:\Users\PC\Desktop\Video.mkv'

getLength(fileToWorkWith)

Apologies if the question is somewhat basic. All I need is to be able to iterate over a group of video files and get their start time and end time.

Thank you!

Answer 1

There is no need to iterate though the output of FFprobe. There is one simple command which returns only the duration of the input file:

ffprobe -v error -show_entries format=duration -of default=noprint_wrappers=1:nokey=1 <input_video>

You can use the following method instead to get the duration:

def get_length(input_video):
    result = subprocess.run(['ffprobe', '-v', 'error', '-show_entries', 'format=duration', '-of', 'default=noprint_wrappers=1:nokey=1', input_video], stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
    return float(result.stdout)

Answer 2

I'd suggest using FFprobe (comes with FFmpeg).

The answer Chamath gave was pretty close, but ultimately failed for me.

Just as a note, I'm using Python 3.5 and 3.6 and this is what worked for me.

import subprocess 

def get_duration(file):
    """Get the duration of a video using ffprobe."""
    cmd = 'ffprobe -i {} -show_entries format=duration -v quiet -of csv="p=0"'.format(file)
    output = subprocess.check_output(
        cmd,
        shell=True, # Let this run in the shell
        stderr=subprocess.STDOUT
    )
    # return round(float(output))  # ugly, but rounds your seconds up or down
    return float(output)

If you want to throw this function into a class and use it in Django (1.8 - 1.11), just change one line and put this function into your class, like so:

def get_duration(file):

to:

def get_duration(self, file):

Note: Using a relative path worked for me locally, but the production server required an absolute path. You can use os.path.abspath(os.path.dirname(file)) to get the path to your video or audio file.

Answer 3

I think Chamath's second comment answers the question: you have a strange character somewhere in your script, either because you are using a ` instead of a ' or you have a word with non-english accents, something like this.

As a remark, for what you are doing you can also try MoviePy which parses the ffmpeg output like you do (but maybe in the future I'll use Chamath's ffprobe method it looks cleaner):

import moviepy.editor as mp
duration =  mp.VideoFileClip("my_video.mp4").duration