Class to help to extract a frame from a video with ffmpeg

ffmpeg.py

# coding=utf-8
from sys import argv
from math import ceil
from re import compile
from subprocess import Popen, PIPE


class FfmpegHelper(object):
    def __init__(self, file_path):
        self.file_path = file_path
        self.ffmpeg = 'ffmpeg'
        self.ffprobe = 'ffprobe'

    @staticmethod
    def time_to_seconds(duration):
        seconds = 0
        parts = map(lambda x: int(ceil(float(x))), duration.split(':'))
        for i, part in enumerate(reversed(parts)):
            seconds += 60**i * part
        return seconds

    @staticmethod
    def seconds_to_time(seconds):
        hours = seconds / 3600
        seconds -= hours * 3600
        minutes = seconds / 60
        seconds -= minutes * 60
        return '%02d:%02d:%02d' % (hours, minutes, seconds)

    def get_default_frame_time(self):
        return self.get_video_duration() / 2

    def get_video_duration(self):
        args = [self.ffprobe,  self.file_path]
        duration_regex = compile(r'Duration: ([0-9:.]*)')
        p = Popen(args, stdout=PIPE, stderr=PIPE)
        stdout, stderr = p.communicate()
        output = stdout + stderr
        match = duration_regex.findall(output)
        if match:
            return self.time_to_seconds(match[0])

    def extract_frame(self, output, seconds=None):
        if not seconds:
            seconds = self.get_default_frame_time()
        args = [self.ffmpeg, '-y', '-ss', seconds, '-i', self.file_path, '-vframes', '1', output]
        p = Popen(args, stdout=PIPE, stderr=PIPE)
        p.communicate()
        return p.returncode == 0

if __name__ == '__main__':
    arguments = argv[1:3]
    if len(arguments) != 2:
        raise ValueError('Please inform video and output args')
    video_path, frame_path = arguments
    ffmpeg = FfmpegHelper(video_path)
    ffmpeg.extract_frame(frame_path)