python-3.x - ffmpeg 以每秒帧数分解视频

Question

有一个命令可以提取每秒提供帧的视频图像

ffmpeg -i "vide.mp4" -vf fps=1 frames/frame_%04d.png -hide_banner

ffmpeg 中是否有命令剪切提供 fps 的视频并将其保存为视频(.mp4/avi)文件，如上面的命令？

我目前拥有的是我创建了一种方法来剪切具有开始和结束时间的视频，但我首先创建了一种获取视频长度的方法，以便我可以根据上述命令生成的帧数来剪切视频。

 def get_length(self):
        """
        Gets the length of a video in seconds

        Returns:
            float : Length of the video
        """

        print("Getting video length: " + self.video_string_path)
        command = 'ffprobe -i "'+self.video_string_path+'" -show_entries format=duration -v quiet -of csv="p=0"'
        self.command = command
        length = str(cmd.execute(command)).strip()
        print("lenght: "+length+" second(s)")
        return float(length)

def cut(self, start_time, duration, output_file_name = 'output_file_name.mp4', save_to =''):
        """
        Cut a video on a specific start time of the video and duration.
        Check ffmpeg documentation https://ffmpeg.org/ffmpeg.html for more information about the parameters

        Parameters:
            start_time : string
                is the value of ffmpeg -ss with the format: 00:00:00.000

            duration : string | int | float
                is the end point where the video will be cut. Can be the same with start_time format but it could also handle integer as in seconds

            output_file_name : string
                is the file name once the file is save in the hardisk

            save_to : string | optional
                is the directory where the file will be saved

        Returns:
            string: file location of the cutted video

        """

        self.make_sure_save_dir_exits(save_to)
        print('Cutting ' + self.video_string_path + ' from ' + start_time + ' to ' + str(duration))
        print('Please wait...')
        file = '"' + self.save_to + output_file_name + '"'
        command = 'ffmpeg -i "' + self.video_string_path + '" -ss ' + str(start_time) + ' -t ' + str(duration) + ' -c copy -y ' + file
        self.command = command
        cmd.execute(command)

        file_loc = self.get_save_to_dir() + output_file_name
        print('Done: Output file was saved to "' + file_loc + '"')

        return file_loc + output_file_name

Answer 1

利用

ffmpeg -ss {start_time} -t {duration} -i "vide.mp4" -vf fps=X -c:a copy out.mp4

其中 X 是您的输出帧速率。

要分割整个文件，

ffmpeg -i "vide.mp4" -vf fps=X
  -f segment -segment_time {duration} -force_key_frames expr:gte(t,n_forced*{duration}) 
  -reset_timestamps 1 -segment_time_delta 1.0 -c:a copy out%d.mp4