video_recorder.py 文件源码

def start(self):
        self.cmdline = (self.backend,
                     '-nostats',
                     '-loglevel', 'error', # suppress warnings
                     '-y',
                     '-r', '%d' % self.frames_per_sec,

                     # input
                     '-f', 'rawvideo',
                     '-s:v', '{}x{}'.format(*self.wh),
                     '-pix_fmt',('rgb32' if self.includes_alpha else 'rgb24'),
                     '-i', '-', # this used to be /dev/stdin, which is not Windows-friendly

                     # output
                     '-vcodec', 'libx264',
                     '-pix_fmt', 'yuv420p',
                     self.output_path
                     )

        logger.debug('Starting ffmpeg with "%s"', ' '.join(self.cmdline))
        if hasattr(os,'setsid'): #setsid not present on Windows
            self.proc = subprocess.Popen(self.cmdline, stdin=subprocess.PIPE, preexec_fn=os.setsid)
        else:
            self.proc = subprocess.Popen(self.cmdline, stdin=subprocess.PIPE)