public function getRemuxStream()
    {
        $urls = $this->getUrl();

        if (!isset($urls[0]) || !isset($urls[1])) {
            throw new Exception(_('This video does not have two URLs.'));
        }

        $process = new Process(
            [
                $this->config->avconv,
                '-v', $this->config->avconvVerbosity,
                '-i', $urls[0],
                '-i', $urls[1],
                '-c', 'copy',
                '-map', '0:v:0 ',
                '-map', '1:a:0',
                '-f', 'matroska',
                'pipe:1',
            ]
        );

        $stream = popen($process->getCommandLine(), 'r');
        if (!is_resource($stream)) {
            throw new Exception(_('Could not open popen stream.'));
        }

        return $stream;
    }