public function dcaEncode($filename = '', $channels = 2)
    {
        // if (! empty($filename) && ! file_exists($filename)) {
        //     return;
        // }

        $flags = [
             '-ac', $channels, // Channels
             '-aa', $this->audioApplication, // Audio application
             '-ab', round($this->bitrate / 1000), // Bitrate
             '-as', round($this->frameSize * 48), // Frame Size
            '-vol', round($this->volume * 2.56), // Volume
              '-i', (empty($filename)) ? 'pipe:0' : "\"{$filename}\"", // Input file
        ];

        $flags = implode(' ', $flags);

        return new Process("{$this->dca} {$flags}");
    }