EPGStationのエンコーダー設定例（QSV, h.264, q=23）

enc_q23.js

const spawn = require('child_process').spawn;
const execFile = require('child_process').execFile;
const ffmpeg = process.env.FFMPEG;
const ffprobe = process.env.FFPROBE;

const input = process.env.INPUT;
const output = process.env.OUTPUT;
const isDualMono = parseInt(process.env.AUDIOCOMPONENTTYPE, 10) == 2;
const args = ['-y'];


// my settings
const video_quality = '23';
const audio_quality = '3';
const videoFilter = 'deinterlace_qsv,fps=30000/1001';

/**
 * 動画長取得関数
 * @param {string} filePath ファイルパス
 * @return number 動画長を返す (秒)
 */
const getDuration = filePath => {
    return new Promise((resolve, reject) => {
        execFile(ffprobe, ['-v', '0', '-show_format', '-of', 'json', filePath], (err, stdout) => {
            if (err) {
                reject(err);

                return;
            }

            try {
                const result = JSON.parse(stdout);
                resolve(parseFloat(result.format.duration));
            } catch (err) {
                reject(err);
            }
        });
    });
};


// QSV
Array.prototype.push.apply(args, [
    '-hwaccel', 'qsv', '-hwaccel_output_format', 'qsv',
    '-init_hw_device', 'qsv=hw', '-filter_hw_device', 'hw',
    '-c:v', 'mpeg2_qsv'
]);

// 字幕用
//Array.prototype.push.apply(args, ['-fix_sub_duration']);
// input 設定
Array.prototype.push.apply(args, ['-i', input, '-map', '0:v']);
// インターレス解除
Array.prototype.push.apply(args, ['-vf', videoFilter]);
// ビデオストリーム設定
Array.prototype.push.apply(args, ['-c:v', 'h264_qsv', '-q', video_quality]);
// オーディオストリーム設定
if (isDualMono) {
    Array.prototype.push.apply(args, [
        '-filter_complex',
        'channelsplit[FL][FR]',
        '-map', '[FL]',
        '-map', '[FR]',
        '-metadata:s:a:0', 'language=jpn',
        '-metadata:s:a:1', 'language=eng',
    ]);
} else {
    Array.prototype.push.apply(args, ['-map', '0:a']);
}
Array.prototype.push.apply(args, ['-c:a', 'libfdk_aac', '-vbr', audio_quality]);
// 字幕ストリーム設定
//Array.prototype.push.apply(args, ['-map', '0:s?', '-c:s', 'mov_text']);


// 出力ファイル
Array.prototype.push.apply(args, [output]);

(async () => {
    // 進捗計算のために動画の長さを取得
    const duration = await getDuration(input);

    const child = spawn(ffmpeg, args);

    /**
     * エンコード進捗表示用に標準出力に進捗情報を吐き出す
     * 出力する JSON
     * {"type":"progress","percent": 0.8, "log": "view log" }
     */
    child.stderr.on('data', data => {
        let strbyline = String(data).split('\n');
        for (let i = 0; i < strbyline.length; i++) {
            let str = strbyline[i];
            if (str.startsWith('frame')) {
                // 想定log
                // frame= 5159 fps= 11 q=29.0 size=  122624KiB time=00:02:51.84 bitrate=5845.8kbits/s dup=19 drop=0 speed=0.372x
                const progress = {};
                const ffmpeg_reg = /frame=\s*(?<frame>\d+)\sfps=\s*(?<fps>\d+(?:\.\d+)?)\sq=\s*(?<q>[+-]?\d+(?:\.\d+)?)\sL?size=\s*(?<size>\d+(?:\.\d+)?)KiB\stime=\s*(?<time>\d+[:\.\d+]*)\sbitrate=\s*(?<bitrate>\d+(?:\.\d+)?)kbits\/s(?:\sdup=\s*(?<dup>\d+))?(?:\sdrop=\s*(?<drop>\d+))?\sspeed=\s*(?<speed>\d+(?:\.\d+)?)x/;
                let ffmatch =str.match(ffmpeg_reg);
                /**
                 * match結果
                 * [
                 *   'frame= 5159 fps= 11 q=29.0 size=  122624KiB time=00:02:51.84 bitrate=5845.8kbits/s dup=19 drop=0 speed=0.372x',
                 *   '5159',
                 *   '11',
                 *   '29.0',
                 *   '122624',
                 *   '00:02:51.84',
                 *   '5845.8',
                 *   '19',
                 *   '0',
                 *   '0.372',
                 *   index: 0,
                 *   input: 'frame= 5159 fps= 11 q=29.0 size=  122624KiB time=00:02:51.84 bitrate=5845.8kbits/s dup=19 drop=0 speed=0.372x    \r',
                 *   groups: [Object: null prototype] {
                 *     frame: '5159',
                 *     fps: '11',
                 *     q: '29.0',
                 *     size: '122624',
                 *     time: '00:02:51.84',
                 *     bitrate: '5845.8',
                 *     dup: '19',
                 *     drop: '0',
                 *     speed: '0.372'
                 *   }
                 * ]
                 */

                if (ffmatch === null) continue;

                progress['frame'] = parseInt(ffmatch.groups.frame);
                progress['fps'] = parseFloat(ffmatch.groups.fps);
                progress['q'] = parseFloat(ffmatch.groups.q);
                progress['size'] = parseInt(ffmatch.groups.size);
                progress['time'] = ffmatch.groups.time;
                progress['bitrate'] = parseFloat(ffmatch.groups.bitrate);
                progress['dup'] = ffmatch.groups.dup == null ? 0 : parseInt(ffmatch.groups.dup);
                progress['drop'] = ffmatch.groups.drop == null ? 0 : parseInt(ffmatch.groups.drop);
                progress['speed'] = parseFloat(ffmatch.groups.speed);

                let current = 0;
                const times = progress.time.split(':');
                for (let i = 0; i < times.length; i++) {
                    if (i == 0) {
                        current += parseFloat(times[i]) * 3600;
                    } else if (i == 1) {
                        current += parseFloat(times[i]) * 60;
                    } else if (i == 2) {
                        current += parseFloat(times[i]);
                    }
                }

                // 進捗率 1.0 で 100%
                const percent = current / duration;
                const log =
                    'frame= ' +
                    progress.frame +
                    ' fps=' +
                    progress.fps +
                    ' size=' +
                    progress.size +
                    ' time=' +
                    progress.time +
                    ' bitrate=' +
                    progress.bitrate +
                    ' drop=' +
                    progress.drop +
                    ' speed=' +
                    progress.speed;

                console.log(JSON.stringify({ type: 'progress', percent: percent, log: log }));
            }
        }
    });

    child.on('error', err => {
        console.error(err);
        throw new Error(err);
    });

    child.on('close', (code) => {
        process.exitCode = code;
    });

    process.on('SIGINT', () => {
        child.kill('SIGINT');
    });
})();