@deepauto/ffcreatorlite/lib/node/albumScene.js

FFCreatorLite is a lightweight and flexible short video production library

'use strict';

/**
 *
 * @class
 */
const Utils = require('../utils/utils');
const FFmpegUtil = require('../utils/ffmpeg');
const FFCon = require('./cons');
const FFContext = require('../core/context');
const ffmpeg = require('fluent-ffmpeg');
const fse = require('fs-extra');
const path = require('path');

class FFAlbumScene extends FFCon {
  constructor(conf) {
    super({ type: 'scene', ...conf });

    this.percent = 0;
    this.directory = '';
    this.context = null;
    this.command = null;
    this.transition = null;
    this.pathId = Utils.uid();
    this.time = conf.time || 3;
    this.imagePaths = conf.imagePaths || [];
    this.duration = this.imagePaths.length * this.time;
    this.fill = conf.fill;
    this.fillOffsetRandom = conf.fillOffsetRandom;
  }

  async start() {
    this.createNewCommand();
    const output = this.addCommandOutputs(this.command);
    const conf = this.rootConf().conf;
    const command = this.command;
    // const command = ffmpeg();
    FFmpegUtil.addDefaultOptions({ command, conf: this.rootConf(), audio: false });
    const fileListFile = path.join(this.directory, `${Utils.uid()}.txt`);
    const fileListContent =
      this.imagePaths.map(image => `file '${image}'\nduration ${this.time}`).join('\n') + '\n';
    fse.writeFileSync(fileListFile, fileListContent, { encoding: 'utf8' });

    command.addInput(fileListFile);
    command.inputOptions(['-f', 'concat', '-safe', '0']);
    if (this.fill) {
      const num = this.fillOffsetRandom ? Math.floor(Math.random() * conf.width) : 0;
      command.videoFilters([
        `scale=w=${conf.width}:h=${conf.height}:force_original_aspect_ratio=increase`,
        `crop=${conf.width}:${conf.height}:(iw-${conf.width + num})/2:(ih-${conf.height})/2`,
      ]);
    } else {
      command.videoFilters(
        `scale=w=${conf.width}:h=${conf.height}:force_original_aspect_ratio=decrease,pad=${conf.width}:${conf.height}:(ow-iw)/2:(oh-ih)/2`,
      );
    }

    return await new Promise((resolve, reject) => {
      command
        .once('end', res => {
          return resolve(output);
        })
        .once('error', reject);
      command.run();
    });
  }

  getFile() {
    return this.filepath;
  }

  getTotalFrames() {
    return this.rootConf().getVal('fps') * this.duration;
  }

  // about command
  createNewCommand() {
    const conf = this.rootConf();
    const threads = conf.getVal('threads');
    const command = FFmpegUtil.createCommand({ threads });
    // command.setDuration(this.duration);

    this.command = command;
    this.context = new FFContext();
  }

  addCommandOutputs(command) {
    let filepath;
    filepath = this.createFilepath();
    command.output(filepath);
    return filepath;
  }

  createFilepath() {
    const { id, pathId } = this;
    const cacheDir = this.rootConf('cacheDir').replace(/[\/\\]$/, '');
    const format = this.rootConf('cacheFormat');
    const directory = path.join(cacheDir, pathId);
    const filepath = path.join(directory, `${id}.${format}`);
    // 确保(directory)存在
    fse.ensureDirSync(directory);

    this.filepath = filepath;
    this.directory = directory;
    return filepath;
  }

  rootConf(key) {
    if (key) {
      return this.conf[key];
    }
    return {
      conf: this.conf,
      getVal: k => this.conf[k],
    };
  }

  async isReady() {
    return true;
  }

  destroy() {
    // 删除文件夹(this.directory);
    fse.removeSync(this.directory);
  }
}

module.exports = FFAlbumScene;