audiobookshelf/server/libs/fluentFfmpeg/options/output.js

/*jshint node:true*/
'use strict';

var utils = require('../utils');


/*
 *! Output-related methods
 */

module.exports = function(proto) {
  /**
   * Add output
   *
   * @method FfmpegCommand#output
   * @category Output
   * @aliases addOutput
   *
   * @param {String|Writable} target target file path or writable stream
   * @param {Object} [pipeopts={}] pipe options (only applies to streams)
   * @return FfmpegCommand
   */
  proto.addOutput =
  proto.output = function(target, pipeopts) {
    var isFile = false;

    if (!target && this._currentOutput) {
      // No target is only allowed when called from constructor
      throw new Error('Invalid output');
    }

    if (target && typeof target !== 'string') {
      if (!('writable' in target) || !(target.writable)) {
        throw new Error('Invalid output');
      }
    } else if (typeof target === 'string') {
      var protocol = target.match(/^([a-z]{2,}):/i);
      isFile = !protocol || protocol[0] === 'file';
    }

    if (target && !('target' in this._currentOutput)) {
      // For backwards compatibility, set target for first output
      this._currentOutput.target = target;
      this._currentOutput.isFile = isFile;
      this._currentOutput.pipeopts = pipeopts || {};
    } else {
      if (target && typeof target !== 'string') {
        var hasOutputStream = this._outputs.some(function(output) {
          return typeof output.target !== 'string';
        });

        if (hasOutputStream) {
          throw new Error('Only one output stream is supported');
        }
      }

      this._outputs.push(this._currentOutput = {
        target: target,
        isFile: isFile,
        flags: {},
        pipeopts: pipeopts || {}
      });

      var self = this;
      ['audio', 'audioFilters', 'video', 'videoFilters', 'sizeFilters', 'options'].forEach(function(key) {
        self._currentOutput[key] = utils.args();
      });

      if (!target) {
        // Call from constructor: remove target key
        delete this._currentOutput.target;
      }
    }

    return this;
  };


  /**
   * Specify output seek time
   *
   * @method FfmpegCommand#seek
   * @category Input
   * @aliases seekOutput
   *
   * @param {String|Number} seek seek time in seconds or as a '[hh:[mm:]]ss[.xxx]' string
   * @return FfmpegCommand
   */
  proto.seekOutput =
  proto.seek = function(seek) {
    this._currentOutput.options('-ss', seek);
    return this;
  };


  /**
   * Set output duration
   *
   * @method FfmpegCommand#duration
   * @category Output
   * @aliases withDuration,setDuration
   *
   * @param {String|Number} duration duration in seconds or as a '[[hh:]mm:]ss[.xxx]' string
   * @return FfmpegCommand
   */
  proto.withDuration =
  proto.setDuration =
  proto.duration = function(duration) {
    this._currentOutput.options('-t', duration);
    return this;
  };


  /**
   * Set output format
   *
   * @method FfmpegCommand#format
   * @category Output
   * @aliases toFormat,withOutputFormat,outputFormat
   *
   * @param {String} format output format name
   * @return FfmpegCommand
   */
  proto.toFormat =
  proto.withOutputFormat =
  proto.outputFormat =
  proto.format = function(format) {
    this._currentOutput.options('-f', format);
    return this;
  };


  /**
   * Add stream mapping to output
   *
   * @method FfmpegCommand#map
   * @category Output
   *
   * @param {String} spec stream specification string, with optional square brackets
   * @return FfmpegCommand
   */
  proto.map = function(spec) {
    this._currentOutput.options('-map', spec.replace(utils.streamRegexp, '[$1]'));
    return this;
  };


  /**
   * Run flvtool2/flvmeta on output
   *
   * @method FfmpegCommand#flvmeta
   * @category Output
   * @aliases updateFlvMetadata
   *
   * @return FfmpegCommand
   */
  proto.updateFlvMetadata =
  proto.flvmeta = function() {
    this._currentOutput.flags.flvmeta = true;
    return this;
  };
};