musix-oss/node_modules/ytdl-core/README.md

node-ytdl-core

Yet another youtube downloading module. Written with only Javascript and a node-friendly streaming interface.

For a CLI version of this, check out ytdl, pully, and yodl.

Support

You can contact us for support on our chat server

Usage

const fs = require('fs');
const ytdl = require('ytdl-core');

ytdl('http://www.youtube.com/watch?v=A02s8omM_hI')
  .pipe(fs.createWriteStream('video.flv'));

API

ytdl(url, [options])

Attempts to download a video from the given url. Returns a readable stream. options can have the following keys

• quality - Video quality to download. Can be an itag value, a list of itag values, or highest/lowest/highestaudio/lowestaudio/highestvideo/lowestvideo. highestaudio/lowestaudio/highestvideo/lowestvideo all prefer audio/video only respectively. Defaults to highest.
• filter - Used to decide what format to download. Can be audioandvideo to filter formats that contain both video and audio, video to filter for formats that contain video, or videoonly for formats that contain video and no additional audio track. Can also be audio or audioonly. You can give a filtering function that gets called with each format available. This function is given the format object as its first argument, and should return true if the format is preferable.
• format - Primarily used to download specific video or audio streams. This can be a specific format object returned from getInfo.
  • Supplying this option will ignore the filter and quality options since the format is explicitly provided.
• range - A byte range in the form {start: INT, end: INT} that specifies part of the file to download, ie {start: 10355705, end: 12452856}.
  • This downloads a portion of the file, and not a separately spliced video.
• begin - What time in the video to begin. Supports formats 00:00:00.000, 0ms, 0s, 0m, 0h, or number of milliseconds. Example: 1:30, 05:10.123, 10m30s. For live videos, this also accepts a unix timestamp or Date, and defaults to Date.now().
  • This option may not work on super short (less than 30s) videos, and has to be at or above 6s, see #129.
  • It may also not work for some formats, see #219.
• liveBuffer - How much time buffer to use for live videos in milliseconds. Default is 20000.
• requestOptions - Anything to merge into the request options which miniget is called with, such as headers.
• highWaterMark - How much of the video download to buffer into memory. See node's docs for more.
• lang - The 2 character symbol of a language. Default is en.

// Example with `filter` option.
ytdl(url, { filter: (format) => format.container === 'mp4' })
  .pipe(fs.createWriteStream('video.mp4'));

Event: info

• ytdl.videoInfo - Info.
• ytdl.videoFormat - Video Format.

Emitted when the a video's info hash is fetched, along with the chosen format metadata to download. format.url might be different if start was given.

Event: response

• http.ServerResponse - Response.

Emitted when the video response has been found and has started downloading or after any successful reconnects. Can be used to get the size of the download.

Event: progress

• number - Chunk byte length.
• number - Total bytes or segments downloaded.
• number - Total bytes or segments.

Emitted whenever a new chunk is received. Passes values describing the download progress.

ytdl.getBasicInfo(url, [options], [callback(err, info)])

Use this if you only want to get metainfo from a video. If callback isn't given, returns a promise.

ytdl.getInfo(url, [options], [callback(err, info)])

Gets metainfo from a video. Includes additional formats, and ready to download deciphered URL. This is what the ytdl() function uses internally. If callback isn't given, returns a promise.

ytdl.downloadFromInfo(info, options)

Once you have received metadata from a video with the ytdl.getInfo function, you may pass that information along with other options to this function.

ytdl.chooseFormat(formats, options)

Can be used if you'd like to choose a format yourself with the options above.

// Example of choosing a video format.
ytdl.getInfo(videoID, (err, info) => {
  if (err) throw err;
  let format = ytdl.chooseFormat(info.formats, { quality: '134' });
  if (format) {
    console.log('Format found!');
  }
});

ytdl.filterFormats(formats, filter)

If you'd like to work with only some formats, you can use the filter option above.

// Example of filtering the formats to audio only.
ytdl.getInfo(videoID, (err, info) => {
  if (err) throw err;
  let audioFormats = ytdl.filterFormats(info.formats, 'audioonly');
  console.log('Formats with only audio: ' + audioFormats.length);
});

ytdl.validateID(id)

Returns true if the given string satisfies YouTube's ID format.

ytdl.validateURL(url)

Returns true if able to parse out a valid video ID.

ytdl.getURLVideoID(url)

Returns a video ID from a YouTube URL.

ytdl.getVideoID(str)

Same as the above ytdl.getURLVideoID(), but can be called with the video ID directly, in which case it returns it. This is what ytdl uses internally.

Limitations

ytdl cannot download videos that fall into the following

• Regionally restricted (requires a proxy)
• Private
• Rentals

YouTube intentionally ratelimits downloads, likely to prevent bandwidth abuse. The download rate is still faster than a media player can play the video, even on 2x. See #294.

Handling Separate Streams

Typically 1080p or better video does not have audio encoded with it. The audio must be downloaded separately and merged via an appropriate encoding library. ffmpeg is the most widely used tool, with many Node.js modules available. Use the format objects returned from ytdl.getInfo to download specific streams to combine to fit your needs. Look at example/ffmpeg.js for an example on doing this.

What if it stops working?

Youtube updates their website all the time, it's not that rare for this to stop working. If it doesn't work for you and you're using the latest version, feel free to open up an issue. Make sure to check if there isn't one already with the same error.

If you'd like to help fix the issue, look at the type of error first. The most common one is

Could not extract signature deciphering actions

Run the tests at test/irl-test.js just to make sure that this is actually an issue with ytdl-core.

mocha test/irl-test.js

These tests are not mocked, and they actually try to start downloading a few videos. If these fail, then it's time to debug.

For getting started with that, you can look at the extractActions() function in /lib/sig.js.

Install

npm install ytdl-core

Tests

Tests are written with mocha

npm test