Downloading a YouTube video through Wget

Question

I am trying to download YouTube videos through Wget. The first thing necessary is to capture the URL of the actual video resource. Suppose I want to download this video: video. Opening up the page in the Firebug console reveals something like this:

The link which I have encircled looks like the link to the resource, for there we see only the video: http://www.youtube.com/v/r-KBncrOggI?version=3&autohide=1. However, when I am trying to download this resource with Wget, a 4 KB file of name r-KBncrOggI@version=3&autohide=1 gets stored in my hard-drive, nothing else. What should I do to get the actual video?

And secondly, is there a way to capture different resources for videos of different resolutions, like 360px, 480px, etc.?

Answer 1

I'm afraid it's not that easy do get the right link for the video resource.

The link you got, http://www.youtube.com/v/r-KBncrOggI?version=3&autohide=1, points to the player rather than the video itself. There is one Perl utility, youtube-download, which is well-maintained and does the trick. This is how to get the HQ version (magic fmt=18) of that video:

stas@Stanislaws-MacBook-Pro:~$ youtube-download -o "{title}.{suffix}" --fmt 18 r-KBncrOggI 
--> Working on r-KBncrOggI
Downloading `Sourav Ganguly in Farhan Akhtar's Show - Oye! It's Friday!.mp4`
75161060/75161060 (100.00%)
Download successful!
stas@Stanislaws-MacBook-Pro:~$

There might be better command-line YouTube Downloaders around. But sorry, one doesn't simply download a video using Firebug and wget any more :(

The only way I know to capture that URL manually is by watching the active downloads of the browser:

That largest data chunks are video data, so you can copy its URL:

http://s.youtube.com/s?lact=111116&uga=m30&volume=4.513679238953965&sd=BBE62AA4AHH1357937949850490&rendering=accelerated&fs=0&decoding=software&nsivbblmax=679542.000&hcbt=105.345&sendtmp=1&fmt=35&w=640&vtmp=1&referrer=None&hl=en_US&nsivbblmin=486355.000&nsivbblmean=603805.166&md=1&plid=AATTCZEEeM825vCx&ns=yt&ptk=youtube_none&csipt=watch7&rt=110.904&tsphab=1&nsiabblmax=129097.000&tspne=0&tpmt=110&nsiabblmin=123113.000&tspfdt=436&hbd=30900552&et=110.146&hbt=30.770&st=70.213&cfps=25&cr=BR&h=480&screenw=1440&nsiabblmean=125949.872&cpn=JlqV9j_oE1jzk7Zc&nsivbblc=343&nsiabblc=343&docid=r-KBncrOggI&len=1302.676&screenh=900&abd=1&pixel_ratio=1&bc=26131333&playerw=854&idpj=0&hcbd=25408143&playerh=510&ldpj=0&fexp=920704,919009,922403,916709,912806,929110,928008,920201,901451,909708,913605,925710,916623,929104,913302,910221,911116,914093,922405,929901&scoville=1&el=detailpage&bd=6676317&nsidf=1&vid=Yfg8gnutZoTD4G5SVKCxpsPvirbqG7pvR&bt=40.333&mos=0&vq=auto

However, for a large video, this will only return a part of the stream unless you figure out the URL query parameter responsible for stream range to be downloaded and adjust it.

A bonus: everything changes periodically as YouTube is constantly evolving. So, don't do that manually unless you carve pain.

Answer 2

Here is one VERY simplified, yet functional version of the youtube-download utility I cited on my another answer:

#!/usr/bin/env perl
use strict;
use warnings;

# CPAN modules we depend on
use JSON::XS;
use LWP::UserAgent;
use URI::Escape;

# Initialize the User Agent
# YouTube servers are weird, so *don't* parse headers!
my $ua = LWP::UserAgent->new(parse_head => 0);

# fetch video page or abort
my $res = $ua->get($ARGV[0]);
die "bad HTTP response" unless $res->is_success;

# scrape video metadata
if ($res->content =~ /\byt\.playerConfig\s*=\s*({.+?});/sx) {

    # parse as JSON or abort
    my $json = eval { decode_json $1 };
    die "bad JSON: $1" if $@;

    # inside the JSON 'args' property, there's an encoded
    # url_encoded_fmt_stream_map property which points
    # to stream URLs and signatures
    while ($json->{args}{url_encoded_fmt_stream_map} =~ /\burl=(http.+?)&sig=([0-9A-F\.]+)/gx) {
        # decode URL and attach signature
        my $url = uri_unescape($1) . "&signature=$2";
        print $url, "\n";
    }
}

Usage example (it returns several URLs to streams with different encoding/quality):

$ perl youtube.pl http://www.youtube.com/watch?v=r-KBncrOggI | head -n 1
http://r19---sn-bg07sner.c.youtube.com/videoplayback?fexp=923014%2C916623%2C920704%2C912806%2C922403%2C922405%2C929901%2C913605%2C925710%2C929104%2C929110%2C908493%2C920201%2C913302%2C919009%2C911116%2C926403%2C910221%2C901451&ms=au&mv=m&mt=1357996514&cp=U0hUTVBNUF9FUUNONF9IR1RCOk01RjRyaG4wTHdQ&id=afe2819dcace8202&ratebypass=yes&key=yt1&newshard=yes&expire=1358022107&ip=201.52.68.216&ipbits=8&upn=m-kyX9-4Tgc&sparams=cp%2Cid%2Cip%2Cipbits%2Citag%2Cratebypass%2Csource%2Cupn%2Cexpire&itag=44&sver=3&source=youtube,quality=large&signature=A1E7E91DD087067ED59101EF2AE421A3503C7FED.87CBE6AE7FB8D9E2B67FEFA9449D0FA769AEA739