YouTubeの動画のURLを取りたい

表題の通りで動画再生用のURLを取得したいです。
youtube-dlでできるのは知っていますがWEBでやりたいのでJavascriptかなにかで知りたいと思います。
そこでこれについてしらべると
https://muunyblue.github.io/0a7d83f084ec258aefd128569dda03d7.html
このようなページを取得しました。
これによると例えば
https://www.youtube.com/watch?v=qJ0_r1Emui8
のURLを得るとき
http://www.youtube.com/get_video_info?video_id=qJ0_r1Emui8
の戻り値から
url_encoded_fmt_stream_map
をとればいいらしい。
そこでやってみた
戻り値をデコードしたら

html
1type=video/mp4;+codecs="avc1.64001F,+mp4a.40.2"&itag=22&quality=hd720&s=ABA3151178B115A0B63BDA7634958122C5F47981.9B13847079D1713F02AC647E51B443C38754F9B6&url=https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&key=yt6&fvip=5&source=youtube&dur=124.133&mv=m&ms=au%2Crdu&ip=60.236.163.195&mime=video%2Fmp4&pl=14&ratebypass=yes&requiressl=yes&mt=1533437737&lmt=1527186336343023&itag=22&ei=i2dmW-PrMMHS4AKwvqPADw&sparams=dur%2Cei%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&expire=1533459435&sp=signature,type=video/webm;+codecs="vp8.0,+vorbis"&itag=43&quality=medium&s=2F360A88DADC6438F2BEAFBBF047FD8611C0693D.93A5CC1F1898A6E722F868AFF935767828A5B227&url=https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=0.000&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=12852728&lmt=1527187047409012&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2Fwebm&pl=14&ratebypass=yes&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=43&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&sp=signature,type=video/mp4;+codecs="avc1.42001E,+mp4a.40.2"&itag=18&quality=medium&s=1118F078B782D3E3BC088573FC515A8AF70CD463.672228D24496A368CEAEA8E5CEFF726DC18CDFF3&url=https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=124.133&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=10758993&lmt=1527185499335421&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2Fmp4&pl=14&ratebypass=yes&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=18&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&sp=signature,type=video/3gpp;+codecs="mp4v.20.3,+mp4a.40.2"&itag=36&quality=small&s=31BB1DD6102D964AA84A793CE1282FE45C60C7CB.B5F4B934311CCD251C28445704D6726180F1DA1D&url=https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=124.180&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=3506038&lmt=1527185495531820&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2F3gpp&pl=14&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=36&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cexpire&sp=signature,type=video/3gpp;+codecs="mp4v.20.3,+mp4a.40.2"&itag=17&quality=small&s=62B93578762AAB414A235305C0BD6BDE3B98855D.6A8502867A1ECAD7C2692A3310ABD547F55EBE70&url=https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=124.180&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=1242836&lmt=1527185492230983&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2F3gpp&pl=14&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=17&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cexpire&sp=signature
2

になった。
このURL=がそれだと思われるので
それを抜き出すと

html
1
2url_encoded_fmt_stream_map=type=video/mp4;+codecs="avc1.64001F,+mp4a.40.2"&itag=22&quality=hd720&s=ABA3151178B115A0B63BDA7634958122C5F47981.9B13847079D1713F02AC647E51B443C38754F9B6&url=
3https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&key=yt6&fvip=5&source=youtube&dur=124.133&mv=m&ms=au%2Crdu&ip=60.236.163.195&mime=video%2Fmp4&pl=14&ratebypass=yes&requiressl=yes&mt=1533437737&lmt=1527186336343023&itag=22&ei=i2dmW-PrMMHS4AKwvqPADw&sparams=dur%2Cei%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&expire=1533459435&sp=signature
4,type=video/webm;+codecs="vp8.0,+vorbis"&itag=43&quality=medium&s=2F360A88DADC6438F2BEAFBBF047FD8611C0693D.93A5CC1F1898A6E722F868AFF935767828A5B227&url=
5https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=0.000&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=12852728&lmt=1527187047409012&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2Fwebm&pl=14&ratebypass=yes&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=43&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&sp=signature
6,type=video/mp4;+codecs="avc1.42001E,+mp4a.40.2"&itag=18&quality=medium&s=1118F078B782D3E3BC088573FC515A8AF70CD463.672228D24496A368CEAEA8E5CEFF726DC18CDFF3&url=
7https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=124.133&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=10758993&lmt=1527185499335421&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2Fmp4&pl=14&ratebypass=yes&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=18&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Cratebypass%2Crequiressl%2Csource%2Cexpire&sp=signature
8,type=video/3gpp;+codecs="mp4v.20.3,+mp4a.40.2"&itag=36&quality=small&s=31BB1DD6102D964AA84A793CE1282FE45C60C7CB.B5F4B934311CCD251C28445704D6726180F1DA1D&url=
9https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=124.180&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=3506038&lmt=1527185495531820&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2F3gpp&pl=14&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=36&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cexpire&sp=signature
10,type=video/3gpp;+codecs="mp4v.20.3,+mp4a.40.2"&itag=17&quality=small&s=62B93578762AAB414A235305C0BD6BDE3B98855D.6A8502867A1ECAD7C2692A3310ABD547F55EBE70&url=
11https://r1---sn-cpbavcx-ioqd.googlevideo.com/videoplayback?initcwndbps=1003750&mm=31%2C29&ipbits=0&c=WEB&mn=sn-cpbavcx-ioqd%2Csn-oguesnzs&id=o-AAGn2e5bjolUWgTKKEppiSjfwiT4glUIoXOkHosQRa6D&mt=1533437737&dur=124.180&mv=m&ms=au%2Crdu&ip=60.236.163.195&clen=1242836&lmt=1527185492230983&expire=1533459435&key=yt6&gir=yes&source=youtube&fvip=5&mime=video%2F3gpp&pl=14&requiressl=yes&ei=i2dmW-PrMMHS4AKwvqPADw&itag=17&sparams=clen%2Cdur%2Cei%2Cgir%2Cid%2Cinitcwndbps%2Cip%2Cipbits%2Citag%2Clmt%2Cmime%2Cmm%2Cmn%2Cms%2Cmv%2Cpl%2Crequiressl%2Csource%2Cexpire&sp=signature

のように
5種類のURLを取れるのが分かります。
ところがこの５種類のURLですがVLCやfirefoxで再生するとどれも無効で再生出来ません。
でもyoutube-dlでURLを取ると再生できるのでなにかこれだけではだめなようなのですが
そのあたりにくわしい人はいませんか？
expireが早いとか、signatureをなおせとかの話なのでしょうか？
WEBで見たけどこれ以上のことは分かりませんでした。