Re: (was Re: Adding a description text property for a track) non-free javascript and ytdl

[Yuchen Pei]

On Thu 2022-03-24 08:14:01 +1100, Yuchen Pei wrote:

> On Wed 2022-03-23 20:32:36 +0100, Alexandre Garreau wrote:
>
>>
>> I don’t see how GET/POST is related: you can use POST without any javascript
>> (both POST and PUT existed before javascript), while for youtube, even any 
>> GET
>> statement provides nothing but a blank page, and you need to execute
>> javascript to get anything.
>>
>
> You can download a yt video by GET only:
>
> wget -O- 2>/dev/null https://youtube.com/watch?v=dQw4w9WgXcQ | grep -oP
> 'ytInitialPlayerResponse\s*=\s*(.+)\s*;</script>' | grep -o '\{.*\}' |
> jq .

This is better:

wget -O- 2>/dev/null https://youtube.com/watch?v=dQw4w9WgXcQ |
grep -oP 'ytInitialPlayerResponse\s*=\s*.+\s*;</script>' |
grep -o '\{.*\}' | jq '."streamingData"'

>From my experiments I've noticed that if you request the same video id
multiple times, initially there's no cipher (you get an "url" field for
each format), but after a few times requesting the same page, you may
get a "signatureCipher" field instead which would need the js
interpreter somehow according to the youtube-dl code.

>
> There you get a json with all the video / audio formats and their links.
>
> Best,
> Yuchen


Best,
Yuchen

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