[extractor/vocaroo] Add Vocaroo extractor

[qbnu]

IMPORTANT: PRs without the template will be CLOSED

Description of your pull request and other information

(Description from ytdl-org/youtube-dl#29369)

Adds support for Vocaroo, "the premier voice recording service." The site lacks any sort of metadata for its uploads and all come down as MP3s, so much of this extractor is hardcoded, making it quite fast. While Vocaroo does allow you to easily download individual files from their site, youtube-dl support will allow users to extract Vocaroo embeds with the generic extractor and download many Vocaroo files at once.

Template

Before submitting a pull request make sure you have:

• At least skimmed through contributing guidelines including yt-dlp coding conventions
• Searched the bugtracker for similar pull requests
• Checked the code with flake8 and ran relevant tests

In order to be accepted and merged into yt-dlp each piece of code must be in public domain or released under Unlicense. Check one of the following options:

• I am the original author of this code and I am willing to release it under Unlicense
• I am not the original author of this code but it is in public domain or released under Unlicense (provide reliable evidence)

What is the purpose of your pull request?

• Fix or improvement to an extractor (Make sure to add/update tests)
• New extractor (Piracy websites will not be accepted)
• Core bug fix/improvement
• New feature (It is strongly recommended to open an issue first)

[pukkandan]

youtube-dl support will allow users to extract Vocaroo embeds with the generic extractor and download many Vocaroo files at once.

The current extractor doesn't seem to support embeds. Provide example

[qbnu]

I added your suggestions, but I want to mention that IDs don't have underscores, and the filename is in the format Vocaroo {id}.mp3 when you click the Download button on the site.

[qbnu]

There is an x-bz-upload-timestamp header in the response which has the UNIX timestamp of when each file was uploaded. Should this be used as the value for timestamp, and is there a way to do it without sending an extra request?

[dirkf]

You can can make a HEAD request in the extractor (or GET if the site doesn't support it) and get the header value out of the response. Any other solution would be overkill.

Actually, sending the request might be a good thing. The extractor currently just guesses that an audio file exists with the given ID, whereas making at least one request will reveal whether the ID is valid (or perhaps that the extractor's guess is no longer valid).

In my test I found that a media1.... URL redirected to media.....

[qbnu]

I made the logic for the media subdomain match the logic of the site

function (e) {
    if (e.length) {
        if (11 == e.length)
            return ControlConfig.mediaMp3FileUrl;
        if (12 == e.length && '1' == e[0])
            return ControlConfig.mediaMp3FileUrl1;
        if (10 == e.length)
            return ControlConfig.mediaMp3FileUrl1
    }
    return ControlConfig.mediaMp3FileUrl
}

In my test I found that a media1.... URL redirected to media.....

Can you give an example? I assumed they were mirrors.

[SuperSonicHub1]

Hey! Looks like some more of my code made it into yt-dlp. I have no issue with my code being used without permission—it is public domain after all—but being mentioned would have been nice; would've been happy to help and would have closed the PR in youtube-dl. That's all; sorry for waking a sleeping thread.

[pukkandan]

@SuperSonicHub1 You are credited in commit message and changelog

[SuperSonicHub1]

Thanks, @pukkandan!