Support for online channel M3 on MTVA Archívum (HU)

[RevSnowfox]

Checklist

• I'm reporting a new site support request
• I've verified that I'm running youtube-dl version 2019.06.08
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that none of provided URLs violate any copyrights
• I've searched the bugtracker for similar site support requests including closed ones

Example URLs

• Single video: https://archivum.mtva.hu/m3/M3-R3FOU0FJU2pyWjVhL3NYOGppSXl3ZDBHRnZ6UitFSE4vdDhyNDgwbHpEcz0
• Single video: https://archivum.mtva.hu/m3/M3-czJjVW85bFBxZXJDcnh2QWx3R0JLN1hzeTJ2Ti9rWHZTK2ZSK1h5b1NiUT0

Description

MTVA (Media Services and Support Trust Fund) is Hungary's state-owned national public-service broadcasting organization, and it's the successor of MTV (state television service) and MR (state radio service). Its archives provide paid access to media, but they recently incorporated the public channel M3.
M3 was an archive channel airing old programming from MTVA's archives, but as of June 1, 2019, it stopped airing as a traditional TV station, and became an online station on MTVA's archive site:
https://archivum.mtva.hu/m3/

According to the site, M3 now follows an online airing schedule where there is a currently airing program, and any program in the schedule is available for 2 hours prior and 8 hours after streaming, giving a 10-hour window for people to access and replay a certain program which is on the schedule.
There are (Hungarian) subtitles provided at least for some of the programs.
On the video pages, the titles are displayed like this:
Lejátszóban: (In the player:)
[program title]
[episode title]

The links provided were available and playable at the time of filing this request.
The programs are available without a registration, and I don't know if the site uses georestriction.

[a-sync]

Url pattern: https://archivum.mtva.hu/m3/*
eg:
https://archivum.mtva.hu/m3/M3-K0VSbHU3Z2JUcWJQK0VjL3RQOVBxb3BYaEZMS3hOZW1wSktmWEhiSmYraz0

Parsable infos in document:

video id

var ACTIVE = "M3-87130999959999A59";

title

<meta property="og:title" content="Mirr-Murr kandúr kalandjai - IV. Sorozat" />

sub-title / episode name (if it exists, it can be concated to the title with space or dash)

<h6 class="active-subtitle hidden">Tengerparti napsütés</h6>

Some other meta that that might be useful 👇

<meta property="og:url" content="https://archivum.mtva.hu/m3/M3-K0VSbHU3Z2JUcWJQK0VjL3RQOVBxb3BYaEZMS3hOZW1wSktmWEhiSmYraz0" />

<meta property="og:site_name" content="MTVA Archívum"/>
<meta property="og:type" content="article" />
<meta property="og:title" content="Mirr-Murr kandúr kalandjai - IV. Sorozat" />
<meta property="og:description" content="Mirr-Murr nagyon vágyik a "tengerparti napsütésre", ezért az egerek nagy szívességet tesznek neki..." />
<meta property="og:image" content="https://archivum.mtva.hu/images/m3/M3-87130999959999A59" />
<meta property="og:image:width" content="1000" />
<meta property="og:image:height" content="1000" />
<link rel="icon" href="https://archivum.mtva.hu/public/img/logo_100_100.png" type="image/x-icon"/>
<link rel="shortcut icon" href="https://archivum.mtva.hu/public/img/logo_100_100.png" type="image/x-icon"/>

Requesting the m3u8 / hls url

A get request must be made to the following url, with the video id.
https://archivum.mtva.hu/m3/stream?no_lb=1&target=M3-87130999959999A59

This returns a nice json, with the url:

{
  "source": "nava",
  "url": "https://stream5.nava.hu/m3_vod/_definst_/amlst:M3-87130999959999A59/playlist.m3u8?type=m3u8&sessid=rwuyue9xdp8yvcek1ula6n49u870df376guqwmq1g7t25xj6g8npdkucsvup305t&lb=rxmD1FPZ8PKJhtRUi1RX6UbE%2B4NSjIBAujqvNjlanxV%2FAfUImxITGHPJ%2FS01nWIl4vNNO8rshPKI%0D%0AxH5sEpHThQ%3D%3D%0D%0A",
  "token": "kwuyuyvec1e9xdp8yula6n49u870df376guqwgq1g7t25xj6m8npdkucsvup305t"
}

All requests need a believable user-agent header.

Subtitles are also available via the video id in srt format:
https://archivum.mtva.hu/subtitle/M3-87130999959999A59.srt

Running the response url with youtube-dl successfully downloads the video.