Integration with Ministra (Stalker) Middleware

Ministra TV Platform (formerly Stalker Middleware) manages subscribers, set-top boxes and the channel list. Alta delivers the channels and the TV archive. Ministra talks to Alta the same way it talks to Flussonic: it adds a temporary token to every channel link, and Alta checks the token with Ministra before the playback starts.

This article shows how to connect Alta to Ministra step by step: live channels with temporary links, TV archive (catch-up) and timeshift.

How it works

1. A subscriber opens a channel on the set-top box.
2. Ministra creates a temporary token and returns the channel link with this token: http://alta.example.com:8102/demo/index.m3u8?token=41771f02a48d1fef09eebe9f0efdaeb8
3. The box requests the playlist from Alta.
4. Alta sends the token to Ministra: http://stalker.example.com/stalker_portal/server/api/chk_flussonic_tmp_link.php?token=...
5. Ministra answers 200 OK if the token is valid, or 403 Forbidden otherwise.
6. Alta returns the playlist and the stream to the box, or 403 Forbidden.

The token is checked once, when the playlist is requested. After that the box plays the stream within its Alta session. By default a live token lives 5 seconds: the box receives a new token every time it opens a channel. Tokens for the TV archive live 8 hours.

For the TV archive Ministra uses the Flussonic DVR link format. Alta supports it out of the box:

Feature	Link created by Ministra
Live	http://<alta>:<port>/<path>/index.m3u8?token=...
Timeshift (from the start of the current hour)	http://<alta>:<port>/<path>/index-<start>-now.m3u8?token=...
Catch-up (program from the EPG)	http://<alta>:<port>/<path>/archive-<start>-<duration>.m3u8?token=...

Read more about these links in URL Format for HLS Access.

Requirements

• Set-top boxes can reach the Alta OTT server port (8102 in this example).
• Alta can reach Ministra over HTTP (port 80 by default).
• For the TV archive: a storage in Alta and an EPG for the channels in Ministra.

In this article:

	Address
Alta OTT server	http://alta.example.com:8102
Ministra	http://stalker.example.com/stalker_portal/
Channel path in Alta	demo

Step 1. Configure Alta

Receiver

Go to Receivers → Create and add the source of the channel. Read more in Receivers.

Storage

The storage is required for the TV archive and timeshift. Skip this step if you need live channels only.

Go to Settings → Storages → Create:

• Name: archive
• Duration: archive depth in hours, for example 24
• Location: directory for the archive, for example /var/lib/alta/archive

Authorizer

Go to Settings → Authorizers → Create:

• Name: stalker
• Default: Deny
• Backends → Add Backend: http://stalker.example.com/stalker_portal/server/api/chk_flussonic_tmp_link.php

Note

Default is applied when Ministra is not reachable. With Deny Alta closes access to the channels until Ministra is back. With Allow the channels stay available without any check. Read more in HTTP Backend.

Channel

Go to Channels → Create:

• Enable: on
• Path: demo. The channel is available at http://alta.example.com:8102/demo/index.m3u8
• Name: Demo Channel
• Variants → main: enable and select the receiver
• Authorizer: stalker
• Storage & Duration → Storage: archive (for the TV archive)

Check that the channel is protected. Without a token Alta answers 403 Forbidden:

curl -I http://alta.example.com:8102/demo/index.m3u8

HTTP/1.1 403 Forbidden

Note

425 Too Early means the channel has just started and Alta has not received enough segments yet. Wait a few seconds and try again.

Step 2. Configure Ministra

Archive server

Skip this step if you need live channels only.

Go to Storage → Storage list → Add storage:

• Title: alta
• IP: address and OTT port of Alta, without http://: alta.example.com:8102
• Apache port: 8102. The field is required, but it is not used for Flussonic DVR
• Maximum of users: for example 1000. If the field is empty, set-top boxes get the error limit when they open the archive
• Additional information → Allow TV recording: Flussonic DVR

Channel

Go to IPTV channels → Channels → Add a channel.

Basic:

• Channel number, Channel name, Genre
• Basic channel: turn it on if you do not use tariff plans. Otherwise add the channel to a service package, or subscribers will not see it

Streaming links → Add link:

• Channel URL: ffmpeg http://alta.example.com:8102/demo/index.m3u8
• Temporary URL: Flussonic

Click Save in the link dialog. The link appears in the Streaming links table with Temporary HTTP-link On:

TV archive:

• TV archive type: Flussonic DVR
• Archive servers: alta
• TV archive address: the channel address in Alta, without ffmpeg: http://alta.example.com:8102/demo/index.m3u8. Ministra builds the archive links from it
• TV archive length: archive depth in hours, the same as the storage duration in Alta, for example 24

EPG:

• XMLTV ID: channel ID in your XMLTV source. Catch-up works only for programs from the EPG

Click Save.

Subscriber

Add a subscriber with the MAC address of the set-top box in Users → Users list → Add user, or use your existing subscribers.

Step 3. Check the integration

1. Open the channel on a set-top box. The channel plays.
2. In Alta open Sessions: the session of the box is in the list.
3. Open the TV archive on the box and play a program from the past.

To check the connection between Alta and Ministra, run this command on the Alta server:

curl -I "http://stalker.example.com/stalker_portal/server/api/chk_flussonic_tmp_link.php?token=test"

403 Forbidden means Ministra is reachable and rejects the unknown token, as expected.

Troubleshooting

Every request gets 403 Forbidden

• Check the backend address in the Alta authorizer with the curl command above.
• Check that Temporary URL of the channel link in Ministra is Flussonic. Without it Ministra does not add the token.
• The token lives 5 seconds. A player that opens the same link later gets 403. The time is set with the tv_tmp_link_ttl option in the Ministra custom.ini.

Alta writes denied requests to the log:

journalctl -u alta | grep "Authorization denied"

The channel list on the set-top box is empty

Turn on Basic channel for the channel or add it to a service package of the subscriber tariff plan.

The archive does not open: error limit

Set Maximum of users of the archive server in Ministra.

Archive programs are shifted in time

Ministra uses the PHP time zone (default_timezone in custom.ini) and the MySQL time zone to calculate program times. If they differ, the archive links point to a wrong time range. Set the same time zone for PHP and MySQL.