Ryde Requirement Specification
Original requirement specification - April 2020
With the lack of any reliable source for STB hardware (a recent ebay purchase of quantity 3 of one item delivered 3 major variants of hardware) BATC believe there is a need for a reproducible DVB-S and DVB-S2 DATV receiver using the Minitiouner hardware and Rpi4 host providing HDMI and Composite outputs.
With the Portsdown and Longmynd software and Minitiouner hardware, the worldwide ATV community has access to some very valuable open source resources and based on these, BATC believe the community has the resources to develop a dedicated DATV receiver.
The primary use cases would be a dedicated DATV receiver for home station use and a low symbol rate DATV receiver with reliable lock detection for remote use at ATV repeater sites. We have developed the following specification and are now looking for a small team of people (or one person) to pick this up and develop a project which will sit alongside Portsdown and Longmynd projects
Outline specification
RF and de-modulation capability
DVB-S and DVB-S2 demodulation is required - frequency range, symbol rate range and FEC choices will be the same as the MiniTiouner system https://wiki.batc.org.uk/MiniTioune
Reception of SCPC transport streams and decoding MPEG 2, H264 and H265 video and MP3 and AAC audio streams. Reception of MCPC streams is not a primary requirement but could be a future enhancement.
The decoded video and audio would be presented on the HDMI port with embedded audio or on a composite video port with separate analogue audio feeds. Simultaneous outputs are not required and the port in use would be selected via the system set up menu.
Hardware
It is envisaged the project will use the MiniTiouner USB tuner card https://wiki.batc.org.uk/MiniTiouner_hardware_Version_2 [Edit - hardware or design] Ideally the host hardware will be the Raspberry Pi 4 although other readily available supported Linux hardware could be used.
No integrated screen is required and the output will be displayed on either an HDMI or Composite monitor.
An infrared remote control is required and it is envisaged the project will use existing standard control hardware and codes – eg https://thepihut.com/products/xmbc-ir-r ... 6YQAvD_BwE
A hardware tuner lock signal should be provided, probably from the RPi GPIO lines.
The user would be expected to provide case and PSU etc.
Code base
It is envisaged the project would use the Longmynd open source Linux ATV receiver developed by Heather Lomond and available here: https://github.com/BritishAmateurTelevi ... b/longmynd
A significant amount of the functionality required for this project is available within the Longmynd implementation in the BATC Portsdown project by Dave Crump and can be used as a basis for this project. https://github.com/BritishAmateurTelevi ... own-buster
Functionality
On initial start up the software should default to composite video out and take the user in to a system set up menu where parameters such as video output, Terrestrial / Satellite operation, LNB volts, LNB offset and the default RF and decode parameters would be selected. Set up of any frequency pre-sets would also be done from this menu.
On normal start up, the decoded video output using the default setup parameters should be displayed.
From the default screen a channel set up menu should be accessible by pressing a single button. This will allow selection of RF frequency (if satellite operation is selected in system menu this will include the LNB offset) and Symbol rate – a number of pre-set frequency options is desirable. Exit will take you to video output display and a button to take you to the system menu would be displayed.
A selectable banner showing receive status, MER and SI information should be displayed across the bottom of the video window.
Network capability
The initial requirement is for a standalone DVB-S / S2 receiver although future enhancements could include remote control over SSH, the ability to view BATC live streams and a TS UDP output. All these functions are already available in the BATC Portsdown / Longmynd system code.