Homebrew Solutions to HDR-FOX Replacement

[antipodean]

You think? Maybe, but I foresee problems with whatever is managing the recording schedule allocating tuners to events, and warning when events are likely to outrun tuners, unless the manager has been programmed to support n tuners (where n is between 1 and a suitable high number).

With 6 tuners and a big enough HDD, you could just spool TV to disk and pick what you want to watch afterwards!

Surely you just need a tuner per mux, is that why you are suggesting 6 tuners?

 

[Ezra Pound]

6 Tuners would cover the contents of the 6 main MUXs (although the bigger transmitters currently have 9 MUXs), BUT the hard disk would not record everything carried on each MUX, it would only record one selected Freeview channel from each MUX

 

[Black Hole]

Surely you just need a tuner per mux, is that why you are suggesting 6 tuners?

That's the idea.

the hard disk would not record everything carried on each MUX

I see no reason it shouldn't, other than data rate considerations.

 

[Ezra Pound]

I see no reason it shouldn't, other than data rate considerations.

And the fact that each tuner would be selecting one MUX at the UHF end and one Freeview channel at the other, do you know of a tuner that outputs all Freeview streams simultaneously?

 

[af123]

And the fact that each tuner would be selecting one MUX at the UHF end and one Freeview channel at the other, do you know of a tuner that outputs all Freeview streams simultaneously?

My dvb-t2 USB stick definitely does. I can dump an entire mux to disk from it. It isn't anything special.

 

[Black Hole]

It's not the tuner that selects one service from the total data stream, it's the post-processing in the media processor.

 

[Ezra Pound]

O.K. so you would only need to get the hard drive to record the equivalent of 138 streams (from the 6 main MUXs) simultaneously, I wonder what this equates to in MBps

 

[Black Hole]

Roughly 70 MB/s. Not totally out of the question, and you could use RAID to bolster the capability. A 1TB drive could grab 3½ hours of output.

 

[MikeSh]

So if I've got this right you would record the 6 MUXes pre-post-processing. Then you'd post-process that recording to get the channel you want.
Would that affect the ability to chase-play or indeed manipulate a programme recording that has finished?

 

[Black Hole]

I'm not suggesting it as a way to go, but it is technically feasible. One would have total coverage of catch-up for whatever period one allocated disk space for, with the ability to play anything within that window (instead of the HDR-FOX 2 hour buffer on one service, an n-hour buffer of all services). Then one could copy out specific programmes to "recorded" storage for manipulation or whatever.

 

[Colsta]

RPi is highly recommended for the server, but I don't know if it can handle as many as 4 tuners.

It's late and I feel bad for saying it but I would strongly disagree with this statement and the other claims made for suitability of the RPi. It's extremely capable as a Kodi headend thanks mainly to the broadcom BCM2835/BCM2836. But I'd have reservations regarding suitability as a server. The arm processor itself is not strong enough for video processing and there's no native SATA support. The GPIO cannot be used for this purpose, either. The only data bus is 1 x USB 2.0 bus over which all interfaces run including ethernet. Figures I've read suggest the practical limit is around 35MB/s before saturation depending on number of devices and contention. So expecting USB tuners, ethernet and storage to work over that is pushing it to say the least.

That's not to say that there aren't other low power RISC options out there. I thought the Cubietruck looked promising when it first came out.

 

[Black Hole]

It sounds like you have some useful knowledge to contribute.

 

[af123]

The arm processor itself is not strong enough for video processing

With the optional licences to enable hardware features, it's perfectly capable of HD playback. The latest version is pretty powerful for general purpose computing too. I agree that the lack of SATA support presents a problem!

 

[Black Hole]

As a server, it wouldn't need video processing unless we are running conversion/ad detection. It would need a high traffic capability though!

 

[Colsta]

With the optional licences to enable hardware features, it's perfectly capable of HD playback.

Please don't think I'm standing on a soapbox to preach to anyone but I can share some info/experience I do have about the Pi's. The Broadcom BCM2835 (or 6 in the Rpi2) is a SoC containing the VideoCore, arm cpu and supporting infrastructure. It's the VideoCore which is the powerhouse in the SoC which as you say is perfectly capable of handling 1080p30 MPEG4 decoding and for which licences can be bought to decode other video formats (I added MPEG2 licences to mine in order to play all content off the Hummy over my home network). The arm cpu by comparison is quite weak, designed as support for the VideoCore (VideoCore bootstraps the arm cpu not the other way round)! That's not to say it isn't still pretty useful especially the newer quad-core version in the RPi2. I had the original model B (256MB which was capable of running mumble and a 'Smokin' Guns' server for 6 players but had to be RMA'd), two of the revised model B's (512MB one running RaspBMC, the other a friend's website) and a Rpi2 which concurrently runs get_iplayer, nginx + php for a website, mumble, youtube-dl and Kodi (it also runs a firewall, IDS and is used as an ssh gateway to access other hosts).
They are very capable machines at a bargain price, but the USB bus throughput, the power supply to the USB ports and the raw processing power of the arm cpu are weak points for the purposes of a PVR server. Having access to the VideoCore processor itself (in a CUDA type arrangement) would drastically improve processing power but you'd still have the problems with usb throughput/power.[/QUOTE]

I agree that the lack of SATA support presents a problem!

That would be my number one feature vote along with a beefed up power interface to support a small hard drive. Then it would be really useful!

 

[Colsta]

I just found this on Kickstarter. It's hardly an HDR-Fox replacement but it can record live tv.

 

[MontysEvilTwin]

Regarding the Raspberry Pi, both the B+, RPi 2 (and presumably RPi 3) can power a portable USB hard drive if you have a reasonable 2A power supply, and set the parameter "max_usb_current=1" (see here). This allows up to 1.2A to be supplied to the four USB ports. I have had no problems using an RPi 2 with the USB ports powering both a wireless dongle and a portable 1TB drive.

 

[Colsta]

Using a HDD was never really the issue, it was the total available USB bandwidth available that was the concern. But I've learnt today that separation may be the key to using Raspberry Pis as a PVR after all, certainly for the barebones record/play function. According to instructions here and here, running a twin tuner server on a separate Pi does appear to work using the TVheadend package (which includes epg scheduling). You can then use a second Pi to run Kodi as a front-end client to display the content. The new Raspberry Pi 3 has a beefier arm cpu included in the BCM2837 offering around 10x the raw performance of the Pi B+ at the same pricepoint which can only help matters. By adopting a modular approach the bill of materials should still be under £150.

Current unknowns are:
* Best way to handle UHF splitting/pass-through to TV
* Ability to support more than two tuners (i.e. record two channels watch a third etc)
* handset integration (basic playback functions can be handled by CEC, but more than this?)
* ability to perform other tasks the Humax custom firmware affords (like detectads, etc)

 

[renzz]

One option not mentioned so far as a standalone solution is to use one of the Linux based STB's that seem popular in Europe, along with one of a couple of opensource PVR images to run it.

Have a look at http://www.world-of-satellite.co.uk/combo-digital-cable-terrestrial-satellite-receivers - there are a number of manufacturers and models that are fairly modular, allowing up to 4 tuners, which can be a mix of DVB-T2/DVB-S2. Some can take internal SATA drives, some of the cheaper one work with USB drives. You can then choose which PVR software you want to run with OpenVIX being one of the more popular (http://www.openvix.co.uk/), others being OpenATV and OpenPLI.

The advantage with the software is that it is opensource - and is designed to support plugins, so you could probably make it do whatever you want. However, having looked a bit at these, the software is clearly designed with the European user in mind, and doesn't support some of the Freeview things we know and love, ie Accurate Record and true series linking. Having said that, there is apparently a "VPS" plugin which is supposed to do what AR does but was written for German users (I think), but may well work with Freeview. As to lack of Series Link, the software does have some pretty powerful search capabilities allowing you to setup searches that will mimic Series Link, a bit like you had in Mystuff for the Topfield (if any old timers used to use that ).

Another advantage is that you can record more than one (or all) channels on a mux using just one tuner, so with multiple tuners, you could have a lot of simultaneous recordings going, dependent on the speed of the box.

There was a long (and now 2-year old) thread over at the Topfield forum along similar lines to this, ie what do we replace our beloved box with. It does make interesting reading, and one user took the plunge and bought one of these Linux STBs and did a review on Youtube - it is worth a read through. Thread is at http://forum.toppy.org.uk/forum/viewtopic.php?t=20627

Given the software is opensource and does allow plugins, there is probably a lot of scope for customising these, considering the skills of some of our members.

 

[Black Hole]

This is sounding good - ideal. even.