Uses for a Raspberry Pi (part 2)

In my last post, I described a few simple, but effective uses for a Raspberry Pi. Here are two more!

4. File server using Samba, and media server using MiniDLNA

The Pi makes for a useful low cost file server. I used this guide to install Samba which enables file shares to be accessed via Windows (and also OS X). It's pretty easy to follow step-by-step. Following that guide, you can also attach a USB drive, making for a cheap network-attached storage (NAS) solution.

Furthermore, you can also install MiniDLNA to allow networked media devices to easily access video and audio on the Pi, though I've not tested this personally.

5. get_iplayer: for UK users (or overseas users with e.g. VPN access)

What's get_iplayer?

For the benefit of those not in the UK, iPlayer is a BBC service that allows users to stream television and radio programmes for a limited time after they are broadcast. It also lets you download them for a limited time, although they are then bogged down with DRM, restricting how you can watch or listen.

get_iplayer is a great open source project that really enhances the usefulness of iPlayer. First of all, it downloads TV and radio shows in DRM-free formats, allowing you to play them back on any device capable of playing those formats, without restriction. Second, it has a really useful PVR feature: you can queue up future programmes that are already in the BBC's current schedule, and you can easily setup PVR searches (e.g. to look for a specific programme title) that can be configured to run periodically and download on any suitable matches.

Installation of get_iplayer

I installed get_iplayer last year on my Pi running Rapsbian; I followed this guide. Since then however, it's now much easier to install and maintain¹, apparently you only need to enter this terminal command now:

sudo apt-get install get-iplayer ffmpeg atomicparsley libmp3-info-perl

For convenience, I changed the default directory that get_iplayer saves in so that it was within a directory that was publically shared via Samba, using a command like

./get_iplayer –-prefs-add –output=/home/shares/public/iPlayer

(Note that for all these commands, I'm assuming that you have changed directory to whichever one get_iplayer is installed.)

--prefs-add, unsurprisingly, adds settings to the get_iplayer defaults. I also used this command:

./get_iplayer --prefs-add --modes=best -–subtitles --subdir --nopurge

• --modes=best downloads the HD versions of a TV programme if it is available
• --subtitles downloads subtitles if available
• --subdir sorts programmes into subdirectories based on their title, while
• --nopurge prevents the deletion of programmes that were recorded more than 30 days ago.

Basic use

There are plenty of usage examples in the documentation which is definitely worth a read and explains all the available options. A simple usage case would be to download all TV programmes that have "Top Gear" in the title or episode info:

./get_iplayer --get "Top Gear"

By default, the type of programme is set to TV. This is equivalent to using the command line option --type=tv. If you are looking for radio shows instead, you need to specify --type=radio. Alternatively, you could use --type=tv,radio and get_iplayer will search both the TV and radio programme lists.

If there are several programmes with the same title (e.g. Newsnight), you can search for all programmes first by:

./get_iplayer "Newsnight"

It shows a list of matching programmes and programme numbers. When I ran this just now, it gave me several matches, but say that I wanted the broadcast from 01/07/2013. Among the nine matches this command gave me, it showed:

611: Newsnight - 01/07/2013, BBC Two, News, TV, default

I can then get that specific programme by just --getting a programme number instead of a title:

./get_iplayer --get 611

Adding searches to the PVR

Adding searches to the PVR is very similar to downloading available shows. As the documentation shows, instead of the --get option, you use --pvr-add:

./get_iplayer --pvr-add=Top_Gear "Top Gear"

This adds a search named Top_Gear which looks for programmes with Top Gear in the title or episode info. This doesn't actually do anything until the PVR searches are executed by the command: ./get_iplayer --pvr

Supposing that we grew tired of Clarkson, Hammond and May's shenanigans, we can remove the PVR search entirely by --pvr-del:

./get_iplayer --pvr-del=Top_Gear

or if we weren't so sure, we could use --pvr-disable="Top Gear" to disable the search and --pvr-enable="Top Gear" to re-enable it at a later date.

Further PVR management options are listed in the documentation. Additionally, there is also a web PVR interface, if you prefer that to using the command line to manage the PVR, although it's advised to have it running on trusted networks for security reasons.

Scheduling the PVR to run

However, it is more convenient to run the PVR regularly rather than have to run it manually. You can add the command to run the PVR to the cron task scheduler. Scheduling tasks by cron is carried out by entering crontab -e and then editing the file to start the job.`

I had a problem where I could run the command

get_iplayer --pvr

and the PVR would work fine from a terminal window, but it failed when running via cron. This was fixed by finding the contents of my current PATH variable (by typing echo $PATH into the terminal) and then copying this into a line in my crontab that started PATH=.

Why I think the PVR is great

What's awesome about the PVR function is that the search terms are persistent. If the PVR is looking out for a particular show, you don't even need to keep an eye out for when your favourite shows start a new series, in case you forget to record it. The PVR feature will automatically catch them for you, without you thinking about it.

Custom commands after downloading recordings

This is another useful feature of get_iplayer. --command runs custom commands after downloading a recording and can pass various bits of information to those commands as arguments. Because of this feature, it's easy to use your own scripts to process your recordings.

Example: automatic downloading of radio tracklistings

Sometimes I'll hear a track that a DJ plays on a radio show and I'll want to make a note of it to look it up later. It's not always that easy to do, occasionally they neglect to mention the title and artist, which can be frustrating when you've heard something amazing.

At least these days tracklistings are usually posted online, but if I'm listening on my iPod Nano (running Rockbox), this means I still need to dig out my phone, fire up a web browser and look it up. It's much easier if the tracklisting is stored together with the radio show for quick reference.

To automate this, I wrote a Python script that downloads BBC tracklistings (bbc_tracklist.py). Once a radio show has been downloaded using get_iplayer, the corresponding tracklisting is saved to a text file in the same directory.

All the bbc_tracklist.py script needs to know is the programme id, which get_iplayer can pass through to it as <pid>. For example:

./get_iplayer --get "Gilles Peterson" --type=radio --command "/home/get_iplayer/bbc_tracklist.py <pid> <dir> <fileprefix>"

My script optionally takes arguments of the directory (to store the tracklisting with the downloaded show) and a filename (to give the text file the same base filename). These are provided by get_iplayer via <dir> and <fileprefix>.

It also works in the same way with PVR searches.

./get_iplayer --pvr-add=Benji_B --type=radio "Benji B" --command "/home/get_iplayer/bbc_tracklist.py <pid> <dir> <fileprefix>

Once this has been setup in a radio PVR search, you can forget about the script entirely. It should execute automatically everytime a show has been downloaded.

Conclusion

get_iplayer does its job superbly well. It has many useful features and seems very stable. Comparing get_iplayer to the TV tuner my main PC has installed, get_iplayer has been used much more for "recording".

Why should this be?

It doesn't matter if you miss a show with get_iplayer since you can still download it several days after broadcast and, with the PVR feature, you probably won't miss it. This isn't possible with a TV card if you missed the only broadcast. get_iplayer also circumvents entirely the problems I occasionally have with my TV signal. Combined with a Samba or miniDLNA setup described above, you can leave the Pi running to periodically save programmes and then either playback files across the network or copy them to another device. Finally, shows downloaded by get_iplayer are ready to playback on many devices immediately; this isn't always the case with TV captures which might require some post-record processing.

Of course, I should mention that, since the video formats are unencumbered with DRM, it's possible to play them with, of course, Raspbmc. :)

So, there you have it. Five handy uses for a Raspberry Pi. If I find further uses for my Pi, I'll definitely be writing about them. In the meantime, feel free to let me know via a comment what you're using your Pi for!