About 6 months ago, Channel 9 launched their ‘Catch Up’ service. Basically this is their way of fighting piracy and allowing people to download Australian made TV shows to watch on their PC. Now, of course, no ‘old media’ service would possibly do this without the wonders of DRM. Channel 9 though, are taking a slightly different approach.

Instead of the normal style of DRM that prevents you copying the file, Channel 9 employs technology from a company called Hiro. Essentially you install the Hiro player, download the file and watch it. The player will insert unskippable ads throughout the video, supposedly evenĀ targetedĀ at your demographic. Now this is actually a fairly neat system, Channel 9 actually encourage you to share the video files over bittorrent etc! The problem, as I’m sure you can guess, is that there’s no player for linux.

So, just to skip to the punchline, yes it IS possible to get these files working on free software (completely legally & without the watermark)! If you just want to know how to do it, jump to the end as I’m going to explain a bit of background first.

Hiro

The Hiro technology is interesting in that it isn’t simply some custom player. The files you download from Channel 9 are actually xvid encoded, albeit a bastard in-bred cousin of what xvid should be. If you simply download the file and play it with vlc or mplayer, it will run, however you will get a nasty watermark over the top of the video and it will almost certainly crash about 30s in when it hits the first advertising blob. There is also some trickiness going on with the audio as, even if you can get the video to keep playing, the audio will jump back to the beginning at this point. Of course, the watermark isn’t just something that’s placed over the top in post-processing like a subtitle, its in the video data itself. To remove it you actually need to filter the video to modify the area covered by the watermark to darken/lighten the pixels affected. Sounds crazy and a tremendous amount of work right? Well thankfully its already been done, by Hiro themselves.

When you install Hiro, you don’t actually install a media player, you install either a DirectShow filter or a Quicktime component depending on your platform. This has the advantage that you can use reasonably standard software to play the files. Its still not much help for linux though.

Before I get onto how to create a ‘normal’ xvid file, I just want to mention something I think should be a concern for free software advocates. As you might know, xvid is an open codec, both for encoding and decoding. Due to the limitations of Quicktime and Windows Media Player, Hiro needs to include an xvid decoder as part of their filter. I’m sure its no surprise to anyone though that they have failed to release any code for this filter, despite it being based off a GPL’d work. IA(definitely)NAL, but I suspect there’s probably some dodginess going on here.

Using Catchup with free software

Very basically, the trick to getting the video working is that it needs to be passed through the filter provided by Hiro. I tried a number of methods to get the files converted for use with mplayer or vlc and in the end, unfortunately, I found that I needed to be using either Windows or OSX to get it done. Smarter minds than mine might be able to get the DirectShow filter (HiroTransform.ax) working with mplayer in a similar manner to how CoreAVC on linux works, but I had no luck.

But, if you have access to OSX, here’s how to do it:

  1. Download and install the Hiro software for Mac. You don’t need to register or anything, in fact, you can delete the application the moment you finish the install. All you need is the Quicktime component it added.
  2. Grab any file from the Catch Up Service (http://video.ninemsn.com.au/catchuptv). I’ve tested this with Underbelly, but all videos should work.
  3. Install ffmpegx (http://ffmpegx.com)
  4. Grab the following little script: CleanCatch.sh
  5. Run:
    chmod +x CleanCatch.sh
    ./CleanCatch.sh <filename>
  6. Voila. Output will be a file called ‘<filename>.clean.MP4′ and should be playable in both VLC and mplayer

Distribution

So, I’m the first to admit that the above is a right royal pain to do, particularly the whole requiring OSX part. To save everyone the hassle though, I believe its possible to simply distribute the modified file. Now again, IANAL, but I’ve gone over the Channel 9 website with a fine tooth comb and can see nothing that forbids me from distributing this newly encoded file. I agreed to no EULA when I downloaded the original video and their site even has the following on it:

You can share the episode with your friends and watch it as many times as you like – online or offline – with no limitations

That whole ‘no limitations’ part is the bit I like. Not only have Channel 9 given me permission to distribute the file, they’ve given it to me unrestricted. I’ve not broken any locks and in fact have really only used the software provided by Channel 9 and a standard transcoding package.

This being the case, I am considering releasing modified versions of Channel 9′s files over bittorrent. I’d love to hear people’s opinions about this before doing so though in case they know more than I (not a hard thing) about such matters.