Multimedia « codeblog

March 30, 2005

tivo dump

Filed under: Multimedia — kees @ 7:16 am

Well, it doesn’t actually make a lot of sense to figure out the encryption used by the TiVoToGo DLL, since TiVo could at any moment change it, the TiVo box’s routines, etc, and force all of us to upgrade. This ends up turning into an arms race, like iTMS. So, a better approach is to just use the DLL itself. Wine and Mplayer both have perfectly well written DLL loaders. All that has to be done is write a DirectShow Pull Pin implementation, following all the public published specs.

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February 25, 2005

.tivo file format

Filed under: Multimedia,Reverse Engineering — kees @ 1:35 am

After I found some details on the .tivo file format, and cooked up some code to produce the same output. So far, there isn’t a lot of detail. It’s mostly just strange stuff. mpegcat finds the MPEG2 stream right where it should be, but supposedly the non-I-frames appear to be encoded.

All the files I’ve downloaded from my TiVo have the same “fingerprint” listed in the XML header, and a different “salt”. The interface for downloading recordings is very simple. Connect to https://[tivo IP]/ and it’ll prompt you for your username and password, which is “tivo” and your “Media Access Key”. After that, you’re all set; browse away. Download speed is rather slow: 500kB/s. Better than 2400 baud. :)

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January 3, 2005

TiVo Home Media

Filed under: Multimedia — kees @ 12:35 pm

Last week a friend of mine told me about the Java HMO (Home Media Option) server. I had no idea it existed and immediately got it set up. This provides your TiVo with a place to get MP3s, streaming audio, and images over your local network through whatever other computer you have around to do the work for it. The regular Windows TiVo HM “Desktop” software isn’t nearly as cool. With the Java HMO, you can get movie listings, web cams, etc. It’s terrific.

Anyway, this was supposed to be about code, but it’s more about a growing itch to patch. It seems that the “Internet Images” module is either very fragile and/or doesn’t like having spaces (or maybe commas?) in the image titles (which it uses for caching in /tmp/javaHMO.cache/)

The overall system is a great design, and I’m currently enjoying watching some great webcams in places that are in daylight while I’m in the dark:

Antarctic Gentoo Penguins
Hanmer Springs, New Zealand
Tembe Elephant Watering Hole, South Africa

I can see elephant butts! :)

TiVo published their networking specs, but only included the broadcast and “desktop” specs. I think it would be cool to have the TiVo share movies with my computer too. Would be great for movie trailers and DVDs. My DVD player is in the other room, so I can’t watch movies in the TiVo room (at least until NetFlix and TiVo get their movie-delivery system finished). It still might be tricky to resample the DVD on the fly. TiVo normally records stuff at half-resolution, so dealing with a full DVD MPEG2 stream would be exciting to say the least. I’ll just have to see what’s on the wire between two TiVos configured to record shows from eachother.

(Edit: Holy crap! My wish is granted in the TiVo->PC direction, at least!)