Hack Allows Copying of TiVo Recordings

While initially tolerant of hackers modifying its product, TiVo may have been unprepared for the power of open source. A new software utility has surfaced with the ability to extract digital video directly off the recording unit, raising numerous copyright concerns. With an added network card, TiVo users may now archive and view recorded television shows on a computer.

The software, dubbed ExtractStream, reads video data stored on the TiVo and copies it to a PC via network interface. Once extracted, the raw video can then be encoded into MPEG format and viewed or transported. Possible applications include archiving favorite shows, or viewing recordings on a laptop while away from home.

A similar solution can be obtained with a TV card, but directly copying from the TiVo offers a couple advantages. Quality is theoretically higher because digital to analog conversion is avoided, as TiVo only supports analog video out. In addition, video capture is quicker because copying occurs at speeds faster than real time.

However, the process is still very complicated. TiVo uses a proprietary media file system (MFS) which functions like a database to store program listings, season passes, wishlists, suggestions, and recordings. Because the secret behind MFS is kept locked up, ExtractStream is forced to simply read raw sectors off the disk.

ExtractStream was derived from PlayStream, the first tool to reverse engineer TiVo's video storage technique. This allows the software to know which sectors to read for each saved video. ExtractStream adds support for TiVo software version 2.0, and the ability to copy data elsewhere.

Although similar in concept to DeCSS, software which allows DVD video to be copied to a hard drive, no encryption is being broken with ExtractStream, keeping clear of any DMCA violations. The MPEG2 video is stored unencrypted, as TiVo had instead relied on its proprietary file system to keep data secure.

It is not clear how TiVo will respond to copyright concerns brought about by the ability to distrubte TiVo recordings. The company has promoted its open-arms strategy for dealing with hackers, who took advantage of the Linux operating system which powers the device. But TiVo may be prompted to change such an open attitude and refuse to provide future service for those who have tinkered with their recorder.

For more information, read further instructions on how to install and use ExtractStream. Source to the program is also available under the GPL.