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Other articles in the series Dominate Your TV



TiVo: Freedom Through Time-Shifting, Part 2

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In last week's issue, I discussed the barriers presented in our lives by the television schedule, and how a Personal Video Recorder's (PVR) trick play functionality adds new flexibility to the television experience. The TiVo's user interface enables the user to choose programs to be recorded based on their titles, and tracks schedule changes through nightly updates. Now we'll look at the change a TiVo can bring to users' lives, how it works and the vibrant user community that has sprung up around it. Also be sure to tune into the TidBITS Talk discussions that have looked at issues such as using the TiVo in countries other than the U.S. and UK, other personal video recorders that compete with the TiVo, and much more.

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Freedom from Television Tyranny -- TiVo helps you find programs, schedule recordings to your heart's content, and ferret out little nuggets you wouldn't have otherwise known about - but is it truly the revolution in watching television that your TiVo-owning friends say it is? We are, after all, talking about a glorified VCR. Or are we?

TiVo changes your viewing habits, but it can also have a profound impact on how your life is structured - especially today when people are spending record numbers of hours in front of their sets. This impact, however, is the hardest part to describe: it's just better, dang it, and when you have a TiVo it seems obviously so. Watching normal TV is now an excruciating experience - I have to choose from the dreck that's currently on or schedule my time around the shows I want to see, and must wait for a commercial break to answer nature's call. Perhaps the best way to illustrate the change TiVo brings is to describe how my girlfriend and I used to live.

Cynthia takes ballet classes three nights a week, and the class schedule dictates our carpool. She needs to be there at 5:30 PM on Mondays, so we're home by 4:45 PM so she can change clothes and get something to eat before dashing out again. I used to channel surf for a while then, despite already knowing that I wouldn't be interested in anything on at that hour. Other nights we'd have dinner around 7:00 PM and eat at the coffee table while watching Friends reruns, even though we already knew the plot lines. On Thursdays Cynthia would race home from ballet to arrive by 10:00 PM and watch ER - she'd burst through the door, flip the TV to channel 4 and catch her breath during the opening credits, still grasping her purse and keys. We subscribed to a premium movie channel package, yet often rented movies.

Once the TiVo arrived, our habits slowly changed. After only a couple of days we noticed that we ate dinner- at the dining room table - whenever we felt like it; there was no need to worry about sandwiching the meal between slices of sitcoms. On Thursdays Cynthia gets home at a leisurely 10:10 PM, changes clothes and eats dinner before settling into ER around 10:30 PM; she fast-forwards through commercials and finishes the program in about forty minutes. We don't rent videos any more, but instead use TiVo's Movie Marquee feature to keep a couple on tap. (The cable company's HBO package became a lot more valuable, and hey, that Encore channel is pretty cool, too.) Since everything we watch is listed in Now Playing, we no longer channel surf to find something tolerable, and we no longer know or care when or on what channel a particular show airs. We watch TV on our schedule, eradicating the concept of prime time. It feels like we watch less television now, because we watch only programs we really like. Just as the Internet removes geography from commerce, TiVo has liberated our television from the broadcast schedule.

Along the way, we find ourselves evangelizing TiVo to friends and family. This is a reflection of the transformation in your life - once we had a PVR, we could see all the flaws in normal television and felt compelled to share the knowledge. Cynthia has entranced her ballet cohorts with tales of its convenience, and my sister-in-law wanted one within five minutes of seeing ours in action. This transformation into a TiVo evangelist is somewhat disconcerting, but apparently normal and undoubtedly accounts for a significant percentage of the 229,000 current TiVo subscribers. I asked several friends what they thought of their TiVos, and their comments were overwhelmingly positive. "I can't imagine life without this device," says a friend who's had a TiVo for only six months.

After Adam briefly mentioned shopping for a TiVo in TidBITS-543, TidBITS Talk caught fire with discussion about PVRs and their possible effects on advertising, given that most PVR owners skip or fast forward through commercials. Plus, once the television stream is digital, it's conceivable that a PVR could actually replace the commercials in television shows with others that were more tailored to individual viewers.

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Under the Hood -- The TiVo recorder uses a combination of surprisingly humble hardware and innovative software. At its heart is a 27 MHz IBM PowerPC 403GCX processor, 16 MB of RAM, and either one or two Maxtor Fireball LCT series IDE hard disks. Video is compressed and stored in the MPEG-2 format, with dedicated encoder and decoder chips (the Sony CXD1922Q and IBM MPEG-2CS22, respectively) doing the heavy lifting. Extensive use of DMA (Direct Memory Access) keeps data moving to and from the hard disks, while the CPU maintains an astonishingly low average busy rate of 11 percent. TiVo uses the open source Linux as the recorder's operating system, with the company's own scheduling modifications coded into the kernel. The TiVo software itself runs as a proprietary application on top of the operating system; video streams are written to TiVo's MFS file system, which is tuned for efficient space management and to extract the maximum performance from the hard drives.

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Interestingly, the recorder is never at rest - to the point that it lacks a power switch. It's always recording a video stream - if it's not recording a specific program, the live television signal is saved into a 30-minute buffer. It's also always playing a video stream - "live" TV is played out of the buffer, with about a one second delay. It's even playing a video stream when you're in the user interface, as the background animations are MPEG2 streams, permanently stored on the disk. Although managing gigabytes of video streams, the TiVo software itself occupies only 24 megabytes of disk space. As of January of 2001, 150,000 TiVo recorders were managing an astonishing 4.5 petabytes of total storage and downloading 5.1 terabytes of daily guide updates. [For reference, a petabyte is 1,024 terabytes, or over one million gigabytes. A terabyte is 1,024 gigabytes. -Geoff]

In April of 2001, TiVo's CTO and co-founder Jim Barton gave a lecture at the University of California at Berkeley entitled, "An Overview of the TiVo Service." His slides are available in PDF format, and the 90-minute lecture can be viewed in RealPlayer and MBONE formats. If you're interested in a highly technical discussion of the TiVo recorder's hardware and software, you won't be disappointed.

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A vibrant and inquisitive user community has sprung up around TiVo, inspired not only by the effect it has on its users' lives, but also by the enticing combination of off-the-shelf components and an open source operating system. The AV Science Web site, an information repository for the home theater set, hosts a dedicated TiVo discussion forum. TiVo staff actively monitor the forum and use it as a means for customer support, communications, and floating the occasional trial balloon. The TiVo Underground section is devoted to hacking the TiVo hardware, discovering hidden software codes, and the like. The most common hack is the addition of larger hard drives, a process that once required arcane knowledge of Linux disk partitions and byte swapping. Today, several software utilities are freely available to aid this process, and one user has written an excellent how-to primer for upgrading your TiVo's hard drive. Enterprising folks have also discovered how to hack an Ethernet card into the recorder and instructing it to get its guide updates via Ethernet instead of the built-in modem. (All of these modifications void your warranty, of course, but that has barely slowed enthusiastic hackers.)

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Limitations and Caveats -- Like most things in this world, TiVo has points of frustration. For starters, the recorders are advertised and priced according to hours of storage. There are four levels of recording quality, and the advertised number is achieved only if you exclusively use the lowest quality setting. This Basic setting uses tight, lossy compression and looks to my eyes about the same as a VCR's Extended Play setting; Medium is less compressed and appears about the same as a VCR's Standard Play. The High and Best qualities both look superb, but you lose a lot of recording capacity - my unit's 14.5 hours of Basic capacity shrinks to 4.3 hours at Best. Basic is fine for talking head shows and most sitcoms; we use it as the default quality on our 14-hour recorder. We use Medium for any show with fast-action shots (e.g. ER or Buffy the Vampire Slayer) and High or Best for anything we want to savor, such as Bruce Springsteen's HBO concert special. Keeping track of recording quality and disk space grows annoying, however, and the hacking community has spawned a storage upgrade cottage industry. TiVo recently floated a survey regarding storage upgrade pricing, and I think they or their hardware partners (perhaps through the service desks at retailers like Circuit City) would do well to offer such an option.

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For the TiVo to work its magic with the program guide, it must use its built-in modem to call in for daily television schedule updates. TiVo's service provides local dialup numbers in most areas, and until recently they offered an 800 number if a local number wasn't available. (The 800 number is still available for existing customers, but was removed from the options given to new customers.) The hacking community has found that the unit's phone call is actually a PPP dialup to UUNET. In light of this discovery, many feel that TiVo should enable the recorder to use a customer's existing ISP account as an alternative dialup method.

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Given that Wishlists contain specific criteria of what I like, and that Suggestions record things TiVo thinks I might like, one assumes that the former influence the latter. This is not the case - the only thing that affects Suggestions is the user's use of the Thumbs Up and Thumbs Down buttons.

I'm often asked, "Can a TiVo record two programs at once?" The answer is "it depends" and "soon, apparently." There are two types of TiVo recorders: stand-alone and DirecTV combination receivers (also known as DirecTiVo). Stand-alone units can receive television from an antenna, cable (analog or digital), or satellite, but they have only one tuner - which means only one recording at a time. DirecTiVo units integrate the satellite receiver and TiVo recorder into the same box and write DirecTV's MPEG2 stream directly to disk. (These units don't have or need the MPEG2 encoder chip and thus can be used only with the DirecTV service.) Integrated recorders also have two hardware tuners, but until now only one of them was actually used. On 20-Aug-01 TiVo announced the release of software version 2.5 to DirecTV combination receivers. This release enables the second tuner and the capability to record two programs simultaneously. During the financial conference call, CEO Mike Ramsay stated that the all DirecTV combination receivers would receive the update during the next few weeks.

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If you receive a lot of channels (from digital cable or satellite), the second setup phone call can take quite a while, and the decompressing/indexing can take hours. If the TiVo recorder comes with version 2.0 of the software it will allow you to watch live TV (and pause, rewind, etc.) during the indexing. Earlier versions make you wait for the indexing to finish; the box doesn't say what version comes pre-installed, but the recorder downloads the latest software during its first daily call. (Digital cable and satellite services also include music channels, for which TiVo isn't very helpful. You can watch a music channel live and play it through your stereo, but TiVo will still want to change the channel when it's time to record a regular program.)

It's also worth noting that TiVo's capability to gather data about customers' viewing habits, and what the company does with that data, has invited scrutiny from privacy advocates. On 26-Mar-01, the Privacy Foundation released a report outlining their concerns regarding the TiVo recorder, which reads, "According to our findings, TiVo gathers enough information to track individual users' home viewing habits while apparently promising not to do so; could identify the personal viewing habits of subscribers at will; [and] has a much more explicit privacy policy disclosure on its Web site than in the printed material that accompanies the purchase of the product."

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The report caught the attention of several major news organizations and prompted three members of the U.S. House of Representatives to ask the Federal Trade Commission to investigate the matter. TiVo quickly released a response to the report, clarifying the company's existing privacy policy, what data is collected, how it is uploaded and used, and the available opt-out option. A response to the FTC's inquiry was released on 03-May-01, and a PDF version appeared on the TiVo Web site. The issue was discussed at length on the AVS Forum, wherein many readers felt the Foundation's report was ill informed and unnecessarily inflammatory. In this discussion, several posts from "Otto" detail the exact contents of the files that are uploaded by the recorder, based on his investigation into the files on the recorder's hard disk.

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Television Transformed -- For anyone who owns a PVR, the experience is so transforming that we wonder how we possibly lived without them. Along the way we notice that we stop watching scheduled television, and watch only the PVR's recorded subset. Thus, it becomes clear that the PVR should not be a separate device, adding further clutter and cable morass, but should instead be integrated into our existing devices. TiVo's DirecTV-integrated receiver is such a device, as are Microsoft's UltimateTV (also a DirecTV-only receiver) and EchoStar's DishPVR 501. As further evidence of this trend, Motorola has announced intentions to integrate ReplayTV technology into their digital set-top boxes, and Panasonic has shipped a television with an integrated ReplayTV PVR. Meanwhile, cable provider Comcast has conducted a trial with TiVo recorders in the Cherry Hill, New Jersey area, and ZDNet reports that Cox conducted a similar trial in Las Vegas, Nevada.

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After living with a TiVo for a year, one thing is for sure - I will never again watch normal television. Having a PVR has turned the uncooperative, cantankerous television into a faithful butler who is attuned to my whims and fancy. Viva la TiVolution!

[Andrew Laurence works in computing at the University of California, Irvine. He is an avid reader, enjoys a large music collection, and doesn't watch all that much TV. Really.]


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