On Wed, May 18, 2005 at 09:07:07AM -0700, Mark Knecht wrote: > The 'proper' way (as per 5C) to handle this in the system is to use > a video display device (probably an AGP VGA card, but it could be a > TV) that has the built in 5C decoding in hardware. That way the data > remains protected until it's put on the screen. Myth TV might be > recording the encrypted data stream for playback at a later time on > it's own PC hardware or a 5C enabled TV. Even within that TV is was > made purposely hard for anyone to get the perfect digital copy, but no > more difficult than it would be to have it in a PC. All technologies > were treated in a more or less equivalent manner. (TTBOMK)
This precludes all features and all future features dependent on understanding the video. In particular, transcoding becomes impossible under such a regime. Commercial skip is next to impossible, as is editing. On screen display is possibly only insofar as it is supported by the decrypting output card -- all of Myth's code for decoding the video becomes useless, to be replaced by the card's decoder. Small preview videos and screen captures are extremely difficult to impossible. Also blocked would be the recent and popular time-compress feature. Rewind, Fast forward and seeking in the stream would be possible only so far as the output card supported a protocol for it. (Is the encryption done on a per-frame basis or on a block basis? If on a per-frame basis, non-decrypting tools could do seeking on their own.) Picture adjustments would be possible only as the display device allows them, including resizing for overscan. And ditto for sound unless you re-digitized the audio after decrypt with added delay. Now, some will point out that if one put these functions into the secured decrypt/display card, one could then write a driver to do them. This misses the point in a couple of ways. First of all a card that can transcode and re-encrypt or do commercial scanning is a pretty mean feat and probably very expensive -- you're effectively taking more and more out of Myth and putting it into the card. In the unlikely event you were to do this your features would be limited by what was in the card. This truly mythical transcoding card would not let you develop new algorithms for transocding or better commercial detection. Indeed, it would not let you do many innovations that were not thought of when the card was created. A general purpose computer is not innovation limited, and an open source system allows innovation from all comers, including the user. This is the point of open source. Truth is, nobody's going to want to build such a card. It's far cheaper to use simpler electronics and lock up the software running the PVR to get your 5C (or cablecard) licence. So big players won't use such cards, they would only serve small players, meaning they would have a limited market. So we are left with MythTV unable to function in many important ways as it sits today, and future innovations needing access to the video almost entirely locked out. We don't know what those future innovations are, but we can be confident they're coming -- or not coming if you needed a 5C licence. And all this for what? It's not to stop skilled crackers from getting access to the data and putting it up as torrents. In fact, it only increases demand for that activity. No, all it does is make your PVR more expensive, stop the average user from doing things and cripple MytyhTV. Why is that worth it? It doesn't protect the business model of the studios who always faced the end user making personal copies from time to time and handing them out to friends. The new threat is the copy on the P2P network, and this system doesn't stop that! So why?
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