jsmeeker said:
Do the MCARDs handle SDV, or are people still screwed there if their cable co. uses it (or plans to use it)
Both the older 'S' CableCards and the new MCARDs can handle SDV. The hardware in the product (in this case, the hardware in the S3 and TivoHD) determines whether bidirectional communication is supported as necessary for SDV.
Products with a built-in unidirectional (one-way) OpenCable receivers cannot support SDV or VOD. Only products with built-in bidirectional (two-way) OpenCable receivers can support SDV. Unfortunately, the current Cable Labs' licensing agreement does not allow anyone to produce bidirectional hardware using their own interface. That is why TivoHD had to use a unidirectional design. If they had used a bidirectional design to support SDV and VOD, then they would have to use the cable company's interface.
The Tivo Series3 and TivoHD both have an on-board, programmable Xilinx FPGA which could be configured to add upstream communication, and hence bi-directional capability to support SDV. However, as noted above, the Cable Labs' licensing agreement currently prohibits that capability in any product with its own interface, so Tivo couldn't add that capability even if all the necessary hardware was in the box.
Tivo has said they are working with cable companies (and Cable Labs') to try and bring SDV capability to the TivoHD. Before that can happen, they've obviously got to drop the requirement that the box use the cable company's interface.
jsmeeker said:
or are people still screwed there if their cable co. uses it (or plans to use it)
How many analog channels does your cable system have?
Most 860-1Ghz systems have 135 channels. Unless you've got 90+ analog channels on your system, they'll have plenty of capacity for HD. Simple equation to find the approximate number of new HD channels your system can support:
Take 135 and subtract
- # of analog channels
- # of digital channels / 12
- # of HD channels / 2.5
- 10 channels (allocated for VOD)
If you are on a 750MHz system, start with 115 and subtract. Some 860MHz systems have 130-132 channels instead of 135.
Take the result and multiply it by 2.5 to find the approximate number of new HD channels your system can support
without SDV.
A bunch of Comcast systems had just 75-80 analog channels before they started migrating (moving) channels to the digital tier, so they were in a much better position than some Charter and Time Warner systems which had upwards of 90-95 analog channels.
