[mythtv-users] Possibly a "dumb" question

[Robert McNamara]

On Fri, Feb 5, 2010 at 8:24 AM, Brian Wood <beww at beww.org> wrote:
> On Friday 05 February 2010 09:14:58 am Eric Sharkey wrote:
>> On Fri, Feb 5, 2010 at 10:55 AM, Robert McNamara
>>
>> <robert.mcnamara at gmail.com> wrote:
>> >> Why can't it just stream the exact file to the TV and let the TV tuner
>> >> receive/decode/render/interlace/deinterlace it. In other words hand it
>> >> to the TV exactly as it were broadcast.
>> >
>> > That would require an QAM modulator
>
> Actually an ATSC modulator, though the two are very similar, and the same
> device could probably do both, perhaps with a firmware change.
>

Actually, if you're attempting to pass through a cable signal
unmolested, you would use a like-type modulation.  Since ATSC and QAM
have different bitrate ceilings, remodulating a signal received via
QAM as ATSC (with its lower bitrate limit) would necessarily require a
transcode in at least some cases.  So yeah, passing through a cable
signal to your TV would require a QAM modulator.

Robert