[mythtv-users] MythTV and analogue TV

[Raymond Wagner]

On 2/19/2011 18:25, Malte Gell wrote:
> Raymond Wagner<raymond at wagnerrp.com>  wrote
>
>> MPEG is a series of specifications for compressed video.  In this case,
>> MPEG encoder cards output MPEG2 video and MPEG Layer 2 audio, in an
>> MPEG2 container.  With the tuner card handling all the capture,
>> encoding, and multiplexing, it is much easier to configure for recording
>> in MythTV, as well as much lighter on your system.  Framegrabbers, such
>> as your tuner card, simply expose a sequence of video frames in a
>> section of memory, which MythTV has to then capture, compress, and
>> synchronize with a separate audio stream.  Its a hassle to deal with,
>> easy to screw up, and causes significant CPU load to do in real time.
> Do all these USB devices lack this MPEG hardware? Are there "premium" models
> that handle MPEG in hardware? I find it hard to find TV hardware that has
> Linux support, I was glad to having found a device that works just with a
> kernel update....

Digital tuners all output compressed video.  The broadcasts themselves 
are compressed, and the tuner just passes the video on to the system 
unaltered.  Analog video must be compressed, and some more expensive 
cards have hardware to do the compression for you.  Note that this is 
different from 'full-featured' cards, which include an MPEG decoder and 
video output.