[mythtv-users] Blu-Ray/HD-DVD versus MythTV HD recordings

Marco Nelissen marcone at xs4all.nl
Wed Mar 21 02:49:59 UTC 2007

Brian Wood wrote:
>On Mar 20, 2007, at 9:06 AM, Boleslaw Ciesielski wrote:
>> Brian Wood wrote:
>>> Add to that the MPEG transport used by the networks and you have MPEG
>>> artifacts that any discriminating viewer will see, most often in
>>> unpredictable motion like sports.
>> What do you mean by that? As long as there no uncorrectable errors,  
>> the
>> MPEG transport should not affect image quality, no?
>I'm not sure where to even start on that one, as ANY compression  
>scheme will degrade the original video, by definition.

Uhm, no. Any LOSSY compression scheme will "by definition" degrade
the original video, however non-lossy compression schemes do not.
Furthermore, the "transport" (as in MPEG Transport Stream) is
merely an encapsulation for the compressed packets. The transport
stream itself therefore has no effect whatsoever on quality.

>You can reduce the problems, but not eliminate them. I suppose if all  
>you were to transmit were complete I-frames then you would have no  
>artifacts, but also no compression.

Wrong again. I-frames are compressed using a lossy compression also,
so you would have both compression and artifacts.

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