[mythtv-users] HDHomeRun - Comcast shut off clear QAM

[Michael T. Dean]

On 12/12/2013 11:32 AM, Mike Perkins wrote:
> On 12/12/13 16:05, Jay Ashworth wrote:
>> From: "Michael T. Dean"
>>> No, I mean, "VDPAU isn't guaranteed to work on all content, or with all
>>> applications". VDPAU works great in MythTV on my PCIe GeForce GT220
>>> (with CPU running in performance mode), but some content (such as that
>>> from my NBC affiliate) trips it up, making video playback/watching with
>>> VDPAU decode useless. And, since there's no way for me to tell MythTV
>>> "only use VDPAU if the content came from channels other than this one,"
>>> I need to use software decode (where /I/--or people smarter than me who
>>> work on ffmpeg and MythTV video decoders can change and fix the
>>> software). And, even if MythTV allowed me to only use VDPAU on content
>>> from certain channels, I'd /still/ need a good CPU that can decode the
>>> high-bitrate MPEG-2 in software--or else I couldn't watch Marvel's
>>> Agents of S.H.I.E.L.D. So, while the Presentation portion of VDPAU is
>>> wonderful, the Decode portion leaves a lot to be desired.
>>
>> Oh, my.  I had no *idea* VDPAU was that sloppy.  Crap, and I just bought
>> a new NV card. <sigh>
>>
> It's not that VDPAU is sloppy, it's just that they can only code it to 
> work with any examples they can get hold of.
>
> It is obvious that although there are allegedly TV "standards" the 
> variation possible inside those standards is so broad that examples 
> will surface that no amount of existing coding can possibly deal with.

Right.

>
> The broadcasters don't care -- the TVs display them alright, don't 
> they? Must be *your* problem, then.
>
> The fact that VDPAU can't handle everything thrown at it is no 
> different than what happens with ffmpeg -- various combinations of 
> changes and/or corruptions in the input stream just can't be predicted 
> or catered for in code up front. It takes someone to experience the 
> problems, capture the offending stream, send it to the coders and for 
> a fix to be added to the next release -- assuming anyone can be 
> bothered, of course.
>

But the difference is that I can't change the silicon in my 
VDPAU-compatible card, nor can I change the code in the nvidia 
proprietary drivers, when the show I want to watch is encoded in such a 
way that VDPAU can't handle it.  I can work on (or find someone else 
interested in working on) ffmpeg code.  And, by choosing a frontend 
system that can use, but doesn't have to use, VDPAU, I have options when 
I want to watch something that VDPAU can't handle.

Mike