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

Andre Newman mythtv-list at dinkum.org.uk
Thu Dec 12 17:04:45 UTC 2013


On 12 Dec 2013, at 17:41, Gary Buhrmaster <gary.buhrmaster at gmail.com> wrote:

> On Thu, Dec 12, 2013 at 4:25 PM, Andre Newman <mythtv-list at dinkum.org.uk> wrote:
> ....
>> And when some other channel buys the same encoder as NBC…
> 
> Hate to tell you this, but there are a limited number of broadcast
> quality encoders out there (and a couple of them (at least used
> to) license the same IP to do the encoding), so it is highly likely
> that many use the same encoder.

My point entirely, there was a load of issues when the BBC started using new bleeding edge firmware supposedly capable to encode 1080i acceptably at 6-9Mbps.

My PS3 has been thoroughly left behind, it can't play most of the 1080i h264 streams MythTV records, Sony update the firmware but I never see any changes to that side.

>  It is usually not the encoder,
> it is the choices that the broadcast engineer makes.  The
> broadcast quality encoders have "billions and billions" of knobs
> to tune to get just what one wants.  Some engineers (essentially)
> leave things near the defaults, others will adjust to achieve what
> they believe is best (and in encoding, "best" still has some
> very subjective input).

I know, I'm one of those Engineers :-)

Most of the people I work with are "defaults" guys, I'm the one that gets drafted in when some more advanced twiddling is required.

I frequently have "hearty debates" with others over what constitutes acceptable picture quality, seems I'm more sensitive to motion artefacts than most, must be years of working in Sports TV.

Most broadcasters will test their transmissions on a selection of TVs and STBs, cable operators will test with their standard STBs. I seriously doubt these guys have a VDPAU card in their test lab, actually a few do (seems like I meet more VDR users than MythTV) as there are many MythTV fans working in Broadcast TV, I usually test really freaky encodes with MythAVTest on my laptop and sometimes on my VDPAU system at home/the office.

I did raise an issue with the BBC once but they said "If it's not Freeview badged they won't use it for testing", then said, thanks we'll look at that on the side.

Andre


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