[mythtvnz] Feedback requested on an article on Digital TV

[Steven Ellis]

Steve Hodge wrote:
> On 10/7/06, Steven Ellis <steven@openmedia.co.nz> wrote:
>> Steve Hodge wrote:
>> > This is certainly never been the case for me. Though One and 2 look
>> > better via DVB-S through MythTV (connected to a plasma via VGA cable)
>> > than via Sky (connected via SVideo). But the technology is the same.
>> > There's no guarentee that FreeView will look any better. You're
>> > assuming that the FreeView partners will do a better job or at least
>> > allocate more bandwidth than Sky do now.
>>
>> Technology is the same, but the bit-rates are way different.
>
> Incidentally, do you think Sky decoders will be able to pick up the
> FreeView channels? Technically they should be able to, right?

They will only pick them up if Sky decides to enable them.

>
>> 1. Sky doesn't use 720x576 for all of its channels (or at least they
>> didn't)
>
> That's poor. Which channels, do you know?

Sorry no. It did used to be quite a number of the channels

>
>> 2. What is Sky's average bit rate vs FreeView ? FreeView appears to be
>> around 4.8Mb
>> 3. Sky only does anamorphic wide-screen on selected channels (at
>> present).
>
> Is FreeView going to be entirely widescreen?

Don't know. Only confirmed widescreen channel is TV3 at this stage

>
>> 4. Not all Sky boxes have component - I agree it is a lot better, but
>> not as good as DVI/HDMI/VGA
>
> SCART RGB should be all but indistinguishable from VGA. The only
> difference is that VGA has separate horizontal and vertical sync
> signals and SCART RGB has a combined sync signal. Certainly my
> plasma's manual lists SCART RGB as being as good as DVI-D and VGA, and
> better than component.

Most people's older CRT TVs don't support RGB over scart. Plus DVI-D is
better than VGA.

>> 5. I don't know anyone who even realises you can feed a Sky box over
>> component, never mind actually doing it.
>
> I don't know anyone doing it, but I have seen the odd mention here and
> there. Part of the problem is that it's not a component signal as I
> thought and not many TVs have full SCART input (at least not many CRT
> TVs). However, if people can't be bothered getting the best signal out
> of their existing equipment, that says a lot to me about how much they
> care about video quality.
>
> Another issue, at least for me, is that you can't set one of the SCART
> outputs to RGB and have the other SCART output on S-Video. The best
> you can do is one RGB and one composite or both S-Video. The S-Video
> connection to my Myth box is far more important than having RGB to the
> TV for the very occassional time I watch that way.
>
> Incidentally, according to their website the MySky decoder does do
> component out as well as RGB.

Yes a lot of people with big screens have switched to MySky because of the
component out.

>> 6. Can you record component ? I don't know of any reasonably priced
>> capture cards that can do component.
>
> I don't know of any either. It's useless for MythTV, I agree. But my
> argument is that the difference between Sky Digital and FreeView won't
> be that great - i.e. that Sky Digital (on the major channels if you
> like) is a reasonable approximation of what FreeView will have to
> offer for the average person. It could be as good as DVD quality, but
> we won't know until we get it. For MythTV, I agree that FreeView will
> be a significant improvement.
>
>> What size and type of screen are you viewing on. A standard CRT up to
>> 32" is very forgiving of SkyTV. Once you move onto LCD and Plasma at
>> 40"+ the difference is huge.
>
> I'm using a 42" plasma. It's a low end one (852x480) so it's not an
> HDTV display. I agree that Sky Digital doesn't look that flash, but
> there is no way it is worse than broadcast.
>
> I got a SCART cable and did some testing today. DVB-S through MythTV
> is definitely softer than Sky->TV using either S-Video or RGB. This is
> quite likely due to the settings on my Myth box. Unfortunately I can't
> do a side by side comparison of Sky's S-Video and RGB outputs (due to
> the above mentioned limitations). I also have no way of viewing the
> TVNZ's DVB-S output except via MythTV.

I've done a comparison on a large HD plasma and Sky over SVideo or
Composite compared with FreeView over DVI/HDMI is majorly different
quality wise.

Also Sky over SVideo/Composite on TV1/2 compared with an analogue aerial
is also a lot worse on a really large screen if they have a good
terrestrial signal. Sky's signal really shows up the MPEG artifacts a lot
more.

>> The bit rate on the wide-screen test channel is usually pretty damn
>> high, way above normal DVD bit rates.
>
> How high? Unless it's much higher than the 4800 kbit/s you mentioned
> earlier I doubt there will be many people who will be able to tell the
> difference between that and DVD.
>
> Certainly TVNZ Wide via MythTV does not look as good as DVD on my
> system, though that could be the fault of my MythTV setup.

How are you feeding the DVD vs the MythTV box. Also play a DVD on the
MythTV box and compare that with TVNZ Wide. I find that the Stargate SG1
episodes on TVNZ wide are better than my DVD copies when played on the
same hardware.

Steve