[mythtv-users] Another BBC HD Audio variance.......

[Another Sillyname]

On 25 January 2011 01:27, Andre <mythtv-list at dinkum.org.uk> wrote:
>
> On 25 Jan 2011, at 00:20, Paul Gardiner wrote:
>
>> On 24/01/2011 21:35, David Knight wrote:
>>> C4 HD is on FreeSat from Sky.... ahem... ;)
>>
>> Presumably you can't pick that up with a DVB-S2 card though?
>>
>>> and Five HD is OK.
>>>
>>> I still have a recording from the early days of BBC HD (Top Gear Arctic
>>> Special) which still looks impressive.
>>>
>>> I really wish Andy Quested and that woman on the BBC Blog had listened to
>>> the complaints instead of just looking for ways to wriggle out of it when
>>> people complained of a drop in quality with the new encoders.
>>
>> Do did it really used to be better.
>
> Yes and no.
>
> I just missed the 20Mb/s days, they were using an encoder that was barely better than mpeg2 but it looked pretty good judging by the short clips I have found, it had problems in the shadows of grainy film masters much as mpeg2 HD does but overall it was pretty good, about as good as a mediocre quality bluray.
>
> They had a good period with new encoder firmware during which they dropped to 16Mb/s, this was pretty good, this is when I started to get myth working with DVBS at a friends place, I still have some recordings from this time. Just before the Beijing Olympics they had some problems with the encoders such that they were forced to run an older firmware (not too happy with their playout people about this I heard), this firmware required ~18-19Mb/s for reasonable results but they had moved a couple of BBC one regions on to the transponder so had to run at 16Mb/s for some months until the problem was resolved, more contractual than technical. This was co-incident with a mislabelled ac3 stream which is a bug in the older firmware.
>
> Round about then I convinced the others in my building that we needed a communal satellite system and I got Freesat working with myth at home.
>
> Then they got new encoders which they tried to run at 9Mbs, you can read the rest on the BBC Blogs :-(
>
> Unfortunately the period of under running the encoders at 16Mb/s seems to have given them the idea that they can get away with less than text book rates!
>
>> I've had Freesat as a source
>> only fairly recently, and thought BBC HD and BBC 1 HD were great.
>
> They are pretty good most of the time, they allow a reasonable maximum rate now, although I've seen better pictures at lower rates at one customer's site.
>
>
>> Certainly miles better than ITV HD, which is usually difficult
>
> ITV HD is still mostly upscaled, occasionally there's something that looks really good but it's not that often.
>
> I find that different decoders look better or worse with different channels, with BBC's old encoders my PS3 looked better than vdpau, now it's the other way around. ITV still looks a little better on the PS3 but there's not much in it since the vdpau re-work in myth. There's significant difference in image quality between the older nvidia cards 9xxx and the GT220 and that's taking the better de-interlacing out of the comparison.
>
> Then there's the TV to take into account... From what I've seen the current BBC HD encoders produce very variable results on different TVs & set top boxes, clearly there's a great deal of difference between manufacturers H264 decoders.
>
> I remember being utterly amazed how much better an MPEG1 VCD looked when played through one of those fancy new MPEG2 decoders in a DVD player;-)
>
> I made some tests with various HD STB's and cheaper professional receivers for a client a couple of years ago, massive differences between manufacturers and that was all mpeg2 720p.
>
>> to distinguish from SD.
>
> I find almost all the SD channels to be truly awful, I can't really watch them any more. SD can look great, a good DVD is excellent, the output from an SD studio or OB Truck is pretty amazing but the rates used for Freeview and Freesat SD are way below what mpeg2 needs to render an ok image, the pictures seem to be 80% artefacts 20% picture these days. Anyone who says SD looks better than even really bad HD can't be looking at the picture!
>
> Of course if they broadcast decent SD pictures we wouldn't need to upgrade all the studio's, trucks etc to HD! As everything is being upgraded to 1080i which is pretty ancient technology (25yr old) this will all need upgrading again to 1080p50/60 in a few years time and again to super hi def at 300fps in about another 10 years.
>
> that's enough ramblings for one day ;-)
>
> Andre
>
>>
>> Paul.
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>
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The repeat was 5.0 as well.....