Could Irish DTT be broadcast at better rates and give better picture?

swoofer

I read on another post the transmission rates for SAORVIEW and was quite surprised at the rates used and the resolution!! With so few channels why not give us best possible instead of least costly? I know DTT is at the moment a lot better than old analogue in some places but so many have big tv's now it would make sense to use higher bit rates and resolution. I know germany transmit 720 x 576 in sd and that is glorious. And hd is 720p but again they use 1920 x 1080.

Why are we adopting such inferior set ups?

gb--

The Cush

Perhaps you should make a submission to the Dept's latest consultation on DTT content.

http://www.dcenr.gov.ie/Press+Releases/New+RT%c3%89+channels+for+digital+TV+Minister+Ryan+asks+public+for+their+views.htm

watty

GBCULLEN wrote: »

IAnd hd is 720p but again they use 1920 x 1080.

Why are we adopting such inferior set ups?

gb--

1920 x1080i is higher resolution than 720p

The main advantage for 720p is 60Hz countries that suffer 3:2 pull down artefacts from 24fps film. It's pointless here. It uses the SAME bitrate approximately.

The Cush

In the Saorview content consultation the resolution for the new channels is

Capacity Required for HD and SD Services

The following technical specifications are being proposed by RTÉNL and are subject to contract negotiations with broadcasters.

Statistical multiplexing will be used for all video services, audio and data services are fixed bit rate.

It is planned to use the following bit rates as part of a statistical multiplexed pool.

High Definition Video (HD)
1 Minimum of 2.0 Mbps
2 Maximum of 9.0 Mbps
3 Weighting 90%
4 Resolution 1440 x 1080i
5 Expected average bit rate 6.0 Mbps

Standard Definition Video (SD)
• Minimum of 1.0 Mbps
• Maximum of 8.0 Mbps
• Weighting 90%
• Resolution 544 x 576
• Expected average bit rate 2.0 Mbps

No indication what the resolution of the existing channels will be in the consultation doc.

parasite

544x576 just isn't good enough, it's noticably blurry to me
/grumble

watty

Maybe bad rescaling on an LCD?

Or a very large screen.

720 x 576 is better. But 544x576 should not be "noticably blurry" on a 32" screen

1440 x 1080i is anamorphic version of square pixel HD 1920x1080i

Really with HD on the horizon is was short sighted for PSB not to get 3 x Mux.

At least with failure of payDTT, the 2nd PSB mux is Brought Forward to "Soon" rather than 2013 (after ASO)

Antenna

parasite wrote: »

I know germany transmit 720 x 576 in sd and that is glorious

I haven't looked recently - but the picture quality of many of the German channels still on ANALOGUE satellite on 19.2 was I would describe 'glorious' (good detail and zero motion blurr etc) compared to any current Irish pictures on any platform.

parasite wrote: »

544x576 just isn't good enough, it's noticably blurry to me
/grumble

A lot of the output of Irish TV suffers from bad motion blur before it enters any transmit chain at all ! - due to lossy compression recording from on-location cameras. This is what I would grumble about.

Also archive footage is usually rather lossy digitised and badly blurrs with motion and camera panning. As an example I saw GAA footage from the 1990s broadcast by RTE on a documentary of a former player a couple of months ago - the old footage was just a megablur with fastmoving action/camera panning

dmm1000

Taking the Irish Digital trial as an example

For SD broadcasts :-

Is there a certain number of Megabytes (megabits ?) bitrate for an SD broadcast channel which will give you the best possible picture ? - meaning that it would be pointless to up the bitrate any further as it couldnt improve the picture much further (at least not to the naked eye)


I ask the same question in relation to lets say whatever flavour of HD RTE will be transmitting (720p / 1080i) or whatever

What are the maximum figures in bit rates for SD and HD broadcasts which we'd need to use which would give us the quality that the Germans provide in their country's broadcasts ?

watty

Yes, but it depends on the program content.