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Spain & HD on DTT

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  • 01-12-2010 1:18am
    #1
    The Cush
    Registered Users Posts: 15,500 ✭✭✭✭


    In Spain the major broadcasters are rolling out HD versions of their channels using 6-7 Mbps which is being regarded as HD without the H.

    RTÉ recently indicated in the Dept of Comms Saorview content consultation that RTÉ 2 HD would be allocated approx 6 Mbps of the first mux. Second class HD by Spanish standards.
    Spain broadcasters must label HD
    From David Del Valle in Madrid

    Following the public complaint made by electronic manufacturers for the lack of a real HDTV in the country, the Government is finalising a new piece of legislation that will oblige broadcasters to label their content, in an attempt to avoid public confusion between HD and standard definition services in the market.

    Several nationwide TV broadcasters -TVE, Tele 5, Antena 3 and La Sexta- and Regional TV stations -TV3, Telemadrid, Canal Sur, TPA, TV Canarias or Aragon TV- are already providing HD services through DTT, but not all the content is real HD.

    Electronic manufacturers are crying out against the poor quality of the present HD TV that the commercial (private) TV channels are offering for lack of enough bandwidth in their respective multiplex with a capacity of up to 4 TV channels.

    The broadcasters are dedicating only 6 to 7 Megabits per second to their HD TV channels, out of the 20 Megabits they have in their multiplexes as none of them are willing to reduce the number of their DTT channels to the benefit of a real HD TV channel. As a way of comparison, it is half the capacity satellite operators are using for HD TV. It is also far from the 8 to 10 Megabits public broadcasters, like RTVE, are using in their HD TV channels.

    For electronic manufacturers, terrestrial broadcasters “are not broadcasting real HD TV”. Even the TV channels acknowledge that they have launched “HD without H”. As a result two different HD TV types are being developed in Spain: a first class HD TV led by satellite operators and distributed by satellite platform Digital Plus and a second class HD TV offered by terrestrial private TV channels.

    Despite this, HD TV in Spain is likely to significantly grow over the next two years to 11.5 million HD TV sets sold in the market in 2011, according to consultancy firm GfK.

    By the end of 2010, 6.6 million HD TV sets will have been sold with another 5.5 million in 2011. So far the HD TV devices already sold are estimated at around 3 to 3.5 million, 10 per cent of the market, so all the industry relies on the Christmas campaign to sell another 3 million.

    GfK is taking for granted that HD TV will be a success in Spain, despite the fact that HD DTT penetration only reaches 18.3 per cent of the country. Even worse around 12 million TV sets in the country, 46 per cent of the total market, are not ready for HDTV and other 11 million need a special STB to watch it, according to the Electronic Association Asimelec.

    http://www.advanced-television.tv/index.php/2010/11/30/spain-broadcasters-must-label-hd/

    rates.jpg


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    #2
    mossym
    Moderators, Sports Moderators Posts: 8,766 Mod ✭✭✭✭mossym


    it's not a direct comparison, due to different compression techniques, mpeg2 vs. mpeg4 efficiency and other factors, but for example, the max bitrate allowed for dvd was about 9.5Mb/sec, in reality no dvd's got close to this, Sony's Superbits where they took off all the extras and increased teh bitrate still got to 6/7 max.

    so using that as a very rough yardstick, what we are getting as HD from broadcasters isnot far above the rates offered by SD DVD, and given they are a higher resolution, means you'd want to be very liberal in your use of the term HD around them. at least there is blu-ray


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    #3
    watty
    Registered Users Posts: 32,417 ✭✭✭✭watty


    It's not as bad as you think

    Using CBR 6Mbps MPEG4 AVC H.264 is about 15Mbps MPEG2.

    Originally MPEG4 offered x2 improvement vs MPEG2 in bitrate for similar quality. Encoder makers are now claiming x2.5 to x3. At the optimistic x3, then CBR MPEG4 @ 6Mbps is 18Mbps if it was MPEG2 at same quality.

    DVD is 720 x 576 = 414,720 bits per frame
    HD DTT is 1440 x 1080 = 1,555,200, or 3.75 times...

    So to compare with DVD, multiply DVD (which is SD) x 3.75 and / 2.5 (3 is a bit optimistic IMO) and assume 4Mbps AVERAGE bit rate on the 9.5Mbps peak ... 4Mbps SD MPEG2 x 3.74 / 2.5 = 6Mbps HD MPEG4!
    A 9.5Mbps peak SD MPEG3 = 14.25 Mbps peak HD MPEG4

    If x3 is true for peak then 11.875Mbps peak HD MPEG4 AVC H.264 L4 = 9.5Mbps MPEG2 SD quality. (i.e. a Sqrt(3.75) x bigger TV on HD than SD should look as good).


    However... if we have Variable Bit rate and Statistical Multiplex, then 6Mbps AVERAGE could have up to 14Mbps or more peak. Maybe even 16 Mbps for very short periods.

    If it's VBR 6Mbps 1440 x1080i is AVERAGE bit rate on stat mux and all "state of the art" encoders then it exceeds DSL with single channel CBR 12Mbps MPEG4 for quality by quite a bit.

    So 6Mbps Average HD with higher peak VBR stat mux is reasonable HD with current MPEG4 encoders. (DIVx /xVid MPEg4 is nothing like as compressed for same quality, this is why much more CPU needed to decode Irish DTT, esp HD).

    With two multiplexes you want to put mix of HD, SD and radio on both to help the Statistical Multiplex.

    I think PSB needs 3 x Mux if RTE1, RTE2, TV3, TG4 and Film Channel are all in HD. Which they should be within a few years.

    Widescreen is STUPID in SD. SD should only EVER have been 4x3. The broadcasters and TV makers should have waited for HD to introduce WS. Also it should have been 1.85:1 and not 1.78:1 IDIOTS.

    So if SD DVD looks good on a 32" TV, then 1.9x should be OK on HD = 60"

    So Irish DTT HD should look better than SD DVD on up to 48" TV and acceptable on up to a 60" set.

    BluRay of best quality, (50% are only DVD quality), should be OK up to 72"


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    #4
    The Cush
    Registered Users Posts: 15,500 ✭✭✭✭The Cush


    mossym wrote: »
    it's not a direct comparison, due to different compression techniques, mpeg2 vs. mpeg4

    Ireland and Spain both use DVB-T/MPEG-4 for HD DTT. The SD channels on the Spanish muxes use MPEG-2.

    The public broadcaster RTVE's HD channel has a higher bit rate because they have access to two muxes.


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    #5
    mossym
    Moderators, Sports Moderators Posts: 8,766 Mod ✭✭✭✭mossym


    The Cush wrote: »
    Ireland and Spain both use DVB-T/MPEG-4 for HD DTT. The SD channels on the Spanish muxes use MPEG-2.

    The public broadcaster RTVE's HD channel has a higher bit rate because they have access to two muxes.

    sorry, was referring to my comparison to DVD, not the different DVB standards


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