1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Please define Hi Def for me.

Discussion in 'TVs' started by vex, Jul 21, 2005.

  1. vex

    vex
    Well-known Member

    Joined:
    Mar 8, 2005
    Messages:
    2,888
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    103
    Location:
    London, Home Counties & North West
    Ratings:
    +261
    As I have a TV background I thought it would be fixed at 720 or 1080 (i or not) but I was chatting to someone yesterday about it and he said he has been running hi def images for the past 3 years!

    Now this is encoded, digital distribution as a pc signal (networked out to mini pc players) so of cource they are running pc style definition.

    My question is, can they call it hi def or is there something different between PC and TV images that is so different he can not do this?

    VEX
     
  2. probedb

    probedb
    Banned

    Joined:
    Aug 20, 2003
    Messages:
    2,653
    Products Owned:
    0
    Products Wanted:
    1
    Trophy Points:
    86
    Location:
    Sheffield
    Ratings:
    +181
    Erm not 100% sure what you mean.

    You can get from various places transport stream recordings from US OTA hi def channels for the PC, these are usually 1080i. If his display can take a 1080i input then he's running hi-def. I'll be connecting my puter at 1280x720 to my LCD when it turns up which is basically the same as 720p over component :)
     
  3. AML

    AML
    Well-known Member

    Joined:
    Jul 22, 2004
    Messages:
    4,989
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Tokyo
    Ratings:
    +229
    I think he is reffering to the difference between Hi def resolution and PC resolution.

    The truth is that there is no difference. Resolution is resolution.

    There is however a difference between a PC monitor and a hi def TV. Usually a plasma or LCD display.

    PC resolution usually go from 1024X768 to 1280X1024 to 1600X1200 and so on.

    They varie and can be changed if the hardware you have allows it.

    Hi Def resolution is already defined and in a way limited to 2 different resolution.

    for 720p its a resolution of 1280X720. The P is for progressive scan. 1080i is a resolution of 1920X1080. I is for interlace.

    Im not sure how the whole interlacing/progressive business works, but in theory progresive should be better than interlace. So the best Hi Def resolution to go for would be 1080p (not "i")

    A PC with the right graphics card and monitor can also display these "hi def" resolutions, but if you ask me it isnt necesary.

    Currently I have a home theater PC that is conected to my Fujitsu plasma and is set to a resolution of 1600X1200. It looks amazing when showing windows media hi def DVDs.

    http://www.microsoft.com/windows/windowsmedia/content_provider/film/hdvideo.aspx

    This is probably (ammong other downloadables) what your friends have been watching for "years".

    The truth is that the US and Japan have been enjoying hi def for quite some time and many US shows are already beeing shown in hi def. Those shows can be downloaded in full hi def (1280X720) and watched through media players like WMP10 on a PC set to the same or higher resolutions.

    There is no real difference as the resolution is the same.

    The quality is good and its better than almost any standard definition programs shown on analog TV.

    Still, im sure once Hi def players like blu Ray and HD DVD come out, we will see another level of quality.
     
  4. Stephen Neal

    Stephen Neal
    Well-known Member

    Joined:
    Mar 29, 2003
    Messages:
    6,080
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    133
    Ratings:
    +681
    HDTV currently exists in a number of different formats.

    In the US it is broadcast in 1080/60i (1080 lines interlaced made up of 60, 540 line fields per second) and 720/60p (720 line progressive made up of 60, 720 line frames per second) - via MPEG2 compression. HDTV displays with component analogue and DVI or HDMI can accept decompressed HD in this format (1080i or 720p), and some TVs (and HD VCRs) also have Firewire/iLink/IEE1394 inputs for compressed MPEG2, and contain MPEG2 decoders in them. (This is useful as D-VHS VCRs are available with Firewire inputs and outputs to record HD broadcasts losslessly)

    There are loads of non-PC solutions - D-VHS/D-Theater VCRs, HDTV TVs, HDTV satellite, cable and OTA digital terrestrial receivers and PVRs for HD in the US.

    There are also PC capture cards (for ATSC and Cable) in the US, and PCs can accept the Firewire MPEG2 outputs from D-VHS VCRs and some set top boxes, these are sources of MPEG2 which can be decoded by the PC themselves for display. If you use the PC solution then you can configure your PC to run in 1080i or 720p (most PC video cards can be persuaded to work in these resolutions using either video drivers or Powerstrip a 3rd party piece of software) to feed a conventional HDTV display in native HD resolution. You can feed displays via a VGA output from the PC, or via a DVI output. VGA to component converters are also available.

    However PCs can also display the HD video in non-HD resolutions. It is perfectly possible to replay 16:9 720p (1280x720 resolution) video on a PC running 4:3 1280x1024 resolution for example.

    In Europe there isn't as much HD at the moment - there are a couple of 1080/50i HDTV services using MPEG2 on satellite - and receivers and PC solutions are both available for these.

    There are also Windows Media DVD-ROMs containg HD video encoded using Windows Media encoding. These are usually replayed on PCs - though some can also be replayed by networked media players connected to PCs (like the Pinnacle Showcenter 200 apparently)

    Sky will be launching an HD service in the next 12 months or so which is expected to support 1080/50i and 720/50p (with broadcasters able to chose the best format for their channels) and connect to displays using ideally HDMI digital connections (or DVI with HDCP encryption) and also analogue component (though this may only work for some output)

    Of course there are other sources of HD - mainly files of off-air recordings made in the US - but the legality of file-sharing these is questionable in some regions.
     
  5. pjskel

    pjskel
    Well-known Member

    Joined:
    Oct 12, 2004
    Messages:
    2,676
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    83
    Location:
    UK
    Ratings:
    +124
    Think of progressive like this:
    You have 2 hands (left and right), if you place them in front of you, at the same time, then you have progressive.
    If you alternate them so that one is only moved at a time, and done fast enough, your eyes will 'think' that both are in front of you at the same time, but in essence, they are not - then you have interlaced.

    As for the jump in resolution when Blu-Ray and HD-DVD make a appearance - that will only be true if the broadcast HD is more compressed. If Sky, etc put out feeds at 12-18 Mbps, then there'd be little if no difference between the two sources.
    For most people though, pre-recorded discs will be their only taste of HD on their Plasmas and LCDs, save for those who bother hooking a PC up and d'lding HD trailers (or *cough, cough* HD broadcasts/movies).
     

Share This Page

Loading...