VideoHelp Forum
+ Reply to Thread
Results 1 to 8 of 8
Thread
  1. What is resolution of broadcast TV signal and how it signal is ok on 16:9 & 4:3 TVs which have different resolution?
    Last edited by Mark22; 24th Sep 2016 at 03:19.
    Quote Quote  
  2. Dinosaur Supervisor KarMa's Avatar
    Join Date
    Jul 2015
    Location
    US
    Search Comp PM
    North American Digital TV (ATSC) is usually broadcasted at either 1920x1080, 1280x720, or 720/704x480. 16:9 content on a 4:3 TV is usually cropped to 4:3 by the TV. 4:3 content on a 16:9 TV would be filled in by black bars on the left and right side.
    Quote Quote  
  3. Member Skiller's Avatar
    Join Date
    Oct 2013
    Location
    Germany
    Search PM
    Flags tell the TV or receiver what shape (4:3 or 16:9) the incoming broadcast is to handle it accordingly. The actual resolution of the broadcast stream is fixed. For standard definition broadcasts it can be up to 720x576i for PAL and 720x480i for NTSC, but it can be lower in the horizontal. The resolution does not change with aspect ratio – that's what the flags are for.

    High definition broadcasts are either 720p or 1080i.
    Quote Quote  
  4. Explorer Case's Avatar
    Join Date
    Feb 2004
    Location
    Middle Earth
    Search Comp PM
    The frame and thus the pixels get stretched to fit the desired aspect ratio, making the pixel-information a bit rectangular/non-square.

    (image from my 2006 archive, so ignore the ‘regular’ adjective ... )
    Quote Quote  
  5. Originally Posted by Mark22 View Post
    What is resolution of broadcast TV signal and how it signal is ok on 16:9 & 4:3 TVs which have different resolution?
    For legacy (SD) there is no resolution but bandwidth and in case of USA video luminance bandwidth is approx 4.2MHz - for DVD bandwidth is equal (theoretically) to 6.75MHz (digital 720 pixels in line) - legacy resolution in pixels will be somewhere around 448 pixels ((720:4.2)/6.75).

    For wide aspect ratio video size is compressed to fit in normal aspect video and TV expand video size back - bandwidth stay same so number of pixels is constant.
    Quote Quote  
  6. Member
    Join Date
    Aug 2006
    Location
    United States
    Search Comp PM
    Originally Posted by KarMa View Post
    North American Digital TV (ATSC) is usually broadcasted at either 1920x1080, 1280x720, or 720/704x480. 16:9 content on a 4:3 TV is usually cropped to 4:3 by the TV. 4:3 content on a 16:9 TV would be filled in by black bars on the left and right side.
    I record TV with an ATSC tuner card. I've captured SD broadcast streams with the following resolutions: 528x480 (4:3), 640x480 (4:3), 704x480 (16:9 and 4:3) and 720x480 (16:9). [Edit] (All of these are 480i.)
    Last edited by usually_quiet; 24th Sep 2016 at 14:32. Reason: accuracy
    Quote Quote  
  7. Member
    Join Date
    Aug 2010
    Location
    San Francisco, California
    Search PM
    Originally Posted by Skiller View Post
    For standard definition broadcasts it can be up to 720x576i for PAL and 720x480i for NTSC, but it can be lower in the horizontal.
    Standard definition in the digital ATSC system, which has almost completely replaced NTSC worldwide, also allows a 480 progressive signal.
    Quote Quote  
  8. Member
    Join Date
    Aug 2006
    Location
    United States
    Search Comp PM
    Originally Posted by JVRaines View Post
    Originally Posted by Skiller View Post
    For standard definition broadcasts it can be up to 720x576i for PAL and 720x480i for NTSC, but it can be lower in the horizontal.
    Standard definition in the digital ATSC system, which has almost completely replaced NTSC worldwide, also allows a 480 progressive signal.
    Have you watched any ATSC channels currently using 480p? I'm wondering if this is another option allowed by the spec which broadcasters are not interested in using. I have only seen various 480i resolutions up to now.
    Quote Quote  



Similar Threads

Visit our sponsor! Try DVDFab and backup Blu-rays!