Talk:480p
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The DVD version often uses a 16:9 ratio, thus carrying additional picture info on either side. —The preceding unsigned comment was added by Lee M (talk • contribs).
- Actually, a 16:9 signal doesn't carry additional picture information. It merely uses the same number of pixels to describe a different aspect ratio image. In other words, the same 720 x 480 resolution is stretched to describe a wider area. Tvaughan1 02:32, 26 October 2006 (UTC)
[edit] 480 p is 720x480
While there are a number of LCD monitors sold with 852x480 resolution, the actual digital television signal format for 480p is 720x480. Noclip- do you have any source that shows 480p has a resolution of 852x480? Tvaughan1 14:39, 25 October 2006 (UTC)
- DVB allows a lot more values than just 720 pixels horizontal resolution for 480p signals and I assume ATSC does the same. What is used is another question. What gets displayed yet another. The nomenclature is used for both, transmitted/stored and displayed signals, and even for native display resolutions. The same applies to all the others (1080i, 720p, 576i …). Christoph Päper 21:24, 25 October 2006 (UTC)
When describing the display resolution we should only use active picture area. I think some of these higher figures for pixel resolution include the horizontal blanking interval. ATSC only allows 720x480, 704x480, or 640x480 (square sampling), although the latter is not commonly used anywhere. Tvaughan1 02:30, 26 October 2006 (UTC)
From what I have tested, Widescreen Anamorphic Film DVD is encoded at 720X480 and then stretched to 853x480.
If 16:9 = 1.777...
Then I would think 853x480 would be the most accurate resolution for widescreen 480p
853x480 = 1.77708333...
854x480 = 1.7791666...
852x480 = 1.775
It just so happens that most EDTVs (plasma) have a native resolution of 853x480.
Also, my understanding of Frame Rate and Refresh Rate is that you have to divide by 1.001 for accurate figures.
24 FPS = 23.976 FPS
30 FPS = 29.97 FPS
60 FPS = 59.94 FPS
48 Hz = 47.952 Hz
60 Hz = 59.94 Hz
72 Hz = 71.928 Hz
120 Hz = 119.8801 Hz
- Television signals are defined by specifications published by organizations like SMPTE, ATSC, ITU and EBU. DVD-Video specifications are defined by the DVD Forum, and they use a subset of MPEG-2. Monitors are manufactured with a variety of display resolutions and signal compatibility, but if the signal doesn't match the display resolution the monitor will either display the video with horizontal or vertical bars, or resample the video to fit the display. You can't use the monitor's resolution to describe a video signal resolution (or more accurately, scanning standard). Tvaughan1 02:07, 7 November 2006 (UTC)
- SMPTE 293M defines a 483p59.94 studio standard. ATSC defines 480p as 720x480. Actually, there are a number of standard definition digital video signal formats that are very similar, but none that have a resolution of 853x480 (that I am aware of). Tvaughan1 02:07, 7 November 2006 (UTC)
- The frame rate can differ by a factor of 1.001 depending on if it is drop-frame video or non drop-frame. Broadcast video is usually drop-frame (29.97 FPS for NTSC). Film is normally 24 FPS non drop-frame. Tvaughan1 02:07, 7 November 2006 (UTC)
