720p is one of the HDTV formats. It means the image has 720 lines of "vertical resolution", i.e. 720 pixels from top to bottom. The p stands for progressive, which means that each frame is a single full-resolution image, unlike some formats that use interlacing.
720p has a horizontal resolution of 1280, so the entire image is 1280x720 pixels (approx. 920,000 pixels in total).
720p can have any of five different frame rates (frames per second, or fps): 720p24, 720p25, 720p30, 720p50 or 720p60. Traditionally, PAL countries use 25fps (50 fields), NTSC countries use 30fps (60 fields). 24fps is the frame rate for film, making this an ideal format to use for film conversions.
When used with 50 or 60 fps, 720p has the best frame rate of the first-generation high-definition formats. This is one advantage it has over 1080i and 1080p. However, future versions of the 1080 formats are envisioned to use higher frame rates, which would give them the edge.
720p is generally compatible with most televisions and computer monitors. Although some image processing is usually required, this applies to other HDTV formats as well.
720p has initially been preferred by sports broadcasters, as it tends to work better with fast-moving images than 1080i and 1080p.
1080p is one of the HDTV formats. It means the image has 1080 lines of "vertical resolution", i.e. 1080 pixels from top to bottom. The p stands for progressive, which means that each frame is a single full-resolution image, unlike 1080i in which each frame consists of two interlaced fields.
1080p video usually has 1920 lines of horizontal resolution, making a total image size of 1920x1080 pixels (2,073,600 total). The aspect ratio is 16x9.
1080p can be specified as 1080p24, 1080p25 or 1080p30 — the additional number refers to the number of frames per second (fps). Traditionally, PAL countries use 25fps, NTSC countries use 30fps. 24fps is the frame rate for film, making this an ideal format to use for film conversions.
In the future it is envisioned that 1080p50 and 1080p60 will become the production standards, combining the benefits of progressive scan with a higher number of total images. Currently, bandwidth considerations make these formats impractical, but this could change with more efficient codecs.
1080i is one of the HDTV formats. It means the image has 1080 lines of "vertical resolution", i.e. 1080 pixels from top to bottom. The i stands for interlaced (see below).
1080i video usually has 1920 lines of horizontal resolution, making a total image size of 1920x1080 pixels and an aspect ratio of 16x9.
There are some variations; for example, HDV has a resolution of 1440x1080 but maintains a widescreen aspect ratio by using rectangular pixels.
1080i is similar to 1080p, except that it uses the interlaced format rather than progressive. This means that each frame consists of two fields each showing only half the pixels. One field shows the odd lines, the other field shows the even lines.
1080i can be specified as 1080i25 or 1080i30 — the additional number refers to the number of frames per second (fps). Traditionally, PAL countries use 25fps, NTSC countries use 30fps.
DTV-HDTV Comparison Chart
Digital television, or DTV, is the new industry standard for broadcasting picture and sound using digital signals, allowing for dramatic improvements in both picture and sound quality vs. conventional NTSC analog programming. DTV programming can be delivered in either of two basic formats: standard analog definition, (SDTV) and High Definition (HDTV).
480 is the number of lines. The "p" refers to progressive, a type of video scanning where all the lines that make up a video picture, or frame, are transmitted simultaneously. There are several progressive digital television formats.
Displays 720p signals as 720p, without any conversion. 720 is the number of lines. The "p" refers to progressive, a type of video scanning where all the lines that make up a video picture, or frame, are transmitted simultaneously. There are several progressive digital television formats.
Displays 1080i signals as 1080i, without any conversion. 1080 is the number of lines. The "i" refers to interlaced, a type of video scanning where the odd- and even-numbered lines of a video picture, or frame, are transmitted consecutively as two separate interleaved fields. Analog NTSC video uses interlaced scanning, as do several digital television formats.
Additionally, 1080p is the shorthand name for a category of video modes. The number 1080 represents 1,080 lines of vertical resolution, while the letter p stands for progressive scan or non-interlaced. 1080p is considered an HDTV video mode. The term usually assumes a widescreen aspect ratio of 16:9, implying a horizontal (display) resolution of 1920 dots across and a frame resolution of 1920 × 1080 or about 2.07 million pixels. The frame rate in hertz can be either implied by the context or specified after the letter p (such as 1080p30, meaning 30 frames per second).
DTV Format Details
HDTV is the highest form of digital television, delivering up to 1,080 interlaced scan lines. HDTV produces images that far surpass any you've ever seen in a home environment! SDTV, or Standard Definition, also represents a dramatic improvement over today's TV, with the added benefit of allowing stations to broadcast multiple programs within the same bandwidth as an HDTV signal.
1080i has a higher resolution and will have better quality but since it is interlaced video it will be more unstable.
The 720p has lower resolution but since it is progressive the image will be more stable and possible less distortion.
I think your preference will depend on how your eyes view the images – the 1080i is too jumpy or unstable for some people and they prefer the 720p resolution.
Progressive scan works in the same manner as your computer monitor. It writes one full frame of video from left to right across the screen every 1/60 of a second. Since the entire image is drawn at one time--as opposed to an interlaced image where the even lines are drawn first, followed by the odd lines--a progressively scanned video image looks more stable than an interlaced one. Progressive scan also introduces fewer motion artifacts, such as jagged diagonal lines and movement in fine detail, into the picture.
Many current progressive players fall back into a very watchable but very soft video mode when they aren't sure whether the source is film or not. In the worst case, the entire film will look excessively soft, which means they're getting exactly no benefit at all from their progressive player.
Just was poking around nd dug this stuff up. Thought it might be nice to share.
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