2007-04-15 19:52:41 · 3 answers · asked by yumsorbet 4 in Consumer Electronics ➔ Home Theater
Today's DVD-Video players invariably incorporate both performance features.
Video and film source material is encoded onto DVD-Video discs using MPEG-2 MP@ML encoding and may be encoded at video resolutions of 720x480, 704x480, 352x480, 352x240 pixels. Most FILM source material is (ideally) encoded as 24 frames per second progressive video and most (NTSC) VIDEO source material is encoded as 29.97 frames per second interlaced video. It is quite common to find both encoded formats being used on the same DVD-Video disc, e.g. a movie encoded as 24 fps progressive video and some or all supplemental material encoded as 29.97 fps interlaced video. Generally most modern DVD-Video players can output native progressive scan video as well as de-interlacing video that has been encoded as interlaced video.
Upscaling is used to increase the apparent resolution of the video image and/or match the video image to a high resolution or high definition display and is a separate performance option or feature found on many current DVD-Video players as well as high definition displays such as HDTVs.
A Brief Background
The raster based video system in North America creates video images sequentially line by line – and pixel by pixel across each line – from top to bottom and left to right across the screen.
Relying upon persistence of vision, the National Television Standards Committee chose to use an interlaced line scanning method for creating video images in the (soon to be replaced) NTSC television system in order to minimize video image flicker while also reducing the bandwidth requirements for video broadcasting.
De-interlacing and Progressive Scan Video
The video image in the NTSC system is comprised of a total of 525 vertical scan lines, of which 483 scan lines make up the visible portion of the video image. The video image consists of two sequential "fields" that combine to form a single "frame" of video. In an interlaced video system the odd numbered scan lines are 'drawn' in the first field of the video image followed by the even numbered scan lines of the second field thereby creating a single frame of video. Interlaced scanning potentially has several drawbacks - most notably motion related artifacts such as loss of resolution whenever there is fast motion in the video along with jaggies, combing, line twitter, line crawl, etc.
The preferred alternative to interlaced scan is known as progressive line scanning or progressive scan for short. Progressive scan video, used throughout the professional video and broadcast industries long before becoming available to consumers, creates each video image by drawing all 525 lines (483 lines visible) for each frame of video. Video that is originally recorded and reproduced using the progressive scan method largely eliminates many of the artifacts that plague the interlaced line scan system. (By the way the computer industry uses progressive scan video almost universally.)
De-interlacing is part of a common, relatively low cost method used to convert interlaced video to de-interlaced (i.e. simulated progressive scan) video. It is difficult to effectively de-interlace interlaced video and de-interlacing will always introduce its own video image artifacts no matter how small. De-interlacing is occasionally followed by line-doubling (aka interpolation) in order to double the 525 lines of video per frame provided the display has the requisite horizontal scan bandwidth. De-interlacing is frequently unable to achieve the full video image quality that is provided by properly encoded native progressive scan source material.
Video Upscaling
Video upscaling (on occasion erroneously referred to as upconverting) is the digital process of converting a lower resolution video image to a higher resolution video image; where necessary it may also include reformatting from one aspect ratio to another. With the significant increase in digital signal processing power upscaling technology, not unlike de-interlacing technology, has improved dramatically within the last several years. Nevertheless upscaling is not without its own problems, e.g. macro-blocking, red push, white crush, etc., and like de-interlacing should be avoided if possible; preference should always be given to native high definition, progressive scan source material. Nevertheless, upscaling will be largely unavoidable at the present time and into the foreseeable future.
Final Comments
The bottom line is that (to the trained eye) de-interlacing and upscaling are almost always less desirable than viewing unadulterated, native progressive scan source material in its unaltered native resolution; the latter is extremely unlikely when using today’s high definition displays to view DVD-Video content. For these and other reasons consumers must choose equipment and source material wisely.
2007-04-16 16:09:57 · answer #1 · answered by ? 5 · 1⤊ 0⤋
While writersblock makes some valid points she fails when she talks about comparing the two. Composite is the worst way to transmit video. Any HDMI player will look great compared to composite even if it's running at 480. As to what you get with a BD player compared to an upscaling player? The ability to play BD disks. Standard DVDs are at 480 lines of resolution. BDs are at 1080 lines. To make it clearer, SD is 307,200 pixels. BD is 2,073,600 pixels, almost 7 times more. That's a heck of a difference. If you wait till next Christmas the prices will be coming down some. For now you might want to go to Wal-mart and grab a cheap upscaling player for about $40 and save your pennies for a BD player once the prices get a little more reasonable.
2016-05-21 01:46:47 · answer #2 · answered by ? 3 · 0⤊ 0⤋
A regular DVD player can output in 480 interlaced (2 fields of 240 lines each)
A progressive player can output in 480p, a single frame of 480 lines
An upscaling DVD player can output in 720p (scales the 480 lines to 720) or 1080i (two fields of 540 lines)
2007-04-15 20:11:23 · answer #3 · answered by TV guy 7 · 2⤊ 0⤋