NTSC stands for the National Television Standards Committee. It is a video signal standard used by the color television industry in the United States and Japan. The NTSC is a common format used by many video compression boards. NTSC video contains frames and fields. Most NTSC video frames consist of two interlaced fields. Each field is displayed as alternating horizontal lines across the screen. Most computer video formats are non-interlaced. The frame aspect ratio used by the NTSC standard format is 4:3. This format uses a 640 by 480 resolution. By using the NTSC standard for digital video, there are two areas of concern when dealing with aspect ratios. They are as follows:- Pixel aspect ratio
- Frame aspect ratio
- NTSC (resolution 648 x 486 - preferred format)
- D-1 NTSC (resolution 720 x 486)
- D-1 NTSC Square Pix (resolution 720 x 540)
This NTSC format uses a 648 by 486 resolution format. This format makes an allowance for a few additional pixels to be created on the screen edge that may be cut off when displayed. This format is also commonly used by many video compression boards. Because this format allows you to display a video without losing the "edges" of your video during playback, this resolution seems to be the preference within the industry.
D-1 NTSC
The D-1 NTSC format uses the same standard frame aspect ratio as the NTSC format. Unlike the NTSC format, the D-1 NTSC format uses a 720 by 486 resolution using rectangular pixels. The D-1 pixels used in the NTSC format are displayed using a vertical axis.
D-1 NTSC Square Pix
This format uses the same standard frame aspect ratio as the NTSC format. Unlike the NTSC format, the D-1 NTSC Square Pix uses a 720 by 540 resolution using rectangular pixels.
PAL
PAL stands for the Phase Alternating Line. This is a video standard used by the color television industry and is the common standard used in Europe. This video signal format sets the video to playback at 25 frames per second which contain 625 lines of pixels in each frame. There are various divisions within the PAL standard which determine what pixel and frame aspect ratios are used. These formats are as follows:
- PAL (resolution 720 x 486)
- D-1 PAL (resolution 720 x 576)
- D-1 PAL Square Pix (resolution 768 x 576)
The D-1 pixels used in the PAL format are displayed using a horizontal axis. This format uses the same standard frame aspect ratio as the PAL format. Unlike the PAL format, the D-1 PAL uses a 720 by 576 resolution.
D-1 PAL Square Pix
This format uses the same standard frame aspect ratio as the PAL format. Unlike the PAL format, the D-1 PAL Square Pix uses a 768 by 576 resolution using rectangular pixels.
HDTV (1280 x 720)
The HDTV stands for High Definition Television. This format is a proposed definition which displays at 1280 by 720 resolution.
[NTSC & PAL video format]
