Resolution and Aspect Ratio

In HDV, the video frame is defined to have an aspect ratio of 16:9. Permitted resolutions are 720p and 1080i.

HDV 720p uses a resolution of 1280x720 square pixels. HDV 1080i uses a resolution of 1440×1080 pixels, but is still displayed with a device aspect ratio of 16:9 This is because the pixel aspect ratio is 1.33:1 stretching the actual pixels to make the proper resolution. This means it has lower horizontal resolution than true 1080 HD formats (1920x1080), but the same applies also to most other widely used HD formats including XDCAM HD, DVCPRO HD and HDCAM, all of which have the same or lower resolution as HDV.

Device Aspect Ratio summary
NTSC/Pal 4:3
HD/HDV 16:9

Pixel Aspect Ratio summary
NTSC .9:1
NTSC Widescreen 1.2:1
HDV 720p 1:1
HDV 1080i/psF 1.33:1
HD 1:1

Despite this, the perceived detail of HDV is much higher than that of PAL or NTSC DV formats. 1440 pixels is still twice the horizontal resolution of SD formats. In total, each HDV frame has 1,555,200 pixels, which is 4.5 times the resolution of NTSC DV (345,600 pixels) and 3.75 times that of PAL DV (414,720 pixels).

The numbers above refer to the luminance (brightness) information only; chrominance (color) information is subsampled (4:2:0 for HDV) to reduce the amount of data, as happens with DV and DVD, although NTSC DV uses a different sampling pattern (4:1:1). In other words, in all these formats, the chrominance resolution is one quarter of the luminance resolution. Most professional video formats use a 4:2:2 sampling pattern, and some high-end formats support 4:4:4, which is to say full chroma sampling.