Video and Audio Coding
HDV video and audio are encoded in digital form, using lossy compression. Video is encoded with the H.262/MPEG-2 Part 2 compression scheme, using 8-bit chroma and luma samples with 4:2:0 chroma subsampling. Stereo audio is encoded with the MPEG-1 Layer 2 compression scheme. The compressed audio and video are multiplexed into a MPEG-2 transport stream, which is typically recorded onto magnetic tape, but can also be stored in a computer file.
The data rate for both the audio and video is constant and is roughly the same as DV data rate. The relatively low video data rate can cause bit rate starvation in scenes that have lots of fine detail, rapid movement or other complex activity like flashing lights, and may result in visible artifacts, such as blockiness and blurring. In contrast to the video, HDV audio bitrate is relatively generous. At the coded bitrate of 384kbit/s, MPEG-1 Layer 2 audio is regarded as perceptually lossless.
Read more about this topic: HDV
Famous quotes containing the word video:
“These people figured video was the Lord’s preferred means of communicating, the screen itself a kind of perpetually burning bush. “He’s in the de-tails,” Sublett had said once. “You gotta watch for Him close.””
—William Gibson (b. 1948)