What is the specification of a DV Codec

[Balamohan]

Hi,
I want to encode some digital video taken from a Sony Camera. I want publish those videos online. I had first tried to convert them in a normal avi format which is played on most pc. But the output quality was hampered. On the same hand after editing the same in Quicktime, it works. It was equipped with a DV format. What is the standard format used for streaming video and how does DV codec help in the same.

[Eric B]

The DV codec, contrary to what is generally said, is not a codec lossless; DV compression slightly compresses the image in a 5:1 ratio and also uses coding YUV 4:2:0 12 bits. During the editing steps so there is a slight Degrade had to re-compression succession. It is recommended for Digital Video recording and editing. If you want to work on Digital Videos then this one is a requirement.

[Glenny]

The multi-generation test is to slightly modify a portion of a film in DV editing software (iMovie 2 here with the DV codec in QuickTime 4.1.2 and QuickTime 5.0.2 on Mac OS to require the editing software has re-compress the film several times to test the quality of the re-DV compression. The DV format is the standard for PAL and NTSC support.

[JonathanD]

A simple calculation can determine the speed of the video stream or 720x576x25x12 bits / second for PAL before compression, either: 118.65 kbits / second. Compression is an approximately 5:1 ratio is obtained in a final compressed stream of about 25 Mbits / second. For the aspect ratio NTSC image on frequency leads to exactly the same values.

[Macarenas]

Encoding DV PAL YUV 4:2:0 color reduces to 12 bits per pixel color coding instead of 24 bits normally required. To do the luminescent component is stored for each pixel and the Red and Blue components are coded as it a pixel on a line two and two. This trick allows color coding to keep the visual image by dividing by 2 the flow, this encoding leads to a deterioration during the first compression. Then during the various re-compression damage due to the color coding is less obvious.