【 Weak current College 】 with you to understand some of the most basic DV parameter index---Power By 【 China power house network 】

DV meanings:

DV = DigitalVideo, digital is relative to the analog, such as household VHS video technology and LaserDisc is analog, VCD and DVD is digital. In this sense, the PC's video processing is digital.

DV = DigitalVideoformat, by Sony, Panasonic, JVC, sharp, Toshiba, and other manufacturers combined with a home digital video format. The so-called DV camera is in this format record video data.

Basic indicators: DV

Rate 25Mbits/s

720x576,25fps(PAL),720x48029.97fps(NTSC)

YUV4:2:0(PAL),YUV4:1:1(NTSC)

Audio 48KHz, 16bit stereo, better than CD quality

DV format and what are the MJPEG/MPEG same and different

DV's core compression algorithm and JPEG/MPEG, is the discrete cosine transform (DCT) and ' encoding. MPEG, DV without use of interframe compression algorithm (motion compensation), but in every frame in the compresses, so that you can have the exact frame of editability.

DV and JPEG (MJPEG), DV on the same frame of two field made between inter-farm compression algorithm, the bit rate allocation be local optimization, resulting in higher than MJPEG compressed .DV compression ratio is 5: 1, quality equivalent to MJPEG 3: 1 compression.

DV quality:--than format, not more than products

To 10 as the highest, you can see the DV quality than common professional gives the betacamsp also, here's a comparison of course only format quality, equipment quality optical system to consider, circuit system quality.

DV rate and storage--I need much of a hard disk?

DV rate is 3.6MByte/s, basically, 1 minutes of dv files on your PC is 200MB, 2 g space can accommodate 9.5 minutes of DV.

On the hard drive speed requirements: previous non-linear editing system is used, the high-speed storage system scsiraid is called av hard disk, because the ide hard drive interface technology behind, driving part is also slow., now the new hard drive, from the start, basic UDMA33 can meet the requirements of the i/o speed DV-key indicators is ongoing transmission speed of the hard disk, IDE hard disk now generally available in more than 6MB/s cope with DV 3.6MB/s is sufficient.

About 2g/4gavi file size limits:

This limit has two conditions:

1) restrictions on the operating system itself, such as win98 can only support the largest 2g file, win98se supports to largest 4g, winnt/2000 use NTFS can support larger.

2) file format itself limits. old avi1.0 format files to the maximum limit is 2G, new avi2.0 (OpenDML) do not have this restriction. This is why in win98se premiere5.1 maximum file in only to 2G, but like the type1dvavi adopts AVI2.0 uleadmediastudiopro6 (Open_DML), there is no such limit.

What is a type1/type2DV?

This is Microsoft's definition of two dvavi file formats .type1 is based on Microsoft directshow, files in video and audio data is the same data flow "ivas" (interleavedvideo & audiostream), type2 is based on the old videoforwindows technology, file video and audio in two streams: vids (videostream) and auds (audiostream), in fact, in type2 in vids that contains audio data, type2 actually repeat this part of the data stored, the file than type1avi type2avi file is slightly larger.

Desktop video has been a technology based on videoforwindows type2DVavi using VFW format, storage, so compatibility better, most video software can handle. Type1DV in 2000 received limited support, such as premiere5.1 type1DVAVI could not be supported. The earliest support type1DV is ulead's mediastudiopro6 and videostudio3DV Edition. Now with the Directshow technology promotion, type1DV support is also getting better and better, now you can support premiere6 type1DV.

(YCrCb) and YUV 4: 2: 2, 4: 1: 1, 4: 2: 0

Mean luminance signals Y and red/blue difference signal sampling format in dv, ntsc is 4: 1: 1, pal uses 4: 2: 0. takes note, 4: 2: 0 is not the blue dropout signal sampling is 0, and 4: 1: 1 compared to horizontally by 1 x color sampling frequency, in the vertical direction to Cr/Cb interval of half way reduce the chromatic aberration sampling.