Broadcast & Professional Video Audio Equipment - HDV

Main Advantages of HDV

On September 30, 2003, the HDV standard was agreed on by four companies: Canon Inc., Sharp

Corporation, Sony Corporation, and the Victor Company of Japan, Limited.

The concept of the HDV standard is to develop a home camcorder, which can record easily high

quality HD movies. The HDV standard can be used with existing DV tape as the recording media.

Thus, by using the mechanisms of a DV camcorder, mitigation of development costs and

development efficiency is realized.

Feature No. 1: Recording HD images on DV tapes

The same videotapes used for DV recordings can also be used for HD recordings, and the

recording time is also equivalent. Furthermore, the main recording mechanisms are also the same

as for the DV standard.

Feature No. 2: MPEG-2 is used as the compression format.

The same MPEG-2 compression format that is used for digital broadcasts and DVDs is also used

for HDV. Efficient compression is possible while maintaining the high quality of HD images.

Therefore, using the same bit rate as for the DV standard, the recording and playing back of high resolution

HD images has been realized. In order to use MPEG-2 to compress the large quantity of

HD image data, which is much more than for the SD format, an extremely large signal processing

circuit is required. However, due to the advancement of semiconductors and signal processing

technology, it is now possible to use this format as a standard for personal devices.

Feature No. 3: Powerful error correction capability

With the MPEG-2 format, which uses interframe compression, the impact of missing data is much

greater than for the DV standard where intraframe compression is used. For this reason, the

amount of correction coding has increased with the HDV standard. Moreover, by turning the DV

correction method that only operates within tracks into a correction method between multiple tracks,

error correction capability has been drastically improved, and the tolerance for data loss in tracks

caused by dropouts is greatly enhanced.

Feature No. 4: Same sound quality as a CD

MPEG-1 Audio Layer II is used for the audio compression format, allowing you to enjoy the same

sound quality as from a CD.

Feature No. 5: Two kinds of recording systems

The HDV standard has two types of recording systems: the 720p (progressive) specification and

the 1080i (interlace) specification.

HDV Recording

DV tapes are used for recording with the HDV standard. Since DV tapes are already widely

available, they serve as a media that is affordable and easily obtainable.

HDV recording method

With the HDV standard, the tape speed and track pitch is the same as for the DV format, and the

main DV mechanisms, such as the data-reading drum and the cassette compartment housing the

tape, can be adopted without any changes. Moreover, the ITI sector and subcode sector structures

are also equivalent to the DV standard, and this has made it possible to record HD video and audio

signals in the same running time as for the DV standard.

ITI sector : The region where the tape is recorded including the tract structure and width

Subcode sector : The region where the index flags and time codes are recorded on the tape

 

Powerful error correction capability

With the MPEG-2 format, which uses interframe compression, the impact of missing data is much

greater than for the DV format where intraframe compression is used. For this reason, the amount

of correction coding has increased with the HDV standard. Moreover, by turning the DV correction

method that only operates within tracks into a correction method between multiple tracks, error

correction capability has been drastically improved, and the tolerance for missing data in tracks

caused by dropouts is greatly enhanced.