Digital-S

From Wikipedia, the free encyclopedia

D-9 or Digital S as it was originally known, is a professional digital videotape format created by JVC in 1995. It is a direct competitor to Digital Betacam. Its name was changed to D-9 in 1999 by the SMPTE.[1] It is used mostly inside Europe and Asia, though has seen some use in the US, most notably by the FOX news channel.[2]


Contents

[edit] Technical details

D-9 uses a tape shell of the VHS formfactor, but the tape itself uses a much higher quality metal particle formulation. The recording system is digital and for video uses DV compression at a 50 Mbit/s bitrate. Video is recorded in 4:2:2 component format at a variety of standard definition resolutions, in either 4:3 or 16:9 aspect ratios. Audio is recorded as 16bit/48 kHz pcm with up to 4 separate channels.[3]

[edit] HD recording

For HD recording, JVC developed an extension to D-9 called D-9 HD. D-9 HD uses twice the number of recording heads to record a 100Mbit/s video bitstream at resolutions of 720p60, 1080i60 and 1080p24. This variant is also able to record 8 channels of PCM audio at 16bit/48 kHz. This is ideal for mastering to AC3 or other multichannel audio compression formats used for broadcasting. The higher data rate means that the recording time of any given tape is cut in half.[4]

[edit] Video quality

Video quality is generally very high; at standard definition resolutions, quality is higher than that of Betacam SP and comparable to Digital Betacam. [5] At HD resolutions, based on specifications, quality is higher than HDCAM but lower than HDCAM SR; unfortunately, no subjective tests have been done comparing these formats.

[edit] Additional information

Although D-9 uses the same video codec (DV) as MiniDV, the video bitrate of D-9 is significantly higher than that of the "pro-sumer" format. DVCPRO achieves bitrate parity with D-9 and D-9 HD, but has a slower tape speed, making it less reliable. Some of the D-9 studio gear is capable of recording with pre-read and is provided with 4 channel audio like digital betacam. SDI interfaces are also provided. There is only one dockable recorder for docking to other cameras and that is the JVC BR-D40.

[edit] References

  1. ^ "D-9: Introduction to the format", Short introduction to the D-9 format. Accessed October 13, 2007.
  2. ^ "D-9 in action worldwide", Shows areas where D-9 is in use. Accessed October 13, 2007.
  3. ^ "D-9 technical specifications", Displays general D-9 technical specifications. Accessed October 13, 2007.
  4. ^ "D-9 HD Technical Specifications", Displays general D9-HD specifications. Accessed October 13, 2007.
  5. ^ "JVC Professional Japan", cites SMPTE/EBU taskforce results. Accessed October 13, 2007.

[edit] External links

[edit] See also