Video and Media Servers: Technology and Applications, Second Edition

Video compression technology has enabled more data to be stored in much less space. The 25 Mb/s motion-JPEG (M-JPEG) systems of several years ago have now migrated to MPEG-2 and DV. Bit rates are reduced to as low as 6-to-8 Mb/s (long GOP) with acceptable picture quality. Board sets for servers are gradually dropping the combination MJPEG/MPEG-2 codecs and producing only MPEG-2 or MPEG-2/DV sets.
Standardization on compressors and bit streams (e.g., MPEG transport streams) are enabling multiple video streams to be multiplexed into a single DS3-like format and transported over satellite to store-and-forward servers. High definition compressed video would not only be stored within the facility, but distributed direct to home either via satellite or 8VSB transmission.
| DRIVE INTERFACE DEVELOPMENT | ||
|---|---|---|
| INTERFACE | MODE | MAX DATA RATE |
| ATA-1 | PIO-0 | 3.3 Mb/s |
| SCSI | SCSI | 5 Mb/s |
| ATA-1 | PIO-1 | 5.2 Mb/s |
| ATA-1 | PIO-2 | 8.3 Mb/s |
| SCSI-2 | Fast-Wide SCSI | 10 Mb/s |
| ATA-2 | PIO-3 | 11.1 Mb/s |
| ATA-3 | PIO-4 | 16.7 Mb/s |
| SCSI-2 | Fast-Wide SCSI | 20 Mb/s |
| SCSI-3 | UltraSCSI | 20 Mb/s |
| ATA-4 | Ultra | 33 Mb/s |
| SCSI-3 | Wide UltraSCSI | 40 Mb/s |
| SCSI-3 | Ultra2 SCSI | 40 Mb/s |
| ATA-5 | Ultra | 66 Mb/s |
| SCSI-3 | Wide Ultra2 SCSI | 80 Mb/s |