Glossary

acoustic echo suppression

For conferencing to be effective, systems must be able to mitigate the impact of echo caused by the loudspeaker audio feeding back into the microphone. The AES algorithm used in SunVideo Plus disables variations caused by double-talk creating consistent echo attenuation.

CellB

A non-proprietary video codec (compression-decompression) format that provides high quality, low bit-rate image compression that can be easily and efficiently decoded in software. CellB is based on Block Truncation Coding (BTC) encoding.

G.711

The G.711 standard, also called Pulse Code Modulation (PCM). A standard method of converting analog signals to digital signals. Typically used in public and private telephone networks, G.711 samples analog data and prepares it for transmission.

G.722

A wide-band (high quality) algorithm with a bandwidth of 50 Hz to 7 KHz. G.722 provides the audio encoding and decoding standardization needed at 48 Kbps, 58 Kbps, or 64 Kbps. Used when high-quality speech is necessary.

G.728

Another low-bitrate audio encoding algorithm. Using a standard analysis-by-synthesis CELP method, G.728 provides toll-quality speech at 16 Kbps.

H.261

The video component of the H.320 video conferencing standard intended for use on communication lines that have multiples of 64-Kbit capacity.

JPEG

The Joint Photographic Experts Group (JPEG) standard consisting of a host of algorithms for still image compression.

MPEG

The Moving Picture Experts Group.

MPEG-1

The first MPEG standard, MPEG-1 is geared for CD-ROM and T1 bit-rate transmission. At 1.5 Mbits/second, the algorithm uses both interframe and intraframe coding to achieve quality video at a lower bandwidth.

PCM

Pulse Code Modulation. See G.711.