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GLOSSARY ORBAN
MODEL
1010
Reliable UDP
reference movie
A .mov file created using a utility program like MakeRefMovie,
available at no cost from Apple for Macintosh and Windows. The file contains the
location of a streaming media file and can also contain the locations of multiple
streaming files. A reference file linked from a web page, for example, can direct a
client player to the on-demand presentation encoded for its particular connection
speed.
reflected stream
A file or live broadcast delivered as a unicast stream. movie and
MP4 QTSS/DSS playlists also generate reflected streams.
relayed stream
A stream that is passed from one server to one or more other serv-
ers. Relays can also be used to generate a multicast stream.
RFC
RIFF
RLE (run length encoded)
RTP (Real-Time Transport Protocol)
A network-transport protocol used for trans-
mitting streaming real-time multimedia content over multicast or unicast network
services, usually used with RTSP and RTCP.
RTCP (Real Time Control Protocol)
RTSP (Real Time Streaming Protocol)
A protocol for controlling a stream of real-
time multimedia content. Sources of data can include both live feeds and stored
clips.
SACD
sample rate
The number of samples per second used for audio. Higher sample rates
yield higher quality audio than lower sample rates.
SAP (Session Announcement Protocol)
A protocol used to announce Internet
multicast conferencing sessions. A conference is announced by periodically multicast-
ing a UDP announcement packet to a multicast address and port. Because SAP is de-
signed for multicast, it is suitable for setting up conference calls, not one-on-one IP
telephone calls.
SBR (Spectral Band Replication)
is a technology that reduces the bitrate neces-
sary for audio codecs to provide high (although not transparent) subjective audio
quality. It transmits only a lower frequency band by means of its base codec, while
the receiver synthesizes higher frequencies from the lower frequency band by a
process similar to that used in harmonic-generating “exciters.” A low-bitrate control
signal is transmitted to the receiver. This signal contains hints for the receiver that
help it conform the generated high frequency signal to the original high frequency
signal present at the transmitter.
scope
also known as TTL
SCSI (Small Computer System Interface)
a parallel interface standard used by
computers for attaching peripheral devices, mainly storage.
SDP (Session Description Protocol)
A text file used with QTSS/Darwin Streaming
Server that provides information about the format, timing, and authorship of a live
streaming broadcast and gives the user’s computer instructions for tuning in.
