Video[edit]
In
telecommunications and
computing,
bit rate (sometimes written
bitrate or as a variable
R[1]) is the number of
bits that are conveyed or processed per unit of time.
The bit rate is
quantified using the
bits per second (
bit/s or
bps) unit, often in conjunction with an
SI prefix such as
kilo- (kbit/s or kbps),
mega- (Mbit/s or Mbps),
giga- (Gbit/s or Gbps) or
tera- (Tbit/s or Tbps). Note that, unlike many other computer-related units, 1 kbit/s is traditionally defined as 1,000 bit/s, not 1,024 bit/s, etc., also before 1999 when SI prefixes were introduced for units of information in the standard
IEC 60027-2.
[2]
16 kbit/s – videophone quality (minimum necessary for a consumer-acceptable "talking head" picture using various video compression schemes)
128–384 kbit/s – business-oriented videoconferencing quality using video compression
1.15 Mbit/s max – VCD quality (using MPEG1 compression)[19]
3.5 Mbit/s typ – Standard-definition television quality (with bit-rate reduction from MPEG-2 compression)
9.8 Mbit/s max – DVD (using MPEG2 compression)[20]
8 to 15 Mbit/s typ – HDTV quality (with bit-rate reduction from MPEG-4 AVC compression)
19 Mbit/s approximate – HDV 720p (using MPEG2 compression)[21]
24 Mbit/s max – AVCHD (using MPEG4 AVC compression)[22]
25 Mbit/s approximate – HDV 1080i (using MPEG2 compression)[21]
29.4 Mbit/s max – HD DVD
40 Mbit/s max – Blu-ray Disc (using MPEG2, AVC or VC-1 compression)[23]