This part of IEC 61883 specifies a protocol for the transport of uncompressed or compressed
video data in the 4:2:2 format of recommendation ITU-R BT.601 (including compatible
extensions to this format for the higher and lower resolutions of other commonly used video
resolutions) over high performance serial bus, as specified by IEEE Std 1394-1995 as
amended by IEEE Std 1394a-2000 and IEEE Std 1394b-2002 (collectively IEEE 1394). The
data formats for the encapsulation of video data are compatible with those specified by
IEC 61883-1. Associated audio data, if any, should be formatted as specified by IEC 61883-6.
There are many commonly used video formats unsupported by IEC 61883, such as MPEG-4,
Windows Media Format (WMF) and the format used by automotive navigation applications.
Support for all or most of these formats in rendering devices would require implementation of
multiple video codecs. This is an undue burden that may be avoided if the source device
converts to ITU-R BT.601 4:2:2 format and, if necessary, compresses the data with a codec
supported by all destination devices. An additional advantage is that on-screen display (OSD)
information may be mixed with video data prior to transmission to the rendering device.
Because ITU-R BT.601 4:2:2 format is widely used internally in contemporary AV equipment,
this specification permits straight-forward integration of IEEE 1394 into these devices and
enables markets whose usage scenarios include single video sources transmitting to one or
more video displays, such as:
- consumer electronic STB or DVD video rendered by multiple displays in the home;
- automotive navigation and entertainment; and
- aeronautical in-flight entertainment.
For the sake of interoperability and bounded implementation complexity, it is essential that
the specification provide the following:
- a 1394 TA controlled list of compression codecs; and
- at a minimum, a reference to one video compression codec.