QVidium QVMP2C-1011 - Manual (Page 34)

User’s Manual v.28 QVidium™ MPEG2+4 Codec
34 of 45 - Copyright 2007-2008 QVidium™ Technologies, Inc.
Definition broadcasting. When you need to encode the video at lower bitrates, the
MPEG2+4 IP Codec allows you to select lower resolutions (352x480 and 352x240 for
NTSC and 352x576 and 352x288 for PAL). Computers, unlike video monitors, use square
pixels. The MPEG2+4 Codec allows for 640x480 (4CIF), 480x480, and 320x240 (CIF)
computer resolutions.
The lowest resolution that the MPEG2+4 Codec supports is 352x240 for NTSC, 320x288
for PAL, and 340x240 for computer monitors. Separate pull-down menus allow
independent selection of NTSC and PAL resolutions. The configuration only makes use of
the appropriate menu for the video format you select and ignores the setting for the non-
appropriate resolution.
Video Resolution (NTSC): The user can select from among 5 standard video resolutions
used with NTSC video: 720x480, 704x480, 640x480, 480x480, 352x480, 352x240, and
320x240. All resolutions are specified as horizontal pixels x vertical pixels. The three
resolutions, 640x480, 480x480, and 320x240, are for use with computer displays and
other devices that display square pixels.
Video Resolution (PAL): The selectable PAL resolutions are: 720x576, 704x576,
640x576, 480x576, 352x576, 352x288, and 320x288 (horizontal x vertical pixels).
Video Aspect Ratio (4:3 or 16:9): Standard Definition NTSC video has a 4:3 aspect ratio.
This is the default setting. However, many new HD Camcorders and video mixing
equipment have NTSC composite outputs. Setting the Aspect Ratio to 16:9 sets bits in the
MPEG elementary stream that tell an MPEG decoder to decode the incoming video
stream with this aspect ratio. However, it does not change the encoding resolution.
Video Input: This selects between the composite video input, S-Video input, and the cable
television (CATV) inputs.
TV Channel: The MPEG2+4 Codec can encode video directly from a cable system. This
specifies the specific cable channel to tune into and encode when the video input is set to
CATV.
Network Parameters
The fields below relate to Ethernet/IP video transport settings.
IP Transport: This selects the type of video IP packet encapsulation and error correction
used by the codec in generating a Video/IP stream. All packetized video transport
mechanisms encapsulate a multiplexed constant bit rate MPEG-2 transport stream.
• ProMPEG is the default and enables an interleaved, parity-based forward error
correction (FEC) as per the ProMPEG Forum’s Code of Practice (COP) 3,
Release 2, Annex A and IETF RFC 2733 for IP encapsulation of video and audio
data.
• ARQ uses QVidium’s patent-pending error correction mechanism based on a time-
constrained selective packet retransmission algorithm, in place of FEC. It also