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Using the internal web pages
Video bit rate
mode
Controls variations in bit rates. For a concise explanation, consult the
note on encoder settings below.
MPEG-4 encoding mode supports the following bit rate modes.
- Constant quality
Keeps image quality constant at the cost
of varying network load.
- Variable bit rate
Same as constant bit rate (see below),
but bit rate is constant for a limited time,
allowing the encoder to use more bits for
difficult GOPs. Frames may be skipped.
- Variable bit rate non-drop
Same as variable bit rate. Frames are
never skipped.
- Constant bit rate
Keeps network load constant at the cost
of varying image quality. Frames may be
dropped.
- Constant bit rate non-drop
The same as Constant bit rate. Frames
are never skipped.
MPEG-2 encoding mode does not support variable bit rate modes. The
value of this parameter is set to
Constant bit rate non-drop
.
MJPEG encoding mode supports
Constant quality
and
Constant bit rate
.
Resolution
Supported resolutions are
D1
,
1/2 D1
,
2/3 D1
,
2CIF
,
CIF
,
QCIF
,
VGA
(640x480)
, and
QVGA (320x240)
. See also table 7.1.
Per video input, the C-54 E will simultaneously handle dual MPEG-2/4
encoding (MPEG-2 in I-frame only) with 1xD1 and 1xCIF or 2CIF at full
frame rate, and Live View encoding at 5 frames per second.
Setting Encoder 1 and Encoder 2 to perform MPEG-4 encoding in D1
resolution at the same time may overtax the hardware.
resolution (hxv) PAL
NTSC
D1 720x576
720x480
2/3 D1
480x576 480x480
1/2 D1
352x576 352x480
2CIF 720x288
720x240
CIF (top field only) 352x288 352x240
QCIF 176x144
176x120
Table 7.1 C-54 E MPEG-2/4, MJPEG resolutions
Note on CIF resolutions:
CIF resolutions (2CIF, CIF, QCIF) use only one of the
two frame fields. When CIF resolution encoded pictures are displayed on a
monitor, the decoder has to simulate the second field (by extrapolation from the
first field) in order to present two frame fields. Here, CIF is mostly used for
recording purposes, as a compromise between video quality and resolution.
GOP length
Distance in frames between two I-frames. This setting is only available in
MPEG-4 encoding mode.
Frame rate
Selectable rates are determined by the video mode (PAL, NTSC) set on
the General tab. PAL: 1-25 fps; NTSC: 1-30 fps.
Note that VLC and
QuickTime only support full frame rates for MPEG-2, Transport Stream.
