CinePlex v3 Manual - Plexon Inc

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2.6.2 Dropped Frames
With CinePlex Version 3 dropped frames occur much less frequently than for earlier
versions. However, in the event that dropped frames ever cause problems,
please contact Plexon Support.
2.6.3 Frame Rate
The instantaneous frame rate observed by Studio is displayed at the bottom of the
Studio window. It should steadily display the user-selected frame rate while
recording. If it does not, the computer is experiencing partial congestion. Partial
congestion is normally caused by non-Plexon applications. Partial congestion
does not result in dropped frames, but tracking and other processing may be
slightly delayed.
2.6.4 Digital Video Recorder AVI Format Files
CinePlex Studio typically records video into motion-JPEG AVI files at a resolution
of 640x480 pixels at up to 80 frames per second, which implies a raw data
rate of over 300 GB/hour. However; to reduce disk usage, CinePlex Studio compresses
the video before it writes it to the AVI file. Studio offers a choice of
MJPEG and MPEG formats. With each format the user may vary the file compression
to find a suitable balance between AVI file size and image quality.
2.6.4.1 Motion JPEG Recordings (MJPEG)
The quality settings for MJPEG range from 20 to 90. At an image quality setting
of 65, an AVI file grows at a rate of approximately 2.1 GB/hour. This growth rate
depends on the complexity of the video image, which affects the compressibility.
2.6.4.2 MPEG Recordings
MPEG is the default recording format because it produces files that are routinely
75 to 90% smaller than the equivalent MJPEG formatted files.
The quality settings for MPEG range from 1 to 10. The values represent the nominal
bit rate divided by 500,000.
While it records, CinePlex Studio continually calculates and displays the amount
of recording time left until the target hard drive fills up. As the hard drive capacity
is neared, CinePlex Studio stops recording.
Note:
Experiment to find the minimum quality setting that yields an acceptable image.
For example, if the user increases the MJPEG quality setting from 65 to 90, the
size of the AVI file doubles using the same recording time—but it does not dramatically
increase the quality of the image. Conversely, if the user reduces the
quality setting from 65 to 20, the size of the AVI file halves using the same
recording time—however, the quality of the image degrades significantly.
The AVI files created by CinePlex Studio are industry-standard AVI-format files
that the user may play with many standard tools, including Microsoft Windows
Media Player, which is pre-installed on most Windows computers. The user may
56 CinePlex