ADS Technologies USBAV-708 INSTANT VIDEOMPX, User Manual

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Multipass Log file
Log header
##map version <Value>
Value is the version number describing the format of the log file.
nframes <Value>
Value is the total number of frames listed in the log file.
Frame numbering begins from zero.
timescale <Value>
Value is some arbitrary number representing the number of intervals
in one second of video.
The timescale is used in combination with
deltaT (see below) .
passes <Value>
Value is the number of passes performed when the log was written.
Frame list
seq <Value>
Value is the sequence number of each frame.
The sequence numbers may appear to be out of order but in fact this
is because they are in
display order. For example, in the section of
log shown the sequence reads 0,2,1 for a set of I,P,B frames
respectively. The order in which these frames must actually be
displayed is I,B,P—or 0,1,2 respectively.
deltaT <Value>
Value is the change in time (based upon the timescale value in the
header) between frames.
In the section of log shown the first three
deltaT values are 0,2400,-
1200. Recalling that frames are listed in decoding order this actually
means the sequence is 0,1200,2400. With respect to the
timescale
value (30000 units) this means the interval between frames (1200
units) is (1200/30000) = 0.04 seconds, and we can derive from this
frame-rate is 1/0.04=25 frames per second.
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