Appeal No. 2002-1510
Application No. 08/882,625 Page 7
eq.36, where t is one of I1, I2, P1, P2, and B.
As a consequence DI1/DP1=XI1/Xp1, XI1 and Xp1 are
the numbers of the generated bits for the
previous frame of the type I1 (intra-frame coding)
and P1 (inter-frame coding), respectively. The
target-bit rate in a GOP is thus allocated
according to the ratio recited in Claim 1.).
From our review of Pecot and Lee, we agree with the examiner
that Lee discloses allocating a target bit rate to picture data
of a current group of pictures (GOP). However, we find from the
disclosure of Lee (col. 35, lines 12-39) that:
Within a GOP, the target bit allocation for each
picture type is also allowed to vary to be adaptive to
the changing scene complexity of the actual video
sequence. The number of bits generated for the
previous picture having the same picture type is used
as the target bit allication. When the number of bits
produced for one frame deviates from the target number
of bits, the bit allocation for the next picture is
adjusted to maintain an acceptable range of bit rate
according to the equation:
where t is a picture type, with t , {I1, I2, P1, P2,
B}, Dt, is target bit allocation for picture type t,
Xt, is the number of generated bits for the previous
frame of the type t, EGOP is the expected GOP bit rate
computed by the most recent data of bits generated for
each frame type, and GGOP is the target GOP bit rate TGOP
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