• Paul Wilkins's avatar
    Minor rate control refactoring and experiments. · 97da8b8c
    Paul Wilkins authored
    Some minor refactoring code relating to estimates of
    bits per MB at a given Q and estimating the allowed Q range.
    Most of the changes here were included in a previous commit.
    This commit seeks to separate out the refactoring from more
    the material changes.
    Two #define control flags have been added for experimentation.
    ONE_SHOT_Q_ESTIMATE force the two pass encoder to
    use its initial Q range estimate for the whole clip even if this results
    in a miss on the target data rate. In effect this tightens the Q range
    seen at the expense of rate control accuracy.
    DISABLE_RC_LONG_TERM_MEM is a related flag that disables the
    long term memory in the rate control. Local adjustments are still
    made to try and better hit the rate target on a per frame basis but
    the impact of rate control misses is not propagated to the remainder
    of the clip. This means that for example an overshoot early on will not
    cause frames later in the clip to be starved of bits. Again the result
    of this relaxation amy be less rate control accuracy especially on short
    The flags are disabled by default for now.
    Change-Id: I7482f980146d8ea033b5d50cc689f772e4bd119e