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Merge "Adjustment to VBR rate correction."

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Paul Wilkins 2016-06-03 17:13:13 +00:00 committed by Gerrit Code Review
commit bfff16af67
1 changed files with 20 additions and 19 deletions
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39
vp9/encoder/vp9_ratectrl.c
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@ -1889,27 +1889,28 @@ static void vbr_rate_correction(VP9_COMP *cpi, int *this_frame_target) {
RATE_CONTROL *const rc = &cpi->rc;
int64_t vbr_bits_off_target = rc->vbr_bits_off_target;
int max_delta;
double position_factor = 1.0;
int frame_window = VPXMIN(16,
((int)cpi->twopass.total_stats.count - cpi->common.current_video_frame));
// How far through the clip are we.
// This number is used to damp the per frame rate correction.
// Range 0 - 1.0
if (cpi->twopass.total_stats.count) {
position_factor = sqrt((double)cpi->common.current_video_frame /
cpi->twopass.total_stats.count);
}
max_delta = (int)(position_factor *
((*this_frame_target * VBR_PCT_ADJUSTMENT_LIMIT) / 100));
// Calcluate the adjustment to rate for this frame.
if (frame_window > 0) {
max_delta = (vbr_bits_off_target > 0)
? (int)(vbr_bits_off_target / frame_window)
: (int)(-vbr_bits_off_target / frame_window);
// vbr_bits_off_target > 0 means we have extra bits to spend
if (vbr_bits_off_target > 0) {
*this_frame_target +=
(vbr_bits_off_target > max_delta) ? max_delta
: (int)vbr_bits_off_target;
} else {
*this_frame_target -=
(vbr_bits_off_target < -max_delta) ? max_delta
: (int)-vbr_bits_off_target;
max_delta = VPXMIN(max_delta,
((*this_frame_target * VBR_PCT_ADJUSTMENT_LIMIT) / 100));
// vbr_bits_off_target > 0 means we have extra bits to spend
if (vbr_bits_off_target > 0) {
*this_frame_target +=
(vbr_bits_off_target > max_delta) ? max_delta
: (int)vbr_bits_off_target;
} else {
*this_frame_target -=
(vbr_bits_off_target < -max_delta) ? max_delta
: (int)-vbr_bits_off_target;
}
}
// Fast redistribution of bits arising from massive local undershoot.