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Change to get_twopass_worst_quality()

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Change to the calculation of the error divisor used in
get_twopass_worst_quality(). This follows on from other
changes to the rate control that impact the output of this
function.

Change-Id: I414fa9aa1e6a68a64dccea17c3712f44b8a0c10c
This commit is contained in:
paulwilkins 2016-05-27 16:04:43 +01:00
parent f9865d1701
commit 552fd02cf0
1 changed files with 5 additions and 30 deletions
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35
vp9/encoder/vp9_firstpass.c
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@ -236,13 +236,6 @@ static void subtract_stats(FIRSTPASS_STATS *section,
section->duration -= frame->duration;
}
// Calculate the linear size relative to a baseline of 1080P
#define BASE_SIZE 2073600.0 // 1920x1080
static double get_linear_size_factor(const VP9_COMP *cpi) {
const double this_area = cpi->initial_width * cpi->initial_height;
return pow(this_area / BASE_SIZE, 0.5);
}
// Calculate an active area of the image that discounts formatting
// bars and partially discounts other 0 energy areas.
#define MIN_ACTIVE_AREA 0.5
@ -1247,7 +1240,7 @@ static double calc_correction_factor(double err_per_mb,
return fclamp(pow(error_term, power_term), 0.05, 5.0);
}
#define ERR_DIVISOR 100.0
#define ERR_DIVISOR 115.0
static int get_twopass_worst_quality(VP9_COMP *cpi,
const double section_err,
double inactive_zone,
@ -1270,7 +1263,6 @@ static int get_twopass_worst_quality(VP9_COMP *cpi,
const int active_mbs = VPXMAX(1, num_mbs - (int)(num_mbs * inactive_zone));
const double av_err_per_mb = section_err / active_mbs;
const double speed_term = 1.0 + 0.04 * oxcf->speed;
double ediv_size_correction;
double last_group_rate_err;
const int target_norm_bits_per_mb = ((uint64_t)target_rate <<
BPER_MB_NORMBITS) / active_mbs;
@ -1280,17 +1272,6 @@ static int get_twopass_worst_quality(VP9_COMP *cpi,
if (is_two_pass_svc(cpi) && cpi->svc.spatial_layer_id > 0)
is_svc_upper_layer = 1;
// Larger image formats are expected to be a little harder to code
// relatively given the same prediction error score. This in part at
// least relates to the increased size and hence coding overheads of
// motion vectors. Some account of this is made through adjustment of
// the error divisor.
ediv_size_correction =
VPXMAX(0.2, VPXMIN(5.0, get_linear_size_factor(cpi)));
if (ediv_size_correction < 1.0)
ediv_size_correction = -(1.0 / ediv_size_correction);
ediv_size_correction *= 4.0;
// based on recent history adjust expectations of bits per macroblock.
last_group_rate_err = (double)twopass->rolling_arf_group_actual_bits /
DOUBLE_DIVIDE_CHECK((double)twopass->rolling_arf_group_target_bits);
@ -1305,7 +1286,7 @@ static int get_twopass_worst_quality(VP9_COMP *cpi,
for (q = rc->best_quality; q < rc->worst_quality; ++q) {
const double factor =
calc_correction_factor(av_err_per_mb,
ERR_DIVISOR - ediv_size_correction,
ERR_DIVISOR,
is_svc_upper_layer ? SVC_FACTOR_PT_LOW :
FACTOR_PT_LOW, FACTOR_PT_HIGH, q,
cpi->common.bit_depth);
@ -2675,21 +2656,12 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->twopass;
GF_GROUP *const gf_group = &twopass->gf_group;
int frames_left;
FIRSTPASS_STATS this_frame;
int target_rate;
LAYER_CONTEXT *const lc = is_two_pass_svc(cpi) ?
&cpi->svc.layer_context[cpi->svc.spatial_layer_id] : 0;
if (lc != NULL) {
frames_left = (int)(twopass->total_stats.count -
lc->current_video_frame_in_layer);
} else {
frames_left = (int)(twopass->total_stats.count -
cm->current_video_frame);
}
if (!twopass->stats_in)
return;
@ -2731,6 +2703,9 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
twopass->active_worst_quality = cpi->oxcf.cq_level;
} else if (cm->current_video_frame == 0 ||
(lc != NULL && lc->current_video_frame_in_layer == 0)) {
const int frames_left = (int)(twopass->total_stats.count -
((lc != NULL) ? lc->current_video_frame_in_layer
: cm->current_video_frame));
// Special case code for first frame.
const int section_target_bandwidth = (int)(twopass->bits_left /
frames_left);