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Experimental rate control change.

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When the codec in VBR (or cq) mode hits its max q limits and is
struggling to hit a target bandwidth, the bit target per frame collapses.

In the first instance normal frames cap out at the maximum allowed
Q and then the ARF and GFs do the same. This latter behavior is not
generally desirable as GFs and ARFs are only effective from a quality
and data rate perspective if they have at lease some level of -Q delta
compared to the surrounding frames.

In this patch I define a separate max Q for GFs and ARFs that is
derived from but somewhat lower than that defined for normal frames.
In effect there is a minimum Q delta that will always be available for
GFs and ARFs regardless of the target rate and MAXQ setting.

This may of course mean that the absolute lowest rate obtainable for
a given clip is somewhat higher.

Change-Id: I268868b28401900d0cd87e51e609cd3b784ab54a
This commit is contained in:
Paul Wilkins 2013-10-07 19:20:10 +01:00
parent 8b989f5b23
commit 704028d435
1 changed files with 29 additions and 20 deletions
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49
vp9/encoder/vp9_onyx_if.c
View File

@ -787,6 +787,7 @@ void vp9_set_speed_features(VP9_COMP *cpi) {
sf->adaptive_motion_search = 1;
sf->auto_mv_step_size = 1;
sf->adaptive_rd_thresh = 2;
sf->recode_loop = 2;
}
if (speed == 2) {
sf->use_square_partition_only = !(cpi->common.frame_type == KEY_FRAME ||
@ -2610,14 +2611,15 @@ static void output_frame_level_debug_stats(VP9_COMP *cpi) {
}
#endif
static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi) {
static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi,
int * bottom_index, int * top_index) {
// Set an active best quality and if necessary active worst quality
int q = cpi->active_worst_quality;
VP9_COMMON *const cm = &cpi->common;
if (cm->frame_type == KEY_FRAME) {
#if !CONFIG_MULTIPLE_ARF
// Handle the special case for key frames forced when we have reached
// Handle the special case for key frames forced when we have75 reached
// the maximum key frame interval. Here force the Q to a range
// based on the ambient Q to reduce the risk of popping.
if (cpi->this_key_frame_forced) {
@ -2663,12 +2665,13 @@ static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi) {
cpi->active_best_quality = cpi->active_worst_quality
+ compute_qdelta(cpi, current_q, current_q * 0.3);
#endif
} else if (cpi->refresh_golden_frame || cpi->refresh_alt_ref_frame) {
} else if (!cpi->is_src_frame_alt_ref &&
(cpi->refresh_golden_frame || cpi->refresh_alt_ref_frame)) {
int high = 2000;
int low = 400;
// Use the lower of cpi->active_worst_quality and recent
// average Q as basis for GF/ARF Q limit unless last frame was
// average Q as basis for GF/ARF best Q limit unless last frame was
// a key frame.
if (cpi->frames_since_key > 1 &&
cpi->avg_frame_qindex < cpi->active_worst_quality) {
@ -2709,14 +2712,10 @@ static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi) {
}
}
} else {
if (!cpi->refresh_alt_ref_frame) {
cpi->active_best_quality = inter_minq[q];
} else {
cpi->active_best_quality = get_active_quality(q, cpi->gfu_boost,
low, high,
gf_low_motion_minq,
gf_high_motion_minq);
}
}
} else {
if (cpi->oxcf.end_usage == USAGE_CONSTANT_QUALITY) {
@ -2732,7 +2731,7 @@ static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi) {
cpi->active_best_quality = inter_minq[q];
#endif
// For the constant/constrained quality mode we don't want
// For the constrained quality mode we don't want
// q to fall below the cq level.
if ((cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY) &&
(cpi->active_best_quality < cpi->cq_target_quality)) {
@ -2760,14 +2759,28 @@ static int pick_q_and_adjust_q_bounds(VP9_COMP *cpi) {
if (cpi->active_worst_quality < cpi->active_best_quality)
cpi->active_worst_quality = cpi->active_best_quality;
// Special case code to try and match quality with forced key frames
// Limit Q range for the adaptive loop.
if (cm->frame_type == KEY_FRAME && !cpi->this_key_frame_forced) {
*top_index = cpi->active_best_quality;
} else if (!cpi->is_src_frame_alt_ref &&
(cpi->refresh_golden_frame || cpi->refresh_alt_ref_frame)) {
*top_index =
(cpi->active_worst_quality + cpi->active_best_quality * 3) / 4;
} else {
*top_index = cpi->active_worst_quality;
}
*bottom_index = cpi->active_best_quality;
if (cpi->oxcf.end_usage == USAGE_CONSTANT_QUALITY) {
q = cpi->active_best_quality;
// Special case code to try and match quality with forced key frames
} else if ((cm->frame_type == KEY_FRAME) && cpi->this_key_frame_forced) {
q = cpi->last_boosted_qindex;
} else {
// Determine initial Q to try
q = vp9_regulate_q(cpi, cpi->this_frame_target);
if (q > *top_index)
q = *top_index;
}
return q;
@ -2906,7 +2919,10 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
vp9_clear_system_state();
q = pick_q_and_adjust_q_bounds(cpi);
q = pick_q_and_adjust_q_bounds(cpi, &bottom_index, &top_index);
q_high = top_index;
q_low = bottom_index;
vp9_compute_frame_size_bounds(cpi, &frame_under_shoot_limit,
&frame_over_shoot_limit);
@ -2930,16 +2946,9 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
q_high = q;
printf("frame:%d q:%d\n", cm->current_video_frame, q);
} else {
#endif
// Limit Q range for the adaptive loop.
bottom_index = cpi->active_best_quality;
top_index = cpi->active_worst_quality;
q_low = cpi->active_best_quality;
q_high = cpi->active_worst_quality;
#if CONFIG_MULTIPLE_ARF
}
#endif
loop_count = 0;
vp9_zero(cpi->rd_tx_select_threshes);
@ -3030,10 +3039,10 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
frame_over_shoot_limit = 1;
active_worst_qchanged = 0;
// Special case handling for forced key frames
if (cpi->oxcf.end_usage == USAGE_CONSTANT_QUALITY) {
loop = 0;
} else {
// Special case handling for forced key frames
if ((cm->frame_type == KEY_FRAME) && cpi->this_key_frame_forced) {
int last_q = q;
int kf_err = vp9_calc_ss_err(cpi->Source,