Commit 0b8a95a0 authored by Ronald S. Bultje's avatar Ronald S. Bultje

Rewrite reference frame costing in the RD loop.

I now see I didn't write a very long description, so let's do it
here then. We took a pretty big quality hit (0.1-0.2%) from my
recent fix of the inversion of arguments to vp8_cost_bit() in the
RD reference frame costing. I looked into it and basically the
costing prevented us from switching reference frames. This is of
course silly, since each frame codes its own prob_intra_coded, so
using last frame cost indications as a limiting factor can never
be right.

Here, I've rewritten that code to estimate costings based partially
on statistics from progress on current frame encoding. Overall,
this gives us a ~0.2%-0.3% improvement over what we had previously
before my argument-inversion-fix, and thus about ~0.4% over current
git (on derf-set), and a little more (0.5-1.0%) on HD/STD-HD/YT.

Change-Id: I79ebd4ccec4d6edbf0e152d9590d103ba2747775
parent c5ddb7f0
......@@ -277,7 +277,7 @@ void calc_ref_probs( int * count, vp8_prob * probs )
tot_count = count[0] + count[1] + count[2] + count[3];
if ( tot_count )
{
probs[0] = (vp8_prob)((count[0] * 255) / tot_count);
probs[0] = (vp8_prob)((count[0] * 255 + (tot_count >> 1)) / tot_count);
probs[0] += !probs[0];
}
else
......@@ -286,7 +286,7 @@ void calc_ref_probs( int * count, vp8_prob * probs )
tot_count -= count[0];
if ( tot_count )
{
probs[1] = (vp8_prob)((count[1] * 255) / tot_count);
probs[1] = (vp8_prob)((count[1] * 255 + (tot_count >> 1)) / tot_count);
probs[1] += !probs[1];
}
else
......@@ -295,7 +295,7 @@ void calc_ref_probs( int * count, vp8_prob * probs )
tot_count -= count[1];
if ( tot_count )
{
probs[2] = (vp8_prob)((count[2] * 255) / tot_count);
probs[2] = (vp8_prob)((count[2] * 255 + (tot_count >> 1)) / tot_count);
probs[2] += !probs[2];
}
else
......
......@@ -219,21 +219,11 @@ void update_skip_probs(VP8_COMP *cpi)
static void update_refpred_stats( VP8_COMP *cpi )
{
VP8_COMMON *const cm = & cpi->common;
MACROBLOCKD *const xd = & cpi->mb.e_mbd;
int mb_row, mb_col;
int i;
int tot_count;
int ref_pred_count[PREDICTION_PROBS][2];
vp8_prob new_pred_probs[PREDICTION_PROBS];
unsigned char pred_context;
unsigned char pred_flag;
int old_cost, new_cost;
// Clear the prediction hit counters
vpx_memset(ref_pred_count, 0, sizeof(ref_pred_count));
// Set the prediction probability structures to defaults
if ( cm->frame_type == KEY_FRAME )
{
......@@ -247,47 +237,17 @@ static void update_refpred_stats( VP8_COMP *cpi )
}
else
{
// For non-key frames.......
// Scan through the macroblocks and collate prediction counts.
xd->mode_info_context = cm->mi;
for (mb_row = 0; mb_row < cm->mb_rows; mb_row++)
{
for (mb_col = 0; mb_col < cm->mb_cols; mb_col++)
{
// Get the prediction context and status
pred_flag = get_pred_flag( xd, PRED_REF );
pred_context = get_pred_context( cm, xd, PRED_REF );
// Count prediction success
ref_pred_count[pred_context][pred_flag]++;
// Step on to the next mb
xd->mode_info_context++;
}
// this is to account for the border in mode_info_context
xd->mode_info_context++;
}
// From the prediction counts set the probabilities for each context
for ( i = 0; i < PREDICTION_PROBS; i++ )
{
// MB reference frame not relevent to key frame encoding
if ( cm->frame_type != KEY_FRAME )
tot_count = cpi->ref_pred_count[i][0] + cpi->ref_pred_count[i][1];
if ( tot_count )
{
// Work out the probabilities for the reference frame predictor
tot_count = ref_pred_count[i][0] + ref_pred_count[i][1];
if ( tot_count )
{
new_pred_probs[i] =
( ref_pred_count[i][0] * 255 ) / tot_count;
new_pred_probs[i] =
( cpi->ref_pred_count[i][0] * 255 + (tot_count >> 1)) / tot_count;
// Clamp to minimum allowed value
new_pred_probs[i] += !new_pred_probs[i];
}
else
new_pred_probs[i] = 128;
// Clamp to minimum allowed value
new_pred_probs[i] += !new_pred_probs[i];
}
else
new_pred_probs[i] = 128;
......@@ -295,12 +255,12 @@ static void update_refpred_stats( VP8_COMP *cpi )
// Decide whether or not to update the reference frame probs.
// Returned costs are in 1/256 bit units.
old_cost =
(ref_pred_count[i][0] * vp8_cost_zero(cm->ref_pred_probs[i])) +
(ref_pred_count[i][1] * vp8_cost_one(cm->ref_pred_probs[i]));
(cpi->ref_pred_count[i][0] * vp8_cost_zero(cm->ref_pred_probs[i])) +
(cpi->ref_pred_count[i][1] * vp8_cost_one(cm->ref_pred_probs[i]));
new_cost =
(ref_pred_count[i][0] * vp8_cost_zero(new_pred_probs[i])) +
(ref_pred_count[i][1] * vp8_cost_one(new_pred_probs[i]));
(cpi->ref_pred_count[i][0] * vp8_cost_zero(new_pred_probs[i])) +
(cpi->ref_pred_count[i][1] * vp8_cost_one(new_pred_probs[i]));
// Cost saving must be >= 8 bits (2048 in these units)
if ( (old_cost - new_cost) >= 2048 )
......
......@@ -620,6 +620,23 @@ static void pick_mb_modes (VP8_COMP *cpi,
}
else
{
int seg_id;
if (xd->segmentation_enabled && cpi->seg0_cnt > 0 &&
!segfeature_active( xd, 0, SEG_LVL_REF_FRAME ) &&
segfeature_active( xd, 1, SEG_LVL_REF_FRAME ) &&
check_segref(xd, 1, INTRA_FRAME) +
check_segref(xd, 1, LAST_FRAME) +
check_segref(xd, 1, GOLDEN_FRAME) +
check_segref(xd, 1, ALTREF_FRAME) == 1)
{
cpi->seg0_progress = (cpi->seg0_idx << 16) / cpi->seg0_cnt;
}
else
{
cpi->seg0_progress = (((mb_col & ~1) * 2 + (mb_row & ~1) * cm->mb_cols + i) << 16) / cm->MBs;
}
*totalrate += vp8cx_pick_mode_inter_macroblock(cpi, x,
recon_yoffset,
recon_uvoffset);
......@@ -627,6 +644,26 @@ static void pick_mb_modes (VP8_COMP *cpi,
// Dummy encode, do not do the tokenization
vp8cx_encode_inter_macroblock(cpi, x, tp,
recon_yoffset, recon_uvoffset, 0);
seg_id = xd->mode_info_context->mbmi.segment_id;
if (cpi->mb.e_mbd.segmentation_enabled && seg_id == 0)
{
cpi->seg0_idx++;
}
if (!xd->segmentation_enabled ||
!segfeature_active( xd, seg_id, SEG_LVL_REF_FRAME ) ||
check_segref(xd, seg_id, INTRA_FRAME) +
check_segref(xd, seg_id, LAST_FRAME) +
check_segref(xd, seg_id, GOLDEN_FRAME) +
check_segref(xd, seg_id, ALTREF_FRAME) > 1)
{
// Get the prediction context and status
int pred_flag = get_pred_flag( xd, PRED_REF );
int pred_context = get_pred_context( cm, xd, PRED_REF );
// Count prediction success
cpi->ref_pred_count[pred_context][pred_flag]++;
}
}
// Keep a copy of the updated left context
......@@ -989,6 +1026,8 @@ void init_encode_frame_mb_context(VP8_COMP *cpi)
x->mb_activity_ptr = cpi->mb_activity_map;
x->act_zbin_adj = 0;
cpi->seg0_idx = 0;
vpx_memset(cpi->ref_pred_count, 0, sizeof(cpi->ref_pred_count));
x->partition_info = x->pi;
......
......@@ -502,6 +502,7 @@ void separate_arf_mbs
else
cpi->static_mb_pct = 0;
cpi->seg0_cnt = ncnt[0];
vp8_enable_segmentation((VP8_PTR) cpi);
}
else
......
......@@ -485,6 +485,8 @@ typedef struct VP8_COMP
MBGRAPH_FRAME_STATS mbgraph_stats[MAX_LAG_BUFFERS];
int mbgraph_n_frames; // number of frames filled in the above
int static_mb_pct; // % forced skip mbs by segmentation
int seg0_progress, seg0_idx, seg0_cnt;
int ref_pred_count[3][2];
int decimation_factor;
int decimation_count;
......
......@@ -2581,7 +2581,66 @@ static void set_i8x8_block_modes(MACROBLOCK *x, int modes[2][4])
}
}
void vp8_estimate_ref_frame_costs(VP8_COMP *cpi, unsigned int * ref_costs )
extern void calc_ref_probs( int * count, vp8_prob * probs );
static void estimate_curframe_refprobs(VP8_COMP *cpi, vp8_prob mod_refprobs[3], int pred_ref)
{
int norm_cnt[MAX_REF_FRAMES];
const int *const rfct = cpi->count_mb_ref_frame_usage;
int intra_count = rfct[INTRA_FRAME];
int last_count = rfct[LAST_FRAME];
int gf_count = rfct[GOLDEN_FRAME];
int arf_count = rfct[ALTREF_FRAME];
// Work out modified reference frame probabilities to use where prediction
// of the reference frame fails
if (pred_ref == INTRA_FRAME)
{
norm_cnt[0] = 0;
norm_cnt[1] = last_count;
norm_cnt[2] = gf_count;
norm_cnt[3] = arf_count;
calc_ref_probs( norm_cnt, mod_refprobs );
mod_refprobs[0] = 0; // This branch implicit
}
else if (pred_ref == LAST_FRAME)
{
norm_cnt[0] = intra_count;
norm_cnt[1] = 0;
norm_cnt[2] = gf_count;
norm_cnt[3] = arf_count;
calc_ref_probs( norm_cnt, mod_refprobs);
mod_refprobs[1] = 0; // This branch implicit
}
else if (pred_ref == GOLDEN_FRAME)
{
norm_cnt[0] = intra_count;
norm_cnt[1] = last_count;
norm_cnt[2] = 0;
norm_cnt[3] = arf_count;
calc_ref_probs( norm_cnt, mod_refprobs );
mod_refprobs[2] = 0; // This branch implicit
}
else
{
norm_cnt[0] = intra_count;
norm_cnt[1] = last_count;
norm_cnt[2] = gf_count;
norm_cnt[3] = 0;
calc_ref_probs( norm_cnt, mod_refprobs );
mod_refprobs[2] = 0; // This branch implicit
}
}
static __inline unsigned weighted_cost(vp8_prob *tab0, vp8_prob *tab1, int idx, int val, int weight)
{
unsigned cost0 = tab0[idx] ? vp8_cost_bit(tab0[idx], val) : 0;
unsigned cost1 = tab1[idx] ? vp8_cost_bit(tab1[idx], val) : 0;
// weight is 16-bit fixed point, so this basically calculates:
// 0.5 + weight * cost1 + (1.0 - weight) * cost0
return (0x8000 + weight * cost1 + (0x10000 - weight) * cost0) >> 16;
}
static void vp8_estimate_ref_frame_costs(VP8_COMP *cpi, int segment_id, unsigned int * ref_costs )
{
VP8_COMMON *cm = &cpi->common;
MACROBLOCKD *xd = &cpi->mb.e_mbd;
......@@ -2590,47 +2649,87 @@ void vp8_estimate_ref_frame_costs(VP8_COMP *cpi, unsigned int * ref_costs )
unsigned int cost;
int pred_ref ;
int pred_flag;
int pred_ctx ;
int i;
int tot_count;
vp8_prob pred_prob, new_pred_prob;
int seg_ref_active;
int seg_ref_count = 0;
seg_ref_active = segfeature_active( xd,
segment_id,
SEG_LVL_REF_FRAME );
vp8_prob pred_prob;
if ( seg_ref_active )
{
seg_ref_count = check_segref( xd, segment_id, INTRA_FRAME ) +
check_segref( xd, segment_id, LAST_FRAME ) +
check_segref( xd, segment_id, GOLDEN_FRAME ) +
check_segref( xd, segment_id, ALTREF_FRAME );
}
// Get the predicted reference for this mb
pred_ref = get_pred_ref( cm, xd );
// Get the context probability for the prediction flag
// Get the context probability for the prediction flag (based on last frame)
pred_prob = get_pred_prob( cm, xd, PRED_REF );
// Predict probability for current frame based on stats so far
pred_ctx = get_pred_context(cm, xd, PRED_REF);
tot_count = cpi->ref_pred_count[pred_ctx][0] + cpi->ref_pred_count[pred_ctx][1];
if ( tot_count )
{
new_pred_prob =
( cpi->ref_pred_count[pred_ctx][0] * 255 + (tot_count >> 1)) / tot_count;
new_pred_prob += !new_pred_prob;
}
else
new_pred_prob = 128;
// Get the set of probabilities to use if prediction fails
mod_refprobs = cm->mod_refprobs[pred_ref];
// For each possible selected reference frame work out a cost.
// TODO: correct handling of costs if segment indicates only a subset of
// reference frames are allowed... though mostly this should come out
// in the wash.
for ( i = 0; i < MAX_REF_FRAMES; i++ )
{
pred_flag = (i == pred_ref);
// Get the prediction for the current mb
cost = vp8_cost_bit( pred_prob, pred_flag );
// for incorrectly predicted cases
if ( ! pred_flag )
if (seg_ref_active && seg_ref_count == 1)
{
if ( mod_refprobs[0] )
cost += vp8_cost_bit( mod_refprobs[0], (i != INTRA_FRAME) );
cost = 0;
}
else
{
pred_flag = (i == pred_ref);
// Get the prediction for the current mb
cost = weighted_cost(&pred_prob, &new_pred_prob, 0,
pred_flag, cpi->seg0_progress);
if (cost > 1024) cost = 768; // i.e. account for 4 bits max.
// Inter coded
if (i != INTRA_FRAME)
// for incorrectly predicted cases
if ( ! pred_flag )
{
if ( mod_refprobs[1] )
cost += vp8_cost_bit( mod_refprobs[1], (i != LAST_FRAME) );
vp8_prob curframe_mod_refprobs[3];
if (i != LAST_FRAME)
if (cpi->seg0_progress)
{
if ( mod_refprobs[2] )
cost += vp8_cost_bit( mod_refprobs[2],
(i != GOLDEN_FRAME));
estimate_curframe_refprobs(cpi, curframe_mod_refprobs, pred_ref);
}
else
{
vpx_memset(curframe_mod_refprobs, 0, sizeof(curframe_mod_refprobs));
}
cost += weighted_cost(mod_refprobs, curframe_mod_refprobs, 0,
(i != INTRA_FRAME), cpi->seg0_progress);
if (i != INTRA_FRAME)
{
cost += weighted_cost(mod_refprobs, curframe_mod_refprobs, 1,
(i != LAST_FRAME), cpi->seg0_progress);
if (i != LAST_FRAME)
{
cost += weighted_cost(mod_refprobs, curframe_mod_refprobs, 2,
(i != GOLDEN_FRAME), cpi->seg0_progress);
}
}
}
}
......@@ -2819,7 +2918,7 @@ void vp8_rd_pick_inter_mode(VP8_COMP *cpi, MACROBLOCK *x, int recon_yoffset, int
// Get estimates of reference frame costs for each reference frame
// that depend on the current prediction etc.
vp8_estimate_ref_frame_costs( cpi, ref_costs );
vp8_estimate_ref_frame_costs( cpi, segment_id, ref_costs );
for (mode_index = 0; mode_index < MAX_MODES; mode_index++)
{
......
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