| /* |
| * Copyright (c) 2001-2016, Alliance for Open Media. All rights reserved |
| * |
| * This source code is subject to the terms of the BSD 2 Clause License and |
| * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License |
| * was not distributed with this source code in the LICENSE file, you can |
| * obtain it at www.aomedia.org/license/software. If the Alliance for Open |
| * Media Patent License 1.0 was not distributed with this source code in the |
| * PATENTS file, you can obtain it at www.aomedia.org/license/patent. |
| */ |
| |
| /* clang-format off */ |
| |
| #ifdef HAVE_CONFIG_H |
| # include "config.h" |
| #endif |
| |
| #include <math.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include "aom_dsp/entcode.h" |
| #include "aom_dsp/entenc.h" |
| #include "av1/common/blockd.h" |
| #include "av1/common/odintrin.h" |
| #include "av1/common/partition.h" |
| #include "av1/common/pvq_state.h" |
| #include "av1/encoder/encodemb.h" |
| #include "av1/encoder/pvq_encoder.h" |
| #include "aom_ports/system_state.h" |
| |
| /*Shift to ensure that the upper bound (i.e. for the max blocksize) of the |
| dot-product of the 1st band of chroma with the luma ref doesn't overflow.*/ |
| #define OD_CFL_FLIP_SHIFT (OD_LIMIT_BSIZE_MAX + 0) |
| |
| void aom_write_symbol_pvq(aom_writer *w, int symb, aom_cdf_prob *cdf, |
| int nsymbs) { |
| if (cdf[0] == 0) |
| aom_cdf_init_q15_1D(cdf, nsymbs, CDF_SIZE(nsymbs)); |
| aom_write_symbol(w, symb, cdf, nsymbs); |
| } |
| |
| static void aom_encode_pvq_codeword(aom_writer *w, od_pvq_codeword_ctx *adapt, |
| const od_coeff *in, int n, int k) { |
| int i; |
| aom_encode_band_pvq_splits(w, adapt, in, n, k, 0); |
| for (i = 0; i < n; i++) if (in[i]) aom_write_bit(w, in[i] < 0); |
| } |
| |
| /* Computes 1/sqrt(i) using a table for small values. */ |
| static double od_rsqrt_table(int i) { |
| static double table[16] = { |
| 1.000000, 0.707107, 0.577350, 0.500000, |
| 0.447214, 0.408248, 0.377964, 0.353553, |
| 0.333333, 0.316228, 0.301511, 0.288675, |
| 0.277350, 0.267261, 0.258199, 0.250000}; |
| if (i <= 16) return table[i-1]; |
| else return 1./sqrt(i); |
| } |
| |
| /*Computes 1/sqrt(start+2*i+1) using a lookup table containing the results |
| where 0 <= i < table_size.*/ |
| static double od_custom_rsqrt_dynamic_table(const double* table, |
| const int table_size, const double start, const int i) { |
| if (i < table_size) return table[i]; |
| else return od_rsqrt_table((int)(start + 2*i + 1)); |
| } |
| |
| /*Fills tables used in od_custom_rsqrt_dynamic_table for a given start.*/ |
| static void od_fill_dynamic_rsqrt_table(double *table, const int table_size, |
| const double start) { |
| int i; |
| for (i = 0; i < table_size; i++) |
| table[i] = od_rsqrt_table((int)(start + 2*i + 1)); |
| } |
| |
| /** Find the codepoint on the given PSphere closest to the desired |
| * vector. Double-precision PVQ search just to make sure our tests |
| * aren't limited by numerical accuracy. |
| * |
| * @param [in] xcoeff input vector to quantize (x in the math doc) |
| * @param [in] n number of dimensions |
| * @param [in] k number of pulses |
| * @param [out] ypulse optimal codevector found (y in the math doc) |
| * @param [out] g2 multiplier for the distortion (typically squared |
| * gain units) |
| * @param [in] pvq_norm_lambda enc->pvq_norm_lambda for quantized RDO |
| * @param [in] prev_k number of pulses already in ypulse that we should |
| * reuse for the search (or 0 for a new search) |
| * @return cosine distance between x and y (between 0 and 1) |
| */ |
| double pvq_search_rdo_double_c(const od_val16 *xcoeff, int n, int k, |
| od_coeff *ypulse, double g2, double pvq_norm_lambda, int prev_k) { |
| int i, j; |
| double xy; |
| double yy; |
| /* TODO - This blows our 8kB stack space budget and should be fixed when |
| converting PVQ to fixed point. */ |
| double x[MAXN]; |
| double xx; |
| double lambda; |
| double norm_1; |
| int rdo_pulses; |
| double delta_rate; |
| xx = xy = yy = 0; |
| for (j = 0; j < n; j++) { |
| x[j] = fabs((float)xcoeff[j]); |
| xx += x[j]*x[j]; |
| } |
| norm_1 = 1./sqrt(1e-30 + xx); |
| lambda = pvq_norm_lambda/(1e-30 + g2); |
| i = 0; |
| if (prev_k > 0 && prev_k <= k) { |
| /* We reuse pulses from a previous search so we don't have to search them |
| again. */ |
| for (j = 0; j < n; j++) { |
| ypulse[j] = abs(ypulse[j]); |
| xy += x[j]*ypulse[j]; |
| yy += ypulse[j]*ypulse[j]; |
| i += ypulse[j]; |
| } |
| } |
| else if (k > 2) { |
| double l1_norm; |
| double l1_inv; |
| l1_norm = 0; |
| for (j = 0; j < n; j++) l1_norm += x[j]; |
| l1_inv = 1./OD_MAXF(l1_norm, 1e-100); |
| for (j = 0; j < n; j++) { |
| double tmp; |
| tmp = k*x[j]*l1_inv; |
| ypulse[j] = OD_MAXI(0, (int)floor(tmp)); |
| xy += x[j]*ypulse[j]; |
| yy += ypulse[j]*ypulse[j]; |
| i += ypulse[j]; |
| } |
| } |
| else OD_CLEAR(ypulse, n); |
| |
| /* Only use RDO on the last few pulses. This not only saves CPU, but using |
| RDO on all pulses actually makes the results worse for reasons I don't |
| fully understand. */ |
| rdo_pulses = 1 + k/4; |
| /* Rough assumption for now, the last position costs about 3 bits more than |
| the first. */ |
| delta_rate = 3./n; |
| /* Search one pulse at a time */ |
| for (; i < k - rdo_pulses; i++) { |
| int pos; |
| double best_xy; |
| double best_yy; |
| pos = 0; |
| best_xy = -10; |
| best_yy = 1; |
| for (j = 0; j < n; j++) { |
| double tmp_xy; |
| double tmp_yy; |
| tmp_xy = xy + x[j]; |
| tmp_yy = yy + 2*ypulse[j] + 1; |
| tmp_xy *= tmp_xy; |
| if (j == 0 || tmp_xy*best_yy > best_xy*tmp_yy) { |
| best_xy = tmp_xy; |
| best_yy = tmp_yy; |
| pos = j; |
| } |
| } |
| xy = xy + x[pos]; |
| yy = yy + 2*ypulse[pos] + 1; |
| ypulse[pos]++; |
| } |
| /* Search last pulses with RDO. Distortion is D = (x-y)^2 = x^2 - 2*x*y + y^2 |
| and since x^2 and y^2 are constant, we just maximize x*y, plus a |
| lambda*rate term. Note that since x and y aren't normalized here, |
| we need to divide by sqrt(x^2)*sqrt(y^2). */ |
| for (; i < k; i++) { |
| double rsqrt_table[4]; |
| int rsqrt_table_size = 4; |
| int pos; |
| double best_cost; |
| pos = 0; |
| best_cost = -1e5; |
| /*Fill the small rsqrt lookup table with inputs relative to yy. |
| Specifically, the table of n values is filled with |
| rsqrt(yy + 1), rsqrt(yy + 2 + 1) .. rsqrt(yy + 2*(n-1) + 1).*/ |
| od_fill_dynamic_rsqrt_table(rsqrt_table, rsqrt_table_size, yy); |
| for (j = 0; j < n; j++) { |
| double tmp_xy; |
| double tmp_yy; |
| tmp_xy = xy + x[j]; |
| /*Calculate rsqrt(yy + 2*ypulse[j] + 1) using an optimized method.*/ |
| tmp_yy = od_custom_rsqrt_dynamic_table(rsqrt_table, rsqrt_table_size, |
| yy, ypulse[j]); |
| tmp_xy = 2*tmp_xy*norm_1*tmp_yy - lambda*j*delta_rate; |
| if (j == 0 || tmp_xy > best_cost) { |
| best_cost = tmp_xy; |
| pos = j; |
| } |
| } |
| xy = xy + x[pos]; |
| yy = yy + 2*ypulse[pos] + 1; |
| ypulse[pos]++; |
| } |
| for (i = 0; i < n; i++) { |
| if (xcoeff[i] < 0) ypulse[i] = -ypulse[i]; |
| } |
| return xy/(1e-100 + sqrt(xx*yy)); |
| } |
| |
| /** Encodes the gain so that the return value increases with the |
| * distance |x-ref|, so that we can encode a zero when x=ref. The |
| * value x=0 is not covered because it is only allowed in the noref |
| * case. |
| * |
| * @param [in] x quantized gain to encode |
| * @param [in] ref quantized gain of the reference |
| * @return interleave-encoded quantized gain value |
| */ |
| static int neg_interleave(int x, int ref) { |
| if (x < ref) return -2*(x - ref) - 1; |
| else if (x < 2*ref) return 2*(x - ref); |
| else return x-1; |
| } |
| |
| int od_vector_is_null(const od_coeff *x, int len) { |
| int i; |
| for (i = 0; i < len; i++) if (x[i]) return 0; |
| return 1; |
| } |
| |
| static double od_pvq_rate(int qg, int icgr, int theta, int ts, |
| const od_adapt_ctx *adapt, const od_coeff *y0, int k, int n, int speed) { |
| double rate; |
| if (k == 0) rate = 0; |
| else if (speed > 0) { |
| int i; |
| int sum; |
| double f; |
| /* Compute "center of mass" of the pulse vector. */ |
| sum = 0; |
| for (i = 0; i < n - (theta != -1); i++) sum += i*abs(y0[i]); |
| f = sum/(double)(k*n); |
| /* Estimates the number of bits it will cost to encode K pulses in |
| N dimensions based on hand-tuned fit for bitrate vs K, N and |
| "center of mass". */ |
| rate = (1 + .4*f)*n*OD_LOG2(1 + OD_MAXF(0, log(n*2*(1*f + .025))*k/n)) + 3; |
| } |
| else { |
| aom_writer w; |
| od_pvq_codeword_ctx cd; |
| int tell; |
| #if !CONFIG_ANS |
| od_ec_enc_init(&w.ec, 1000); |
| #else |
| # error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| OD_COPY(&cd, &adapt->pvq.pvq_codeword_ctx, 1); |
| #if !CONFIG_ANS |
| tell = od_ec_enc_tell_frac(&w.ec); |
| #else |
| # error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| aom_encode_pvq_codeword(&w, &cd, y0, n - (theta != -1), k); |
| #if !CONFIG_ANS |
| rate = (od_ec_enc_tell_frac(&w.ec)-tell)/8.; |
| od_ec_enc_clear(&w.ec); |
| #else |
| # error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| } |
| if (qg > 0 && theta >= 0) { |
| /* Approximate cost of entropy-coding theta */ |
| rate += .9*OD_LOG2(ts); |
| if (qg == icgr) rate -= .5; |
| } |
| return rate; |
| } |
| |
| #define MAX_PVQ_ITEMS (20) |
| /* This stores the information about a PVQ search candidate, so we can sort |
| based on K. */ |
| typedef struct { |
| int gain; |
| int k; |
| od_val32 qtheta; |
| int theta; |
| int ts; |
| od_val32 qcg; |
| } pvq_search_item; |
| |
| int items_compare(pvq_search_item *a, pvq_search_item *b) { |
| /* Break ties in K with gain to ensure a stable sort. |
| Otherwise, the order depends on qsort implementation. */ |
| return a->k == b->k ? a->gain - b->gain : a->k - b->k; |
| } |
| |
| /** Perform PVQ quantization with prediction, trying several |
| * possible gains and angles. See draft-valin-videocodec-pvq and |
| * http://jmvalin.ca/slides/pvq.pdf for more details. |
| * |
| * @param [out] out coefficients after quantization |
| * @param [in] x0 coefficients before quantization |
| * @param [in] r0 reference, aka predicted coefficients |
| * @param [in] n number of dimensions |
| * @param [in] q0 quantization step size |
| * @param [out] y pulse vector (i.e. selected PVQ codevector) |
| * @param [out] itheta angle between input and reference (-1 if noref) |
| * @param [out] vk total number of pulses |
| * @param [in] beta per-band activity masking beta param |
| * @param [out] skip_diff distortion cost of skipping this block |
| * (accumulated) |
| * @param [in] is_keyframe whether we're encoding a keyframe |
| * @param [in] pli plane index |
| * @param [in] adapt probability adaptation context |
| * @param [in] qm QM with magnitude compensation |
| * @param [in] qm_inv Inverse of QM with magnitude compensation |
| * @param [in] pvq_norm_lambda enc->pvq_norm_lambda for quantized RDO |
| * @param [in] speed Make search faster by making approximations |
| * @return gain index of the quatized gain |
| */ |
| static int pvq_theta(od_coeff *out, const od_coeff *x0, const od_coeff *r0, |
| int n, int q0, od_coeff *y, int *itheta, int *vk, |
| od_val16 beta, double *skip_diff, int is_keyframe, int pli, |
| const od_adapt_ctx *adapt, const int16_t *qm, const int16_t *qm_inv, |
| double pvq_norm_lambda, int speed) { |
| od_val32 g; |
| od_val32 gr; |
| od_coeff y_tmp[MAXN + 3]; |
| int i; |
| /* Number of pulses. */ |
| int k; |
| /* Companded gain of x and reference, normalized to q. */ |
| od_val32 cg; |
| od_val32 cgr; |
| int icgr; |
| int qg; |
| /* Best RDO cost (D + lamdba*R) so far. */ |
| double best_cost; |
| double dist0; |
| /* Distortion (D) that corresponds to the best RDO cost. */ |
| double best_dist; |
| double dist; |
| /* Sign of Householder reflection. */ |
| int s; |
| /* Dimension on which Householder reflects. */ |
| int m; |
| od_val32 theta; |
| double corr; |
| int best_k; |
| od_val32 best_qtheta; |
| od_val32 gain_offset; |
| int noref; |
| double skip_dist; |
| int cfl_enabled; |
| int skip; |
| double gain_weight; |
| od_val16 x16[MAXN]; |
| od_val16 r16[MAXN]; |
| int xshift; |
| int rshift; |
| /* Give more weight to gain error when calculating the total distortion. */ |
| gain_weight = 1.0; |
| OD_ASSERT(n > 1); |
| corr = 0; |
| #if !defined(OD_FLOAT_PVQ) |
| /* Shift needed to make x fit in 16 bits even after rotation. |
| This shift value is not normative (it can be changed without breaking |
| the bitstream) */ |
| xshift = OD_MAXI(0, od_vector_log_mag(x0, n) - 15); |
| /* Shift needed to make the reference fit in 15 bits, so that the Householder |
| vector can fit in 16 bits. |
| This shift value *is* normative, and has to match the decoder. */ |
| rshift = OD_MAXI(0, od_vector_log_mag(r0, n) - 14); |
| #else |
| xshift = 0; |
| rshift = 0; |
| #endif |
| for (i = 0; i < n; i++) { |
| #if defined(OD_FLOAT_PVQ) |
| /*This is slightly different from the original float PVQ code, |
| where the qm was applied in the accumulation in od_pvq_compute_gain and |
| the vectors were od_coeffs, not od_val16 (i.e. double).*/ |
| x16[i] = x0[i]*(double)qm[i]*OD_QM_SCALE_1; |
| r16[i] = r0[i]*(double)qm[i]*OD_QM_SCALE_1; |
| #else |
| x16[i] = OD_SHR_ROUND(x0[i]*qm[i], OD_QM_SHIFT + xshift); |
| r16[i] = OD_SHR_ROUND(r0[i]*qm[i], OD_QM_SHIFT + rshift); |
| #endif |
| corr += OD_MULT16_16(x16[i], r16[i]); |
| } |
| cfl_enabled = is_keyframe && pli != 0 && !OD_DISABLE_CFL; |
| cg = od_pvq_compute_gain(x16, n, q0, &g, beta, xshift); |
| cgr = od_pvq_compute_gain(r16, n, q0, &gr, beta, rshift); |
| if (cfl_enabled) cgr = OD_CGAIN_SCALE; |
| /* gain_offset is meant to make sure one of the quantized gains has |
| exactly the same gain as the reference. */ |
| #if defined(OD_FLOAT_PVQ) |
| icgr = (int)floor(.5 + cgr); |
| #else |
| icgr = OD_SHR_ROUND(cgr, OD_CGAIN_SHIFT); |
| #endif |
| gain_offset = cgr - OD_SHL(icgr, OD_CGAIN_SHIFT); |
| /* Start search with null case: gain=0, no pulse. */ |
| qg = 0; |
| dist = gain_weight*cg*cg*OD_CGAIN_SCALE_2; |
| best_dist = dist; |
| best_cost = dist + pvq_norm_lambda*od_pvq_rate(0, 0, -1, 0, adapt, NULL, 0, |
| n, speed); |
| noref = 1; |
| best_k = 0; |
| *itheta = -1; |
| OD_CLEAR(y, n); |
| best_qtheta = 0; |
| m = 0; |
| s = 1; |
| corr = corr/(1e-100 + g*(double)gr/OD_SHL(1, xshift + rshift)); |
| corr = OD_MAXF(OD_MINF(corr, 1.), -1.); |
| if (is_keyframe) skip_dist = gain_weight*cg*cg*OD_CGAIN_SCALE_2; |
| else { |
| skip_dist = gain_weight*(cg - cgr)*(cg - cgr) |
| + cgr*(double)cg*(2 - 2*corr); |
| skip_dist *= OD_CGAIN_SCALE_2; |
| } |
| if (!is_keyframe) { |
| /* noref, gain=0 isn't allowed, but skip is allowed. */ |
| od_val32 scgr; |
| scgr = OD_MAXF(0,gain_offset); |
| if (icgr == 0) { |
| best_dist = gain_weight*(cg - scgr)*(cg - scgr) |
| + scgr*(double)cg*(2 - 2*corr); |
| best_dist *= OD_CGAIN_SCALE_2; |
| } |
| best_cost = best_dist + pvq_norm_lambda*od_pvq_rate(0, icgr, 0, 0, adapt, |
| NULL, 0, n, speed); |
| best_qtheta = 0; |
| *itheta = 0; |
| noref = 0; |
| } |
| dist0 = best_dist; |
| if (n <= OD_MAX_PVQ_SIZE && !od_vector_is_null(r0, n) && corr > 0) { |
| od_val16 xr[MAXN]; |
| int gain_bound; |
| int prev_k; |
| pvq_search_item items[MAX_PVQ_ITEMS]; |
| int idx; |
| int nitems; |
| double cos_dist; |
| idx = 0; |
| gain_bound = OD_SHR(cg - gain_offset, OD_CGAIN_SHIFT); |
| /* Perform theta search only if prediction is useful. */ |
| theta = OD_ROUND32(OD_THETA_SCALE*acos(corr)); |
| m = od_compute_householder(r16, n, gr, &s, rshift); |
| od_apply_householder(xr, x16, r16, n); |
| prev_k = 0; |
| for (i = m; i < n - 1; i++) xr[i] = xr[i + 1]; |
| /* Compute all candidate PVQ searches within a reasonable range of gain |
| and theta. */ |
| for (i = OD_MAXI(1, gain_bound - 1); i <= gain_bound + 1; i++) { |
| int j; |
| od_val32 qcg; |
| int ts; |
| int theta_lower; |
| int theta_upper; |
| /* Quantized companded gain */ |
| qcg = OD_SHL(i, OD_CGAIN_SHIFT) + gain_offset; |
| /* Set angular resolution (in ra) to match the encoded gain */ |
| ts = od_pvq_compute_max_theta(qcg, beta); |
| theta_lower = OD_MAXI(0, (int)floor(.5 + |
| theta*OD_THETA_SCALE_1*2/M_PI*ts) - 2); |
| theta_upper = OD_MINI(ts - 1, (int)ceil(theta*OD_THETA_SCALE_1*2/M_PI*ts)); |
| /* Include the angles within a reasonable range. */ |
| for (j = theta_lower; j <= theta_upper; j++) { |
| od_val32 qtheta; |
| qtheta = od_pvq_compute_theta(j, ts); |
| k = od_pvq_compute_k(qcg, j, 0, n, beta); |
| items[idx].gain = i; |
| items[idx].theta = j; |
| items[idx].k = k; |
| items[idx].qcg = qcg; |
| items[idx].qtheta = qtheta; |
| items[idx].ts = ts; |
| idx++; |
| OD_ASSERT(idx < MAX_PVQ_ITEMS); |
| } |
| } |
| nitems = idx; |
| cos_dist = 0; |
| /* Sort PVQ search candidates in ascending order of pulses K so that |
| we can reuse all the previously searched pulses across searches. */ |
| qsort(items, nitems, sizeof(items[0]), |
| (int (*)(const void *, const void *))items_compare); |
| /* Search for the best gain/theta in order. */ |
| for (idx = 0; idx < nitems; idx++) { |
| int j; |
| od_val32 qcg; |
| int ts; |
| double cost; |
| double dist_theta; |
| double sin_prod; |
| od_val32 qtheta; |
| /* Quantized companded gain */ |
| qcg = items[idx].qcg; |
| i = items[idx].gain; |
| j = items[idx].theta; |
| /* Set angular resolution (in ra) to match the encoded gain */ |
| ts = items[idx].ts; |
| /* Search for the best angle within a reasonable range. */ |
| qtheta = items[idx].qtheta; |
| k = items[idx].k; |
| /* Compute the minimal possible distortion by not taking the PVQ |
| cos_dist into account. */ |
| dist_theta = 2 - 2.*od_pvq_cos(theta - qtheta)*OD_TRIG_SCALE_1; |
| dist = gain_weight*(qcg - cg)*(qcg - cg) + qcg*(double)cg*dist_theta; |
| dist *= OD_CGAIN_SCALE_2; |
| /* If we have no hope of beating skip (including a 1-bit worst-case |
| penalty), stop now. */ |
| if (dist > dist0 + 1.0*pvq_norm_lambda && k != 0) continue; |
| sin_prod = od_pvq_sin(theta)*OD_TRIG_SCALE_1*od_pvq_sin(qtheta)* |
| OD_TRIG_SCALE_1; |
| /* PVQ search, using a gain of qcg*cg*sin(theta)*sin(qtheta) since |
| that's the factor by which cos_dist is multiplied to get the |
| distortion metric. */ |
| if (k == 0) { |
| cos_dist = 0; |
| OD_CLEAR(y_tmp, n-1); |
| } |
| else if (k != prev_k) { |
| cos_dist = pvq_search_rdo_double(xr, n - 1, k, y_tmp, |
| qcg*(double)cg*sin_prod*OD_CGAIN_SCALE_2, pvq_norm_lambda, prev_k); |
| } |
| prev_k = k; |
| /* See Jmspeex' Journal of Dubious Theoretical Results. */ |
| dist_theta = 2 - 2.*od_pvq_cos(theta - qtheta)*OD_TRIG_SCALE_1 |
| + sin_prod*(2 - 2*cos_dist); |
| dist = gain_weight*(qcg - cg)*(qcg - cg) + qcg*(double)cg*dist_theta; |
| dist *= OD_CGAIN_SCALE_2; |
| /* Do approximate RDO. */ |
| cost = dist + pvq_norm_lambda*od_pvq_rate(i, icgr, j, ts, adapt, y_tmp, |
| k, n, speed); |
| if (cost < best_cost) { |
| best_cost = cost; |
| best_dist = dist; |
| qg = i; |
| best_k = k; |
| best_qtheta = qtheta; |
| *itheta = j; |
| noref = 0; |
| OD_COPY(y, y_tmp, n - 1); |
| } |
| } |
| } |
| /* Don't bother with no-reference version if there's a reasonable |
| correlation. */ |
| if (n <= OD_MAX_PVQ_SIZE && (corr < .5 |
| || cg < (od_val32)(OD_SHL(2, OD_CGAIN_SHIFT)))) { |
| int gain_bound; |
| int prev_k; |
| gain_bound = OD_SHR(cg, OD_CGAIN_SHIFT); |
| prev_k = 0; |
| /* Search for the best gain (haven't determined reasonable range yet). */ |
| for (i = OD_MAXI(1, gain_bound); i <= gain_bound + 1; i++) { |
| double cos_dist; |
| double cost; |
| od_val32 qcg; |
| qcg = OD_SHL(i, OD_CGAIN_SHIFT); |
| k = od_pvq_compute_k(qcg, -1, 1, n, beta); |
| /* Compute the minimal possible distortion by not taking the PVQ |
| cos_dist into account. */ |
| dist = gain_weight*(qcg - cg)*(qcg - cg); |
| dist *= OD_CGAIN_SCALE_2; |
| if (dist > dist0 && k != 0) continue; |
| cos_dist = pvq_search_rdo_double(x16, n, k, y_tmp, |
| qcg*(double)cg*OD_CGAIN_SCALE_2, pvq_norm_lambda, prev_k); |
| prev_k = k; |
| /* See Jmspeex' Journal of Dubious Theoretical Results. */ |
| dist = gain_weight*(qcg - cg)*(qcg - cg) |
| + qcg*(double)cg*(2 - 2*cos_dist); |
| dist *= OD_CGAIN_SCALE_2; |
| /* Do approximate RDO. */ |
| cost = dist + pvq_norm_lambda*od_pvq_rate(i, 0, -1, 0, adapt, y_tmp, k, |
| n, speed); |
| if (cost <= best_cost) { |
| best_cost = cost; |
| best_dist = dist; |
| qg = i; |
| noref = 1; |
| best_k = k; |
| *itheta = -1; |
| OD_COPY(y, y_tmp, n); |
| } |
| } |
| } |
| k = best_k; |
| theta = best_qtheta; |
| skip = 0; |
| if (noref) { |
| if (qg == 0) skip = OD_PVQ_SKIP_ZERO; |
| } |
| else { |
| if (!is_keyframe && qg == 0) { |
| skip = (icgr ? OD_PVQ_SKIP_ZERO : OD_PVQ_SKIP_COPY); |
| } |
| if (qg == icgr && *itheta == 0 && !cfl_enabled) skip = OD_PVQ_SKIP_COPY; |
| } |
| /* Synthesize like the decoder would. */ |
| if (skip) { |
| if (skip == OD_PVQ_SKIP_COPY) OD_COPY(out, r0, n); |
| else OD_CLEAR(out, n); |
| } |
| else { |
| if (noref) gain_offset = 0; |
| g = od_gain_expand(OD_SHL(qg, OD_CGAIN_SHIFT) + gain_offset, q0, beta); |
| od_pvq_synthesis_partial(out, y, r16, n, noref, g, theta, m, s, |
| qm_inv); |
| } |
| *vk = k; |
| *skip_diff += skip_dist - best_dist; |
| /* Encode gain differently depending on whether we use prediction or not. |
| Special encoding on inter frames where qg=0 is allowed for noref=0 |
| but not noref=1.*/ |
| if (is_keyframe) return noref ? qg : neg_interleave(qg, icgr); |
| else return noref ? qg - 1 : neg_interleave(qg + 1, icgr + 1); |
| } |
| |
| /** Encodes a single vector of integers (eg, a partition within a |
| * coefficient block) using PVQ |
| * |
| * @param [in,out] w multi-symbol entropy encoder |
| * @param [in] qg quantized gain |
| * @param [in] theta quantized post-prediction theta |
| * @param [in] in coefficient vector to code |
| * @param [in] n number of coefficients in partition |
| * @param [in] k number of pulses in partition |
| * @param [in,out] model entropy encoder state |
| * @param [in,out] adapt adaptation context |
| * @param [in,out] exg ExQ16 expectation of gain value |
| * @param [in,out] ext ExQ16 expectation of theta value |
| * @param [in] cdf_ctx selects which cdf context to use |
| * @param [in] is_keyframe whether we're encoding a keyframe |
| * @param [in] code_skip whether the "skip rest" flag is allowed |
| * @param [in] skip_rest when set, we skip all higher bands |
| * @param [in] encode_flip whether we need to encode the CfL flip flag now |
| * @param [in] flip value of the CfL flip flag |
| */ |
| void pvq_encode_partition(aom_writer *w, |
| int qg, |
| int theta, |
| const od_coeff *in, |
| int n, |
| int k, |
| generic_encoder model[3], |
| od_adapt_ctx *adapt, |
| int *exg, |
| int *ext, |
| int cdf_ctx, |
| int is_keyframe, |
| int code_skip, |
| int skip_rest, |
| int encode_flip, |
| int flip) { |
| int noref; |
| int id; |
| noref = (theta == -1); |
| id = (qg > 0) + 2*OD_MINI(theta + 1,3) + 8*code_skip*skip_rest; |
| if (is_keyframe) { |
| OD_ASSERT(id != 8); |
| if (id >= 8) id--; |
| } |
| else { |
| OD_ASSERT(id != 10); |
| if (id >= 10) id--; |
| } |
| /* Jointly code gain, theta and noref for small values. Then we handle |
| larger gain and theta values. For noref, theta = -1. */ |
| aom_write_symbol_pvq(w, id, &adapt->pvq.pvq_gaintheta_cdf[cdf_ctx][0], |
| 8 + 7*code_skip); |
| if (encode_flip) { |
| /* We could eventually do some smarter entropy coding here, but it would |
| have to be good enough to overcome the overhead of the entropy coder. |
| An early attempt using a "toogle" flag with simple adaptation wasn't |
| worth the trouble. */ |
| aom_write_bit(w, flip); |
| } |
| if (qg > 0) { |
| int tmp; |
| tmp = *exg; |
| generic_encode(w, &model[!noref], qg - 1, &tmp, 2); |
| OD_IIR_DIADIC(*exg, qg << 16, 2); |
| } |
| if (theta > 1) { |
| int tmp; |
| tmp = *ext; |
| generic_encode(w, &model[2], theta - 2, &tmp, 2); |
| OD_IIR_DIADIC(*ext, theta << 16, 2); |
| } |
| aom_encode_pvq_codeword(w, &adapt->pvq.pvq_codeword_ctx, in, |
| n - (theta != -1), k); |
| } |
| |
| /** Quantizes a scalar with rate-distortion optimization (RDO) |
| * @param [in] x unquantized value |
| * @param [in] q quantization step size |
| * @param [in] delta0 rate increase for encoding a 1 instead of a 0 |
| * @param [in] pvq_norm_lambda enc->pvq_norm_lambda for quantized RDO |
| * @retval quantized value |
| */ |
| int od_rdo_quant(od_coeff x, int q, double delta0, double pvq_norm_lambda) { |
| int n; |
| /* Optimal quantization threshold is 1/2 + lambda*delta_rate/2. See |
| Jmspeex' Journal of Dubious Theoretical Results for details. */ |
| n = OD_DIV_R0(abs(x), q); |
| if ((double)abs(x)/q < (double)n/2 + pvq_norm_lambda*delta0/(2*n)) { |
| return 0; |
| } |
| else { |
| return OD_DIV_R0(x, q); |
| } |
| } |
| |
| /** Encode a coefficient block (excepting DC) using PVQ |
| * |
| * @param [in,out] enc daala encoder context |
| * @param [in] ref 'reference' (prediction) vector |
| * @param [in] in coefficient block to quantize and encode |
| * @param [out] out quantized coefficient block |
| * @param [in] q0 scale/quantizer |
| * @param [in] pli plane index |
| * @param [in] bs log of the block size minus two |
| * @param [in] beta per-band activity masking beta param |
| * @param [in] is_keyframe whether we're encoding a keyframe |
| * @param [in] qm QM with magnitude compensation |
| * @param [in] qm_inv Inverse of QM with magnitude compensation |
| * @param [in] speed Make search faster by making approximations |
| * @param [in] pvq_info If null, conisdered as RDO search mode |
| * @return Returns block skip info indicating whether DC/AC are coded. |
| * bit0: DC is coded, bit1: AC is coded (1 means coded) |
| * |
| */ |
| PVQ_SKIP_TYPE od_pvq_encode(daala_enc_ctx *enc, |
| od_coeff *ref, |
| const od_coeff *in, |
| od_coeff *out, |
| int q_dc, |
| int q_ac, |
| int pli, |
| int bs, |
| const od_val16 *beta, |
| int is_keyframe, |
| const int16_t *qm, |
| const int16_t *qm_inv, |
| int speed, |
| PVQ_INFO *pvq_info){ |
| int theta[PVQ_MAX_PARTITIONS]; |
| int qg[PVQ_MAX_PARTITIONS]; |
| int k[PVQ_MAX_PARTITIONS]; |
| od_coeff y[OD_TXSIZE_MAX*OD_TXSIZE_MAX]; |
| int *exg; |
| int *ext; |
| int nb_bands; |
| int i; |
| const int *off; |
| int size[PVQ_MAX_PARTITIONS]; |
| generic_encoder *model; |
| double skip_diff; |
| int tell; |
| uint16_t *skip_cdf; |
| od_rollback_buffer buf; |
| int dc_quant; |
| int flip; |
| int cfl_encoded; |
| int skip_rest; |
| int skip_dir; |
| int skip_theta_value; |
| const unsigned char *pvq_qm; |
| double dc_rate; |
| int use_masking; |
| PVQ_SKIP_TYPE ac_dc_coded; |
| |
| aom_clear_system_state(); |
| |
| use_masking = enc->use_activity_masking; |
| |
| if (use_masking) |
| pvq_qm = &enc->state.pvq_qm_q4[pli][0]; |
| else |
| pvq_qm = 0; |
| |
| exg = &enc->state.adapt->pvq.pvq_exg[pli][bs][0]; |
| ext = enc->state.adapt->pvq.pvq_ext + bs*PVQ_MAX_PARTITIONS; |
| skip_cdf = enc->state.adapt->skip_cdf[2*bs + (pli != 0)]; |
| model = enc->state.adapt->pvq.pvq_param_model; |
| nb_bands = OD_BAND_OFFSETS[bs][0]; |
| off = &OD_BAND_OFFSETS[bs][1]; |
| |
| if (use_masking) |
| dc_quant = OD_MAXI(1, q_dc * pvq_qm[od_qm_get_index(bs, 0)] >> 4); |
| else |
| dc_quant = OD_MAXI(1, q_dc); |
| |
| tell = 0; |
| for (i = 0; i < nb_bands; i++) size[i] = off[i+1] - off[i]; |
| skip_diff = 0; |
| flip = 0; |
| /*If we are coding a chroma block of a keyframe, we are doing CfL.*/ |
| if (pli != 0 && is_keyframe) { |
| od_val32 xy; |
| xy = 0; |
| /*Compute the dot-product of the first band of chroma with the luma ref.*/ |
| for (i = off[0]; i < off[1]; i++) { |
| #if defined(OD_FLOAT_PVQ) |
| xy += ref[i]*(double)qm[i]*OD_QM_SCALE_1* |
| (double)in[i]*(double)qm[i]*OD_QM_SCALE_1; |
| #else |
| od_val32 rq; |
| od_val32 inq; |
| rq = ref[i]*qm[i]; |
| inq = in[i]*qm[i]; |
| xy += OD_SHR(rq*(int64_t)inq, OD_SHL(OD_QM_SHIFT + OD_CFL_FLIP_SHIFT, |
| 1)); |
| #endif |
| } |
| /*If cos(theta) < 0, then |theta| > pi/2 and we should negate the ref.*/ |
| if (xy < 0) { |
| flip = 1; |
| for(i = off[0]; i < off[nb_bands]; i++) ref[i] = -ref[i]; |
| } |
| } |
| for (i = 0; i < nb_bands; i++) { |
| int q; |
| |
| if (use_masking) |
| q = OD_MAXI(1, q_ac * pvq_qm[od_qm_get_index(bs, i + 1)] >> 4); |
| else |
| q = OD_MAXI(1, q_ac); |
| |
| qg[i] = pvq_theta(out + off[i], in + off[i], ref + off[i], size[i], |
| q, y + off[i], &theta[i], &k[i], beta[i], &skip_diff, is_keyframe, |
| pli, enc->state.adapt, qm + off[i], qm_inv + off[i], |
| enc->pvq_norm_lambda, speed); |
| } |
| od_encode_checkpoint(enc, &buf); |
| if (is_keyframe) out[0] = 0; |
| else { |
| int n; |
| n = OD_DIV_R0(abs(in[0] - ref[0]), dc_quant); |
| if (n == 0) { |
| out[0] = 0; |
| } else { |
| int tell2; |
| od_rollback_buffer dc_buf; |
| |
| dc_rate = -OD_LOG2((double)(OD_ICDF(skip_cdf[3]) - OD_ICDF(skip_cdf[2]))/ |
| (double)(OD_ICDF(skip_cdf[2]) - OD_ICDF(skip_cdf[1]))); |
| dc_rate += 1; |
| |
| #if !CONFIG_ANS |
| tell2 = od_ec_enc_tell_frac(&enc->w.ec); |
| #else |
| #error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| od_encode_checkpoint(enc, &dc_buf); |
| generic_encode(&enc->w, &enc->state.adapt->model_dc[pli], |
| n - 1, &enc->state.adapt->ex_dc[pli][bs][0], 2); |
| #if !CONFIG_ANS |
| tell2 = od_ec_enc_tell_frac(&enc->w.ec) - tell2; |
| #else |
| #error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| dc_rate += tell2/8.0; |
| od_encode_rollback(enc, &dc_buf); |
| |
| out[0] = od_rdo_quant(in[0] - ref[0], dc_quant, dc_rate, |
| enc->pvq_norm_lambda); |
| } |
| } |
| #if !CONFIG_ANS |
| tell = od_ec_enc_tell_frac(&enc->w.ec); |
| #else |
| #error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| /* Code as if we're not skipping. */ |
| aom_write_symbol(&enc->w, 2 + (out[0] != 0), skip_cdf, 4); |
| ac_dc_coded = AC_CODED + (out[0] != 0); |
| cfl_encoded = 0; |
| skip_rest = 1; |
| skip_theta_value = is_keyframe ? -1 : 0; |
| for (i = 1; i < nb_bands; i++) { |
| if (theta[i] != skip_theta_value || qg[i]) skip_rest = 0; |
| } |
| skip_dir = 0; |
| if (nb_bands > 1) { |
| for (i = 0; i < 3; i++) { |
| int j; |
| int tmp; |
| tmp = 1; |
| // ToDo(yaowu): figure out better stop condition without gcc warning. |
| for (j = i + 1; j < nb_bands && j < PVQ_MAX_PARTITIONS; j += 3) { |
| if (theta[j] != skip_theta_value || qg[j]) tmp = 0; |
| } |
| skip_dir |= tmp << i; |
| } |
| } |
| if (theta[0] == skip_theta_value && qg[0] == 0 && skip_rest) nb_bands = 0; |
| |
| /* NOTE: There was no other better place to put this function. */ |
| if (pvq_info) |
| av1_store_pvq_enc_info(pvq_info, qg, theta, k, y, nb_bands, off, size, |
| skip_rest, skip_dir, bs); |
| |
| for (i = 0; i < nb_bands; i++) { |
| int encode_flip; |
| /* Encode CFL flip bit just after the first time it's used. */ |
| encode_flip = pli != 0 && is_keyframe && theta[i] != -1 && !cfl_encoded; |
| if (i == 0 || (!skip_rest && !(skip_dir & (1 << ((i - 1)%3))))) { |
| pvq_encode_partition(&enc->w, qg[i], theta[i], y + off[i], |
| size[i], k[i], model, enc->state.adapt, exg + i, ext + i, |
| (pli != 0)*OD_TXSIZES*PVQ_MAX_PARTITIONS + bs*PVQ_MAX_PARTITIONS + i, |
| is_keyframe, i == 0 && (i < nb_bands - 1), skip_rest, encode_flip, flip); |
| } |
| if (i == 0 && !skip_rest && bs > 0) { |
| aom_write_symbol(&enc->w, skip_dir, |
| &enc->state.adapt->pvq.pvq_skip_dir_cdf[(pli != 0) + 2*(bs - 1)][0], 7); |
| } |
| if (encode_flip) cfl_encoded = 1; |
| } |
| #if !CONFIG_ANS |
| tell = od_ec_enc_tell_frac(&enc->w.ec) - tell; |
| #else |
| #error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| /* Account for the rate of skipping the AC, based on the same DC decision |
| we made when trying to not skip AC. */ |
| { |
| double skip_rate; |
| if (out[0] != 0) { |
| skip_rate = -OD_LOG2((OD_ICDF(skip_cdf[1]) - OD_ICDF(skip_cdf[0]))/ |
| (double)OD_ICDF(skip_cdf[3])); |
| } |
| else { |
| skip_rate = -OD_LOG2(OD_ICDF(skip_cdf[0])/ |
| (double)OD_ICDF(skip_cdf[3])); |
| } |
| tell -= (int)floor(.5+8*skip_rate); |
| } |
| if (nb_bands == 0 || skip_diff <= enc->pvq_norm_lambda/8*tell) { |
| if (is_keyframe) out[0] = 0; |
| else { |
| int n; |
| n = OD_DIV_R0(abs(in[0] - ref[0]), dc_quant); |
| if (n == 0) { |
| out[0] = 0; |
| } else { |
| int tell2; |
| od_rollback_buffer dc_buf; |
| |
| dc_rate = -OD_LOG2((double)(OD_ICDF(skip_cdf[1]) - OD_ICDF(skip_cdf[0]))/ |
| (double)OD_ICDF(skip_cdf[0])); |
| dc_rate += 1; |
| |
| #if !CONFIG_ANS |
| tell2 = od_ec_enc_tell_frac(&enc->w.ec); |
| #else |
| #error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| od_encode_checkpoint(enc, &dc_buf); |
| generic_encode(&enc->w, &enc->state.adapt->model_dc[pli], |
| n - 1, &enc->state.adapt->ex_dc[pli][bs][0], 2); |
| #if !CONFIG_ANS |
| tell2 = od_ec_enc_tell_frac(&enc->w.ec) - tell2; |
| #else |
| #error "CONFIG_PVQ currently requires !CONFIG_ANS." |
| #endif |
| dc_rate += tell2/8.0; |
| od_encode_rollback(enc, &dc_buf); |
| |
| out[0] = od_rdo_quant(in[0] - ref[0], dc_quant, dc_rate, |
| enc->pvq_norm_lambda); |
| } |
| } |
| /* We decide to skip, roll back everything as it was before. */ |
| od_encode_rollback(enc, &buf); |
| aom_write_symbol(&enc->w, out[0] != 0, skip_cdf, 4); |
| ac_dc_coded = (out[0] != 0); |
| if (is_keyframe) for (i = 1; i < 1 << (2*bs + 4); i++) out[i] = 0; |
| else for (i = 1; i < 1 << (2*bs + 4); i++) out[i] = ref[i]; |
| } |
| if (pvq_info) |
| pvq_info->ac_dc_coded = ac_dc_coded; |
| return ac_dc_coded; |
| } |
