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Diffstat (limited to 'third_party/aom/av1/encoder/pvq_encoder.c')
| -rw-r--r-- | third_party/aom/av1/encoder/pvq_encoder.c | 988 |
1 files changed, 988 insertions, 0 deletions
diff --git a/third_party/aom/av1/encoder/pvq_encoder.c b/third_party/aom/av1/encoder/pvq_encoder.c new file mode 100644 index 000000000..ab63f1b7d --- /dev/null +++ b/third_party/aom/av1/encoder/pvq_encoder.c @@ -0,0 +1,988 @@ +/* + * 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_DAALA_EC + od_ec_enc_init(&w.ec, 1000); +#else +# error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#endif + OD_COPY(&cd, &adapt->pvq.pvq_codeword_ctx, 1); +#if CONFIG_DAALA_EC + tell = od_ec_enc_tell_frac(&w.ec); +#else +# error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#endif + aom_encode_pvq_codeword(&w, &cd, y0, n - (theta != -1), k); +#if CONFIG_DAALA_EC + rate = (od_ec_enc_tell_frac(&w.ec)-tell)/8.; + od_ec_enc_clear(&w.ec); +#else +# error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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)(skip_cdf[3] - skip_cdf[2])/ + (double)(skip_cdf[2] - skip_cdf[1])); + dc_rate += 1; + +#if CONFIG_DAALA_EC + tell2 = od_ec_enc_tell_frac(&enc->w.ec); +#else +#error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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_DAALA_EC + tell2 = od_ec_enc_tell_frac(&enc->w.ec) - tell2; +#else +#error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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_DAALA_EC + tell = od_ec_enc_tell_frac(&enc->w.ec); +#else +#error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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_DAALA_EC + tell = od_ec_enc_tell_frac(&enc->w.ec) - tell; +#else +#error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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((skip_cdf[1] - skip_cdf[0])/ + (double)skip_cdf[3]); + } + else { + skip_rate = -OD_LOG2(skip_cdf[0]/ + (double)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)(skip_cdf[1] - skip_cdf[0])/ + (double)skip_cdf[0]); + dc_rate += 1; + +#if CONFIG_DAALA_EC + tell2 = od_ec_enc_tell_frac(&enc->w.ec); +#else +#error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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_DAALA_EC + tell2 = od_ec_enc_tell_frac(&enc->w.ec) - tell2; +#else +#error "CONFIG_PVQ currently requires CONFIG_DAALA_EC." +#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; +} |