aom/aom_dsp/quantize.c

/*
 * Copyright (c) 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.
 */

#include "aom_dsp/quantize.h"
#include "aom_mem/aom_mem.h"

void quantize_b_helper_c(const tran_low_t *coeff_ptr, intptr_t n_coeffs,
                         const int16_t *zbin_ptr, const int16_t *round_ptr,
                         const int16_t *quant_ptr,
                         const int16_t *quant_shift_ptr, tran_low_t *qcoeff_ptr,
                         tran_low_t *dqcoeff_ptr, const int16_t *dequant_ptr,
                         uint16_t *eob_ptr, const int16_t *scan,
                         const int16_t *iscan, const qm_val_t *qm_ptr,
                         const qm_val_t *iqm_ptr, const int log_scale) {
  const int zbins[2] = { ROUND_POWER_OF_TWO(zbin_ptr[0], log_scale),
                         ROUND_POWER_OF_TWO(zbin_ptr[1], log_scale) };
  const int nzbins[2] = { zbins[0] * -1, zbins[1] * -1 };
  int i, non_zero_count = (int)n_coeffs, eob = -1;
  (void)iscan;

  memset(qcoeff_ptr, 0, n_coeffs * sizeof(*qcoeff_ptr));
  memset(dqcoeff_ptr, 0, n_coeffs * sizeof(*dqcoeff_ptr));

  // Pre-scan pass
  for (i = (int)n_coeffs - 1; i >= 0; i--) {
    const int rc = scan[i];
    const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
    const int coeff = coeff_ptr[rc] * wt;

    if (coeff < (zbins[rc != 0] * (1 << AOM_QM_BITS)) &&
        coeff > (nzbins[rc != 0] * (1 << AOM_QM_BITS)))
      non_zero_count--;
    else
      break;
  }

  // Quantization pass: All coefficients with index >= zero_flag are
  // skippable. Note: zero_flag can be zero.
  for (i = 0; i < non_zero_count; i++) {
    const int rc = scan[i];
    const int coeff = coeff_ptr[rc];
    const int coeff_sign = (coeff >> 31);
    const int abs_coeff = (coeff ^ coeff_sign) - coeff_sign;
    int tmp32;

    const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
    if (abs_coeff * wt >= (zbins[rc != 0] << AOM_QM_BITS)) {
      int64_t tmp =
          clamp(abs_coeff + ROUND_POWER_OF_TWO(round_ptr[rc != 0], log_scale),
                INT16_MIN, INT16_MAX);
      tmp *= wt;
      tmp32 = (int)(((((tmp * quant_ptr[rc != 0]) >> 16) + tmp) *
                     quant_shift_ptr[rc != 0]) >>
                    (16 - log_scale + AOM_QM_BITS));  // quantization
      qcoeff_ptr[rc] = (tmp32 ^ coeff_sign) - coeff_sign;
      const int iwt = iqm_ptr != NULL ? iqm_ptr[rc] : (1 << AOM_QM_BITS);
      const int dequant =
          (dequant_ptr[rc != 0] * iwt + (1 << (AOM_QM_BITS - 1))) >>
          AOM_QM_BITS;
      const tran_low_t abs_dqcoeff = (tmp32 * dequant) >> log_scale;
      dqcoeff_ptr[rc] = (tran_low_t)((abs_dqcoeff ^ coeff_sign) - coeff_sign);

      if (tmp32) eob = i;
    }
  }
  *eob_ptr = eob + 1;
}

void highbd_quantize_b_helper_c(
    const tran_low_t *coeff_ptr, intptr_t n_coeffs, const int16_t *zbin_ptr,
    const int16_t *round_ptr, const int16_t *quant_ptr,
    const int16_t *quant_shift_ptr, tran_low_t *qcoeff_ptr,
    tran_low_t *dqcoeff_ptr, const int16_t *dequant_ptr, uint16_t *eob_ptr,
    const int16_t *scan, const int16_t *iscan, const qm_val_t *qm_ptr,
    const qm_val_t *iqm_ptr, const int log_scale) {
  int i, eob = -1;
  const int zbins[2] = { ROUND_POWER_OF_TWO(zbin_ptr[0], log_scale),
                         ROUND_POWER_OF_TWO(zbin_ptr[1], log_scale) };
  const int nzbins[2] = { zbins[0] * -1, zbins[1] * -1 };
  int dequant;
  int idx_arr[4096];
  (void)iscan;
  int idx = 0;

  memset(qcoeff_ptr, 0, n_coeffs * sizeof(*qcoeff_ptr));
  memset(dqcoeff_ptr, 0, n_coeffs * sizeof(*dqcoeff_ptr));

  // Pre-scan pass
  for (i = 0; i < n_coeffs; i++) {
    const int rc = scan[i];
    const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
    const int coeff = coeff_ptr[rc] * wt;

    // If the coefficient is out of the base ZBIN range, keep it for
    // quantization.
    if (coeff >= (zbins[rc != 0] * (1 << AOM_QM_BITS)) ||
        coeff <= (nzbins[rc != 0] * (1 << AOM_QM_BITS)))
      idx_arr[idx++] = i;
  }

  // Quantization pass: only process the coefficients selected in
  // pre-scan pass. Note: idx can be zero.
  for (i = 0; i < idx; i++) {
    const int rc = scan[idx_arr[i]];
    const int coeff = coeff_ptr[rc];
    const int coeff_sign = (coeff >> 31);
    const qm_val_t wt = qm_ptr != NULL ? qm_ptr[rc] : (1 << AOM_QM_BITS);
    const qm_val_t iwt = iqm_ptr != NULL ? iqm_ptr[rc] : (1 << AOM_QM_BITS);
    const int abs_coeff = (coeff ^ coeff_sign) - coeff_sign;
    const int64_t tmp1 =
        abs_coeff + ROUND_POWER_OF_TWO(round_ptr[rc != 0], log_scale);
    const int64_t tmpw = tmp1 * wt;
    const int64_t tmp2 = ((tmpw * quant_ptr[rc != 0]) >> 16) + tmpw;
    const int abs_qcoeff = (int)((tmp2 * quant_shift_ptr[rc != 0]) >>
                                 (16 - log_scale + AOM_QM_BITS));
    qcoeff_ptr[rc] = (tran_low_t)((abs_qcoeff ^ coeff_sign) - coeff_sign);
    dequant =
        (dequant_ptr[rc != 0] * iwt + (1 << (AOM_QM_BITS - 1))) >> AOM_QM_BITS;
    const tran_low_t abs_dqcoeff = (abs_qcoeff * dequant) >> log_scale;
    dqcoeff_ptr[rc] = (tran_low_t)((abs_dqcoeff ^ coeff_sign) - coeff_sign);
    if (abs_qcoeff) eob = idx_arr[i];
  }
  *eob_ptr = eob + 1;
}

/* These functions should only be called when quantisation matrices
   are not used. */
void aom_quantize_b_c(const tran_low_t *coeff_ptr, intptr_t n_coeffs,
                      const int16_t *zbin_ptr, const int16_t *round_ptr,
                      const int16_t *quant_ptr, const int16_t *quant_shift_ptr,
                      tran_low_t *qcoeff_ptr, tran_low_t *dqcoeff_ptr,
                      const int16_t *dequant_ptr, uint16_t *eob_ptr,
                      const int16_t *scan, const int16_t *iscan) {
  quantize_b_helper_c(coeff_ptr, n_coeffs, zbin_ptr, round_ptr, quant_ptr,
                      quant_shift_ptr, qcoeff_ptr, dqcoeff_ptr, dequant_ptr,
                      eob_ptr, scan, iscan, NULL, NULL, 0);
}

void aom_quantize_b_32x32_c(const tran_low_t *coeff_ptr, intptr_t n_coeffs,
                            const int16_t *zbin_ptr, const int16_t *round_ptr,
                            const int16_t *quant_ptr,
                            const int16_t *quant_shift_ptr,
                            tran_low_t *qcoeff_ptr, tran_low_t *dqcoeff_ptr,
                            const int16_t *dequant_ptr, uint16_t *eob_ptr,
                            const int16_t *scan, const int16_t *iscan) {
  quantize_b_helper_c(coeff_ptr, n_coeffs, zbin_ptr, round_ptr, quant_ptr,
                      quant_shift_ptr, qcoeff_ptr, dqcoeff_ptr, dequant_ptr,
                      eob_ptr, scan, iscan, NULL, NULL, 1);
}

void aom_quantize_b_64x64_c(const tran_low_t *coeff_ptr, intptr_t n_coeffs,
                            const int16_t *zbin_ptr, const int16_t *round_ptr,
                            const int16_t *quant_ptr,
                            const int16_t *quant_shift_ptr,
                            tran_low_t *qcoeff_ptr, tran_low_t *dqcoeff_ptr,
                            const int16_t *dequant_ptr, uint16_t *eob_ptr,
                            const int16_t *scan, const int16_t *iscan) {
  quantize_b_helper_c(coeff_ptr, n_coeffs, zbin_ptr, round_ptr, quant_ptr,
                      quant_shift_ptr, qcoeff_ptr, dqcoeff_ptr, dequant_ptr,
                      eob_ptr, scan, iscan, NULL, NULL, 2);
}

void aom_highbd_quantize_b_c(const tran_low_t *coeff_ptr, intptr_t n_coeffs,
                             const int16_t *zbin_ptr, const int16_t *round_ptr,
                             const int16_t *quant_ptr,
                             const int16_t *quant_shift_ptr,
                             tran_low_t *qcoeff_ptr, tran_low_t *dqcoeff_ptr,
                             const int16_t *dequant_ptr, uint16_t *eob_ptr,
                             const int16_t *scan, const int16_t *iscan) {
  highbd_quantize_b_helper_c(coeff_ptr, n_coeffs, zbin_ptr, round_ptr,
                             quant_ptr, quant_shift_ptr, qcoeff_ptr,
                             dqcoeff_ptr, dequant_ptr, eob_ptr, scan, iscan,
                             NULL, NULL, 0);
}

void aom_highbd_quantize_b_32x32_c(
    const tran_low_t *coeff_ptr, intptr_t n_coeffs, const int16_t *zbin_ptr,
    const int16_t *round_ptr, const int16_t *quant_ptr,
    const int16_t *quant_shift_ptr, tran_low_t *qcoeff_ptr,
    tran_low_t *dqcoeff_ptr, const int16_t *dequant_ptr, uint16_t *eob_ptr,
    const int16_t *scan, const int16_t *iscan) {
  highbd_quantize_b_helper_c(coeff_ptr, n_coeffs, zbin_ptr, round_ptr,
                             quant_ptr, quant_shift_ptr, qcoeff_ptr,
                             dqcoeff_ptr, dequant_ptr, eob_ptr, scan, iscan,
                             NULL, NULL, 1);
}

void aom_highbd_quantize_b_64x64_c(
    const tran_low_t *coeff_ptr, intptr_t n_coeffs, const int16_t *zbin_ptr,
    const int16_t *round_ptr, const int16_t *quant_ptr,
    const int16_t *quant_shift_ptr, tran_low_t *qcoeff_ptr,
    tran_low_t *dqcoeff_ptr, const int16_t *dequant_ptr, uint16_t *eob_ptr,
    const int16_t *scan, const int16_t *iscan) {
  highbd_quantize_b_helper_c(coeff_ptr, n_coeffs, zbin_ptr, round_ptr,
                             quant_ptr, quant_shift_ptr, qcoeff_ptr,
                             dqcoeff_ptr, dequant_ptr, eob_ptr, scan, iscan,
                             NULL, NULL, 2);
}