/* * Copyright (c) 2010 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #include "quant_common.h" static int dc_qlookup[QINDEX_RANGE]; static int ac_qlookup[QINDEX_RANGE]; #define ACDC_MIN 4 void vp9_init_quant_tables() { int i; int current_val = 4; int last_val = 4; int ac_val; for (i = 0; i < QINDEX_RANGE; i++) { ac_qlookup[i] = current_val; current_val = (int)((double)current_val * 1.02); if (current_val == last_val) current_val++; last_val = current_val; ac_val = ac_qlookup[i]; dc_qlookup[i] = (0.000000305 * ac_val * ac_val * ac_val) + (-0.00065 * ac_val * ac_val) + (0.9 * ac_val) + 0.5; if (dc_qlookup[i] < ACDC_MIN) dc_qlookup[i] = ACDC_MIN; } } int vp9_dc_quant(int QIndex, int Delta) { int retval; QIndex = QIndex + Delta; if (QIndex > MAXQ) QIndex = MAXQ; else if (QIndex < 0) QIndex = 0; retval = dc_qlookup[ QIndex ]; return retval; } int vp9_dc2quant(int QIndex, int Delta) { int retval; QIndex = QIndex + Delta; if (QIndex > MAXQ) QIndex = MAXQ; else if (QIndex < 0) QIndex = 0; retval = dc_qlookup[ QIndex ]; return retval; } int vp9_dc_uv_quant(int QIndex, int Delta) { int retval; QIndex = QIndex + Delta; if (QIndex > MAXQ) QIndex = MAXQ; else if (QIndex < 0) QIndex = 0; retval = dc_qlookup[ QIndex ]; return retval; } int vp9_ac_yquant(int QIndex) { int retval; if (QIndex > MAXQ) QIndex = MAXQ; else if (QIndex < 0) QIndex = 0; retval = ac_qlookup[ QIndex ]; return retval; } int vp9_ac2quant(int QIndex, int Delta) { int retval; QIndex = QIndex + Delta; if (QIndex > MAXQ) QIndex = MAXQ; else if (QIndex < 0) QIndex = 0; retval = (ac_qlookup[ QIndex ] * 775) / 1000; if (retval < 4) retval = 4; return retval; } int vp9_ac_uv_quant(int QIndex, int Delta) { int retval; QIndex = QIndex + Delta; if (QIndex > MAXQ) QIndex = MAXQ; else if (QIndex < 0) QIndex = 0; retval = ac_qlookup[ QIndex ]; return retval; }