22012ee994
The commit added a final rounding choice for 8x8 forward dct to get rid of a sign bias at DC position and improve the accuracry in term of round trip error for 8x8 fDCT/iDCT. This commit also enabled forward 8x8 dct test. Change-Id: Ib67f99b0a24d513e230c7812bc04569d472fdc50
169 lines
5.0 KiB
C++
169 lines
5.0 KiB
C++
/*
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* Copyright (c) 2012 The WebM project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include <math.h>
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#include <stdlib.h>
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#include <string.h>
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#include "third_party/googletest/src/include/gtest/gtest.h"
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extern "C" {
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#include "vp9_rtcd.h"
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}
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#include "acm_random.h"
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#include "vpx/vpx_integer.h"
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using libvpx_test::ACMRandom;
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namespace {
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TEST(VP9Fdct8x8Test, SignBiasCheck) {
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ACMRandom rnd(ACMRandom::DeterministicSeed());
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int16_t test_input_block[64];
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int16_t test_output_block[64];
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const int pitch = 16;
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int count_sign_block[64][2];
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const int count_test_block = 100000;
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memset(count_sign_block, 0, sizeof(count_sign_block));
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for (int i = 0; i < count_test_block; ++i) {
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// Initialize a test block with input range [-255, 255].
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for (int j = 0; j < 64; ++j)
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test_input_block[j] = rnd.Rand8() - rnd.Rand8();
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vp9_short_fdct8x8_c(test_input_block, test_output_block, pitch);
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for (int j = 0; j < 64; ++j) {
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if (test_output_block[j] < 0)
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++count_sign_block[j][0];
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else if (test_output_block[j] > 0)
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++count_sign_block[j][1];
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}
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}
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for (int j = 0; j < 64; ++j) {
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const bool bias_acceptable = (abs(count_sign_block[j][0] -
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count_sign_block[j][1]) < 1000);
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EXPECT_TRUE(bias_acceptable)
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<< "Error: 8x8 FDCT has a sign bias > 1%"
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<< " for input range [-255, 255] at index " << j;
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}
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memset(count_sign_block, 0, sizeof(count_sign_block));
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for (int i = 0; i < count_test_block; ++i) {
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// Initialize a test block with input range [-15, 15].
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for (int j = 0; j < 64; ++j)
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test_input_block[j] = (rnd.Rand8() >> 4) - (rnd.Rand8() >> 4);
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vp9_short_fdct8x8_c(test_input_block, test_output_block, pitch);
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for (int j = 0; j < 64; ++j) {
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if (test_output_block[j] < 0)
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++count_sign_block[j][0];
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else if (test_output_block[j] > 0)
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++count_sign_block[j][1];
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}
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}
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for (int j = 0; j < 64; ++j) {
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const bool bias_acceptable = (abs(count_sign_block[j][0] -
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count_sign_block[j][1]) < 10000);
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EXPECT_TRUE(bias_acceptable)
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<< "Error: 8x8 FDCT has a sign bias > 10%"
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<< " for input range [-15, 15] at index " << j;
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}
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};
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TEST(VP9Fdct8x8Test, RoundTripErrorCheck) {
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ACMRandom rnd(ACMRandom::DeterministicSeed());
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int max_error = 0;
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double total_error = 0;
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const int count_test_block = 100000;
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for (int i = 0; i < count_test_block; ++i) {
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int16_t test_input_block[64];
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int16_t test_temp_block[64];
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int16_t test_output_block[64];
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// Initialize a test block with input range [-255, 255].
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for (int j = 0; j < 64; ++j)
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test_input_block[j] = rnd.Rand8() - rnd.Rand8();
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const int pitch = 16;
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vp9_short_fdct8x8_c(test_input_block, test_temp_block, pitch);
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for (int j = 0; j < 64; ++j){
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if(test_temp_block[j] > 0) {
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test_temp_block[j] += 2;
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test_temp_block[j] /= 4;
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test_temp_block[j] *= 4;
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} else {
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test_temp_block[j] -= 2;
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test_temp_block[j] /= 4;
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test_temp_block[j] *= 4;
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}
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}
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vp9_short_idct8x8_c(test_temp_block, test_output_block, pitch);
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for (int j = 0; j < 64; ++j) {
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const int diff = test_input_block[j] - test_output_block[j];
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const int error = diff * diff;
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if (max_error < error)
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max_error = error;
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total_error += error;
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}
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}
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EXPECT_GE(1, max_error)
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<< "Error: 8x8 FDCT/IDCT has an individual roundtrip error > 1";
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EXPECT_GE(count_test_block/5, total_error)
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<< "Error: 8x8 FDCT/IDCT has average roundtrip error > 1/5 per block";
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};
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TEST(VP9Fdct8x8Test, ExtremalCheck) {
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ACMRandom rnd(ACMRandom::DeterministicSeed());
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int max_error = 0;
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double total_error = 0;
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const int count_test_block = 100000;
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for (int i = 0; i < count_test_block; ++i) {
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int16_t test_input_block[64];
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int16_t test_temp_block[64];
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int16_t test_output_block[64];
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// Initialize a test block with input range {-255, 255}.
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for (int j = 0; j < 64; ++j)
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test_input_block[j] = rnd.Rand8() % 2 ? 255 : -256;
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const int pitch = 16;
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vp9_short_fdct8x8_c(test_input_block, test_temp_block, pitch);
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vp9_short_idct8x8_c(test_temp_block, test_output_block, pitch);
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for (int j = 0; j < 64; ++j) {
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const int diff = test_input_block[j] - test_output_block[j];
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const int error = diff * diff;
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if (max_error < error)
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max_error = error;
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total_error += error;
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}
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EXPECT_GE(1, max_error)
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<< "Error: Extremal 8x8 FDCT/IDCT has an"
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<< " individual roundtrip error > 1";
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EXPECT_GE(count_test_block/5, total_error)
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<< "Error: Extremal 8x8 FDCT/IDCT has average"
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<< " roundtrip error > 1/5 per block";
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}
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};
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} // namespace
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