Commit b5c50ae9 authored by James Zern's avatar James Zern Committed by Gerrit Code Review

Merge "Revert "add range_check for fdct in vp10""

parents 3080691e 43a4900e
......@@ -44,8 +44,6 @@ LIBVPX_TEST_SRCS-$(CONFIG_VP9_ENCODER) += vp9_lossless_test.cc
LIBVPX_TEST_SRCS-$(CONFIG_VP9_ENCODER) += vp9_end_to_end_test.cc
LIBVPX_TEST_SRCS-$(CONFIG_VP9_ENCODER) += vp9_ethread_test.cc
LIBVPX_TEST_SRCS-$(CONFIG_VP10_ENCODER) += vp10_dct_test.cc
LIBVPX_TEST_SRCS-yes += decode_test_driver.cc
LIBVPX_TEST_SRCS-yes += decode_test_driver.h
LIBVPX_TEST_SRCS-$(CONFIG_ENCODERS) += encode_test_driver.cc
......
#include <stdlib.h>
#include "third_party/googletest/src/include/gtest/gtest.h"
#include "test/acm_random.h"
#include "test/util.h"
#include "vp10/encoder/dct.c"
using libvpx_test::ACMRandom;
namespace {
void reference_dct_1d(const double *in, double *out, int size) {
const double PI = 3.141592653589793238462643383279502884;
const double kInvSqrt2 = 0.707106781186547524400844362104;
for (int k = 0; k < size; ++k) {
out[k] = 0; // initialize out[k]
for (int n = 0; n < size; ++n) {
out[k] += in[n] * cos(PI * (2 * n + 1) * k / (2*size));
}
if (k == 0)
out[k] = out[k] * kInvSqrt2;
}
}
typedef void (*FdctFuncRef)(const double *in, double *out, int size);
typedef void (*IdctFuncRef)(const double *in, double *out, int size);
typedef void (*FdctFunc)(const tran_low_t *in, tran_low_t *out);
typedef void (*IdctFunc)(const tran_low_t *in, tran_low_t *out);
class TransTestBase {
public:
virtual ~TransTestBase() {}
protected:
double max_error;
int txfmSize;
FdctFunc fwd_txfm;
FdctFuncRef fwd_txfm_ref;
virtual void RunFwdAccuracyCheck() {
tran_low_t* input = new tran_low_t[txfmSize];
tran_low_t* output = new tran_low_t[txfmSize];
double* refInput = new double[txfmSize];
double* refOutput = new double[txfmSize];
ACMRandom rnd(ACMRandom::DeterministicSeed());
const int count_test_block = 5000;
for (int ti = 0; ti < count_test_block; ++ti) {
for (int ni = 0; ni < txfmSize; ++ni) {
input[ni] = rnd.Rand8() - rnd.Rand8();
refInput[ni] = (double)input[ni];
}
fwd_txfm(input, output);
fwd_txfm_ref(refInput, refOutput, txfmSize);
for (int ni = 0; ni < txfmSize; ++ni) {
EXPECT_LE(abs(output[ni]-(tran_low_t)round(refOutput[ni])),
max_error);
}
}
delete[] input;
delete[] output;
delete[] refInput;
delete[] refOutput;
}
};
typedef std::tr1::tuple<FdctFunc, FdctFuncRef, int, int> FdctParam;
class Vp10FwdDct
: public TransTestBase,
public ::testing::TestWithParam<FdctParam> {
public:
virtual void SetUp() {
fwd_txfm = GET_PARAM(0);
fwd_txfm_ref = GET_PARAM(1);
txfmSize = GET_PARAM(2);
max_error = GET_PARAM(3);
}
virtual void TearDown(){}
};
TEST_P(Vp10FwdDct, RunFwdAccuracyCheck) {
RunFwdAccuracyCheck();
}
INSTANTIATE_TEST_CASE_P(
C, Vp10FwdDct,
::testing::Values(
FdctParam(&fdct4, &reference_dct_1d, 4, 1),
FdctParam(&fdct8, &reference_dct_1d, 8, 1),
FdctParam(&fdct16, &reference_dct_1d, 16, 2),
FdctParam(&fdct32, &reference_dct_1d, 32, 4))
);
} // namespace
......@@ -20,701 +20,216 @@
#include "vpx_dsp/fwd_txfm.h"
#include "vpx_ports/mem.h"
static INLINE void range_check(const tran_low_t *input,
const int size,
const int bitNum) {
#if CONFIG_COEFFICIENT_RANGE_CHECKING
int i;
for (i = 0; i < size; ++i) {
assert(abs(input[i]) < (1 << bitNum));
}
#endif
}
static void fdct4(const tran_low_t *input, tran_low_t *output) {
tran_high_t temp;
tran_low_t step[4];
// stage 0
range_check(input, 4, 11);
// stage 1
output[0] = input[0] + input[3];
output[1] = input[1] + input[2];
output[2] = -input[2] + input[1];
output[3] = -input[3] + input[0];
range_check(output, 4, 12);
// stage 2
temp = output[0] * cospi_16_64 + output[1] * cospi_16_64;
step[0] = fdct_round_shift(temp);
temp = output[1] * -cospi_16_64 + output[0] * cospi_16_64;
step[1] = fdct_round_shift(temp);
temp = output[2] * cospi_24_64 + output[3] * cospi_8_64;
step[2] = fdct_round_shift(temp);
temp = output[3] * cospi_24_64 + output[2] * -cospi_8_64;
step[3] = fdct_round_shift(temp);
range_check(step, 4, 13);
// stage 3
output[0] = step[0];
output[1] = step[2];
output[2] = step[1];
output[3] = step[3];
range_check(output, 4, 13);
tran_high_t step[4];
tran_high_t temp1, temp2;
step[0] = input[0] + input[3];
step[1] = input[1] + input[2];
step[2] = input[1] - input[2];
step[3] = input[0] - input[3];
temp1 = (step[0] + step[1]) * cospi_16_64;
temp2 = (step[0] - step[1]) * cospi_16_64;
output[0] = (tran_low_t)fdct_round_shift(temp1);
output[2] = (tran_low_t)fdct_round_shift(temp2);
temp1 = step[2] * cospi_24_64 + step[3] * cospi_8_64;
temp2 = -step[2] * cospi_8_64 + step[3] * cospi_24_64;
output[1] = (tran_low_t)fdct_round_shift(temp1);
output[3] = (tran_low_t)fdct_round_shift(temp2);
}
static void fdct8(const tran_low_t *input, tran_low_t *output) {
tran_high_t temp;
tran_low_t step[8];
// stage 0
range_check(input, 8, 12);
tran_high_t s0, s1, s2, s3, s4, s5, s6, s7; // canbe16
tran_high_t t0, t1, t2, t3; // needs32
tran_high_t x0, x1, x2, x3; // canbe16
// stage 1
output[0] = input[0] + input[7];
output[1] = input[1] + input[6];
output[2] = input[2] + input[5];
output[3] = input[3] + input[4];
output[4] = -input[4] + input[3];
output[5] = -input[5] + input[2];
output[6] = -input[6] + input[1];
output[7] = -input[7] + input[0];
range_check(output, 8, 13);
// stage 2
step[0] = output[0] + output[3];
step[1] = output[1] + output[2];
step[2] = -output[2] + output[1];
step[3] = -output[3] + output[0];
step[4] = output[4];
temp = output[5] * -cospi_16_64 + output[6] * cospi_16_64;
step[5] = fdct_round_shift(temp);
temp = output[6] * cospi_16_64 + output[5] * cospi_16_64;
step[6] = fdct_round_shift(temp);
step[7] = output[7];
range_check(step, 8, 14);
// stage 3
temp = step[0] * cospi_16_64 + step[1] * cospi_16_64;
output[0] = fdct_round_shift(temp);
temp = step[1] * -cospi_16_64 + step[0] * cospi_16_64;
output[1] = fdct_round_shift(temp);
temp = step[2] * cospi_24_64 + step[3] * cospi_8_64;
output[2] = fdct_round_shift(temp);
temp = step[3] * cospi_24_64 + step[2] * -cospi_8_64;
output[3] = fdct_round_shift(temp);
output[4] = step[4] + step[5];
output[5] = -step[5] + step[4];
output[6] = -step[6] + step[7];
output[7] = step[7] + step[6];
range_check(output, 8, 14);
// stage 4
step[0] = output[0];
step[1] = output[1];
step[2] = output[2];
step[3] = output[3];
temp = output[4] * cospi_28_64 + output[7] * cospi_4_64;
step[4] = fdct_round_shift(temp);
temp = output[5] * cospi_12_64 + output[6] * cospi_20_64;
step[5] = fdct_round_shift(temp);
temp = output[6] * cospi_12_64 + output[5] * -cospi_20_64;
step[6] = fdct_round_shift(temp);
temp = output[7] * cospi_28_64 + output[4] * -cospi_4_64;
step[7] = fdct_round_shift(temp);
range_check(step, 8, 14);
// stage 5
output[0] = step[0];
output[1] = step[4];
output[2] = step[2];
output[3] = step[6];
output[4] = step[1];
output[5] = step[5];
output[6] = step[3];
output[7] = step[7];
range_check(output, 8, 14);
s0 = input[0] + input[7];
s1 = input[1] + input[6];
s2 = input[2] + input[5];
s3 = input[3] + input[4];
s4 = input[3] - input[4];
s5 = input[2] - input[5];
s6 = input[1] - input[6];
s7 = input[0] - input[7];
// fdct4(step, step);
x0 = s0 + s3;
x1 = s1 + s2;
x2 = s1 - s2;
x3 = s0 - s3;
t0 = (x0 + x1) * cospi_16_64;
t1 = (x0 - x1) * cospi_16_64;
t2 = x2 * cospi_24_64 + x3 * cospi_8_64;
t3 = -x2 * cospi_8_64 + x3 * cospi_24_64;
output[0] = (tran_low_t)fdct_round_shift(t0);
output[2] = (tran_low_t)fdct_round_shift(t2);
output[4] = (tran_low_t)fdct_round_shift(t1);
output[6] = (tran_low_t)fdct_round_shift(t3);
// Stage 2
t0 = (s6 - s5) * cospi_16_64;
t1 = (s6 + s5) * cospi_16_64;
t2 = (tran_low_t)fdct_round_shift(t0);
t3 = (tran_low_t)fdct_round_shift(t1);
// Stage 3
x0 = s4 + t2;
x1 = s4 - t2;
x2 = s7 - t3;
x3 = s7 + t3;
// Stage 4
t0 = x0 * cospi_28_64 + x3 * cospi_4_64;
t1 = x1 * cospi_12_64 + x2 * cospi_20_64;
t2 = x2 * cospi_12_64 + x1 * -cospi_20_64;
t3 = x3 * cospi_28_64 + x0 * -cospi_4_64;
output[1] = (tran_low_t)fdct_round_shift(t0);
output[3] = (tran_low_t)fdct_round_shift(t2);
output[5] = (tran_low_t)fdct_round_shift(t1);
output[7] = (tran_low_t)fdct_round_shift(t3);
}
static void fdct16(const tran_low_t *input, tran_low_t *output) {
tran_high_t temp;
tran_low_t step[16];
// stage 0
range_check(input, 16, 13);
// stage 1
output[0] = input[0] + input[15];
output[1] = input[1] + input[14];
output[2] = input[2] + input[13];
output[3] = input[3] + input[12];
output[4] = input[4] + input[11];
output[5] = input[5] + input[10];
output[6] = input[6] + input[9];
output[7] = input[7] + input[8];
output[8] = -input[8] + input[7];
output[9] = -input[9] + input[6];
output[10] = -input[10] + input[5];
output[11] = -input[11] + input[4];
output[12] = -input[12] + input[3];
output[13] = -input[13] + input[2];
output[14] = -input[14] + input[1];
output[15] = -input[15] + input[0];
range_check(output, 16, 14);
// stage 2
step[0] = output[0] + output[7];
step[1] = output[1] + output[6];
step[2] = output[2] + output[5];
step[3] = output[3] + output[4];
step[4] = -output[4] + output[3];
step[5] = -output[5] + output[2];
step[6] = -output[6] + output[1];
step[7] = -output[7] + output[0];
step[8] = output[8];
step[9] = output[9];
temp = output[10] * -cospi_16_64 + output[13] * cospi_16_64;
step[10] = fdct_round_shift(temp);
temp = output[11] * -cospi_16_64 + output[12] * cospi_16_64;
step[11] = fdct_round_shift(temp);
temp = output[12] * cospi_16_64 + output[11] * cospi_16_64;
step[12] = fdct_round_shift(temp);
temp = output[13] * cospi_16_64 + output[10] * cospi_16_64;
step[13] = fdct_round_shift(temp);
step[14] = output[14];
step[15] = output[15];
range_check(step, 16, 15);
// stage 3
output[0] = step[0] + step[3];
output[1] = step[1] + step[2];
output[2] = -step[2] + step[1];
output[3] = -step[3] + step[0];
output[4] = step[4];
temp = step[5] * -cospi_16_64 + step[6] * cospi_16_64;
output[5] = fdct_round_shift(temp);
temp = step[6] * cospi_16_64 + step[5] * cospi_16_64;
output[6] = fdct_round_shift(temp);
output[7] = step[7];
output[8] = step[8] + step[11];
output[9] = step[9] + step[10];
output[10] = -step[10] + step[9];
output[11] = -step[11] + step[8];
output[12] = -step[12] + step[15];
output[13] = -step[13] + step[14];
output[14] = step[14] + step[13];
output[15] = step[15] + step[12];
range_check(output, 16, 16);
// stage 4
temp = output[0] * cospi_16_64 + output[1] * cospi_16_64;
step[0] = fdct_round_shift(temp);
temp = output[1] * -cospi_16_64 + output[0] * cospi_16_64;
step[1] = fdct_round_shift(temp);
temp = output[2] * cospi_24_64 + output[3] * cospi_8_64;
step[2] = fdct_round_shift(temp);
temp = output[3] * cospi_24_64 + output[2] * -cospi_8_64;
step[3] = fdct_round_shift(temp);
step[4] = output[4] + output[5];
step[5] = -output[5] + output[4];
step[6] = -output[6] + output[7];
step[7] = output[7] + output[6];
step[8] = output[8];
temp = output[9] * -cospi_8_64 + output[14] * cospi_24_64;
step[9] = fdct_round_shift(temp);
temp = output[10] * -cospi_24_64 + output[13] * -cospi_8_64;
step[10] = fdct_round_shift(temp);
step[11] = output[11];
step[12] = output[12];
temp = output[13] * cospi_24_64 + output[10] * -cospi_8_64;
step[13] = fdct_round_shift(temp);
temp = output[14] * cospi_8_64 + output[9] * cospi_24_64;
step[14] = fdct_round_shift(temp);
step[15] = output[15];
range_check(step, 16, 16);
// stage 5
output[0] = step[0];
output[1] = step[1];
output[2] = step[2];
output[3] = step[3];
temp = step[4] * cospi_28_64 + step[7] * cospi_4_64;
output[4] = fdct_round_shift(temp);
temp = step[5] * cospi_12_64 + step[6] * cospi_20_64;
output[5] = fdct_round_shift(temp);
temp = step[6] * cospi_12_64 + step[5] * -cospi_20_64;
output[6] = fdct_round_shift(temp);
temp = step[7] * cospi_28_64 + step[4] * -cospi_4_64;
output[7] = fdct_round_shift(temp);
output[8] = step[8] + step[9];
output[9] = -step[9] + step[8];
output[10] = -step[10] + step[11];
output[11] = step[11] + step[10];
output[12] = step[12] + step[13];
output[13] = -step[13] + step[12];
output[14] = -step[14] + step[15];
output[15] = step[15] + step[14];
range_check(output, 16, 16);
// stage 6
step[0] = output[0];
step[1] = output[1];
step[2] = output[2];
step[3] = output[3];
step[4] = output[4];
step[5] = output[5];
step[6] = output[6];
step[7] = output[7];
temp = output[8] * cospi_30_64 + output[15] * cospi_2_64;
step[8] = fdct_round_shift(temp);
temp = output[9] * cospi_14_64 + output[14] * cospi_18_64;
step[9] = fdct_round_shift(temp);
temp = output[10] * cospi_22_64 + output[13] * cospi_10_64;
step[10] = fdct_round_shift(temp);
temp = output[11] * cospi_6_64 + output[12] * cospi_26_64;
step[11] = fdct_round_shift(temp);
temp = output[12] * cospi_6_64 + output[11] * -cospi_26_64;
step[12] = fdct_round_shift(temp);
temp = output[13] * cospi_22_64 + output[10] * -cospi_10_64;
step[13] = fdct_round_shift(temp);
temp = output[14] * cospi_14_64 + output[9] * -cospi_18_64;
step[14] = fdct_round_shift(temp);
temp = output[15] * cospi_30_64 + output[8] * -cospi_2_64;
step[15] = fdct_round_shift(temp);
range_check(step, 16, 16);
// stage 7
output[0] = step[0];
output[1] = step[8];
output[2] = step[4];
output[3] = step[12];
output[4] = step[2];
output[5] = step[10];
output[6] = step[6];
output[7] = step[14];
output[8] = step[1];
output[9] = step[9];
output[10] = step[5];
output[11] = step[13];
output[12] = step[3];
output[13] = step[11];
output[14] = step[7];
output[15] = step[15];
range_check(output, 16, 16);
}
static void fdct32(const tran_low_t *input, tran_low_t *output) {
tran_high_t temp;
tran_low_t step[32];
// stage 0
range_check(input, 32, 14);
// stage 1
output[0] = input[0] + input[31];
output[1] = input[1] + input[30];
output[2] = input[2] + input[29];
output[3] = input[3] + input[28];
output[4] = input[4] + input[27];
output[5] = input[5] + input[26];
output[6] = input[6] + input[25];
output[7] = input[7] + input[24];
output[8] = input[8] + input[23];
output[9] = input[9] + input[22];
output[10] = input[10] + input[21];
output[11] = input[11] + input[20];
output[12] = input[12] + input[19];
output[13] = input[13] + input[18];
output[14] = input[14] + input[17];
output[15] = input[15] + input[16];
output[16] = -input[16] + input[15];
output[17] = -input[17] + input[14];
output[18] = -input[18] + input[13];
output[19] = -input[19] + input[12];
output[20] = -input[20] + input[11];
output[21] = -input[21] + input[10];
output[22] = -input[22] + input[9];
output[23] = -input[23] + input[8];
output[24] = -input[24] + input[7];
output[25] = -input[25] + input[6];
output[26] = -input[26] + input[5];
output[27] = -input[27] + input[4];
output[28] = -input[28] + input[3];
output[29] = -input[29] + input[2];
output[30] = -input[30] + input[1];
output[31] = -input[31] + input[0];
range_check(output, 32, 15);
// stage 2
step[0] = output[0] + output[15];
step[1] = output[1] + output[14];
step[2] = output[2] + output[13];
step[3] = output[3] + output[12];
step[4] = output[4] + output[11];
step[5] = output[5] + output[10];
step[6] = output[6] + output[9];
step[7] = output[7] + output[8];
step[8] = -output[8] + output[7];
step[9] = -output[9] + output[6];
step[10] = -output[10] + output[5];
step[11] = -output[11] + output[4];
step[12] = -output[12] + output[3];
step[13] = -output[13] + output[2];
step[14] = -output[14] + output[1];
step[15] = -output[15] + output[0];
step[16] = output[16];
step[17] = output[17];
step[18] = output[18];
step[19] = output[19];
temp = output[20] * -cospi_16_64 + output[27] * cospi_16_64;
step[20] = fdct_round_shift(temp);
temp = output[21] * -cospi_16_64 + output[26] * cospi_16_64;
step[21] = fdct_round_shift(temp);
temp = output[22] * -cospi_16_64 + output[25] * cospi_16_64;
step[22] = fdct_round_shift(temp);
temp = output[23] * -cospi_16_64 + output[24] * cospi_16_64;
step[23] = fdct_round_shift(temp);
temp = output[24] * cospi_16_64 + output[23] * cospi_16_64;
step[24] = fdct_round_shift(temp);
temp = output[25] * cospi_16_64 + output[22] * cospi_16_64;
step[25] = fdct_round_shift(temp);
temp = output[26] * cospi_16_64 + output[21] * cospi_16_64;
step[26] = fdct_round_shift(temp);
temp = output[27] * cospi_16_64 + output[20] * cospi_16_64;
step[27] = fdct_round_shift(temp);
step[28] = output[28];
step[29] = output[29];
step[30] = output[30];
step[31] = output[31];
range_check(step, 32, 16);
static void fdct16(const tran_low_t in[16], tran_low_t out[16]) {
tran_high_t step1[8]; // canbe16
tran_high_t step2[8]; // canbe16
tran_high_t step3[8]; // canbe16
tran_high_t input[8]; // canbe16
tran_high_t temp1, temp2; // needs32
// step 1
input[0] = in[0] + in[15];
input[1] = in[1] + in[14];
input[2] = in[2] + in[13];
input[3] = in[3] + in[12];
input[4] = in[4] + in[11];
input[5] = in[5] + in[10];
input[6] = in[6] + in[ 9];
input[7] = in[7] + in[ 8];
step1[0] = in[7] - in[ 8];
step1[1] = in[6] - in[ 9];
step1[2] = in[5] - in[10];
step1[3] = in[4] - in[11];
step1[4] = in[3] - in[12];
step1[5] = in[2] - in[13];
step1[6] = in[1] - in[14];
step1[7] = in[0] - in[15];
// fdct8(step, step);
{
tran_high_t s0, s1, s2, s3, s4, s5, s6, s7; // canbe16
tran_high_t t0, t1, t2, t3; // needs32
tran_high_t x0, x1, x2, x3; // canbe16
// stage 3
output[0] = step[0] + step[7];
output[1] = step[1] + step[6];
output[2] = step[2] + step[5];
output[3] = step[3] + step[4];
output[4] = -step[4] + step[3];
output[5] = -step[5] + step[2];
output[6] = -step[6] + step[1];
output[7] = -step[7] + step[0];
output[8] = step[8];
output[9] = step[9];
temp = step[10] * -cospi_16_64 + step[13] * cospi_16_64;
output[10] = fdct_round_shift(temp);
temp = step[11] * -cospi_16_64 + step[12] * cospi_16_64;
output[11] = fdct_round_shift(temp);
temp = step[12] * cospi_16_64 + step[11] * cospi_16_64;
output[12] = fdct_round_shift(temp);
temp = step[13] * cospi_16_64 + step[10] * cospi_16_64;
output[13] = fdct_round_shift(temp);
output[14] = step[14];
output[15] = step[15];
output[16] = step[16] + step[23];
output[17] = step[17] + step[22];
output[18] = step[18] + step[21];
output[19] = step[19] + step[20];
output[20] = -step[20] + step[19];
output[21] = -step[21] + step[18];
output[22] = -step[22] + step[17];
output[23] = -step[23] + step[16];
output[24] = -step[24] + step[31];
output[25] = -step[25] + step[30];
output[26] = -step[26] + step[29];
output[27] = -step[27] + step[28];
output[28] = step[28] + step[27];
output[29] = step[29] + step[26];
output[30] = step[30] + step[25];
output[31] = step[31] + step[24];
range_check(output, 32, 17);
// stage 1
s0 = input[0] + input[7];
s1 = input[1] + input[6];
s2 = input[2] + input[5];
s3 = input[3] + input[4];
s4 = input[3] - input[4];
s5 = input[2] - input[5];
s6 = input[1] - input[6];
s7 = input[0] - input[7];
// fdct4(step, step);
x0 = s0 + s3;
x1 = s1 + s2;
x2 = s1 - s2;
x3 = s0 - s3;
t0 = (x0 + x1) * cospi_16_64;
t1 = (x0 - x1) * cospi_16_64;
t2 = x3 * cospi_8_64 + x2 * cospi_24_64;
t3 = x3 * cospi_24_64 - x2 * cospi_8_64;
out[0] = (tran_low_t)fdct_round_shift(t0);
out[4] = (tran_low_t)fdct_round_shift(t2);
out[8] = (tran_low_t)fdct_round_shift(t1);
out[12] = (tran_low_t)fdct_round_shift(t3);
// Stage 2
t0 = (s6 - s5) * cospi_16_64;
t1 = (s6 + s5) * cospi_16_64;
t2 = fdct_round_shift(t0);
t3 = fdct_round_shift(t1);
// Stage 3
x0 = s4 + t2;
x1 = s4 - t2;
x2 = s7 - t3;
x3 = s7 + t3;
// Stage 4
t0 = x0 * cospi_28_64 + x3 * cospi_4_64;
t1 = x1 * cospi_12_64 + x2 * cospi_20_64;
t2 = x2 * cospi_12_64 + x1 * -cospi_20_64;
t3 = x3 * cospi_28_64 + x0 * -cospi_4_64;
out[2] = (tran_low_t)fdct_round_shift(t0);
out[6] = (tran_low_t)fdct_round_shift(t2);
out[10] = (tran_low_t)fdct_round_shift(t1);
out[14] = (tran_low_t)fdct_round_shift(t3);
}
// stage 4
step[0] = output[0] + output[3];
step[1] = output[1] + output[2];
step[2] = -output[2] + output[1];
step[3] = -output[3] + output[0];
step[4] = output[4];
temp = output[5] * -cospi_16_64 + output[6] * cospi_16_64;
step[5] = fdct_round_shift(temp);