brouter/brouter-codec/src/test/java/btools/codec/StatCoderContextTest.java
2022-07-25 06:14:46 +02:00

108 lines
3.1 KiB
Java

package btools.codec;
import java.util.Arrays;
import java.util.Random;
import org.junit.Assert;
import org.junit.Test;
public class StatCoderContextTest {
@Test
public void noisyVarBitsEncodeDecodeTest() {
byte[] ab = new byte[40000];
StatCoderContext ctx = new StatCoderContext(ab);
for (int noisybits = 1; noisybits < 12; noisybits++) {
for (int i = 0; i < 1000; i++) {
ctx.encodeNoisyNumber(i, noisybits);
}
}
ctx.closeAndGetEncodedLength();
ctx = new StatCoderContext(ab);
for (int noisybits = 1; noisybits < 12; noisybits++) {
for (int i = 0; i < 1000; i++) {
int value = ctx.decodeNoisyNumber(noisybits);
if (value != i) {
Assert.fail("value mismatch: noisybits=" + noisybits + " i=" + i + " value=" + value);
}
}
}
}
@Test
public void noisySignedVarBitsEncodeDecodeTest() {
byte[] ab = new byte[80000];
StatCoderContext ctx = new StatCoderContext(ab);
for (int noisybits = 0; noisybits < 12; noisybits++) {
for (int i = -1000; i < 1000; i++) {
ctx.encodeNoisyDiff(i, noisybits);
}
}
ctx.closeAndGetEncodedLength();
ctx = new StatCoderContext(ab);
for (int noisybits = 0; noisybits < 12; noisybits++) {
for (int i = -1000; i < 1000; i++) {
int value = ctx.decodeNoisyDiff(noisybits);
if (value != i) {
Assert.fail("value mismatch: noisybits=" + noisybits + " i=" + i + " value=" + value);
}
}
}
}
@Test
public void predictedValueEncodeDecodeTest() {
byte[] ab = new byte[80000];
StatCoderContext ctx = new StatCoderContext(ab);
for (int value = -100; value < 100; value += 5) {
for (int predictor = -200; predictor < 200; predictor += 7) {
ctx.encodePredictedValue(value, predictor);
}
}
ctx.closeAndGetEncodedLength();
ctx = new StatCoderContext(ab);
for (int value = -100; value < 100; value += 5) {
for (int predictor = -200; predictor < 200; predictor += 7) {
int decodedValue = ctx.decodePredictedValue(predictor);
if (value != decodedValue) {
Assert.fail("value mismatch: value=" + value + " predictor=" + predictor + " decodedValue=" + decodedValue);
}
}
}
}
@Test
public void sortedArrayEncodeDecodeTest() {
Random rand = new Random();
int size = 1000000;
int[] values = new int[size];
for (int i = 0; i < size; i++) {
values[i] = rand.nextInt() & 0x0fffffff;
}
values[5] = 175384; // force collision
values[8] = 175384;
values[15] = 275384; // force neighbours
values[18] = 275385;
Arrays.sort(values);
byte[] ab = new byte[3000000];
StatCoderContext ctx = new StatCoderContext(ab);
ctx.encodeSortedArray(values, 0, size, 0x08000000, 0);
ctx.closeAndGetEncodedLength();
ctx = new StatCoderContext(ab);
int[] decodedValues = new int[size];
ctx.decodeSortedArray(decodedValues, 0, size, 27, 0);
for (int i = 0; i < size; i++) {
if (values[i] != decodedValues[i]) {
Assert.fail("mismatch at i=" + i + " " + values[i] + "<>" + decodedValues[i]);
}
}
}
}