brouter/brouter-codec/src/test/java/btools/codec/StatCoderContextTest.java
2019-06-29 10:11:59 +02:00

128 lines
3.2 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 = 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 = 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 = 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 = 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] );
}
}
}
}