GitHub/sdrtrunk
1
0
Fork 0
mirror of https://github.com/DSheirer/sdrtrunk.git synced 2026-11-12 16:47:31 -05:00
Code Issues Packages Projects Releases 2 Wiki Activity

Performance improvements (#746)

Browse Source 
* Misc minor performance improvements

* Use more concise loop syntax

* Use more concise Collection sort syntax

* Use StringUtils pad methods

* Optimize some loops and double-map-lookups

* Optimize array instantiation

There are two styles to convert a collection to an array: either
using a pre-sized array (like c.toArray(new String[c.size()])) or
using an empty array (like c.toArray(new String[0]).

In older Java versions using pre-sized array was recommended,
as the reflection call which is necessary to create an array
of proper size was quite slow. However since late updates of
OpenJDK 6 this call was intrinsified, making the performance
of the empty array version the same and sometimes even better,
compared to the pre-sized version. Also passing pre-sized array
is dangerous for a concurrent or synchronized collection as
a data race is possible between the size and toArray call
which may result in extra nulls at the end of the array,
if the collection was concurrently shrunk during the operation.

* Cleanup string concatenation

* Use EnumMap where possible

* Use FastMath instead of Math

* Initialize complex things only once

* Reduce method size to aloow more JIT inlining

* remove map of short->float

* Move field to local variable

* Cleanup Map lookup

Co-authored-by: Rob Ekl <xwq876@zebra.com>
This commit is contained in:
robekl
2020-04-25 07:57:56 -04:00
committed by GitHub
parent 649258bd2b
commit 39f6d6c831
186 changed files with 2840 additions and 3464 deletions
Download Patch File Download Diff File Expand all files Collapse all files

19
src/main/java/io/github/dsheirer/dsp/gain/AutomaticGainControl.java
View File

@@ -4,6 +4,7 @@ import io.github.dsheirer.buffer.DoubleCircularBuffer;
import io.github.dsheirer.buffer.RealCircularBuffer;
import io.github.dsheirer.sample.buffer.ReusableBufferQueue;
import io.github.dsheirer.sample.buffer.ReusableFloatBuffer;
import org.apache.commons.math3.util.FastMath;
/*******************************************************************************
* SDR Trunk
@@ -74,10 +75,10 @@ public class AutomaticGainControl
private static final double ATTACK_FALL_TIME_CONSTANT = 0.005;
private static final double ATTACK_RISE_ALPHA = 1.0 -
Math.exp(-1.0 / SAMPLE_RATE * ATTACK_RISE_TIME_CONSTANT);
FastMath.exp(-1.0 / SAMPLE_RATE * ATTACK_RISE_TIME_CONSTANT);
private static final double ATTACK_FALL_ALPHA = 1.0 -
Math.exp(-1.0 / SAMPLE_RATE * ATTACK_FALL_TIME_CONSTANT);
FastMath.exp(-1.0 / SAMPLE_RATE * ATTACK_FALL_TIME_CONSTANT);
/* AGC decay value in milliseconds (20 to 5000) */
private static final double DECAY = 200;
@@ -87,10 +88,10 @@ public class AutomaticGainControl
private static final double DECAY_RISEFALL_RATIO = 0.3;
private static final double DECAY_RISE_ALPHA = 1.0 -
Math.exp(-1.0 / (SAMPLE_RATE * DECAY * .001 * DECAY_RISEFALL_RATIO));
FastMath.exp(-1.0 / (SAMPLE_RATE * DECAY * .001 * DECAY_RISEFALL_RATIO));
private static final double DECAY_FALL_ALPHA = 1.0 -
Math.exp(-1.0 / (SAMPLE_RATE * DECAY * .001));
FastMath.exp(-1.0 / (SAMPLE_RATE * DECAY * .001));
/* Hang timer release decay time constant in seconds */
@SuppressWarnings("unused")
@@ -110,7 +111,7 @@ public class AutomaticGainControl
private static final double MANUAL_GAIN = 0.0;
private static final double MANUAL_AGC_GAIN = MAX_MANUAL_AMPLITUDE *
Math.pow(10.0, MANUAL_GAIN / 20.0);
FastMath.pow(10.0, MANUAL_GAIN / 20.0);
/* Specifies dB reduction in output at knee from max output level (0 - 10dB) */
private static final double SLOPE_FACTOR = 2.0;
@@ -120,7 +121,7 @@ public class AutomaticGainControl
private static final double GAIN_SLOPE = SLOPE_FACTOR / 100.0;
private static final double FIXED_GAIN = AGC_OUT_SCALE *
Math.pow(10.0, KNEE * (GAIN_SLOPE - 1.0));
FastMath.pow(10.0, KNEE * (GAIN_SLOPE - 1.0));
/* Constant for calc log() so that a value of 0 magnitude = -8 */
private static final double MIN_CONSTANT = 3.2767E-4;
@@ -178,7 +179,7 @@ public class AutomaticGainControl
if(mAGCEnabled)
{
double currentMagnitude = Math.log10(Math.abs(currentSample) + MIN_CONSTANT) - Math.log10(MAX_AMPLITUDE);
double currentMagnitude = FastMath.log10(FastMath.abs(currentSample) + MIN_CONSTANT) - FastMath.log10(MAX_AMPLITUDE);
double delayedMagnitude = mMagnitudeBuffer.get(currentMagnitude);
@@ -212,7 +213,7 @@ public class AutomaticGainControl
mDecayAverage = ((1.0 - DECAY_FALL_ALPHA) * mDecayAverage) + (DECAY_RISE_ALPHA * mPeakMagnitude);
}
double magnitude = (mAttackAverage > mDecayAverage) ? mAttackAverage : mDecayAverage;
double magnitude = FastMath.max(mAttackAverage, mDecayAverage);
if(magnitude < KNEE)
{
@@ -220,7 +221,7 @@ public class AutomaticGainControl
}
else
{
gain = AGC_OUT_SCALE * Math.pow(10.0, magnitude * (GAIN_SLOPE - 1.0));
gain = AGC_OUT_SCALE * FastMath.pow(10.0, magnitude * (GAIN_SLOPE - 1.0));
}
}