CodecUtils.java example

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jpcsp-master
/*
This file is part of jpcsp.

Jpcsp is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Jpcsp is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Jpcsp.  If not, see <http://www.gnu.org/licenses/>.
 */
package jpcsp.media.codec.util;

import static java.lang.Math.max;
import static java.lang.Math.min;
import jpcsp.memory.IMemoryWriter;
import jpcsp.memory.MemoryWriter;

public class CodecUtils {
	// FLT_EPSILON the minimum positive number such that 1.0 + FLT_EPSILON != 1.0
	public static final float FLT_EPSILON = 1.19209290E-07F;
	public static final float M_SQRT1_2 = 0.707106781186547524401f; // 1/sqrt(2)
	public static final float M_PI = (float) Math.PI;
	public static final float M_SQRT2 = 1.41421356237309504880f; // sqrt(2)

	public static final int ff_log2_tab[] = {
        0,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,4,
        5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
        6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
        7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7
	};

	private static int convertSampleFloatToInt16(float sample) {
		return min(max((int) (sample * 32768f + 0.5f), -32768), 32767) & 0xFFFF;
	}

	public static void writeOutput(float[][] samples, int outputAddr, int numberOfSamples, int decodedChannels, int outputChannels) {
		IMemoryWriter writer = MemoryWriter.getMemoryWriter(outputAddr, numberOfSamples * 2 * outputChannels, 2);
		switch (outputChannels) {
			case 1:
				for (int i = 0; i < numberOfSamples; i++) {
					int sample = convertSampleFloatToInt16(samples[0][i]);
					writer.writeNext(sample);
				}
				break;
			case 2:
				if (decodedChannels == 1) {
					// Convert decoded mono into output stereo
					for (int i = 0; i < numberOfSamples; i++) {
						int sample = convertSampleFloatToInt16(samples[0][i]);
						writer.writeNext(sample);
						writer.writeNext(sample);
					}
				} else {
					for (int i = 0; i < numberOfSamples; i++) {
						int lsample = convertSampleFloatToInt16(samples[0][i]);
						int rsample = convertSampleFloatToInt16(samples[1][i]);
						writer.writeNext(lsample);
						writer.writeNext(rsample);
					}
				}
				break;
		}
		writer.flush();
	}

	public static int avLog2(int n) {
		if (n == 0) {
			return 0;
		}
		return 31 - Integer.numberOfLeadingZeros(n);
	}

	private static final float log2 = (float) Math.log(2.0);

	public static float log2f(float n) {
		return (float) Math.log(n) / log2;
	}

	public static int lrintf(float n) {
		return (int) Math.rint(n);
	}

	public static float exp2f(float n) {
		return (float) Math.pow(2.0, n);
	}

	public static float sqrtf(float n) {
		return (float) Math.sqrt(n);
	}

	public static float cosf(float n) {
		return (float) Math.cos(n);
	}

	public static float sinf(float n) {
		return (float) Math.sin(n);
	}

	public static float atanf(float n) {
		return (float) Math.atan(n);
	}

	public static float atan2f(float y, float x) {
		return (float) Math.atan2(y, x);
	}
}