CAFLoader.java

/**
 * Copyright 2008 - 2015 The Loon Game Engine Authors
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 * 
 * @project loon
 * @author cping
 * @email：javachenpeng@yahoo.com
 * @version 0.5
 */
package loon.jni;

import java.io.File;
import java.io.UnsupportedEncodingException;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

import loon.LSystem;

import org.robovm.apple.foundation.NSData;
import org.robovm.apple.foundation.NSDataReadingOptions;
import org.robovm.apple.foundation.NSErrorException;

import static loon.jni.OpenAL.*;

public class CAFLoader {

	private static final NSDataReadingOptions READ_OPTS = new NSDataReadingOptions(
			NSDataReadingOptions.MappedIfSafe.value()
					| NSDataReadingOptions.Uncached.value());

	public static class CAFDesc {

		public double sampleRate;

		public String formatID;

		public int formatFlags;

		public int bytesPerPacket;

		public int framesPerPacket;

		public int channelsPerFrame;

		public int bitsPerChannel;

		public CAFDesc(byte[] data) {
			this(ByteBuffer.wrap(data).order(ByteOrder.BIG_ENDIAN));
		}

		public CAFDesc(ByteBuffer buf) {
			sampleRate = buf.getDouble();
			formatID = getString(buf, 4);
			formatFlags = buf.getInt();
			bytesPerPacket = buf.getInt();
			framesPerPacket = buf.getInt();
			channelsPerFrame = buf.getInt();
		}

		public int getALFormat() {
			switch (channelsPerFrame) {
			case 1:
				return (bitsPerChannel == 8) ? AL_FORMAT_MONO8
						: AL_FORMAT_MONO16;
			case 2:
				return (bitsPerChannel == 8) ? AL_FORMAT_STEREO8
						: AL_FORMAT_STEREO16;
			default:
				return AL_FORMAT_STEREO16;
			}
		}

		@Override
		public String toString() {
			return String
					.format("CAFHeader: sampleRate=%f formatID=%s formatFlags=%x bytesPerPacket=%d "
							+ "framesPerPacket=%d channelsPerFrame=%d bitsPerChannel=%d",
							sampleRate, formatID, formatFlags, bytesPerPacket,
							framesPerPacket, channelsPerFrame, bitsPerChannel);
		}
	}

	public static void load(File path, int bufferId) {
		NSData data = null;
		try {
			data = NSData.read(path, READ_OPTS);
			load(data.asByteBuffer(), path.getName(), bufferId);
		} catch (NSErrorException e) {
			throw new RuntimeException(e.toString());
		} finally {
			if (data != null) {
				data.dispose();
			}
		}
	}

	public static void load(ByteBuffer data, String source, int bufferId) {
		ByteBuffer buf = data.duplicate().order(ByteOrder.BIG_ENDIAN);
		if (!getString(buf, 4).equals("caff")) {
			throw new RuntimeException("Input file not CAFF: " + source);
		}
		buf.position(buf.position() + 4);
		CAFDesc desc = null;
		int offset = 8, dataOffset = 0, dataLength = 0;
		do {
			String type = getString(buf, 4);
			int size = (int) buf.getLong();
			offset += 12;
			if (type.equals("data")) {
				if (size <= 0) {
					size = buf.limit() - offset;
				}
				dataOffset = offset;
				dataLength = size;

			} else if (type.equals("desc")) {
				desc = new CAFDesc(buf);
				if ("ima4".equalsIgnoreCase(desc.formatID))
					throw new RuntimeException("Cannot use compressed CAFF. "
							+ "Use AIFC for compressed audio on iOS.");
			}

			offset += size;
			buf.position(offset);
		} while (dataOffset == 0);
		data.position(dataOffset);
		data.limit(dataLength);
		alBufferData(bufferId, desc.getALFormat(), data, dataLength,
				(int) desc.sampleRate);
		int error = alGetError();
		if (error != AL_NO_ERROR) {
			throw new RuntimeException("AL error " + error);
		}
	}

	protected static String getString(ByteBuffer buf, int length) {
		byte[] data = new byte[length];
		buf.get(data);
		try {
			return new String(data, LSystem.ENCODING);
		} catch (UnsupportedEncodingException uee) {
			throw new RuntimeException(uee);
		}
	}
}