/*
* RED5 Open Source Flash Server - http://code.google.com/p/red5/
*
* Copyright 2006-2012 by respective authors (see below). All rights reserved.
*
* 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.
*/
package org.red5.server.net.rtmp;
import org.apache.mina.core.buffer.IoBuffer;
import org.red5.server.net.rtmp.message.Constants;
/**
* RTMP utilities class.
*
* @author The Red5 Project (red5@osflash.org)
* @author Luke Hubbard, Codegent Ltd (luke@codegent.com)
* @author Art Clarke (aclarke@xuggle.com)
*/
public class RTMPUtils implements Constants {
/**
* Writes reversed integer to buffer.
*
* @param out Buffer
* @param value Integer to write
*/
public static void writeReverseIntOld(IoBuffer out, int value) {
byte[] bytes = new byte[4];
IoBuffer rev = IoBuffer.allocate(4);
rev.putInt(value);
rev.flip();
bytes[3] = rev.get();
bytes[2] = rev.get();
bytes[1] = rev.get();
bytes[0] = rev.get();
out.put(bytes);
rev.free();
rev = null;
}
/**
* Writes reversed integer to buffer.
*
* @param out Buffer
* @param value Integer to write
*/
public static void writeReverseInt(IoBuffer out, int value) {
out.put((byte) (0xFF & value));
out.put((byte) (0xFF & (value >> 8)));
out.put((byte) (0xFF & (value >> 16)));
out.put((byte) (0xFF & (value >> 24)));
}
/**
*
* @param out output buffer
* @param value value to write
*/
public static void writeMediumInt(IoBuffer out, int value) {
out.put((byte) (0xFF & (value >> 16)));
out.put((byte) (0xFF & (value >> 8)));
out.put((byte) (0xFF & (value >> 0)));
}
/**
*
* @param in input
* @return unsigned int
*/
public static int readUnsignedMediumInt(IoBuffer in) {
final byte a = in.get();
final byte b = in.get();
final byte c = in.get();
int val = 0;
val += (a & 0xff) << 16;
val += (b & 0xff) << 8;
val += (c & 0xff);
return val;
}
/**
*
* @param in input
* @return unsigned medium (3 byte) int.
*/
public static int readUnsignedMediumIntOld(IoBuffer in) {
byte[] bytes = new byte[3];
in.get(bytes);
int val = 0;
val += (bytes[0] & 0xFF) * 256 * 256;
val += (bytes[1] & 0xFF) * 256;
val += (bytes[2] & 0xFF);
return val;
}
/**
*
* @param in input
* @return signed 3-byte int
*/
public static int readMediumIntOld(IoBuffer in) {
IoBuffer buf = IoBuffer.allocate(4);
buf.put((byte) 0x00);
buf.put(in.get());
buf.put(in.get());
buf.put(in.get());
buf.flip();
int value = buf.getInt();
buf.free();
buf = null;
return value;
}
/**
*
* @param in input
* @return signed 3 byte int
*/
public static int readMediumInt(IoBuffer in) {
final byte a = in.get();
final byte b = in.get();
final byte c = in.get();
// Fix unsigned values
int val = 0;
val += (a & 0xff) << 16;
val += (b & 0xff) << 8;
val += (c & 0xff);
return val;
}
/**
* Read integer in reversed order.
*
* @param in Input buffer
* @return Integer
*/
public static int readReverseInt(IoBuffer in) {
final byte a = in.get();
final byte b = in.get();
final byte c = in.get();
final byte d = in.get();
int val = 0;
val += (d & 0xff) << 24;
val += (c & 0xff) << 16;
val += (b & 0xff) << 8;
val += (a & 0xff);
return val;
}
/**
* Encodes header size marker and channel id into header marker.
* @param out output buffer
*
* @param headerSize Header size marker
* @param channelId Channel used
*/
public static void encodeHeaderByte(IoBuffer out, byte headerSize, int channelId) {
if (channelId <= 63) {
out.put((byte) ((headerSize << 6) + channelId));
} else if (channelId <= 320) {
out.put((byte) (headerSize << 6));
out.put((byte) (channelId - 64));
} else {
out.put((byte) ((headerSize << 6) | 1));
channelId -= 64;
out.put((byte) (channelId & 0xff));
out.put((byte) (channelId >> 8));
}
}
/**
* Decode channel id.
*
* @param header Header
* @param byteCount byte count
* @return Channel id
*/
public static int decodeChannelId(int header, int byteCount) {
if (byteCount == 1) {
return (header & 0x3f);
} else if (byteCount == 2) {
return 64 + (header & 0xff);
} else {
return 64 + ((header >> 8) & 0xff) + ((header & 0xff) << 8);
}
}
/**
* Decode header size.
*
* @param header Header byte
* @param byteCount byte count
* @return Header size byte
*/
public static byte decodeHeaderSize(int header, int byteCount) {
if (byteCount == 1) {
return (byte) (header >> 6);
} else if (byteCount == 2) {
return (byte) (header >> 14);
} else {
return (byte) (header >> 22);
}
}
/**
* Return header length from marker value.
*
* @param headerSize Header size marker value
* @return Header length
*/
public static int getHeaderLength(byte headerSize) {
switch (headerSize) {
case HEADER_NEW:
return 12;
case HEADER_SAME_SOURCE:
return 8;
case HEADER_TIMER_CHANGE:
return 4;
case HEADER_CONTINUE:
return 1;
default:
return -1;
}
}
/**
* Compares two RTMP time stamps, accounting for time stamp wrapping.
*
* @param a First time stamp
* @param b Second time stamp
* @return -1 if a < b, 1 if a > b, or 0 if a == b
*/
public static int compareTimestamps(final int a, final int b) {
long diff = diffTimestamps(a, b);
return diff < 0 ? -1 : (diff > 0 ? 1 : 0);
}
/**
* Calculates the delta between two time stamps, adjusting
* for time stamp wrapping.
*
* @param a First time stamp
* @param b Second time stamp
* @return the distance between a and b, which will be negative if a is less than b.
*/
public static long diffTimestamps(final int a, final int b) {
// first convert each to unsigned integers
final long unsignedA = a & 0xFFFFFFFFL;
final long unsignedB = b & 0xFFFFFFFFL;
// then find the delta
final long delta = unsignedA-unsignedB;
return delta;
}
}