Android Open Source - rfcx-guardian-android Encoding Configuration

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License

The source code is released under:

Apache License

Java Source Code

/*
 * Copyright (C) 2010  Preston Lacey http://javaflacencoder.sourceforge.net/
 * All Rights Reserved.//from w  w w. j a  v a  2s .c  om
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

package net.sourceforge.javaFlacEncoder;

/**
 * This class defines the configuration options that are allowed to change
 * within a FLAC stream. Options here may be changed from one frame to the next.
 * In general, the settings should not need altered, but the option to do so
 * remains.
 * 
 * @author Preston Lacey
 */
public class EncodingConfiguration implements Cloneable {

  /**
   * Defines the options for channel configuration to use. LEFT & RIGHT
   * channels refers to stereo audio as expected. INDEPENDENT channels refer to
   * each channel encoded separately. SIDE channel is the difference of the
   * LEFT and RIGHT channels(LEFT-RIGHT). MID channel is the integer average of
   * LEFT and RIGHT channels( (LEFT+RIGHT)/2 ). Options using MID and/or SIDE
   * channels may benefit encoding by taking advantage of similarities between
   * the channels, and are available in FLAC for STEREO streams only. In
   * general, ENCODER_CHOICE should be chosen.
   */
  public enum ChannelConfig {
    /** Encode channels independently **/
    INDEPENDENT,
    /** Encode LEFT and SIDE channels for stereo stream */
    LEFT_SIDE,
    /** Encode RIGHT and SIDE channels for stereo stream */
    RIGHT_SIDE,
    /** Encode MID and SIDE channels for stereo stream */
    MID_SIDE,
    /** Encode all options possible, and take the best(slow)*/
    EXHAUSTIVE,
    /** Let the encoder decide which to use.(recommended) */
    ENCODER_CHOICE
  };

  /**
   * Defines the various subframe types that may be used. If you don't know
   * what these are, choose EXHAUSTIVE(for description of subframe types, see
   * the flac format documentation at http://flac.sourceforge.net/format.html)
   */
  public enum SubframeType {
    /** Constant subframe, do not choose unless you are sure you're encoding
     * digital silence */
    CONSTANT,
    /** Decent compression, fasted option */
    FIXED,
    /** Better compression, slower */
    LPC,
    /** No compression, simply wraps unencoded audio into a FLAC stream */
    VERBATIM,
    /** Best compression, slightly slower than LPC alone, lets encoder choose
     * the best(Recommended). */
    EXHAUSTIVE
  }
   
  /** Maximum LPC order possible(as defined by FLAC format) */
  public static final int MAX_LPC_ORDER = 32;
  /** Minimum LPC order possible(as defined by FLAC format) */
  public static final int MIN_LPC_ORDER = 1;
  /** Maximum Rice Partition order possible(as defined by FLAC Format) */
  public static final int MAX_RICE_PARTITION_ORDER = 15;
  /** Default subframe type to use*/
  public static final SubframeType DEFAULT_SUBFRAME_TYPE = SubframeType.EXHAUSTIVE;
  /** Default channel configuration */
  public static final ChannelConfig DEFAULT_CHANNEL_CONFIG = ChannelConfig.ENCODER_CHOICE;
  /** Default maximum lpc order to use */
  public static final int DEFAULT_MAX_LPC_ORDER = 12;
  /** Default minimum lpc order to use */
  public static final int DEFAULT_MIN_LPC_ORDER = 1;
  /** Default maximum Rice partition order */
  public static final int DEFAULT_MAX_RICE_ORDER = 0;


  ChannelConfig channelConfig;
  SubframeType subframeType;
  int minimumLPCOrder = 1;
  int maximumLPCOrder = 16;
  int maximumRicePartitionOrder = 0;

  /**
   * Constructor, uses defaults for all options. These defaults should be good
   * for most purposes.
   */
  public EncodingConfiguration() {
    subframeType = DEFAULT_SUBFRAME_TYPE;
    channelConfig = DEFAULT_CHANNEL_CONFIG;
    maximumLPCOrder = DEFAULT_MAX_LPC_ORDER;
    minimumLPCOrder = DEFAULT_MIN_LPC_ORDER;
    maximumRicePartitionOrder = DEFAULT_MAX_RICE_ORDER;
  }

  /**
   * Copy constructor.
   * @param e EncodingConfiguration object to copy. Must not be null.
   */
  public EncodingConfiguration(EncodingConfiguration e) {
    subframeType = e.subframeType;
    channelConfig = e.channelConfig;
    minimumLPCOrder = e.minimumLPCOrder;
    maximumLPCOrder = e.maximumLPCOrder;
    maximumRicePartitionOrder = e.maximumRicePartitionOrder;
  }

  /**
   * Set the channel configuration to use. Channel configuration refers to the
   * way multiple channels are processed. See documentation for
   * {@link ChannelConfig ChannelConfig} for more info on choices.
   * @param conf Channel configuration to use.
   */
  public void setChannelConfig(ChannelConfig conf) {
    channelConfig = conf;
  }

  /**
   * Get the current channel configuration value.
   * @return current channel configuration value
   */
  public ChannelConfig getChannelConfig() {
    return channelConfig;
  }

  /**
   * Set the subframe type to use. This refers to the way each subframe(channel)
   * is compressed. See documentation for {@link SubframeType SubframeType} for
   * more info on choices.
   * @param type
   */
  public void setSubframeType(SubframeType type) {
    subframeType = type;
  }

  /**
   * Get the current subframe type
   * @return current subframe type
   */
  public SubframeType getSubframeType() {
    return subframeType;
  }

  /**
   * Get current minimum LPC order
   * @return current minimum lpc order
   */
  public int getMinLPCOrder() { return minimumLPCOrder; }

  /**
   * Get maximum LPC order
   * @return current maximum lpc order
   */
  public int getMaxLPCOrder() { return maximumLPCOrder; }
  /**
   * Set the minimum LPC order. If order given is out of the valid range(as
   * defined by {@link EncodingConfiguration#MAX_LPC_ORDER MAX_LPC_ORDER} and
   * {@link EncodingConfiguration#MIN_LPC_ORDER MIN_LPC_ORDER}), it will be
   * set to the closest valid value instead.
   * @param order minimum LPC order to use
   */
  public void setMinLPCOrder(int order) {
    minimumLPCOrder = (order < MIN_LPC_ORDER) ? MIN_LPC_ORDER:order;
    minimumLPCOrder = (minimumLPCOrder > MAX_LPC_ORDER) ?
    MAX_LPC_ORDER:minimumLPCOrder;
  }
  /**
   * Set the maximum LPC order. If order given is out of the valid range
   * (as defined by {@link EncodingConfiguration#MAX_LPC_ORDER MAX_LPC_ORDER}
   * and {@link EncodingConfiguration#MIN_LPC_ORDER MIN_LPC_ORDER}), it will be
   * set to the closest valid value instead.
   * @param order maximum LPC order to use
   */
  public void setMaxLPCOrder(int order) {
    maximumLPCOrder = (order < MIN_LPC_ORDER) ? MIN_LPC_ORDER:order;
    maximumLPCOrder = (maximumLPCOrder > MAX_LPC_ORDER) ?
    MAX_LPC_ORDER:maximumLPCOrder;
  }
}

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