public abstract class

BaseAudioProcessor

extends java.lang.Object

implements AudioProcessor

 java.lang.Object

↳androidx.media3.common.audio.BaseAudioProcessor

Subclasses:

BaseAudioProcessor, TeeAudioProcessor, SilenceSkippingAudioProcessor, ChannelMixingAudioProcessor, ToInt16PcmAudioProcessor, SpeedChangingAudioProcessor

Gradle dependencies

compile group: 'androidx.media3', name: 'media3-common', version: '1.5.0-alpha01'

  • groupId: androidx.media3
  • artifactId: media3-common
  • version: 1.5.0-alpha01

Artifact androidx.media3:media3-common:1.5.0-alpha01 it located at Google repository (https://maven.google.com/)

Overview

Base class for audio processors that keep an output buffer and an internal buffer that is reused whenever input is queued. Subclasses should override BaseAudioProcessor to return the output audio format for the processor if it's active.

Summary

Fields
protected AudioProcessor.AudioFormatinputAudioFormat

The current input audio format.

protected AudioProcessor.AudioFormatoutputAudioFormat

The current output audio format.

Constructors
publicBaseAudioProcessor()

Methods
public final AudioProcessor.AudioFormatconfigure(AudioProcessor.AudioFormat inputAudioFormat)

public final voidflush()

public java.nio.ByteBuffergetOutput()

protected final booleanhasPendingOutput()

Returns whether the current output buffer has any data remaining.

public booleanisActive()

public booleanisEnded()

protected AudioProcessor.AudioFormatonConfigure(AudioProcessor.AudioFormat inputAudioFormat)

Called when the processor is configured for a new input format.

protected voidonFlush()

Called when the processor is flushed, directly or as part of resetting.

protected voidonQueueEndOfStream()

Called when the end-of-stream is queued to the processor.

protected voidonReset()

Called when the processor is reset.

public final voidqueueEndOfStream()

protected final java.nio.ByteBufferreplaceOutputBuffer(int size)

Replaces the current output buffer with a buffer of at least size bytes and returns it.

public final voidreset()

from java.lang.Objectclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Fields

protected AudioProcessor.AudioFormat inputAudioFormat

The current input audio format.

protected AudioProcessor.AudioFormat outputAudioFormat

The current output audio format.

Constructors

public BaseAudioProcessor()

Methods

public final AudioProcessor.AudioFormat configure(AudioProcessor.AudioFormat inputAudioFormat)

public boolean isActive()

public final void queueEndOfStream()

public java.nio.ByteBuffer getOutput()

public boolean isEnded()

public final void flush()

public final void reset()

protected final java.nio.ByteBuffer replaceOutputBuffer(int size)

Replaces the current output buffer with a buffer of at least size bytes and returns it. Callers should write to the returned buffer then flip it so it can be read via BaseAudioProcessor.getOutput().

protected final boolean hasPendingOutput()

Returns whether the current output buffer has any data remaining.

protected AudioProcessor.AudioFormat onConfigure(AudioProcessor.AudioFormat inputAudioFormat)

Called when the processor is configured for a new input format.

protected void onQueueEndOfStream()

Called when the end-of-stream is queued to the processor.

protected void onFlush()

Called when the processor is flushed, directly or as part of resetting.

protected void onReset()

Called when the processor is reset.

Source

/*
 * Copyright (C) 2019 The Android Open Source Project
 *
 * 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 androidx.media3.common.audio;

import androidx.annotation.CallSuper;
import androidx.media3.common.util.UnstableApi;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;

/**
 * Base class for audio processors that keep an output buffer and an internal buffer that is reused
 * whenever input is queued. Subclasses should override {@link #onConfigure(AudioFormat)} to return
 * the output audio format for the processor if it's active.
 */
@UnstableApi
public abstract class BaseAudioProcessor implements AudioProcessor {

  /** The current input audio format. */
  protected AudioFormat inputAudioFormat;

  /** The current output audio format. */
  protected AudioFormat outputAudioFormat;

  private AudioFormat pendingInputAudioFormat;
  private AudioFormat pendingOutputAudioFormat;
  private ByteBuffer buffer;
  private ByteBuffer outputBuffer;
  private boolean inputEnded;

  public BaseAudioProcessor() {
    buffer = EMPTY_BUFFER;
    outputBuffer = EMPTY_BUFFER;
    pendingInputAudioFormat = AudioFormat.NOT_SET;
    pendingOutputAudioFormat = AudioFormat.NOT_SET;
    inputAudioFormat = AudioFormat.NOT_SET;
    outputAudioFormat = AudioFormat.NOT_SET;
  }

  @Override
  public final AudioFormat configure(AudioFormat inputAudioFormat)
      throws UnhandledAudioFormatException {
    pendingInputAudioFormat = inputAudioFormat;
    pendingOutputAudioFormat = onConfigure(inputAudioFormat);
    return isActive() ? pendingOutputAudioFormat : AudioFormat.NOT_SET;
  }

  @CallSuper
  @Override
  public boolean isActive() {
    return pendingOutputAudioFormat != AudioFormat.NOT_SET;
  }

  @Override
  public final void queueEndOfStream() {
    inputEnded = true;
    onQueueEndOfStream();
  }

  @CallSuper
  @Override
  public ByteBuffer getOutput() {
    ByteBuffer outputBuffer = this.outputBuffer;
    this.outputBuffer = EMPTY_BUFFER;
    return outputBuffer;
  }

  @CallSuper
  @SuppressWarnings("ReferenceEquality")
  @Override
  public boolean isEnded() {
    return inputEnded && outputBuffer == EMPTY_BUFFER;
  }

  @Override
  public final void flush() {
    outputBuffer = EMPTY_BUFFER;
    inputEnded = false;
    inputAudioFormat = pendingInputAudioFormat;
    outputAudioFormat = pendingOutputAudioFormat;
    onFlush();
  }

  @Override
  public final void reset() {
    flush();
    buffer = EMPTY_BUFFER;
    pendingInputAudioFormat = AudioFormat.NOT_SET;
    pendingOutputAudioFormat = AudioFormat.NOT_SET;
    inputAudioFormat = AudioFormat.NOT_SET;
    outputAudioFormat = AudioFormat.NOT_SET;
    onReset();
  }

  /**
   * Replaces the current output buffer with a buffer of at least {@code size} bytes and returns it.
   * Callers should write to the returned buffer then {@link ByteBuffer#flip()} it so it can be read
   * via {@link #getOutput()}.
   */
  protected final ByteBuffer replaceOutputBuffer(int size) {
    if (buffer.capacity() < size) {
      buffer = ByteBuffer.allocateDirect(size).order(ByteOrder.nativeOrder());
    } else {
      buffer.clear();
    }
    outputBuffer = buffer;
    return buffer;
  }

  /** Returns whether the current output buffer has any data remaining. */
  protected final boolean hasPendingOutput() {
    return outputBuffer.hasRemaining();
  }

  /** Called when the processor is configured for a new input format. */
  protected AudioFormat onConfigure(AudioFormat inputAudioFormat)
      throws UnhandledAudioFormatException {
    return AudioFormat.NOT_SET;
  }

  /** Called when the end-of-stream is queued to the processor. */
  protected void onQueueEndOfStream() {
    // Do nothing.
  }

  /** Called when the processor is flushed, directly or as part of resetting. */
  protected void onFlush() {
    // Do nothing.
  }

  /** Called when the processor is reset. */
  protected void onReset() {
    // Do nothing.
  }
}