1 /*
2  * Copyright 2020 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package org.hyphonate.megaaudio.player;
17 
18 public abstract class AudioSource {
AudioSource()19     public AudioSource() {}
20 
21     /**
22      * Called before the stream starts to allow initialization of the source
23      * @param numFrames The number of frames that will be requested in each pull() call.
24      * @param numChans The number of channels in the stream.
25      */
init(int numFrames, int numChans)26     public void init(int numFrames, int numChans) {}
27 
start()28     public void start() {}
stop()29     public void stop() {}
30 
31     /**
32      * reset a stream to the beginning.
33      */
reset()34     public void reset() {}
35 
36     /**
37      * triggers some event in the AudioSource. Whatever that event is is up to the AudioSource
38      * subclass.
39      */
trigger()40     public void trigger() {}
41 
42     /**
43      * Process a request for audio data.
44      * @param audioData The buffer to be filled.
45      * @param numFrames The number of frames of audio to provide.
46      * @param numChans The number of channels (in the buffer) required by the player.
47      * @return The number of frames actually generated. If this value is less than that
48      * requested, it may be interpreted by the player as the end of playback.
49      * Note that the player will be blocked by this call.
50      * Note that the data is assumed to be *interleaved*.
51      */
pull(float[] audioData, int numFrames, int numChans)52     public abstract int pull(float[] audioData, int numFrames, int numChans);
53 }
54