1/*
2 * Copyright (C) 2011 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
17package com.android.ex.variablespeed;
18
19import com.android.common.io.MoreCloseables;
20
21import android.content.Context;
22import android.content.res.AssetFileDescriptor;
23import android.net.Uri;
24
25import java.io.FileDescriptor;
26import java.io.FileNotFoundException;
27import java.lang.reflect.Field;
28
29/**
30 * Provides all the native calls through to the underlying audio library.
31 * <p>
32 * You should not use this class directly. Prefer to use the {@link VariableSpeed}
33 * class instead.
34 */
35/*package*/ class VariableSpeedNative {
36    /*package*/ static void loadLibrary() throws UnsatisfiedLinkError, SecurityException {
37        System.loadLibrary("variablespeed");
38    }
39
40    /*package*/ static boolean playFromContext(Context context, Uri uri)
41            throws FileNotFoundException {
42        AssetFileDescriptor afd = context.getContentResolver().openAssetFileDescriptor(uri, "r");
43        try {
44            FileDescriptor fileDescriptor = afd.getFileDescriptor();
45            Field descriptorField = fileDescriptor.getClass().getDeclaredField("descriptor");
46            descriptorField.setAccessible(true);
47            int fd = descriptorField.getInt(fileDescriptor);
48            VariableSpeedNative.playFileDescriptor(fd, afd.getStartOffset(), afd.getLength());
49            return true;
50        } catch (SecurityException e) {
51            // Fall through.
52        } catch (NoSuchFieldException e) {
53            // Fall through.
54        } catch (IllegalArgumentException e) {
55            // Fall through.
56        } catch (IllegalAccessException e) {
57            // Fall through.
58        } finally {
59            MoreCloseables.closeQuietly(afd);
60        }
61        return false;
62    }
63
64    /*package*/ static native void playUri(String uri);
65
66    /*package*/ static native void playFileDescriptor(int fd, long offset, long length);
67
68    /*package*/ static native void setVariableSpeed(float speed);
69
70    /*package*/ static native void startPlayback();
71
72    /*package*/ static native void stopPlayback();
73
74    /*package*/ static native void shutdownEngine();
75
76    /*package*/ static native int getCurrentPosition();
77
78    /*package*/ static native int getTotalDuration();
79
80    /*package*/ static void initializeEngine(EngineParameters params) {
81        initializeEngine(params.getTargetFrames(),
82                params.getWindowDuration(), params.getWindowOverlapDuration(),
83                params.getMaxPlayBufferCount(), params.getInitialRate(),
84                params.getDecodeBufferInitialSize(), params.getDecodeBufferMaxSize(),
85                params.getStartPositionMillis(), params.getAudioStreamType());
86    }
87
88    private static native void initializeEngine(int targetFrames,
89            float windowDuration, float windowOverlapDuration, int maxPlayBufferCount,
90            float initialRate, int decodeBufferInitialSize, int decodeBufferMaxSize,
91            int startPositionMillis, int audioStreamType);
92}
93