udio系统在Android中负责音频方面输入/输出层次，一般负责播放PCM声音输出和从外部获取PCM声音，以及管理声音设备和设置。这里主要是谈谈其中录制这块：AudioRecorder。
相对于MediaRecorder来说，AudioRecorder更接近底层，为我们封装的方法也更少。而且音频的采样率、声道等等都可以参数配置，但是问题是在模拟器中AudioRecorder却不怎么好用。
Rexsee实现这个类的方法倒真的很值得学习研究。关于Audio系统中其它几个类，如AudioCapture、AudioPlayer，也可以在rexsee的开源社区里找到，全部开放的：http://www.rexsee.com/CN/helpReference.php
如下是源码。。
/*
* Copyright (C) 2011 The Rexsee Open Source Project
*
* Licensed under the Rexsee License, Version 1.0 (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.rexsee.com/CN/legal/license.html
*
* 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 rexsee.multimedia;
import rexsee.core.browser.ActivityResult.ActivityResultListener;
import rexsee.core.browser.JavascriptInterface;
import rexsee.core.browser.RexseeBrowser;
import rexsee.core.browser.UrlListener;
import rexsee.core.lang.RexseeLanguage;
import rexsee.core.transportation.RexseeUpload;
import android.app.Activity;
import android.content.ContentResolver;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.provider.MediaStore.Audio.Media;
public class RexseeAudioRecorder implements JavascriptInterface {
private static final String INTERFACE_NAME = "AudioRecorder";
@Override
public String getInterfaceName() {
return mBrowser.application.resources.prefix + INTERFACE_NAME;
}
@Override
public JavascriptInterface getInheritInterface(RexseeBrowser childBrowser) {
return this;
}
@Override
public JavascriptInterface getNewInterface(RexseeBrowser childBrowser) {
return new RexseeAudioRecorder(childBrowser);
}
public static final String EVENT_ONRECORDAUDIOSUCCESSED = "onRecordAudioSuccessed";
public static final String EVENT_ONRECORDAUDIOFAILED = "onRecordAudioFailed";
public static final String URI_MEDIA_AUDIO = "content://media/external/audio/media";
private String mediaFile = null;
private final RexseeBrowser mBrowser;
public RexseeAudioRecorder(RexseeBrowser browser) {
mBrowser = browser;
browser.eventList.add(EVENT_ONRECORDAUDIOSUCCESSED);
browser.eventList.add(EVENT_ONRECORDAUDIOFAILED);
browser.urlListeners.add(new UrlListener(mBrowser.application.resources.prefix + ":audio") {
@Override
public void run(Context context, final RexseeBrowser browser, final String url) {
new Thread() {
@Override
public void run() {
String html = "
"; html += ""; ContentResolver contentResolver = mBrowser.getContext().getContentResolver(); browser.progressDialog.show(RexseeLanguage.PROGRESS_ONGOING); Cursor cursor = contentResolver.query(Uri.parse(URI_MEDIA_AUDIO), new String[]{"_id", "_data"}, null, null, "_id desc"); html += ""; if (cursor.getCount() == 0) { html += ""; } else { for (int i = 0; i < cursor.getCount(); i++) { cursor.moveToPosition(i); html += ""; } } cursor.close(); html += "
audio found.
<td onclick="\" +="" browser.function.getinterfacename()="" ".go("="" uri_media_audio="" "="" cursor.getint(0)="" ");\"="" style="'border-bottom:1px" solid="" #222222;="" padding:10="" 5="" 10="" 5;word-break:break-all;="">" + cursor.getString(1) + "
"; html += ""; html += ""; browser.function.loadHTMLWithoutHistory(html); } }.start(); } @Override public boolean shouldAddToHistory(Context context, RexseeBrowser browser, String url) { return true; } }); } public String getLastMediaAudio() { ContentResolver contentResolver = mBrowser.getContext().getContentResolver(); Cursor cursor = contentResolver.query(Uri.parse(URI_MEDIA_AUDIO), new String[]{"_data"}, null, null, "_id desc"); if (cursor == null || cursor.getCount() == 0) return ""; cursor.moveToFirst(); String rtn = "file://" + cursor.getString(0); cursor.close(); return rtn; } public void record() { try { Intent intent = new Intent(Media.RECORD_SOUND_ACTION); mBrowser.activityResult.start(intent, new ActivityResultListener() { @Override public void run(int resultCode, Intent resultIntent) { if (resultCode == Activity.RESULT_OK) { mediaFile = getLastMediaAudio(); mBrowser.eventList.run(EVENT_ONRECORDAUDIOSUCCESSED, new String[]{mediaFile}); } else { mediaFile = null; mBrowser.eventList.run(EVENT_ONRECORDAUDIOFAILED); } } }); } catch (Exception e) { mBrowser.exception(getInterfaceName(), e); } } public void prepareUpload() { if (mediaFile == null) { mBrowser.exception(getInterfaceName(), "Audio is not ready."); } else { RexseeUpload uploadObject = (RexseeUpload) mBrowser.interfaceList.get(mBrowser.application.resources.prefix + RexseeUpload.INTERFACE_NAME); if (uploadObject == null) { mBrowser.exception(getInterfaceName(), "Upload object is not ready."); } else { uploadObject.selectedFiles.add(mediaFile); } } } public void upload(String action, String name) { if (mediaFile == null) { mBrowser.exception(getInterfaceName(), "Audio is not ready."); } else { RexseeUpload uploadObject = (RexseeUpload) mBrowser.interfaceList.get(mBrowser.application.resources.prefix + RexseeUpload.INTERFACE_NAME); if (uploadObject == null) { mBrowser.exception(getInterfaceName(), "Upload object is not ready."); } else { uploadObject.clear(); uploadObject.selectedFiles.add(mediaFile); uploadObject.upload(action, name); } } } }
