MediaRecorder崩溃？

Question

我要录制视频，但它不起作用

public void startRecord() {
    if (preVideo()) {
        mRecorder.start();
    }
    isRecording = true;
}

public boolean preVideo() {
    if (mCamera == null) {
        return false;
    }

    mRecorder = new MediaRecorder();
    mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);

    CamcorderProfile cpHigh = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
    mRecorder.setProfile(cpHigh);
    mRecorder.setOutputFile(createFile().toString());
    mRecorder.setVideoSize(mFrameWidth, mFrameHeight);

    return true;
}

和逻辑猫；

致命异常:主进程: pt.chambino.p.pulse，PID: 6578 java.lang.IllegalStateException at android.media.MediaRecorder.start(原生方法)在org.opencv.android.MyJavaCameraView.startRecord(MyJavaCameraView.java:375) at pt.chambino.p.pulse.App.onRecord(App.java:241) at pt.chambino.p.pulse.App.onOptionsItemSelected(App.java:213) at android.app.Activity.onMenuItemSelected(Activity.java:2600) at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(( com.android.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:735) at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java: at PhoneWindow.java:1019)(在com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:874) at com.android.internal.view.menu.ActionMenuView.invokeItem(ActionMenuView.java:546) )在com.android.internal.view.menu.ActionMenuItemView.onClick(ActionMenuItemView.java:119) at android.view.View.performClick(View.java:4569)在android.view.View$PerformClick.run(View.java:18553) at android.os.Handler.handleCallback(Handler.java:733)在android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:212)在android.app.ActivityThread。java.lang.reflect.Method.invoke(Method.java:515)的java.lang.reflect.Method.invokeNative(原生方法)的main(ActivityThread.java:5151)在com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:684)在dalvik.system.NativeStart.main(本地方法)

Answer 1

有两种方法可以使用IllegalStateException来触发MediaRecorder.start()

• 您正在使用的录音输入已经在使用中
• 您还没有为录制MediaRecorder做好适当的准备。

考虑一下来自文献资料的状态图

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不考虑第一个选项，因为没有足够的信息来确认或拒绝它，如果我要比较您的代码流，那么您似乎遗漏了两个步骤：

• setOutputFormat
• prepare

您还将视频源设置为您的手机屏幕而不是照相机，因此我将更改您的代码如下：

public void startRecord() {
    try {
        if (preVideo()) {
            mRecorder.start();
            isRecording = true;
        }
    } catch(IOException | IllegalStateException e) {
        e.printStackTrace();
        // Error handling
    }
}

public boolean preVideo() throws IllegalStateException, IOException {
    if (mCamera == null) {
        return false;
    }

    mRecorder = new MediaRecorder();
    mRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
    mRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
    mRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);

    CamcorderProfile cpHigh = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
    mRecorder.setProfile(cpHigh);
    mRecorder.setOutputFile(createFile().toString());
    mRecorder.setVideoSize(mFrameWidth, mFrameHeight);

    mRecorder.prepare();

    return true;
}

Answer 2

替换：

mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);

，下面是：

mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);