android FM手动调频流程

首先来看一下流程图：

2.滑动刻度盘HorizontalNumberPicker控件在监听事件里使用方法valueToFrequency(newVal)

1.长按左右箭头居中的频率字符串，弹出FrequencyPickerDialog调频对话框确定调用tuneRadio(frequency)调频。

获取到频率

 protected int valueToFrequency(int value) {
        mFrequency = mPrefs.getLowerLimit() + value *
                              mPrefs.getFrequencyStepSize();
        return mFrequency;
    }

发送一个handler 回调一个tuneRadio(frequency)调频。

 Runnable mRadioChangeFrequency = new Runnable(){
        public void run() {
            mUpdatePickerValue = false;
            tuneRadio(mFrequency);
        }
    };

3.手动点击按钮左右箭头, 通过监听调用：

int frequency =FmSharedPreferences.getNextTuneFrequency();

int frequency =FmSharedPreferences.getPrevTuneFrequency();

tuneRadio(frequency);进行调频

getNextTuneFrequency()方法通过判断频率最大限制范围，后加200（刻度）

getPrevTuneFrequency()方法通过判断频率最小限制范围，后减200（刻度）

调频方法分析

private void tuneRadio(int frequency)

 private void tuneRadio(int frequency){
       /* Issue the tune command only if tuneCommand is already not active */
       if((mService != null) && (mCommandActive != CMD_TUNE) && isFmOn()) {
          boolean bStatus = false;
          try {
              bStatus = mService.tune(frequency);
              if (bStatus) {
                  postTimeoutHandler(CMD_TUNE);
              }else {
                if (isFmOn()) {
                   mCommandFailed = CMD_TUNE;
                   Log.e(LOGTAG, "mService.tune failed");
                   showDialog(DIALOG_CMD_FAILED);
                }
              }mTunedStation.setName("");
              mTunedStation.setPI(0);
              mTunedStation.setPty(0);
              updateStationInfoToUI();
          }catch (RemoteException e) {
             e.printStackTrace();
          }
       }else {
          Log.e(LOGTAG, "Delayed Tune handler stopped");
       }
    }

通过回调引用类调用FMRadioService类的tune()方法进行调频

bStatus = mService.tune(frequency);

发送一个广播连接是否超时

postTimeoutHandler(CMD_TUNE);

设置调频名字，更新FMRadioUI界面信息

mTunedStation.setName("");

mTunedStation.setPI(0);

mTunedStation.setPty(0);

updateStationInfoToUI()

（通过IFMRadioSrevice.aidl通信机制onbind返回的类的引用调用FMRadioService中的调频方法）

FMRadioService中的tune方法

public boolean tune(int frequency)

 public boolean tune(int frequency) {
       boolean bCommandSent=false;
       double doubleFrequency = frequency/1000.00;

       Log.d(LOGTAG, "tuneRadio:  " + doubleFrequency);
       if (mReceiver != null)
       {
          mReceiver.setStation(frequency);
          bCommandSent = true;
       }
       return bCommandSent;
    }

调用FMReceiver类的setStation方法调频

public boolean setStation (intfrequencyKHz)

 public boolean setStation (int frequencyKHz) {
       int ret;

       mControl.setFreq(frequencyKHz);
       ret = mControl.setStation(sFd);
       if(ret < 0 )
       {
          return false;
       }
       else
       {
          return true;
       }
    }

调用FMRxControls类（FM读取控制台信息）设置频率

mControl.setFreq(frequencyKHz);

设置优化调频核心指定的频率

ret = mControl.setStation(sFd);

 

 public int setStation(int fd) {
     Log.d(TAG, "** Tune Using: "+fd);
     int ret = FmReceiverJNI.setFreqNative(fd, mFreq);
     Log.d(TAG, "** Returned: "+ret);
     return ret;
  }

最后调用FmReceiverJNI类

setFreqNative(fd, mFreq); 本地方法 JNI到 cpp文件

 /*native interface */
 static jint android_hardware_fmradio_FmReceiverJNI_setFreqNative
     (JNIEnv * env, jobject thiz, jint fd, jint freq)
 {
     int err;
     double tune;
     struct v4l2_frequency freq_struct;
     freq_struct.type = V4L2_TUNER_RADIO;
     freq_struct.frequency = (freq*TUNE_MULT/1000);
     err = ioctl(fd, VIDIOC_S_FREQUENCY, &freq_struct);
     if(err < 0){
             return FM_JNI_FAILURE;
     }
     return FM_JNI_SUCCESS;
 }

首先来看一下流程图：

2.滑动刻度盘HorizontalNumberPicker控件在监听事件里使用方法valueToFrequency(newVal)

1.长按左右箭头居中的频率字符串，弹出FrequencyPickerDialog调频对话框确定调用tuneRadio(frequency)调频。

获取到频率

 protected int valueToFrequency(int value) {
        mFrequency = mPrefs.getLowerLimit() + value *
                              mPrefs.getFrequencyStepSize();
        return mFrequency;
    }

发送一个handler 回调一个tuneRadio(frequency)调频。

 Runnable mRadioChangeFrequency = new Runnable(){
        public void run() {
            mUpdatePickerValue = false;
            tuneRadio(mFrequency);
        }
    };

3.手动点击按钮左右箭头, 通过监听调用：

int frequency =FmSharedPreferences.getNextTuneFrequency();

int frequency =FmSharedPreferences.getPrevTuneFrequency();

tuneRadio(frequency);进行调频

getNextTuneFrequency()方法通过判断频率最大限制范围，后加200（刻度）

getPrevTuneFrequency()方法通过判断频率最小限制范围，后减200（刻度）

调频方法分析

private void tuneRadio(int frequency)

 private void tuneRadio(int frequency){
       /* Issue the tune command only if tuneCommand is already not active */
       if((mService != null) && (mCommandActive != CMD_TUNE) && isFmOn()) {
          boolean bStatus = false;
          try {
              bStatus = mService.tune(frequency);
              if (bStatus) {
                  postTimeoutHandler(CMD_TUNE);
              }else {
                if (isFmOn()) {
                   mCommandFailed = CMD_TUNE;
                   Log.e(LOGTAG, "mService.tune failed");
                   showDialog(DIALOG_CMD_FAILED);
                }
              }mTunedStation.setName("");
              mTunedStation.setPI(0);
              mTunedStation.setPty(0);
              updateStationInfoToUI();
          }catch (RemoteException e) {
             e.printStackTrace();
          }
       }else {
          Log.e(LOGTAG, "Delayed Tune handler stopped");
       }
    }

通过回调引用类调用FMRadioService类的tune()方法进行调频

bStatus = mService.tune(frequency);

发送一个广播连接是否超时

postTimeoutHandler(CMD_TUNE);

设置调频名字，更新FMRadioUI界面信息

mTunedStation.setName("");

mTunedStation.setPI(0);

mTunedStation.setPty(0);

updateStationInfoToUI()

（通过IFMRadioSrevice.aidl通信机制onbind返回的类的引用调用FMRadioService中的调频方法）

FMRadioService中的tune方法

public boolean tune(int frequency)

 public boolean tune(int frequency) {
       boolean bCommandSent=false;
       double doubleFrequency = frequency/1000.00;

       Log.d(LOGTAG, "tuneRadio:  " + doubleFrequency);
       if (mReceiver != null)
       {
          mReceiver.setStation(frequency);
          bCommandSent = true;
       }
       return bCommandSent;
    }

调用FMReceiver类的setStation方法调频

public boolean setStation (intfrequencyKHz)

 public boolean setStation (int frequencyKHz) {
       int ret;

       mControl.setFreq(frequencyKHz);
       ret = mControl.setStation(sFd);
       if(ret < 0 )
       {
          return false;
       }
       else
       {
          return true;
       }
    }

调用FMRxControls类（FM读取控制台信息）设置频率

mControl.setFreq(frequencyKHz);

设置优化调频核心指定的频率

ret = mControl.setStation(sFd);

 

 public int setStation(int fd) {
     Log.d(TAG, "** Tune Using: "+fd);
     int ret = FmReceiverJNI.setFreqNative(fd, mFreq);
     Log.d(TAG, "** Returned: "+ret);
     return ret;
  }

最后调用FmReceiverJNI类

setFreqNative(fd, mFreq); 本地方法 JNI到 cpp文件

 /*native interface */
 static jint android_hardware_fmradio_FmReceiverJNI_setFreqNative
     (JNIEnv * env, jobject thiz, jint fd, jint freq)
 {
     int err;
     double tune;
     struct v4l2_frequency freq_struct;
     freq_struct.type = V4L2_TUNER_RADIO;
     freq_struct.frequency = (freq*TUNE_MULT/1000);
     err = ioctl(fd, VIDIOC_S_FREQUENCY, &freq_struct);
     if(err < 0){
             return FM_JNI_FAILURE;
     }
     return FM_JNI_SUCCESS;
 }