dac_codec.c

stm32.rar

  /* Insure the index parity */
  AudioDataIndex &= 0xFFFFFFFE;

  /* Resume playing from the new position */
  DAC_CODEC_Play((GetVar_AudioDataIndex()));
}

/*******************************************************************************
* Function Name  : DAC_CODEC_UpdateStatus
* Description    : Check if STOP or PAUSE command are generated and performs the 
*                :  relative action (STOP or PAUSE playing)
* Input          : None.
* Output         : None.
* Return         : None.
*******************************************************************************/
void DAC_CODEC_UpdateStatus(void)
{ 
  /* STOP command is generated => Stop playing the audio file */
  if (GetVar_AudioPlayStatus() == AudioPlayStatus_STOPPED)
  {
    DAC_CODEC_Stop();
  }
  
  /* PAUSE Command is generated => PAUSE playing the audio File */
  if (GetVar_AudioPlayStatus() == AudioPlayStatus_PAUSED)
  {
    DAC_CODEC_Pause();
  }
}

/*******************************************************************************
* Function Name  : GetVar_DataStartAddr
* Description    : returns DataStartAddr variable value (used by stm32f10x_it.c file).
* Input          : None
* Output         : None
* Return         : AudioDataIndex
*******************************************************************************/
u32 GetVar_DataStartAddr(void)
{ 
  return DataStartAddr;
}


/*******************************************************************************
* Function Name  : GetVar_CurrentVolume
* Description    : returns CurrentVolume variable value (used by extern files).
* Input          : None
* Output         : None
* Return         : CurrentVolume
*******************************************************************************/
u8 GetVar_CurrentVolume(void)
{ 
  return CurrentVolume;
}

/*******************************************************************************
* Function Name  : DAC_CODEC_WaveParsing
* Description    : Checks the format of the .WAV file and gets information about
*                  the audio format. This is done by reading the value of a
*                  number of parameters stored in the file header and comparing
*                  these to the values expected authenticates the format of a
*                  standard .WAV  file (44 bytes will be read). If  it is a valid
*                  .WAV file format, it continues reading the header to determine
*                  the  audio format such as the sample rate and the sampled data
*                  size. If the audio format is supported by this application,
*                  it retrieves the audio format in WAVE_Format structure and
*                  returns a zero value. Otherwise the function fails and the
*                  return value is nonzero.In this case, the return value specifies
*                  the cause of  the function fails. The error codes that can be
*                  returned by this function are declared in the header file.
* Input          : None
* Output         : None
* Return         : Zero value if the function succeed, otherwise it return
*                  a nonzero value which specifies the error code.
*******************************************************************************/
ErrorCode DAC_CODEC_WaveParsing(u8* HeaderTab)
{
  u32 Temp = 0x00;
  u32 ExtraFormatBytes = 0; 
  
  /* Initialize the HeaderTabIndex variable */
  HeaderTabIndex = 0;

  /* Read chunkID, must be 'RIFF'	----------------------------------------------*/
  Temp = ReadUnit(4, BigEndian);
  if(Temp != ChunkID)
  {
    return(Unvalid_RIFF_ID);
  }
  /* Read the file length ----------------------------------------------------*/
  WAVE_Format.RIFFchunksize = ReadUnit(4, LittleEndian);
	
  /* Read the file format, must be 'WAVE' ------------------------------------*/
  Temp = ReadUnit(4, BigEndian);
  if(Temp != FileFormat)
  {
    return(Unvalid_WAVE_Format);
  }
  /* Read the format chunk, must be 'fmt ' -----------------------------------*/
  Temp = ReadUnit(4, BigEndian);
  if(Temp != FormatID)
  {
    return(Unvalid_FormatChunk_ID);
  }
  /* Read the length of the 'fmt' data, must be 0x10 -------------------------*/
  Temp = ReadUnit(4, LittleEndian);
  if(Temp != 0x10)
  {
    ExtraFormatBytes = 1;
  }
  /* Read the audio format, must be 0x01 (PCM) -------------------------------*/
  WAVE_Format.FormatTag = ReadUnit(2, LittleEndian);
  if(WAVE_Format.FormatTag != WAVE_FORMAT_PCM)
  {
    return(Unsupporetd_FormatTag);	
  }	
  /* Read the number of channels: 0x02->Stereo 0x01->Mono --------------------*/
  WAVE_Format.NumChannels = ReadUnit(2, LittleEndian);

  /* Read the Sample Rate ----------------------------------------------------*/
  WAVE_Format.SampleRate = ReadUnit(4, LittleEndian);

  /* Update the OCA value according to the .WAV file Sample Rate */
  switch(WAVE_Format.SampleRate)
  {
    case SampleRate_8000 : TIM2ARRValue = 9000; break; /* 8KHz = 72MHz / 9000 */
    case SampleRate_11025: TIM2ARRValue = 6531; break; /* 11.025KHz = 72MHz / 6531 */
    case SampleRate_22050: TIM2ARRValue = 3265; break; /* 22.05KHz = 72MHz / 3265 */  
    case SampleRate_44100: TIM2ARRValue = 1633; break; /* 44.1KHz = 72MHz / 1633 */    
    default: return(Unsupporetd_Sample_Rate);
  }

  /* Read the Byte Rate ------------------------------------------------------*/
  WAVE_Format.ByteRate = ReadUnit(4, LittleEndian);
	
  /* Read the block alignment ------------------------------------------------*/
  WAVE_Format.BlockAlign = ReadUnit(2, LittleEndian);
	
  /* Read the number of bits per sample --------------------------------------*/
  WAVE_Format.BitsPerSample = ReadUnit(2, LittleEndian);
  if(WAVE_Format.BitsPerSample != Bits_Per_Sample_16)
  {
    return(Unsupporetd_Bits_Per_Sample);
  }
  /* If there are Extra format bytes, these bytes will be defined in "Fact Chunk" */
  if(ExtraFormatBytes == 1)
  {
    /* Read th Extra format bytes, must be 0x00 ------------------------------*/
    Temp = ReadUnit(2, LittleEndian);
    if(Temp != 0x00)
    {
      return(Unsupporetd_ExtraFormatBytes);
    }
    /* Read the Fact chunk, must be 'fact' -----------------------------------*/
    Temp = ReadUnit(4, BigEndian);
    if(Temp != FactID)
    {
      return(Unvalid_FactChunk_ID);
    }
    /* Read Fact chunk data Size ---------------------------------------------*/
    Temp = ReadUnit(4, LittleEndian);

    /* Set the index to start reading just after the header end */
    HeaderTabIndex += Temp;
  }
  /* Read the Data chunk, must be 'data' -------------------------------------*/
  Temp = ReadUnit(4, BigEndian);
  if(Temp != DataID)
  {
    return(Unvalid_DataChunk_ID);
  }
  /* Read the number of sample data ------------------------------------------*/
  WAVE_Format.DataSize = ReadUnit(4, LittleEndian);

  /* Set the data pointer at the beginning of the effective audio data */
	DataStartAddr += HeaderTabIndex;
  
  return(Valid_WAVE_File);	
}

/*******************************************************************************
* Function Name  : GetVar_AudioDataIndex
* Description    : returns AudioDataIndex variable value (used by stm32f10x_it.c file).
* Input          : None
* Output         : None
* Return         : AudioDataIndex
*******************************************************************************/
u32 GetVar_AudioDataIndex(void)
{ 
  return AudioDataIndex;
}

/*******************************************************************************
* Function Name  : SetVar_AudioDataIndex
* Description    : Sets AudioDataIndex variable value (used by stm32f10x_it.c file).
* Input          : None
* Output         : None
* Return         : AudioDataIndex
*******************************************************************************/
void SetVar_AudioDataIndex(u32 value)
{ 
  AudioDataIndex = value;
}

/*******************************************************************************
* Function Name  : IncrementVar_AudioDataIndex
* Description    : Increment the AudioDataIndex variable.
* Input          : - IncrementNumber: number of incrementations.
* Output         : None
* Return         : None
*******************************************************************************/
void IncrementVar_AudioDataIndex(u32 IncrementNumber)
{ 
  AudioDataIndex += (u32)IncrementNumber;
  
  if (AudioDataIndex >= AudioDataLength)
  {
    ResetVar_AudioDataIndex();
    Decrement_AudioReplay();
  }
}

/*******************************************************************************
* Function Name  : DecrementVar_AudioDataIndex
* Description    : Set the AudioDataIndex variable to 1.
* Input          : None
* Output         : None
* Return         : None.
*******************************************************************************/
void DecrementVar_AudioDataIndex(u32 DecrementNumber)
{ 
  if (DecrementNumber >= AudioDataIndex)
  {
    ResetVar_AudioDataIndex();
  }
  else
  { 
    AudioDataIndex -= (u32)DecrementNumber;
  }
}

/*******************************************************************************
* Function Name  : ResetVar_AudioDataIndex
* Description    : Reset the AudioDataIndex variable.
* Input          : None
* Output         : None
* Return         : None
*******************************************************************************/
void ResetVar_AudioDataIndex(void)
{ 
  AudioDataIndex = DataStartAddr;

  /* Send the read command to the media */
  Media_StartReadSequence(AudioFileAddress + DataStartAddr + 1);
}

/*******************************************************************************
* Function Name  : GetVar_SendDummyData
* Description    : returns SendDummyData variable value (used by stm32f10x_it.c file).
* Input          : None
* Output         : None
* Return         : SendDummyData
*******************************************************************************/
u32 GetVar_SendDummyData(void)
{ 
  return SendDummyData;
}

/*******************************************************************************
* Function Name  : SetVar_SendDummyData
* Description    : Set the SendDummyData variable to 1.
* Input          : None
* Output         : None
* Return         : SendDummyData
*******************************************************************************/
u32 SetVar_SendDummyData(void)
{ 
  SendDummyData = (u32)0x1;
 
  return SendDummyData;
}

/*******************************************************************************
* Function Name  : ResetVar_SendDummyData
* Description    : Reset the SendDummyData variable to 0.
* Input          : None
* Output         : None
* Return         : SendDummyData
*******************************************************************************/
u32 ResetVar_SendDummyData(void)
{ 
  SendDummyData = (u32)0;
 
  return SendDummyData;
}

/*******************************************************************************
* Function Name  : GetVar_AudioPlayStatus
* Description    : returns AudioPlayStatus variable value (used by stm32f10x_it.c file).
* Input          : None
* Output         : None
* Return         : AudioPlayStatus value.
*******************************************************************************/
u32 GetVar_AudioPlayStatus(void)
{ 
  return AudioPlayStatus;
}

/*******************************************************************************
* Function Name  : SetVar_AudioPlayStatus
* Description    : Set the AudioDataIndex variable to Status.
* Input          : Status: could be AudioPlayStatus_STOPPED, AudioPlayStatus_PLAYING
*                :        or AudioPlayStatus_PAUSED.
* Output         : None
* Return         : AudioPlayStatus value.
*******************************************************************************/
u32 SetVar_AudioPlayStatus(u32 Status)
{ 
  AudioPlayStatus = (u32)Status;
 
  return AudioPlayStatus;
}

/*******************************************************************************
* Function Name  : GetVar_AudioReplay
* Description    : returns AudioReplay variable value.
* Input          : None
* Output         : None
* Return         : AudioReplay	value.