'Class module
Sub Class_Globals
Dim BufferSize As Int
Dim SampleRate As Int
Dim ChannelConfig As Int
Dim AudioFormat As Int
Dim AudioSource As Int
Dim NoChnls,BitsPerSample,DataSize As Int
Dim AR As AudioRecord
Dim Record As Thread
Dim StartTime As Long
Dim OutFile As RandomAccessFile
End Sub
'Initializes the object. You can add parameters to this method if needed.
Public Sub Initialize
Record.Initialise("Rec")
'Set up recording parameters Not all parameters will be supported on all
'devices
AudioSource=AR.A_SRC_MIC
SampleRate=44100
ChannelConfig=AR.Ch_Conf_Mono
NoChnls=1
AudioFormat=AR.Af_PCM_16
BitsPerSample=16
'Determine the required min buffer size
BufferSize=AR.GetMinBufferSize(SampleRate,ChannelConfig,AudioFormat)
If BufferSize < 0 Then
Msgbox("Buffer error, Hardware does not support recording with the given parameters","Buffer error")
End If
AR.Initialize(AudioSource,SampleRate,ChannelConfig,AudioFormat,BufferSize)
'Test settings
' AR.SetNotificationMarkerPosition(3000)
' AR.SetPositionNotificationPeriod(2000)
'delete the file if it exists to avoid problems with Random access files
If File.Exists(File.DirRootExternal,"test.wav") Then
File.Delete(File.DirRootExternal,"test.wav")
End If
'Initialize the output file
OutFile.Initialize2(File.DirRootExternal,"test.wav",False,True)
'Write the Wave file header
WriteWavHeader
AR.StartRecording
'enable restriction of recording time for testing
StartTime=DateTime.Now
'Start the thread to record on
Record.Start(Null,"Recording",Null)
End Sub
Sub WriteWavHeader
Dim Pos,IntLen,ShLen,StrLen As Int
Pos=0
IntLen=4
ShLen=2
StrLen=4
OutFile.WriteBytes(Array As Byte(Asc("R"),Asc("I"),Asc("F"),Asc("F")),0,StrLen,Pos)
Pos=Pos+IntLen
OutFile.WriteInt(0,Pos) 'Final size not yet known
Pos=Pos+IntLen
OutFile.WriteBytes(Array As Byte(Asc("W"),Asc("A"),Asc("V"),Asc("E")),0,StrLen,Pos)
Pos=Pos+IntLen
OutFile.WriteBytes(Array As Byte(Asc("f"),Asc("m"),Asc("t"),Asc(" ")),0,StrLen,Pos)
Pos=Pos+IntLen
OutFile.WriteInt(16,Pos) 'Sub chunk size 16 for PCM
Pos=Pos+IntLen
OutFile.WriteShort(1,Pos) 'Audio Format, 1 for PCM
Pos=Pos+ShLen
OutFile.WriteShort(1,Pos) 'No of Channels
Pos=Pos+ShLen
OutFile.WriteInt(SampleRate,Pos)
Pos=Pos+IntLen
OutFile.WriteInt(SampleRate*BitsPerSample*NoChnls/8,Pos) 'Byte Rate
Pos=Pos+IntLen
OutFile.WriteShort(NoChnls*BitsPerSample/8,Pos) 'Block align, NumberOfChannels*BitsPerSample/8
Pos=Pos+ShLen
OutFile.WriteShort(BitsPerSample,Pos) 'BitsPerSample
Pos=Pos+ShLen
OutFile.WriteBytes(Array As Byte(Asc("d"),Asc("a"),Asc("t"),Asc("a")),0,StrLen,Pos)
Pos=Pos+IntLen
OutFile.WriteInt(0,Pos) 'Data chunk size (Not yet known)
Log("Pos "&Pos)
End Sub
Sub UpdateHeader
Log("DataSize "&DataSize)
OutFile.WriteInt(36+DataSize,4)
OutFile.WriteInt(DataSize,40)
OutFile.Flush
OutFile.Close
End Sub
Sub Rec_Ended(endedOK As Boolean,Error As String)
'Stop recording and release resources
AR.stop
AR.release
UpdateHeader
If endedOK Then
'Finish writing the WAVE Header
UpdateHeader
Log("Thread Rec EndedOK "&endedOK&" "&Error)
'Load the recorded file into Media player as a test
End If
End Sub
Sub Recording
'ReSet the data size
DataSize=0
Log("Recording...")
'Do the recording
'I've read that the read methods are blocking and won't return until
' the buffer is full. Which appears to be the case in my testing.
' data has to be read pretty much immediately or it will get overwritten
Do While True
Dim RecData() As Byte
Dim Sum As Int
RecData=AR.ReadBytes(0,BufferSize)
OutFile.WriteBytes(RecData,0,RecData.Length,44+DataSize)
DataSize=DataSize+RecData.Length
For i = 0 To 480 Step 2 'Approx 5ms worth of data
Sum=Sum+(RecData(i)*256)+RecData(i+1)
Next
Record.RunOnGuiThread("Showvolume",Array As Object(Sum))
'Check if interupt requested
If Record.IsInterrupted Then Exit
'Check if recording time is up
If DateTime.Now > StartTime+"10000" Then Exit
Loop
End Sub
Sub AudioRecord_PeriodPassed
'Just for testing
Log("PPCalled")
End Sub
Sub Showvolume(Sum As Int)
Sum=Sum/240+(32767/2)
Log("Ampl:" & Sum)
'Convert To dB
Sum=20*Logarithm(Sum/32767,10)
'DbLbl.Text=Sum&" dB"
Log("dB: " & Sum)
End Sub
Sub stop
AR.stop
AR.release
UpdateHeader
If Record.Running Then Record.Interrupt
Log("Stopped")
End Sub
