Dim MicrophoneData() As Short = 'add code here that gets microphone audio sample
If MicrophoneData.Length > 0 Then
Dim SumOfDifferences As Long = 0 'an Int would probably be large enough, but... to be sure, to be sure
For I = 1 to MicrophoneData.Length - 1
SumOfDifferences = SumOfDifferences + Abs(MicrophoneData(I) - MicrophoneData(I - 1))
Next I
Dim AverageDifferenceAkaSoundLevel As Int = SumOfDifferences / (MicrophoneData.Length - 1)
End If SumOfDifferences = SumOfDifferences + Bit.And(MicrophoneData(I) - MicrophoneData(I - 1), 0xFFFF)
www.b4x.com
#Region Project Attributes
#ApplicationLabel: Knock
#VersionCode: 1
#VersionName:
#BridgeLogger: True
'SupportedOrientations possible values: unspecified, landscape or portrait.
#SupportedOrientations: unspecified
#CanInstallToExternalStorage: False
#End Region
#Region Activity Attributes
#FullScreen: False
#IncludeTitle: True
#End Region
Sub Process_Globals
'These global variables will be declared once when the application starts.
'These variables can be accessed from all modules.
Private timer1 As Timer
Private streamer As AudioStreamer
End Sub
Sub Globals
'These global variables will be redeclared each time the activity is created.
Dim buffers As List
Dim Lbl As Button
Dim btnPlay As Button
Dim btnStartRec As Button
Dim btnStopRec As Button
Private rp As RuntimePermissions
' Private recordingStart As Long
End Sub
Sub Activity_Create(FirstTime As Boolean)
buffers.Initialize
timer1.Initialize("timer1", 1000)
Screen
End Sub
Sub Activity_Resume
End Sub
Sub Activity_Pause (UserClosed As Boolean)
End Sub
Sub Screen
Lbl.Initialize("None")
Lbl.Color=Colors.LightGray
Lbl.Gravity=Gravity.FILL
Lbl.Text="Время"
Activity.AddView(Lbl, 20%x, 31%y, 60%x, 10%y)
btnStartRec.Initialize("StartRec")
btnStartRec.Color=Colors.Gray
btnStartRec.Gravity=Gravity.FILL
btnStartRec.Text="START"
Activity.AddView(btnStartRec, 10%x, 2%y, 30%x, 10%y)
btnStopRec.Initialize("StopRec")
btnStopRec.Color=Colors.Gray
btnStopRec.Gravity=Gravity.FILL
btnStopRec.Text="STOP"
Activity.AddView(btnStopRec, 50%x, 2%y, 30%x, 10%y)
btnPlay.Initialize("Play")
btnPlay.Color=Colors.Gray
btnPlay.Gravity=Gravity.FILL
btnPlay.Text="PLAY"
Activity.AddView(btnPlay, 10%x, 16%y, 30%x, 10%y)
End Sub
Private Sub StartRec_Click
rp.CheckAndRequest(rp.PERMISSION_RECORD_AUDIO)
Wait For Activity_PermissionResult (Permission As String, Result As Boolean)
If Result = False Then
MsgboxAsync("No permission", "")
Return
End If
If streamer.PlayerBufferSize = 0 Then
streamer.Initialize("streamer", 44100, True, 16, streamer.VOLUME_MUSIC)
' streamer.Initialize("streamer", 92000, True, 16, streamer.VOLUME_MUSIC)
End If
buffers.Clear
streamer.StartRecording
recordingStart = DateTime.Now
timer1.Enabled = True
Timer1_Tick
btnPlay.Enabled = False
End Sub
Private Sub StopRec_Click
streamer.StopRecording
timer1.Enabled = False
btnPlay.Enabled = True
Lbl.Text = ""
End Sub
Private Sub Play_Click
btnStartRec.Enabled = False
streamer.StartPlaying
For Each b() As Byte In buffers
streamer.Write(b)
Next
streamer.Write(Null) 'when this "message" will be processed, the player will stop.
End Sub
Private Sub streamer_PlaybackComplete
Log("PlaybackComplete")
btnStartRec.Enabled = True
End Sub
Private Sub streamer_RecordBuffer (Buffer() As Byte)
buffers.Add(Buffer)
End Sub
Sub streamer_Error
Log(LastException)
End Sub
Private Sub Timer1_Tick
Dim razmer As Long, v As Int, b As String, db As Float
Log("tick")
' Lbl.Text = "Recording: " & _
' Round((DateTime.Now - recordingStart) / DateTime.TicksPerSecond) & " seconds"
razmer=buffers.size
If razmer>22 Then
b=buffers.Get(razmer-1)
v=Bit.ParseInt(b.SubString(4),16)
db=Logarithm(v,10)
Lbl.Text = "Size bufer " & razmer & " Vol: " & db
End If
' Lbl.Text = sm.dBValue
End Sub
I will see if I can get your code running here and check this hypothesis out.
now to check out sound level stuff 
just realised most of that is specified in the AudioStreamer.Initialize call 
I think I've got enough to get you to the finish line.
in the buffer's element, the first 3 bytes are always the same [B@ . So I'm trying to parse the rest of the 7 byte string. But I don't know how to correctly decode the right-useful part of the buffer element. Simply converting to decimal is probably not the right solution.Righto, the only oddity so far is that I had to uncomment "Private recordingStart As Long" to make it compilable.
Yikes wtf? it ran first try: recorded audio, and played it back too
Buffers is a List of received recorded Byte()s - so I'll Log the lengths of those as they're received
That's working, so now to work out what format those bytes are in eg 8 or 16 bit samples, big or little endian, signed or unsigned, mono or stero
Lol I am such an Einstein
Righto mono 16 so now just need to work out if big or little endian, and signed (two's complement or sign+magnitude) or unsigned (presumably offset by 32768)
Looks like little endian two's complement = sounds like job for ByteConverter.ShortsFromBytes
Ok, after a few more off-the-track-and-into-the-bushes incidents
Sub Process_Globals
'These global variables will be declared once when the application starts.
'These variables can be accessed from all modules.
Private xui As XUI
Private timer1 As Timer
Private streamer As AudioStreamer
Dim SlowDown As Int = 0
End SubPrivate Sub streamer_RecordBuffer (Buffer() As Byte)
buffers.Add(Buffer)
SlowDown = SlowDown + Buffer.Length
If SlowDown > 30000 Then
SlowDown = SlowDown - 30000
Dim bc As ByteConverter
bc.LittleEndian = True
Dim Sample16() As Short = bc.ShortsFromBytes(Buffer)
Dim ThisSample As Short = Sample16(0)
Dim MinSample As Short = ThisSample
Dim MaxSample As Short = ThisSample
Dim DiffSum As Long = 0
For I = 1 To Sample16.Length - 1 'note starts from 1 not 0, so that there is always a previous sample
Dim PreviousSample As Short = ThisSample
ThisSample = Sample16(I)
Dim Difference As Int = ThisSample - PreviousSample
If Difference < 0 Then 'manual absolute to keep inner loop free of floating point operations
Difference = -Difference
End If
DiffSum = DiffSum + Difference
If ThisSample < MinSample Then
MinSample = ThisSample
else if ThisSample > MaxSample Then
MaxSample = ThisSample
End If
Next
Dim DiffAverage As Int = DiffSum / (Sample16.Length - 1)
Log(DateTime.Now & TAB & Sample16.Length & TAB & MinSample & TAB & MaxSample & TAB & DiffAverage)
End If
End SubLogger connected to: HMD Global Nokia C01 Plus
--------- beginning of system
--------- beginning of crash
--------- beginning of main
tick
1665559949653 1792 -81 105 17
1665559949970 1792 -49 56 7
tick
1665559950333 1792 -41 41 4
1665559950667 1792 -39 57 5
1665559951005 1792 -217 255 48
tick
1665559951349 1792 -516 367 51
1665559951684 1792 -1236 1699 71
1665559952003 1792 -130 111 16
tick
1665559952365 1792 -8554 5381 108
1665559952699 1792 -3947 4140 141
1665559953063 1792 -235 218 34
tick
1665559953382 1792 -145 104 17
1665559953716 1792 -81 87 12
1665559954079 1792 -11357 9402 261
tick
1665559954397 1792 -1281 1476 26
1665559954748 1792 -74 81 12
1665559955093 1792 -100 101 12
tick
1665559955415 1792 -18565 25289 773
1665559955795 1792 -1056 1148 53
1665559956111 1792 -85 95 12
tick
1665559956430 1792 -83 93 12
1665559956791 1792 -99 90 13
1665559957126 1792 -25817 23718 636
tick
1665559957444 1792 -528 398 26
1665559957808 1792 -83 75 12
1665559958142 1792 -3554 4522 50
tick
1665559958520 1792 -3402 2693 42
1665559958823 1792 -27953 27997 930
1665559959156 1792 -385 395 64
tick
1665559959521 1792 -109 116 22
1665559959839 1792 -184 182 31
1665559960173 1792 -148 261 21
tick
1665559960537 1792 -78 94 12
1665559960856 1792 -77 72 11
1665559961188 1792 -85 91 11
tick
1665559961552 1792 -81 96 12Sub Globals
'These global variables will be redeclared each time the activity is created.
Dim buffers As List
Dim Lbl As Button
Dim btnPlay As Button
Dim btnStartRec As Button
Dim btnStopRec As Button
Private rp As RuntimePermissions
Private recordingStart As Long 'was commented out... but why?
Dim SoundLevelBar As ProgressBar
End Sub
Sub Screen
Lbl.Initialize("None")
Lbl.Color=Colors.LightGray
Lbl.Gravity=Gravity.FILL
Lbl.Text="Время"
Activity.AddView(Lbl, 20%x, 31%y, 60%x, 10%y)
btnStartRec.Initialize("StartRec")
btnStartRec.Color=Colors.Gray
btnStartRec.Gravity=Gravity.FILL
btnStartRec.Text="START"
Activity.AddView(btnStartRec, 10%x, 2%y, 30%x, 10%y)
btnStopRec.Initialize("StopRec")
btnStopRec.Color=Colors.Gray
btnStopRec.Gravity=Gravity.FILL
btnStopRec.Text="STOP"
Activity.AddView(btnStopRec, 50%x, 2%y, 30%x, 10%y)
btnPlay.Initialize("Play")
btnPlay.Color=Colors.Gray
btnPlay.Gravity=Gravity.FILL
btnPlay.Text="PLAY"
Activity.AddView(btnPlay, 10%x, 16%y, 30%x, 10%y)
SoundLevelBar.Initialize("SoundLevelBar")
Activity.AddView(SoundLevelBar, 10%x, 60%y, 80%x, 10%y)
End SubPrivate Sub streamer_RecordBuffer (Buffer() As Byte)
buffers.Add(Buffer)
' Log(Buffer.Length)
' SlowDown = SlowDown + Buffer.Length
' If SlowDown > 30000 Then
' SlowDown = SlowDown - 30000
Dim bc As ByteConverter
bc.LittleEndian = True
Dim Sample16() As Short = bc.ShortsFromBytes(Buffer)
Dim ThisSample As Short = Sample16(0)
Dim MinSample As Short = ThisSample
Dim MaxSample As Short = ThisSample
Dim DiffSum As Long
For I = 1 To Sample16.Length - 1 'note starts from 1 not 0
Dim PreviousSample As Short = ThisSample
ThisSample = Sample16(I)
Dim Difference As Int = ThisSample - PreviousSample
If Difference < 0 Then
Difference = -Difference
End If
DiffSum = DiffSum + Difference
If ThisSample < MinSample Then
MinSample = ThisSample
else if ThisSample > MaxSample Then
MaxSample = ThisSample
End If
Next
Dim DiffAverage As Int = DiffSum / (Sample16.Length - 1)
' Log(DiffAverage)
' Log(DateTime.Now & TAB & Sample16.Length & TAB & MinSample & TAB & MaxSample & TAB & DiffAverage)
SoundLevelBar.Progress = Logarithm(DiffAverage, 32768) * 100
' End If
End SubI thought maybe if I increase the frequency in the streamer, then the element in the buffer will become shorter. What frequency values can be used to make the duration of the analyzed buffer element smaller. Perhaps some fixed standard frequencies should be used?
