Modules/std/audio/audiodata update

[AdamStrangeParticipant]

Here’s a modified version of SetSample

The original was unfinished and was just a place holder. Here is the completed version.

You can test it by using getsample and feeding the result back with setsample

Monkey

#rem monkeydoc @hidden Sets a sample at a given sample index. @index must be in the range 0 to Length-1. @sample is a float from -1 to 1 with 0 being the zero point or no sound. @Using GetSample and manipulating the result sent back to SetSample you can: @ sample * 2 doubles the volume @ sample * 0.5 halves the volume #end Method SetSample( index:Int, sample:Float, channel:Int = 0 ) DebugAssert( index >= 0 And index < _length ) Select _format Case AudioFormat.Mono8 if sample > 0 Then sample = (1.0-sample)*127 Else sample = (-sample-1.0)*127 End if _data[index] = ubyte(sample) Case AudioFormat.Stereo8 if sample > 0 Then sample = (1.0-sample)*127 Else sample = (-sample-1.0)*127 End If _data[index*2+(channel&1)] = ubyte(sample) Case AudioFormat.Mono16 sample *= 128 sample = (sample+1)*255 Cast<Short Ptr>( _data )[index] = ushort(sample) Case AudioFormat.Stereo16 sample *= 128 sample = (sample+1)*255 Cast<Short Ptr>( _data )[index*2+(channel&1)] = ushort(sample) End End

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#rem monkeydoc @hidden Sets a sample at a given sample index. @index must be in the range 0 to Length-1. @sample is a float from -1 to 1 with 0 being the zero point or no sound. @Using GetSample and manipulating the result sent back to SetSample you can: @ sample * 2 doubles the volume @ sample * 0.5 halves the volume #end Method SetSample( index:Int, sample:Float, channel:Int = 0 ) DebugAssert( index >= 0 And index < _length )   Select _format Case AudioFormat.Mono8 if sample > 0 Then sample =  (1.0-sample)*127 Else sample =  (-sample-1.0)*127 End if   _data[index] = ubyte(sample) Case AudioFormat.Stereo8 if sample > 0 Then sample =  (1.0-sample)*127 Else sample =  (-sample-1.0)*127 End If   _data[index*2+(channel&1)] =  ubyte(sample)   Case AudioFormat.Mono16 sample *= 128 sample = (sample+1)*255   Cast<Short Ptr>( _data )[index] = ushort(sample)   Case AudioFormat.Stereo16 sample *= 128 sample = (sample+1)*255   Cast<Short Ptr>( _data )[index*2+(channel&1)] = ushort(sample) End End

[scurtyParticipant]

You’ve got skill Adam! Keep it up!

[Mark SiblyKeymaster]

Nice attempt but it’s not quite right – the Mono8 case at least is broken (haven’t looked at others) as it will convert 1.0 to 0 (should be 255). But this is a long overdue addition anyway so here’s my attempt:

Monkey

Method SetSample( index:Int,sample:Float,channel:Int=0 ) DebugAssert( index>=0 And index<_length ) Select _format Case AudioFormat.Mono8 _data[index]=Clamp( sample * 128.0 + 128.0,0.0,255.0 ) Case AudioFormat.Stereo8 _data[index*2+(channel&1)]=Clamp( sample * 128.0 + 128.0,0.0,255.0 ) Case AudioFormat.Mono16 Cast<Short Ptr>( _data )[index]=Clamp( sample * 32768.0,-32768.0,32767.0 ) Case AudioFormat.Stereo16 Cast<Short Ptr>( _data )[index*2+(channel&1)]=Clamp( sample * 32768.0,-32768.0,32767.0 ) End End #rem monkeydoc Gets a sample at a given sample index. @index must be in the range [0,Length). #end Method GetSample:Float( index:Int,channel:Int=0 ) 'Ok, note that this never returns quite +1.0 as there is one less int above 0 than below 'eg: range of signed ints is [-128,+127] ' DebugAssert( index>=0 And index<_length ) Select _format Case AudioFormat.Mono8 Return ( _data[index] - 128.0 ) / 128.0 Case AudioFormat.Stereo8 Return ( _data[index*2+(channel&1)] - 128.0 ) / 128.0 Case AudioFormat.Mono16 Return Cast<Short Ptr>( _data )[index]/32768.0 Case AudioFormat.Stereo16 Return Cast<Short Ptr>( _data )[index*2+(channel&1)]/32768.0 End Return 0 End

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Method SetSample( index:Int,sample:Float,channel:Int=0 ) DebugAssert( index>=0 And index<_length ) Select _format Case AudioFormat.Mono8 _data[index]=Clamp( sample * 128.0 + 128.0,0.0,255.0 ) Case AudioFormat.Stereo8 _data[index*2+(channel&1)]=Clamp( sample * 128.0 + 128.0,0.0,255.0 ) Case AudioFormat.Mono16 Cast<Short Ptr>( _data )[index]=Clamp( sample * 32768.0,-32768.0,32767.0 ) Case AudioFormat.Stereo16 Cast<Short Ptr>( _data )[index*2+(channel&1)]=Clamp( sample * 32768.0,-32768.0,32767.0 ) End End #rem monkeydoc Gets a sample at a given sample index. @index must be in the range [0,Length). #end Method GetSample:Float( index:Int,channel:Int=0 ) 'Ok, note that this never returns quite +1.0 as there is one less int above 0 than below 'eg: range of signed ints is [-128,+127] ' DebugAssert( index>=0 And index<_length ) Select _format Case AudioFormat.Mono8 Return ( _data[index] - 128.0 ) / 128.0 Case AudioFormat.Stereo8 Return ( _data[index*2+(channel&1)] - 128.0 ) / 128.0 Case AudioFormat.Mono16 Return Cast<Short Ptr>( _data )[index]/32768.0 Case AudioFormat.Stereo16 Return Cast<Short Ptr>( _data )[index*2+(channel&1)]/32768.0 End Return 0 End

Note that GetSample will never actually quite return +1.0 (it will return .999 etc for max sample value). This reflects the fact that there are actually fewer sample values>0 than there are <0. Googling around suggests this is the best way to handle that. You can still SetSample 1.0 for max value no problems, it just wont read back as exactly that.

[Mark SiblyKeymaster]

And here’s a little test app:

Monkey

#Import "<std>" Using std.. Function Main() Local data:=New AudioData[4] data[0]=New AudioData( 1,AudioFormat.Mono8,11025 ) data[1]=New AudioData( 1,AudioFormat.Stereo8,11025 ) data[2]=New AudioData( 1,AudioFormat.Mono16,11025 ) data[3]=New AudioData( 1,AudioFormat.Stereo16,11025 ) For Local i:=0 Until 4 Print "i="+i For Local f:=-1.0 To 1.0 Step .125 Print "SetSample="+f data[i].SetSample( 0,f ) Print "GetSample="+data[i].GetSample( 0 ) Next Next End

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#Import "<std>"   Using std..   Function Main() Local data:=New AudioData[4] data[0]=New AudioData( 1,AudioFormat.Mono8,11025 ) data[1]=New AudioData( 1,AudioFormat.Stereo8,11025 ) data[2]=New AudioData( 1,AudioFormat.Mono16,11025 ) data[3]=New AudioData( 1,AudioFormat.Stereo16,11025 ) For Local i:=0 Until 4 Print "i="+i For Local f:=-1.0 To 1.0 Step .125 Print "SetSample="+f data[i].SetSample( 0,f ) Print "GetSample="+data[i].GetSample( 0 ) Next Next   End

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