Float

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Float (or fully IEEE floating point with single precision) is one of the samples types of AviSynth's audio. For a converter see [http://www.h-schmidt.net/FloatConverter/IEEE754.html here].
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''This page is about the ''Float ''audio format.'' <br>
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:''For the variable type, see [[Script_variables]].'' <br>
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:''For the'' <code>Float()</code> ''function, go to [[Internal_functions#Float]].'' <br>
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:''For the {{Deep_color}} format, go to [[Float_(color_format)]]''
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 +
 
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'''Float''' (or fully IEEE floating point with single precision) is one of the [[ConvertAudio|AviSynth audio sample formats]].
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The samples of this type have normal values between -1.0 (= 0xBF800000) and +1.0 (= 0x3F800000). Values outside this range are usable as long as the audio remains in Float format, but will create audio clipping if [[ConvertAudio|converted]] to an integer format: 8, 16, 24 or 32 integer bits. For safety, you can call [[Normalize]] before converting from Float to Integer.
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ColorBarsHD ## audio format = Float; range -1.0 - +1.0
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Amplify(1000.0) ## range -1000.0 - +1000.0
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Amplify(0.001) ## range -1.0 - +1.0
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## output: unchanged
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ColorBarsHD ## audio format = Float; range -1.0 - +1.0
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Amplify(1000.0) ## range -1000.0 - +1000.0
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ConvertAudioTo16bit ## convert to Integer; severe clipping
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Amplify(0.001) ## still clipping
  
The samples of this type have values between -1.00000 (= 0xBF800000) and 1.000000 (= 0x3F800000).
 
  
 
The value of such a IEEE-754 number is computed as: sign * 2^exponent * 1.mantissa, using the following scheme:
 
The value of such a IEEE-754 number is computed as: sign * 2^exponent * 1.mantissa, using the following scheme:
  
[ 1 Sign Bit | 8 Bit Exponent  | 23 Bit Mantissa ]
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<code>[ 1 Sign Bit | 8 Bit Exponent  | 23 Bit Mantissa ]</code>
  
 
* The sign bit is 1 (negative) or 0 (positive).
 
* The sign bit is 1 (negative) or 0 (positive).
 
* The exponent runs from -127 (00000000) to 0 (0111111) to 128 (11111111).  
 
* The exponent runs from -127 (00000000) to 0 (0111111) to 128 (11111111).  
* The mantissa m1m2m3 ... means m1/2 + m2/4 + m3/8 + ... in decimal. Sometimes people denote "1.m1m2m3..." as the mantissa (like is done in the converter above).
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* The mantissa m1m2m3 ... means m1/2 + m2/4 + m3/8 + ... in decimal. Sometimes people denote "1.m1m2m3..." as the mantissa (like is done in the converter below).
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For an on-line converter between decimal numbers and IEEE 754 floating point, see [http://www.h-schmidt.net/FloatConverter/IEEE754.html here].
  
 
Examples:
 
Examples:
  
  0x3F800000 = 00111111100000000000000000000000 (binary, see [http://easycalculation.]com/hex-converter.php]
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  0x3F800000 = 00111111100000000000000000000000 (binary, see [http://easycalculation.com/hex-converter.php])
 
   
 
   
 
  Sign Bit      Exp      1.Mantissa
 
  Sign Bit      Exp      1.Mantissa
Line 24: Line 43:
 
and
 
and
  
0xBF800000 = 10111111100000000000000000000000
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0xBF800000 = 10111111100000000000000000000000
 
   
 
   
 
  Sign Bit      Exp      1.Mantissa
 
  Sign Bit      Exp      1.Mantissa
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  Sign bit is negative, exponent = 0, 1.mantissa = 1, so the number is -1.0
 
  Sign bit is negative, exponent = 0, 1.mantissa = 1, so the number is -1.0
  
source: [http://www.opferman.net/Text/ieee.txt]
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and
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0x800000 = 01001011000000000000000000000000
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Sign Bit      Exp      1.Mantissa
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0          10010110  00000000000000000000000
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150 - 127 = 23    1.0 bitshift 23 places
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Sign bit is positive, exponent = 23, 1.mantissa = 1, so the number is 8388608
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source: [https://web.archive.org/web/20120728135435/http://www.opferman.net/Text/ieee.txt opferman.net]
  
 
[[Category:Glossary]]
 
[[Category:Glossary]]

Latest revision as of 21:25, 28 October 2019

This page is about the Float audio format.

For the variable type, see Script_variables.
For the Float() function, go to Internal_functions#Float.
For the Deep Color format, go to Float_(color_format)


Float (or fully IEEE floating point with single precision) is one of the AviSynth audio sample formats.

The samples of this type have normal values between -1.0 (= 0xBF800000) and +1.0 (= 0x3F800000). Values outside this range are usable as long as the audio remains in Float format, but will create audio clipping if converted to an integer format: 8, 16, 24 or 32 integer bits. For safety, you can call Normalize before converting from Float to Integer.

ColorBarsHD ## audio format = Float; range -1.0 - +1.0
Amplify(1000.0) ## range -1000.0 - +1000.0
Amplify(0.001) ## range -1.0 - +1.0
## output: unchanged
ColorBarsHD ## audio format = Float; range -1.0 - +1.0
Amplify(1000.0) ## range -1000.0 - +1000.0
ConvertAudioTo16bit ## convert to Integer; severe clipping
Amplify(0.001) ## still clipping


The value of such a IEEE-754 number is computed as: sign * 2^exponent * 1.mantissa, using the following scheme:

[ 1 Sign Bit | 8 Bit Exponent | 23 Bit Mantissa ]

  • The sign bit is 1 (negative) or 0 (positive).
  • The exponent runs from -127 (00000000) to 0 (0111111) to 128 (11111111).
  • The mantissa m1m2m3 ... means m1/2 + m2/4 + m3/8 + ... in decimal. Sometimes people denote "1.m1m2m3..." as the mantissa (like is done in the converter below).

For an on-line converter between decimal numbers and IEEE 754 floating point, see here.

Examples:

0x3F800000 = 00111111100000000000000000000000 (binary, see [1])

Sign Bit      Exp       1.Mantissa
0          01111111  00000000000000000000000

127 - 127 = 0     1.0 bitshift 0 places

Sign bit is positive, exponent = 0, 1.mantissa = 1, so the number is +1.0

and

0xBF800000 = 10111111100000000000000000000000

Sign Bit      Exp       1.Mantissa
1          01111111  00000000000000000000000

127 - 127 = 0     1.0 bitshift 0 places

Sign bit is negative, exponent = 0, 1.mantissa = 1, so the number is -1.0

and

0x800000 = 01001011000000000000000000000000

Sign Bit      Exp       1.Mantissa
0          10010110  00000000000000000000000

150 - 127 = 23     1.0 bitshift 23 places

Sign bit is positive, exponent = 23, 1.mantissa = 1, so the number is 8388608

source: opferman.net

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