# Float

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− | Float (or fully IEEE floating point with single precision) is one of the | + | ''This page is about the ''Float ''audio format''. ''For the variable type, see [[Script_variables]]''. ''For the'' <code>Float()</code> ''function, go to [[Internal_functions#Float]]'' |

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+ | '''Float''' (or fully IEEE floating point with single precision) is one of the [[ConvertAudio|AviSynth audio sample formats]]. | ||

The samples of this type have values between -1.00000 (= 0xBF800000) and 1.000000 (= 0x3F800000). | The samples of this type have values between -1.00000 (= 0xBF800000) and 1.000000 (= 0x3F800000). | ||

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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 ] | + | <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). | * 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). | ||

+ | |||

+ | 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: | ||

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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] | + | source: [http://www.opferman.net/Text/ieee.txt opferman.net] |

[[Category:Glossary]] | [[Category:Glossary]] |

## Revision as of 17:29, 17 September 2014

*This page is about the *Float *audio format*. *For the variable type, see Script_variables*. *For the* `Float()`

*function, go to Internal_functions#Float*

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

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:

`[ 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 above).

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

source: opferman.net