ResampleAudio
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* Accepts any number of channels. | * Accepts any number of channels. | ||
* The conversion is skipped if the sample rate is already at the given rate. | * The conversion is skipped if the sample rate is already at the given rate. | ||
| − | * Supports ''fractional'' resampling (where {{FuncArg|new_rate_denominator}} | + | * Supports ''fractional'' resampling (where {{FuncArg|new_rate_denominator}} ≠ 1). |
| + | * Note, internal rounding may affect [[Clip_properties|AudioDuration]] slightly – see [[#Examples|example]] below. | ||
</div> | </div> | ||
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|ResampleAudio(clip ''clip'', ''int new_rate_numerator'' [, int ''new_rate_denominator'' ] ) | |ResampleAudio(clip ''clip'', ''int new_rate_numerator'' [, int ''new_rate_denominator'' ] ) | ||
}} | }} | ||
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| + | :{{Par2|clip |clip|}} | ||
| + | ::Source clip. Supported [[ConvertAudio|audio sample types]]: 16-bit integer and [[Float|32-bit floating-point]]. | ||
| + | ::Other sample types (8-, 24- and 32-bit integer) are automatically converted to floating-point. | ||
:{{Par2|new_rate_numerator|int|}} | :{{Par2|new_rate_numerator|int|}} | ||
| − | ::Set new sample rate | + | ::Set the numerator for the new sample rate. |
:{{Par2|new_rate_denominator|int|1}} | :{{Par2|new_rate_denominator|int|1}} | ||
::Set the denominator for the new sample rate. Default 1. | ::Set the denominator for the new sample rate. Default 1. | ||
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</div> | </div> | ||
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''# final sample rate:'' | ''# final sample rate:'' | ||
[[AssumeSampleRate]](Ar) | [[AssumeSampleRate]](Ar) | ||
| − | [[AssumeFPS]](Nfr_num, Nfr_den, | + | [[AssumeFPS]](Nfr_num, Nfr_den, false) |
</div> | </div> | ||
<div style="max-width:62em" > | <div style="max-width:62em" > | ||
| − | In the example above, the | + | In the example above, the intermediate sample rate needs to be |
| − | :( | + | :<tt>([[Clip_properties|AudioRate]]*[[Clip_properties|FramerateNumerator]]*Nfr_den=1)/([[Clip_properties|FramerateDenominator]]*Nfr_num=25)</tt> |
| + | :or <tt>(44100 * 24000 * 1) / (1001 * 25)</tt> = 42293.706294... | ||
but because audio sample rates are always integers, 42293.706294 must be rounded to 42294, <br> | but because audio sample rates are always integers, 42293.706294 must be rounded to 42294, <br> | ||
| − | which results in a time slippage of about 30ms per hour. | + | which results in a time slippage of about 30ms per hour. |
</div> | </div> | ||
Revision as of 20:10, 27 February 2016
High-quality change of audio sample rate.
- Accepts any number of channels.
- The conversion is skipped if the sample rate is already at the given rate.
- Supports fractional resampling (where new_rate_denominator ≠ 1).
- Note, internal rounding may affect AudioDuration slightly – see example below.
Syntax and Parameters
ResampleAudio(clip clip, int new_rate_numerator [, int new_rate_denominator ] )
- clip clip =
- Source clip. Supported audio sample types: 16-bit integer and 32-bit floating-point.
- Other sample types (8-, 24- and 32-bit integer) are automatically converted to floating-point.
- int new_rate_numerator =
- Set the numerator for the new sample rate.
- int new_rate_denominator = 1
- Set the denominator for the new sample rate. Default 1.
Examples
- Resample audio to 48 kHz:
source = WavSource("c:\audio.wav") return ResampleAudio(source, 48000)
- Exact 4% speed up for PAL telecine:
Nfr_num = 25 Nfr_den = 1 AviSource("C:\Film.avi") # 23.976 fps, 44100Hz Ar = AudioRate # intermediate sample rate: ResampleAudio(Ar*FramerateNumerator*Nfr_den, FramerateDenominator*Nfr_num) # final sample rate: AssumeSampleRate(Ar) AssumeFPS(Nfr_num, Nfr_den, false)
In the example above, the intermediate sample rate needs to be
- (AudioRate*FramerateNumerator*Nfr_den=1)/(FramerateDenominator*Nfr_num=25)
- or (44100 * 24000 * 1) / (1001 * 25) = 42293.706294...
but because audio sample rates are always integers, 42293.706294 must be rounded to 42294,
which results in a time slippage of about 30ms per hour.
Changes
| v2.56 | Added new_sample_rate=float. |
