BeFa - Revision history

Reel.Deal: add Operation Overview and a few corrections

2020-06-19T18:09:43Z

add Operation Overview and a few corrections

← Older revision		Revision as of 20:09, 19 June 2020
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	<br>		<br>
	== Description ==		== Description ==
	[[BeFa]]: Band Eliminate Filter for Audio.		[[BeFa]]: Band Eliminate Filter for Audio. This plugin is designed to remove time signals by removing only specific frequency bands.<br>
			This is a ported version of the [https://www.marumo.ne.jp/auf/#befa AviUtl Filter Plug-in made by (MOGI, Kazuhiro).]


	'''Note''': the following documentation was translated from Japanese with online translators, it may not be 100% accurate.		'''Note''': the following documentation was translated from Japanese with online translators, it may not be 100% accurate.
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	<br>		<br>
	::{{Par2\| \|clip\| }}		::{{Par2\| \|clip\| }}
	:::Input clip.		:::Input clip; must have audio and only 16-bit audio is supported.
	<br>		<br>
	::{{Par2\|sec\|float\|1.3}}		::{{Par2\|sec\|float\|1.3}}
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	:::Specify from 0 to 100%. If the graph is hard to see, lower the gain to make it easier to see.		:::Specify from 0 to 100%. If the graph is hard to see, lower the gain to make it easier to see.
	<br>		<br>
			==Operation Overview==

			This filter is implemented as a FIR filter having a linear phase (group delay flat) characteristic by a real discrete Fourier transform (DFT). The product of the input sequence and the impulse response of the filter is convolved and the inverse DFT is performed to obtain the output sequence.

			The value specified for dftsize (2048 points by default) is set as one block, and 1/4 blocks are overlapped and the following filter processing is performed. (Overlap method)<br>
			In addition, in the overlapping portion, the ratio is linearly reduced in the front block and increased in the rear block, and finally added. It is decomposed into dftzise frequency components by real number DFT, and the band of radius (bandwidth+1) is blocked around the designated frequency band component.

			(By default, one bandwidth is sampling frequency/2/dftsize, which is 10Hz at 44.1KHz (11Hz at 48KHz), so 1000Hz is the center of -400 to +400Hz and 2000Hz is the center of -110 to +. Block 110Hz.)

			However, if simply blocked by a rectangle, vibration (noise) with a frequency characteristic called the Gibbs phenomenon occurs. Therefore, as a preventive measure, an impulse sequence multiplied by a window function can be used. (Because this is cut off by a finite number of Fourier coefficients, the input sequence is in Audio 16bit format and is not normalized at the time of actual conversion, so 32768 times the actual value is calculated.
			<br>
			<br>
	== Examples ==		== Examples ==
	BeFa with default values filters for 1.3 seconds from the beginning and fades in for 0.3 seconds.		BeFa with default values filters for 1.3 seconds from the beginning and fades in for 0.3 seconds.

Reel.Deal: /* Syntax and Parameters */ minor corrections

2020-06-18T17:14:47Z

Syntax and Parameters: minor corrections

← Older revision		Revision as of 19:14, 18 June 2020
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	::{{Par2\|bandwidth\|int\|40}}		::{{Par2\|bandwidth\|int\|40}}
	:::Sets the width of the removal frequency. Range: 0 to ~~512~~		:::Sets the width of the removal frequency. Range: 1 to 1024
	:::Units are the number of points in the frequency domain after the discrete Fourier transform.		:::Units are the number of points in the frequency domain after the discrete Fourier transform.
	:::One unit of width is = sampling frequency / 2 / (2^dftsize) [Hz].		:::One unit of width is = sampling frequency / 2 / (2^dftsize) [Hz].
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	<br>		<br>
	::{{Par2\|bandwidth2\|int\|-1}}		::{{Par2\|bandwidth2\|int\|-1}}
	:::Set the width of the second removal frequency. Range: -1 to ~~512~~		:::Set the width of the second removal frequency. Range: 1 to 1024
	:::When -1 is specified, <code>bandwidth2</code> = (bandwidth+7)/8		:::When -1 is specified, <code>bandwidth2</code> = (bandwidth+7)/8
	<br>		<br>
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	:::*2 : Hamming window		:::*2 : Hamming window
	:::*3 : Blackman window (Wide band, lacking sharpness, not suitable for time signal removal)		:::*3 : Blackman window (Wide band, lacking sharpness, not suitable for time signal removal)
	:::When specified, the frequency region specified by the width is not set to 0, but it is processed with a gentle characteristic so that it is close to 0 at the center and close to the original signal at the edges. When checking, use a wider width than usual.		:::When specified, the frequency region specified by the width is not set to 0, but it is processed with a gentle characteristic so that it is close to 0 at the center and close to the original signal at the edges.
			:::When checking, use a wider width than usual.
	<br>		<br>
	::{{Par2\|mode\|int\|0}}		::{{Par2\|mode\|int\|0}}

Reel.Deal: category

2020-06-18T17:07:06Z

Reel.Deal: BeFa: add documentation (translated from Japanese with online translators)

2020-06-18T17:06:18Z

BeFa: add documentation (translated from Japanese with online translators)

Show changes

Raffriff42: redirect for convenient searching

2015-11-08T05:02:54Z

redirect for convenient searching

New page

#REDIRECT [[External_filters#Audio_Filters]]
{{FilterCat|External_filters|Audio_filters|}}

← Older revision		Revision as of 19:07, 18 June 2020
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	{{~~FilterCat4~~\|External_filters\|Plugins~~\|Plugins_x64~~\|Audio_filters}}		{{FilterCat\|External_filters\|Plugins\|Audio_filters}}
	{{Filter3		{{Filter3
	\| 1={{Author/kiraru2002}}		\| 1={{Author/kiraru2002}}