Adaptive Differential Pulse Code Modulation - Revision history

Porcuswiki: "linear"

2022-01-01T20:59:42Z

"linear"

← Older revision		Revision as of 20:59, 1 January 2022
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	'''Adaptive Differential Pulse Code Modulation''' ('''ADPCM''') is a very widely used lossy coding scheme.		'''Adaptive Differential Pulse Code Modulation''' ('''ADPCM''') is a very widely used lossy coding scheme.

	The acronym refers to waveform codecs which instead of quantizing the sound signal directly, like [[PCM]] codecs, quantize the difference between the sound signal and a prediction that has been made of the sound signal. If the prediction is accurate then the difference between the real and predicted sound samples will have a lower variance than the real sound samples, and will be accurately quantized with fewer bits than would be needed to quantize the original sound samples. At the decoder the quantized difference signal is added to the predicted signal to give the reconstructed sound signal.		The acronym refers to waveform codecs which instead of quantizing the sound signal directly, like [[PCM\|linear PCM]] codecs, quantize the difference between the sound signal and a prediction that has been made of the sound signal. If the prediction is accurate then the difference between the real and predicted sound samples will have a lower variance than the real sound samples, and will be accurately quantized with fewer bits than would be needed to quantize the original sound samples. At the decoder the quantized difference signal is added to the predicted signal to give the reconstructed sound signal.

	Implementations come from a variety of vendors. Some are proprietary, other are open, and there are drastic variations among them with regards to flexibility and quality:		Implementations come from a variety of vendors. Some are proprietary, other are open, and there are drastic variations among them with regards to flexibility and quality:

Speckmade at 16:53, 13 June 2007

2007-06-13T16:53:00Z

← Older revision		Revision as of 16:53, 13 June 2007
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	~~ADPCM (~~Adaptive Differential Pulse Code Modulation) is a very widely used lossy coding scheme.		'''Adaptive Differential Pulse Code Modulation''' ('''ADPCM''') is a very widely used lossy coding scheme.

	The acronym refers to waveform codecs which instead of quantizing the sound signal directly, like [[PCM]] codecs, quantize the difference between the sound signal and a prediction that has been made of the sound signal. If the prediction is accurate then the difference between the real and predicted sound samples will have a lower variance than the real sound samples, and will be accurately quantized with fewer bits than would be needed to quantize the original sound samples. At the decoder the quantized difference signal is added to the predicted signal to give the reconstructed sound signal.		The acronym refers to waveform codecs which instead of quantizing the sound signal directly, like [[PCM]] codecs, quantize the difference between the sound signal and a prediction that has been made of the sound signal. If the prediction is accurate then the difference between the real and predicted sound samples will have a lower variance than the real sound samples, and will be accurately quantized with fewer bits than would be needed to quantize the original sound samples. At the decoder the quantized difference signal is added to the predicted signal to give the reconstructed sound signal.

Speckmade: ADPCM moved to Adaptive Differential Pulse Code Modulation

2007-06-13T16:51:29Z

ADPCM moved to Adaptive Differential Pulse Code Modulation

← Older revision	Revision as of 16:51, 13 June 2007
(No difference)

Pepoluan: Category:Technical

2006-09-08T18:46:00Z

Category:Technical

← Older revision		Revision as of 18:46, 8 September 2006
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	Several game vendors also implemented their own ADPCM variations: EA ADPCM, Sony XA ADPCM, Sierra Online DPCM, Interplay MVE DPCM, Id RoQ DPCM and so on.		Several game vendors also implemented their own ADPCM variations: EA ADPCM, Sony XA ADPCM, Sierra Online DPCM, Interplay MVE DPCM, Id RoQ DPCM and so on.


			[[Category:Technical]]

Rjamorim at 20:07, 11 May 2005

2005-05-11T20:07:02Z

← Older revision		Revision as of 20:07, 11 May 2005
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	* [[OptimFROG]] dual-stream		* [[OptimFROG]] dual-stream

	Several game vendors also implemented their own ADPCM variations: EA ADPCM, Sony XA ADPCM, and so on.		Several game vendors also implemented their own ADPCM variations: EA ADPCM, Sony XA ADPCM, Sierra Online DPCM, Interplay MVE DPCM, Id RoQ DPCM and so on.

Rjamorim at 20:12, 30 March 2005

2005-03-30T20:12:13Z

New page

ADPCM (Adaptive Differential Pulse Code Modulation) is a very widely used lossy coding scheme.

The acronym refers to waveform codecs which instead of quantizing the sound signal directly, like [[PCM]] codecs, quantize the difference between the sound signal and a prediction that has been made of the sound signal. If the prediction is accurate then the difference between the real and predicted sound samples will have a lower variance than the real sound samples, and will be accurately quantized with fewer bits than would be needed to quantize the original sound samples. At the decoder the quantized difference signal is added to the predicted signal to give the reconstructed sound signal.

Implementations come from a variety of vendors. Some are proprietary, other are open, and there are drastic variations among them with regards to flexibility and quality:

* IMA (International Multimedia Association) ADPCM
* Microsoft ADPCM
(the aforementioned variations are, by far, the most popular ones, specially IMA)
* CCITT G721 A-Law and µ-Law
* CCITT G726 and G727
* Apple [[MACE]]
* [[WavPack]] lossy
* [[OptimFROG]] dual-stream

Several game vendors also implemented their own ADPCM variations: EA ADPCM, Sony XA ADPCM, and so on.