WavPack - Revision history

Crybaby: /* Linkify Golomb */

2007-08-16T07:40:41Z

Linkify Golomb

← Older revision		Revision as of 00:40, 16 August 2007
Line 100:		Line 100:

	=== Samples coding ===		=== Samples coding ===
	Samples are stored in metadata block with ID=0x0A and are packed with modified Golomb codes. Decoding process is specified below where get_unary() is the function which returns length of '1'-bits string (i.e. 111110b = 5, 10b = 1).		Samples are stored in metadata block with ID=0x0A and are packed with modified [[Golomb\|Golomb codes]]. Decoding process is specified below where get_unary() is the function which returns length of '1'-bits string (i.e. 111110b = 5, 10b = 1).
	Codeset is adaptively divided into four sets and every code has unary prefix (possibly escaped) defining interval of this code and mantis part like in Golomb code.		Codeset is adaptively divided into four sets and every code has unary prefix (possibly escaped) defining interval of this code and mantis part like in [[Golomb\|Golomb code]].

	if(last_zero){		if(last_zero){

Bryant: fleshed out some format details

2007-08-15T05:37:18Z

fleshed out some format details

← Older revision		Revision as of 22:37, 14 August 2007
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	* Website: http://www.wavpack.com/		* Website: http://www.wavpack.com/
	* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)		* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)
			* Theory/Whitepaper: http://www.wavpack.com/WavPack.pdf
	* FOURCC (unofficial): WVPK		* FOURCC (unofficial): WVPK

Line 17:		Line 18:
	Block header (all data is stored in little-endian words)		Block header (all data is stored in little-endian words)
	4 bytes - 'wvpk'		4 bytes - 'wvpk'
	32 bits - block size		32 bits - total block size (not counting this field or 'wvpk')
	16 bits - version		16 bits - version (current valid versions are 0x402 - 0x410)
	8 bits - track number		8 bits - track number (not currently implemented)
	8 bits - track sub index		8 bits - track sub index (not currently implemented)
	32 bits - total samples in file (may be 0xFFFFFFFF)		32 bits - total samples in file (may be 0xFFFFFFFF if unknown)
	32 bits - offset in samples for current block (i.e. how ~~much~~ samples should be decoded by now)		32 bits - offset in samples for current block (i.e. how many samples should be decoded by now)
	32 bits - samples in this block		32 bits - samples in this block (may be 0 if no audio present)
	32 bits - flags		32 bits - flags
	32 bits - CRC		32 bits - CRC
Line 38:		Line 39:
	bits 9-10 - hybrid profile flags		bits 9-10 - hybrid profile flags
	bits 11-12 - multi-channel start and end blocks		bits 11-12 - multi-channel start and end blocks
	bits 13-17 - shift ~~parameter?~~		bits 13-17 - left-shift places when bitdepth is not a multiple of 8 (e.g. 12-bit, 20-bit)
	bits 18-22 - ~~scaling parameter?~~		bits 18-22 - maximum magnitude of decoded data (can be used to optimize decoding arithmetic)
	bits 23-26 - sampling rate index		bits 23-26 - sampling rate index (15 = unknown/custom)
			bit 27 - reserved (okay to ignore if encountered)
			bit 28 - robust block (experimental, okay to ignore if encountered)
			bit 29 - IIR filter for negative noise shaping in hybrid mode
			bit 30 - false stereo (stream is stereo but this block's data is mono, version >= 0x410)
			bit 31 - low-latency block (experimental, do not decode if encountered)

	=== Metadata ===		=== Metadata ===
Line 51:		Line 57:

	IDs:		IDs:
	* ~~0x01~~ - ~~encoder info~~		* 0x00 - dummy (used for padding)
	* 0x02 - decorrelation terms		* 0x02 - decorrelation terms
	* 0x03 - decorrelation weights		* 0x03 - decorrelation weights
	* 0x04 - decorrelation samples		* 0x04 - decorrelation samples
	* 0x05 - entropy info		* 0x05 - entropy info
			* 0x06 - hybrid profile
			* 0x07 - noise shaping profile (wvc file)
			* 0x08 - floating-point data profile
			* 0x09 - large or shifted integer profile
	* 0x0A - packed samples		* 0x0A - packed samples
			* 0x0B - packed correction data (wvc file)
			* 0x0C - packed overflow bits from floating-point or large integers
			* 0x0D - multichannel information (including Microsoft channel mask)

			* 0x20 - RIFF header for .wav files (before audio)
			* 0x21 - RIFF trailer for .wav files (after audio)
			* 0x25 - some encoding details for info purposes
			* 0x26 - 16-byte MD5 sum of raw audio data
			* 0x27 - non-standard sampling rate

	=== Decorrelation terms ===		=== Decorrelation terms ===

Roberto: Add unofficial fourcc

2006-10-07T23:31:42Z

Add unofficial fourcc

← Older revision		Revision as of 16:31, 7 October 2006
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	* Website: http://www.wavpack.com/		* Website: http://www.wavpack.com/
	* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)		* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)
			* FOURCC (unofficial): WVPK

	WavPack is an open source lossless audio coding algorithm with floating point data support and optional lossy audio compression.		WavPack is an open source lossless audio coding algorithm with floating point data support and optional lossy audio compression.

Kostya at 05:04, 27 September 2006

2006-09-27T05:04:23Z

← Older revision		Revision as of 22:04, 26 September 2006
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	=== Decorrelation terms ===		=== Decorrelation terms ===
	~~TODO~~		Decorrelation terms are stored in one byte, lower 5 bits indicate predictor type, high 3 bits contain delta value.

			Possible predictor values:
			0-5 - predictors for stereo, only predictors 2-4 are implemented
			6-12 - predictor uses 1-7 samples for prediction
			13-16 - reserved
			17-18 - predictor does prediction by two samples

	=== Decorrelation weights ===		=== Decorrelation weights ===

Kostya: More info

2006-09-26T05:20:16Z

More info

@@ Line 3: / Line 3: @@
 * Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)
-WavPack is an open source lossless audio coding algorithm.
+WavPack is an open source lossless audio coding algorithm with floating point data support and optional lossy audio compression.
 == WavPack v.4 ==
@@ Line 10: / Line 10: @@
 WavPack file consists of blocks each beginning with 'wvpk'. Every block contains all information about sound data - sampling rate, channels, bits per sample, etc.
 and so-called metadata. Metadata may contain different coefficients using for restoring samples, correction bitstream and actual compressed samples.
 === Samples coding ===

Kostya at 05:01, 25 September 2006

2006-09-25T05:01:41Z

← Older revision		Revision as of 22:01, 24 September 2006
Line 13:		Line 13:
	=== Samples coding ===		=== Samples coding ===
	Samples are stored in metadata block with ID=0x0A and are packed with modified Golomb codes. Decoding process is specified below where get_unary() is the function which returns length of '1'-bits string (i.e. 111110b = 5, 10b = 1).		Samples are stored in metadata block with ID=0x0A and are packed with modified Golomb codes. Decoding process is specified below where get_unary() is the function which returns length of '1'-bits string (i.e. 111110b = 5, 10b = 1).
	Codeset is adaptively divided into four sets and every code has unary prefix (possibly escaped) defining interval of this code and		Codeset is adaptively divided into four sets and every code has unary prefix (possibly escaped) defining interval of this code and mantis part like in Golomb code.

	if(last_zero){		if(last_zero){

Kostya: Correct information about residue coding

2006-09-25T04:57:43Z

Correct information about residue coding

← Older revision		Revision as of 21:57, 24 September 2006
Line 12:		Line 12:

	=== Samples coding ===		=== Samples coding ===
	Samples are stored in metadata block with ID=0x0A and are packed with modified ~~Rice~~ codes. Decoding process is specified below where get_unary() is the function which returns length of '1'-bits string (i.e. 111110b = 5, 10b = 1).		Samples are stored in metadata block with ID=0x0A and are packed with modified Golomb codes. Decoding process is specified below where get_unary() is the function which returns length of '1'-bits string (i.e. 111110b = 5, 10b = 1).
			Codeset is adaptively divided into four sets and every code has unary prefix (possibly escaped) defining interval of this code and

	n = get_unary();		if(last_zero){
	if(n >= 2) n = getbits(n);		n = 0;
	~~set next~~ n ~~values to zero~~		last_zero = 0;
			}else{
	n = ~~get_unary~~();		n = get_unary();
			if(n == 16){
			n2 = get_unary();
			if(n2 < 2) n += n2;
			else n += (1 << (n2-1)) \| getbits(n2-1);
			}
			last_one = n & 1;
			if(last_one)
			n = (n>>1) + 1;
			else
			n = n >> 1;
			last_zero = !last_one;
			}
	if(n == 0){		if(n == 0){
	base = 0;		base = 0;
	add = median[0] - 1;		add = median[0] - 1;
	decrease median[0];		decrease median[0];
	} else if(n == 1){		} else if(n == 1){
	base = median[0];		base = median[0];
	add = median[1] - 1;		add = median[1] - 1;
	increase median[0];		increase median[0];
	decrease median[1];		decrease median[1];
	} else {		} else {
	base = median[0] + median[1] + median[2] * (n - 2);		base = median[0] + median[1] + median[2] * (n - 2);
	add = median[2] - 1;		add = median[2] - 1;
	increase median[0];		increase median[0];
	increase median[1];		increase median[1];
	if(n == 2) derease median[2];		if(n == 2) derease median[2];
	else increase median[2];		else increase median[2];
	}		}
	n = ~~base~~ + ~~getbits~~(~~add~~);		k = log2(add);
	~~next value~~ = n;		ex = (1 << k) - add - 1;
			t2 = getbits(k - 1);
			if(t2 >= ex)
			t2 = t2 * 2 - ex + getbit();
			sign = getbit();
			if(sign==0) result = base + t2;
			else result = ~(base + t2);

	[[Category:Container Formats]]		[[Category:Container Formats]]
	[[Category:Audio Codecs]]		[[Category:Audio Codecs]]
	[[Category:Lossless Audio Codecs]]		[[Category:Lossless Audio Codecs]]

Kostya at 05:02, 24 September 2006

2006-09-24T05:02:42Z

@@ Line 3: / Line 3: @@
 * Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)
-WavPak is an open source lossless audio coding algorithm.
+WavPack is an open source lossless audio coding algorithm.
 [[Category:Container Formats]]
 [[Category:Audio Codecs]]
 [[Category:Lossless Audio Codecs]]

Dashcloud: Update samples link

2006-08-18T03:51:08Z

Update samples link

← Older revision		Revision as of 20:51, 17 August 2006
Line 1:		Line 1:
	* Extension: wv		* Extension: wv
	* Website: http://www.wavpack.com/		* Website: http://www.wavpack.com/
	* Samples: http://mplayerhq.hu~~/MPlayer/samples~~/A-codecs/lossless/ (luckynight.wv)		* Samples: http://samples.mplayerhq.hu/A-codecs/lossless/ (luckynight.wv)

	WavPak is an open source lossless audio coding algorithm.		WavPak is an open source lossless audio coding algorithm.

Multimedia Mike: sample link

2006-05-25T21:49:42Z

sample link

← Older revision		Revision as of 14:49, 25 May 2006
Line 1:		Line 1:
	* Extension: wv		* Extension: wv
	* Website: [http://www.wavpack.com/ http://~~www~~.~~wavpack~~.~~com/]~~		* Website: http://www.wavpack.com/
			* Samples: http://mplayerhq.hu/MPlayer/samples/A-codecs/lossless/ (luckynight.wv)

	WavPak is an open source lossless audio coding algorithm.		WavPak is an open source lossless audio coding algorithm.

			[[Category:Container Formats]]
	[[Category:Audio Codecs]]		[[Category:Audio Codecs]]
	[[Category:Lossless Audio Codecs]]		[[Category:Lossless Audio Codecs]]