WAV - Revision history

>Atari74user at 19:50, 25 March 2016

2016-03-25T19:50:33Z

← Older revision		Revision as of 15:50, 25 March 2016
Line 3:		Line 3:
	WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 made it prominent.		WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 made it prominent.

	The following is a ~~overly~~ simple description of a WAV file and will generally only work when it contains PCM data~~. This isn't so bad since thats what 90% want to work with~~.		The following is a simple description of a WAV file and will generally only work when it contains PCM data.

>Atari74user at 07:26, 21 March 2016

2016-03-21T07:26:32Z

← Older revision		Revision as of 03:26, 21 March 2016
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	Waveform Audio File Format, WAV was introduced by Microsoft and IBM.		Waveform Audio File Format (WAV) was introduced by Microsoft and IBM.

	WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 made it prominent.		WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 made it prominent.

>Atari74user at 00:18, 21 March 2016

2016-03-21T00:18:45Z

← Older revision		Revision as of 20:18, 20 March 2016
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	dword data_ckSize; /* length of data chunk */		dword data_ckSize; /* length of data chunk */
	};		};



			Back to [[Sample File Formats (Audio)]]

>Atari74user at 00:17, 21 March 2016

2016-03-21T00:17:21Z

← Older revision		Revision as of 20:17, 20 March 2016
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	The format for a wave file is as follows:		The format for a wave file is as follows:


	Offset Description		Offset Description
	------------------		------------------

>Atari74user at 00:17, 21 March 2016

2016-03-21T00:17:10Z

← Older revision		Revision as of 20:17, 20 March 2016
Line 20:		Line 20:
	Offset Description		Offset Description
	------------------		------------------

	0x00 chunk id 'RIFF'		0x00 chunk id 'RIFF'
	0x04 chunk size (32-bits)		0x04 chunk size (32-bits)

>Atari74user at 00:16, 21 March 2016

2016-03-21T00:16:44Z

← Older revision		Revision as of 20:16, 20 March 2016
Line 18:		Line 18:
	The format for a wave file is as follows:		The format for a wave file is as follows:

	Offset Description		Offset Description
	------ -----------		------------------
	0x00 chunk id 'RIFF'		0x00 chunk id 'RIFF'
	0x04 chunk size (32-bits)		0x04 chunk size (32-bits)
Line 30:		Line 30:
	0x1C average bytes per second		0x1C average bytes per second
	0x20 number of bytes per sample		0x20 number of bytes per sample
	1 = 8-bit mono		1 = 8-bit mono
	2 = 8-bit stereo or		2 = 8-bit stereo or
	16-bit mono		16-bit mono
	4 = 16-bit stereo		4 = 16-bit stereo
	0x22 number of bits in a sample		0x22 number of bits in a sample
	0x24 data chunk id 'data'		0x24 data chunk id 'data'

>Atari74user at 00:15, 21 March 2016

2016-03-21T00:15:44Z

← Older revision		Revision as of 20:15, 20 March 2016
Line 1:		Line 1:
	Waveform Audio File Format, WAV was introduced by Microsoft and IBM.		Waveform Audio File Format, WAV was introduced by Microsoft and IBM.

	WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 ~~has~~ made it ~~important to know about.~~		WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 made it prominent.

	Rob Ryan was kind enough to send me a description of the RIFF format. Unfortunately, it is too big to include here (27 k), but I've made it available for anonymous ftp at ftp://ftp.cwi.nl/pub/audio/RIFF-format.

	~~Conor Frederick Prischmann <conor@owlnet.rice.edu> points to ftp://ftp.ircam.fr/pub/music/~~.

	The following is a overly simple description of a WAV file and will generally only work when it contains PCM data. This isn't so bad since thats what 90% want to work with.		The following is a overly simple description of a WAV file and will generally only work when it contains PCM data. This isn't so bad since thats what 90% want to work with.


	WAVe file format (Microsoft)		WAVe file format (Microsoft)
	----------------------------		----------------------------

	Wave files are a part of a file interchange format, called		Wave files are a part of a file interchange format, called
	RIFF, created by Microsoft. The format basically is composed		RIFF, created by Microsoft. The format basically is composed
	of a collection of data chunks. Each chunk has a 32-bit Id		of a collection of data chunks. Each chunk has a 32-bit Id
	field, followed by a 32-bit chunk length, followed by the		field, followed by a 32-bit chunk length, followed by the
	chunk data. Note that values are in Intel form (ie: big-		chunk data. Note that values are in Intel form (ie: big-
	endian notation).		endian notation).

	The format for a wave file is as follows:		The format for a wave file is as follows:

	Offset Description		Offset Description
	------ -----------		------ -----------
	0x00 chunk id 'RIFF'		0x00 chunk id 'RIFF'
	0x04 chunk size (32-bits)		0x04 chunk size (32-bits)
	0x08 wave chunk id 'WAVE'		0x08 wave chunk id 'WAVE'
	0x0C format chunk id 'fmt '		0x0C format chunk id 'fmt '
	0x10 format chunk size (32-bits)		0x10 format chunk size (32-bits)
	0x14 format tag (currently pcm)		0x14 format tag (currently pcm)
	0x16 number of channels 1=mono, 2=stereo		0x16 number of channels 1=mono, 2=stereo
	0x18 sample rate in hz		0x18 sample rate in hz
	0x1C average bytes per second		0x1C average bytes per second
	0x20 number of bytes per sample		0x20 number of bytes per sample
	1 = 8-bit mono		1 = 8-bit mono
	2 = 8-bit stereo or		2 = 8-bit stereo or
	16-bit mono		16-bit mono
	4 = 16-bit stereo		4 = 16-bit stereo
	0x22 number of bits in a sample		0x22 number of bits in a sample
	0x24 data chunk id 'data'		0x24 data chunk id 'data'
	0x28 length of data chunk (32-bits)		0x28 length of data chunk (32-bits)
	0x2C Sample data		0x2C Sample data


	Notes		Notes
	-----		-----

	1. Lengths do not include the chunk Id or the length bytes.		1. Lengths do not include the chunk Id or the length bytes.
	e.g.: if the data length is 1204 then the length of		e.g. if the data length is 1204 then the length of sample data is 1204 and not 1204-(4+4)
	sample data is 1204 and not 1204-(4+4)

	~~2. For samples with more than 1 channel, channel 0 data will~~
	~~start and be followed by channel 1 for a given sample~~
	~~then the next sample will follow.~~
	~~e.g.: for 8-bit stereo the samples will sample0left,~~
	~~sample0right, sample1left, sample1right, etc.~~

	3. ~~8-bit~~ samples ~~are stored in excess-128 notation~~. ~~This~~		2. For samples with more than 1 channel, channel 0 data will
	~~means that~~ the ~~value 0 is stored as 128~~, ~~a value 1 is~~		start and be followed by channel 1 for a given sample then the next sample will follow.
	~~stored as 129~~, ~~a value of -1 is stored as 127 and so on~~.		e.g. for 8-bit stereo the samples will sample0left,
			sample0right, sample1left, sample1right, etc.

	4. 16-bit samples are stored as 2's compliment signed		3. 8-bit samples are stored in excess-128 notation. This means that the value 0 is stored as 128, a value 1 is
	numbers.		stored as 129, a value of -1 is stored as 127 and so on.
			4. 16-bit samples are stored as 2's compliment signed numbers.


	Sample C Structure		Sample C Structure
	------------------		------------------

	typedef unsigned word;		typedef unsigned word;
	typedef unsigned long dword;		typedef unsigned long dword;

	struct WAVEheader		struct WAVEheader
	{		{
	char ckID[4]; /* chunk id 'RIFF' */		char ckID[4]; /* chunk id 'RIFF' */
	dword ckSize; /* chunk size */		dword ckSize; /* chunk size */
	char wave_ckID[4]; /* wave chunk id 'WAVE' */		char wave_ckID[4]; /* wave chunk id 'WAVE' */
	char fmt_ckID[4]; /* format chunk id 'fmt ' */		char fmt_ckID[4]; /* format chunk id 'fmt ' */
	dword fmt_ckSize; /* format chunk size */		dword fmt_ckSize; /* format chunk size */
	word formatTag; /* format tag currently pcm */		word formatTag; /* format tag currently pcm */
	word nChannels; /* number of channels */		word nChannels; /* number of channels */
	dword nSamplesPerSec; /* sample rate in hz */		dword nSamplesPerSec; /* sample rate in hz */
	dword nAvgBytesPerSec; /* average bytes per second */		dword nAvgBytesPerSec; /* average bytes per second */
	word nBlockAlign; /* number of bytes per sample */		word nBlockAlign; /* number of bytes per sample */
	word nBitsPerSample; /* number of bits in a sample */		word nBitsPerSample; /* number of bits in a sample */
	char data_ckID[4]; /* data chunk id 'data' */		char data_ckID[4]; /* data chunk id 'data' */
	dword data_ckSize; /* length of data chunk */		dword data_ckSize; /* length of data chunk */
	};		};

>Atari74user: Created page with "Waveform Audio File Format, WAV was introduced by Microsoft and IBM. WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 has made it important to know ..."

2016-03-21T00:10:03Z

Created page with "Waveform Audio File Format, WAV was introduced by Microsoft and IBM. WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 has made it important to know ..."

New page

Waveform Audio File Format, WAV was introduced by Microsoft and IBM.

WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 has made it important to know about.

Rob Ryan was kind enough to send me a description of the RIFF format. Unfortunately, it is too big to include here (27 k), but I've made it available for anonymous ftp at ftp://ftp.cwi.nl/pub/audio/RIFF-format.

Conor Frederick Prischmann <conor@owlnet.rice.edu> points to ftp://ftp.ircam.fr/pub/music/.

The following is a overly simple description of a WAV file and will generally only work when it contains PCM data. This isn't so bad since thats what 90% want to work with.

WAVe file format (Microsoft)
----------------------------

Wave files are a part of a file interchange format, called
RIFF, created by Microsoft. The format basically is composed
of a collection of data chunks. Each chunk has a 32-bit Id
field, followed by a 32-bit chunk length, followed by the
chunk data. Note that values are in Intel form (ie: big-
endian notation).

The format for a wave file is as follows:

Offset Description
------ -----------
0x00 chunk id 'RIFF'
0x04 chunk size (32-bits)
0x08 wave chunk id 'WAVE'
0x0C format chunk id 'fmt '
0x10 format chunk size (32-bits)
0x14 format tag (currently pcm)
0x16 number of channels 1=mono, 2=stereo
0x18 sample rate in hz
0x1C average bytes per second
0x20 number of bytes per sample
1 = 8-bit mono
2 = 8-bit stereo or
16-bit mono
4 = 16-bit stereo
0x22 number of bits in a sample
0x24 data chunk id 'data'
0x28 length of data chunk (32-bits)
0x2C Sample data

Notes
-----

1. Lengths do not include the chunk Id or the length bytes.
e.g.: if the data length is 1204 then the length of
sample data is 1204 and not 1204-(4+4)

2. For samples with more than 1 channel, channel 0 data will
start and be followed by channel 1 for a given sample
then the next sample will follow.
e.g.: for 8-bit stereo the samples will sample0left,
sample0right, sample1left, sample1right, etc.

3. 8-bit samples are stored in excess-128 notation. This
means that the value 0 is stored as 128, a value 1 is
stored as 129, a value of -1 is stored as 127 and so on.

4. 16-bit samples are stored as 2's compliment signed
numbers.

Sample C Structure
------------------

typedef unsigned word;
typedef unsigned long dword;

struct WAVEheader
{
char ckID[4]; /* chunk id 'RIFF' */
dword ckSize; /* chunk size */
char wave_ckID[4]; /* wave chunk id 'WAVE' */
char fmt_ckID[4]; /* format chunk id 'fmt ' */
dword fmt_ckSize; /* format chunk size */
word formatTag; /* format tag currently pcm */
word nChannels; /* number of channels */
dword nSamplesPerSec; /* sample rate in hz */
dword nAvgBytesPerSec; /* average bytes per second */
word nBlockAlign; /* number of bytes per sample */
word nBitsPerSample; /* number of bits in a sample */
char data_ckID[4]; /* data chunk id 'data' */
dword data_ckSize; /* length of data chunk */
};