WAV - Revision history

AtariWikiSysop: 8 revisions imported

2018-06-03T23:14:26Z

8 revisions imported

Atari74user at 19:50, 25 March 2016

2016-03-25T19:50:33Z

Atari74user at 07:26, 21 March 2016

2016-03-21T07:26:32Z

Atari74user at 00:18, 21 March 2016

2016-03-21T00:18:45Z

Atari74user at 00:17, 21 March 2016

2016-03-21T00:17:21Z

Atari74user at 00:17, 21 March 2016

2016-03-21T00:17:10Z

Atari74user at 00:16, 21 March 2016

2016-03-21T00:16:44Z

Atari74user at 00:15, 21 March 2016

2016-03-21T00:15:44Z

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 */
};

← Older revision		Revision as of 19:50, 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.

← Older revision		Revision as of 07:26, 21 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 made it prominent.		WAVE is RIFF's equivalent of AIFF, and its inclusion in Microsoft Windows 3.1 made it prominent.

← Older revision		Revision as of 00:18, 21 March 2016
Line 80:		Line 80:
	dword data_ckSize; /* length of data chunk */		dword data_ckSize; /* length of data chunk */
	};		};
		+
		+
		+
		+	Back to [[Sample File Formats (Audio)]]

← Older revision	Revision as of 23:14, 3 June 2018
(No difference)

@@ Line 18: / Line 18: @@
 The format for a wave file is as follows:
 Offset Description
 ------------------

@@ Line 20: / Line 20: @@
 Offset Description
 ------------------
 x00     chunk id 'RIFF'
 x04     chunk size (32-bits)

@@ Line 18: / Line 18: @@
 The format for a wave file is as follows:
-Offset    Description
+Offset Description
-------    -----------
+------------------
 x00     chunk id 'RIFF'
 x04     chunk size (32-bits)
@@ Line 30: / Line 30: @@
 x1C     average bytes per second
 x20     number of bytes per sample
 =  8-bit mono
 =  8-bit stereo or
 -bit mono
 = 16-bit stereo
 x22     number of bits in a sample
 x24     data chunk id 'data'

@@ Line 1: / Line 1: @@
 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.
 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
-         ------    -----------
+------    -----------
 x00     chunk id 'RIFF'
 x04     chunk size (32-bits)
 x08     wave chunk id 'WAVE'
 x0C     format chunk id 'fmt '
 x10     format chunk size (32-bits)
 x14     format tag (currently pcm)
 x16     number of channels 1=mono, 2=stereo
 x18     sample rate in hz
 x1C     average bytes per second
 x20     number of bytes per sample
 =  8-bit mono
 =  8-bit stereo or
 -bit mono
 = 16-bit stereo
 x22     number of bits in a sample
 x24     data chunk id 'data'
 x28     length of data chunk (32-bits)
 x2C     Sample data
-         Notes
+Notes
-         -----
+-----
 .   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)
-.   8-bit samples are stored in excess-128 notation.  This
+.   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,
-.   16-bit samples are stored as 2's compliment signed
+.   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.
-         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       */
-            };
+};