documentation of similarities and (noteworthy) differencies between Unix systems git clone https://hacktivis.me/git/cross-unix-documentation.git
commit: ad4e4ee4e4bc53c6ce7aef369d597b6a81c8f8b2
parent 95fc9cde4ca17edfeba2463212ba7fe30c84d25d
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Fri, 12 Mar 2021 16:05:43 +0100

man5x/au.5x: Enhance with documentation from Sun


1 file changed, 28 insertions(+), 12 deletions(-)

diff --git a/man5x/au.5x b/man5x/au.5x @@ -15,21 +15,24 @@ which is an attempt to provide documentation of similarities and (noteworthy) di .Nm is a simple Audio Format that came from Sun/NeXT, it is widely supported on Unix systems. .Ss Header -Each field are 32-bits big-endian integers. +All fields are 32-bits (so 4 octets) unsigned big-endian integers. .Bl -tag -width Ds -.It Magic-signature -".snd" (0x2E736E64) -.It Offset -number of bytes the header contains -.It Lenght -0 or 0xFFFFFFFF for undefined -.It Encoding +.It magic +Always equal to 0x2E736E64 (".snd") +.It header size +number of octets the header contains; 24 if no further info was added +.It data size +number of octets the data contains; 0 or 0xFFFFFFFF for undefined +.It encoding refer to codecs section -.It Sample rate -in Hz -.It Channels -1 for mono, 2 for stereo, ... +.It sample rate +number of samples per seconds (aka Hz). Common ones are 8000, 11025, 16000, 22050, 32000, 44100, and 48000 Hz. +.It channels +Number of interleaved channels. 1 for mono, 2 for stereo, ... .El +.Pp +You may append information after the header in multiple of 8 octets that is terminated and filled with NULL octets. +Pure ASCII is the strongly suggested usage but it seen as implementation defined. .Ss Codecs .Bl -tag -width Ds .It 01 @@ -46,15 +49,28 @@ unsigned 8-bit linear PCM 32-bit IEEE floating point .It 07 64-bit IEEE floating point +.It 23 +4-bit CCITT G.721 ADPCM +.It 25 +CCITT G.723 3-bit ADPCM .It 27 8-bit G.711 A-law .El +.Pp +Note: Linear PCM data is signed and zero-centered. .Sh SOURCE .Bl -bullet -compact .It .Lk https://code.9front.org/hg/plan9front/file/default/sys/src/cmd/audio/sundec 9front's /sys/src/cmd/audio/sundec .It .Lk https://wiki.multimedia.cx/index.php/Au/snd Au/snd - MultimediaWiki +.It +.Lk https://pubs.opengroup.org/external/auformat.html AU - Audio File Format © Sun Microsystems 1992 +.It +.Xr audio_filehdr 3 , +.Xr audio_hdr 3 +.It +.Lk https://docs.python.org/3/library/sunau.html Python3 sunau module documentation .El .Sh AUTHORS .An Haelwenn (lanodan) Monnier Aq Mt contact+c-u-d@hacktivis.me