NetBSD/usr.bin/file/magdir/vorbis

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#------------------------------------------------------------------------------
# vorbis: file(1) magic for Ogg/Vorbis files
#
# From Felix von Leitner <leitner@fefe.de>
# Extended by Beni Cherniavsky <cben@crosswinds.net>
# Further extended by Greg Wooledge <greg@wooledge.org>
#
# Most (everything but the number of channels and bitrate) is commented
# out with `##' as it's not interesting to the average user. The most
# probable things advanced users would want to uncomment are probably
# the number of comments and the encoder version.
#
# --- Ogg Framing ---
0 string OggS Ogg data
>4 byte !0 UNKNOWN REVISION %u
##>4 byte 0 revision 0
>4 byte 0
##>>14 lelong x (Serial %lX)
# --- First vorbis packet - general header ---
>>28 string \x01vorbis \b, Vorbis audio,
>>>35 lelong !0 UNKNOWN VERSION %lu,
##>>>35 lelong 0 version 0,
>>>35 lelong 0
>>>>39 ubyte 1 mono,
>>>>39 ubyte 2 stereo,
>>>>39 ubyte >2 %u channels,
>>>>40 lelong x %lu Hz
# Minimal, nominal and maximal bitrates specified when encoding
>>>>48 string <\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff \b,
# The above tests if at least one of these is specified:
>>>>>44 lelong !-1
# Vorbis RC2 has a bug which puts -1000 in the min/max bitrate fields
# instead of -1.
>>>>>>44 lelong !-1000
>>>>>>>44 lelong x >%lu
>>>>>48 lelong !-1
>>>>>>48 lelong x ~%lu
>>>>>52 lelong !-1
>>>>>>52 lelong !-1000
>>>>>>>52 lelong x <%lu
>>>>>48 string <\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff kbps
# -- Second vorbis header packet - the comments
# A kludge to read the vendor string. It's a counted string, not a
# zero-terminated one, so file(1) can't read it in a generic way.
# libVorbis is the only one existing currently, so I detect specifically
# it. The interesting value is the cvs date (8 digits decimal).
# Post-RC1 Ogg files have the second header packet (and thus the version)
# in a different place, so we must use an indirect offset.
>>>(84.b+85) string \x03vorbis
>>>>(84.b+96) string/c Xiphophorus\ libVorbis\ I \b, created by: Xiphophorus libVorbis I
>>>>>(84.b+120) string >00000000 %.8s
# Map to beta version numbers:
>>>>>>(84.b+120) string <20000508 (<beta1 - prepublic)
>>>>>>(84.b+120) string 20000508 (beta1/2)
>>>>>>(84.b+120) string >20000508
>>>>>>>(84.b+120) string <20001031 (beta2-3)
>>>>>>(84.b+120) string 20001031 (beta3)
>>>>>>(84.b+120) string >20001031
>>>>>>>(84.b+120) string <20010225 (beta3-4)
>>>>>>(84.b+120) string 20010225 (beta4)
>>>>>>(84.b+120) string >20010225
>>>>>>>(84.b+120) string <20010615 (beta4-RC1)
>>>>>>(84.b+120) string 20010615 (RC1)
>>>>>>(84.b+120) string 20010813 (RC2)
>>>>>>(84.b+120) string 20010816 (RC2 - Garf tuned v1)
>>>>>>(84.b+120) string 20011014 (RC2 - Garf tuned v2)
>>>>>>(84.b+120) string 20011217 (pre-RC3 CVS)
>>>>>>(84.b+120) string 20011231 (RC3)
# The string has not changed from beta1 to 2 - they are indistinguishable.
# Then come the comments, again length-counted (and number-counted).
# Some looping constructs and registers would allow reading them but now
# it's impossible. However we can print the number of comments present
# (skipping by the vendor string length):
##>>>>(109.l.113) lelong 0 \b, no comments
##>>>>(109.l+113) lelong >0 \b, %lu comments