Mpeg audio identification from ckane@best.com

1 files changed, 137 insertions, 0 deletions

diff --git a/usr.bin/file/magdir/audio b/usr.bin/file/magdir/audio
index b4db4e9c18c..e34bd6f575e 100644
--- a/usr.bin/file/magdir/audio
+++ b/usr.bin/file/magdir/audio
@@ -88,3 +88,140 @@
 #0	string		MAS_U		ULT(imate) Module sound data
 #0x2c	string		SCRM		ScreamTracker III Module sound data
 #0	string		Extended Module	Extended Module sound data
+
+#------------------------
+# MPEG:  file(1) magic for MPEG audio.
+#
+# From <ckane@best.com>
+# Show MPEG level, layer, kbit/s, hz, stereo/mono for an MPG audio file.
+# This section is lengthy because the kbit/s rate depends on the
+# level and layer, and file(1) doesn't allow math on the values.
+#
+
+####### MPEG begins with three hex 'f' nibbles.
+0	beshort&0xfff0	0xfff0		MPEG
+####### Level 2
+>1	byte&0x08	0x00		2.0
+>>1	byte&0x06	0x00		Layer Unknown,
+####### Level 2, Layers I, II, and III
+>>1	byte&0x06	0x02		Layer III,
+>>>2	byte&0xf0	0x00		0 kbit/s,
+>>>2	byte&0xf0	0x10		8 kbit/s,
+>>>2	byte&0xf0	0x20		16 kbit/s,
+>>>2	byte&0xf0	0x30		24 kbit/s,
+>>>2	byte&0xf0	0x40		32 kbit/s,
+>>>2	byte&0xf0	0x50		40 kbit/s,
+>>>2	byte&0xf0	0x60		48 kbit/s,
+>>>2	byte&0xf0	0x70		56 kbit/s,
+>>>2	byte&0xf0	0x80		64 kbit/s,
+>>>2	byte&0xf0	0x90		80 kbit/s,
+>>>2	byte&0xf0	0xa0		96 kbit/s,
+>>>2	byte&0xf0	0xb0		112 kbit/s,
+>>>2	byte&0xf0	0xc0		128 kbit/s,
+>>>2	byte&0xf0	0xd0		144 kbit/s,
+>>>2	byte&0xf0	0xe0		160 kbit/s,
+>>>2	byte&0xf0	0xf0		? kbit/s,
+>>1	byte&0x06	0x04		Layer II,
+>>>2	byte&0xf0	0x00		0 kbit/s,
+>>>2	byte&0xf0	0x10		8 kbit/s,
+>>>2	byte&0xf0	0x20		16 kbit/s,
+>>>2	byte&0xf0	0x30		24 kbit/s,
+>>>2	byte&0xf0	0x40		32 kbit/s,
+>>>2	byte&0xf0	0x50		40 kbit/s,
+>>>2	byte&0xf0	0x60		48 kbit/s,
+>>>2	byte&0xf0	0x70		56 kbit/s,
+>>>2	byte&0xf0	0x80		64 kbit/s,
+>>>2	byte&0xf0	0x90		80 kbit/s,
+>>>2	byte&0xf0	0xa0		96 kbit/s,
+>>>2	byte&0xf0	0xb0		112 kbit/s,
+>>>2	byte&0xf0	0xc0		128 kbit/s,
+>>>2	byte&0xf0	0xd0		144 kbit/s,
+>>>2	byte&0xf0	0xe0		160 kbit/s,
+>>>2	byte&0xf0	0xf0		? kbit/s,
+>>1	byte&0x06	0x06		Layer I,
+>>>2	byte&0xf0	0x00		0 kbit/s,
+>>>2	byte&0xf0	0x10		32 kbit/s,
+>>>2	byte&0xf0	0x20		48 kbit/s,
+>>>2	byte&0xf0	0x30		56 kbit/s,
+>>>2	byte&0xf0	0x40		64 kbit/s,
+>>>2	byte&0xf0	0x50		80 kbit/s,
+>>>2	byte&0xf0	0x60		96 kbit/s,
+>>>2	byte&0xf0	0x70		112 kbit/s,
+>>>2	byte&0xf0	0x80		128 kbit/s,
+>>>2	byte&0xf0	0x90		144 kbit/s,
+>>>2	byte&0xf0	0xa0		160 kbit/s,
+>>>2	byte&0xf0	0xb0		176 kbit/s,
+>>>2	byte&0xf0	0xc0		192 kbit/s,
+>>>2	byte&0xf0	0xd0		224 kbit/s,
+>>>2	byte&0xf0	0xe0		256 kbit/s,
+>>>2	byte&0xf0	0xf0		? kbit/s,
+####### Level 2, Hz
+>>2	byte&0x0c	0x00		22050 Hz
+>>2	byte&0x0c	0x04		24000 Hz
+>>2	byte&0x0c	0x08		16000 Hz
+>>2	byte&0x0c	0x0c		? Hz
+####### Level 1 decoding
+>1	byte&0x08	0x08		1.0
+>>1	byte&0x06	0x00		Layer Unknown.
+####### Level 1, Layers I, II, and III
+>>1	byte&0x06	0x02		Layer III,
+>>>2	byte&0xf0	0x00		0 kbit/s,
+>>>2	byte&0xf0	0x10		32 kbit/s,
+>>>2	byte&0xf0	0x20		40 kbit/s,
+>>>2	byte&0xf0	0x30		48 kbit/s,
+>>>2	byte&0xf0	0x40		56 kbit/s,
+>>>2	byte&0xf0	0x50		64 kbit/s,
+>>>2	byte&0xf0	0x60		80 kbit/s,
+>>>2	byte&0xf0	0x70		96 kbit/s,
+>>>2	byte&0xf0	0x80		112 kbit/s,
+>>>2	byte&0xf0	0x90		128 kbit/s,
+>>>2	byte&0xf0	0xa0		160 kbit/s,
+>>>2	byte&0xf0	0xb0		192 kbit/s,
+>>>2	byte&0xf0	0xc0		224 kbit/s,
+>>>2	byte&0xf0	0xd0		256 kbit/s,
+>>>2	byte&0xf0	0xe0		320 kbit/s,
+>>>2	byte&0xf0	0xf0		? kbit/s,
+>>1	byte&0x06	0x04		Layer II,
+>>>2	byte&0xf0	0x00		0 kbit/s,
+>>>2	byte&0xf0	0x10		32 kbit/s,
+>>>2	byte&0xf0	0x20		48 kbit/s,
+>>>2	byte&0xf0	0x30		56 kbit/s,
+>>>2	byte&0xf0	0x40		64 kbit/s,
+>>>2	byte&0xf0	0x50		80 kbit/s,
+>>>2	byte&0xf0	0x60		96 kbit/s,
+>>>2	byte&0xf0	0x70		112 kbit/s,
+>>>2	byte&0xf0	0x80		128 kbit/s,
+>>>2	byte&0xf0	0x90		160 kbit/s,
+>>>2	byte&0xf0	0xa0		192 kbit/s,
+>>>2	byte&0xf0	0xb0		224 kbit/s,
+>>>2	byte&0xf0	0xc0		256 kbit/s,
+>>>2	byte&0xf0	0xd0		320 kbit/s,
+>>>2	byte&0xf0	0xe0		384 kbit/s,
+>>>2	byte&0xf0	0xf0		? kbit/s,
+>>1	byte&0x06	0x06		Layer I,
+>>>2	byte&0xf0	0x00		0 kbit/s,
+>>>2	byte&0xf0	0x10		32 kbit/s,
+>>>2	byte&0xf0	0x20		64 kbit/s,
+>>>2	byte&0xf0	0x30		96 kbit/s,
+>>>2	byte&0xf0	0x40		128 kbit/s,
+>>>2	byte&0xf0	0x50		160 kbit/s,
+>>>2	byte&0xf0	0x60		192 kbit/s,
+>>>2	byte&0xf0	0x70		224 kbit/s,
+>>>2	byte&0xf0	0x80		256 kbit/s,
+>>>2	byte&0xf0	0x90		288 kbit/s,
+>>>2	byte&0xf0	0xa0		320 kbit/s,
+>>>2	byte&0xf0	0xb0		352 kbit/s,
+>>>2	byte&0xf0	0xc0		384 kbit/s,
+>>>2	byte&0xf0	0xd0		416 kbit/s,
+>>>2	byte&0xf0	0xe0		448 kbit/s,
+>>>2	byte&0xf0	0xf0		? kbit/s,
+####### Level 2, Hz
+>>2	byte&0x0c	0x00		44100 Hz
+>>2	byte&0x0c	0x04		48000 Hz
+>>2	byte&0x0c	0x08		32000 Hz
+>>2	byte&0x0c	0x0c		? Hz
+####### Stereo or Mono
+>3	byte&0xc0	0x00		stereo
+>3	byte&0xc0	0x40		joint-stereo
+>3	byte&0xc0	0x80		dual-channel
+>3	byte&0xc0	0xc0		mono