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authorJames Courtier-Dutton <James@superbug.co.uk>2006-07-28 22:27:56 +0100
committerJaroslav Kysela <perex@suse.cz>2006-09-23 10:39:37 +0200
commit7012b2dac71988f61b520b33c70c63be372b5994 (patch)
treef6dd2ee18b2d2604b3822e5c14331ad60e126e0e /sound/pci
parent4e195a7b78618c89b06547f3140e67a69ec23272 (diff)
[ALSA] snd-emu10k1: Add a comment explaining the conversion function for dB gain.
Signed-off-by: James Courtier-Dutton <James@superbug.co.uk> Signed-off-by: Jaroslav Kysela <perex@suse.cz>
Diffstat (limited to 'sound/pci')
-rw-r--r--sound/pci/emu10k1/emufx.c1
1 files changed, 1 insertions, 0 deletions
diff --git a/sound/pci/emu10k1/emufx.c b/sound/pci/emu10k1/emufx.c
index 00fc904c251..13cd6ce8981 100644
--- a/sound/pci/emu10k1/emufx.c
+++ b/sound/pci/emu10k1/emufx.c
@@ -267,6 +267,7 @@ static const u32 treble_table[41][5] = {
{ 0x37c4448b, 0xa45ef51d, 0x262f3267, 0x081e36dc, 0xfd8f5d14 }
};
+/* dB gain = (float) 20 * log10( float(db_table_value) / 0x8000000 ) */
static const u32 db_table[101] = {
0x00000000, 0x01571f82, 0x01674b41, 0x01783a1b, 0x0189f540,
0x019c8651, 0x01aff763, 0x01c45306, 0x01d9a446, 0x01eff6b8,