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Player sound quality improvements by Julien Boissinot

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@1284 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Linus Nielsen Feltzing 2002-07-01 12:32:23 +00:00
parent 447185b6bb
commit b81ce1e9a1
1 changed files with 49 additions and 3 deletions
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52
firmware/mpeg.c
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@ -200,7 +200,6 @@ static unsigned int treble_table[] =
0x5f800 /* 15dB */
};
#if 0
static unsigned int prescale_table[] =
{
0x80000, /* 0db */
@ -221,7 +220,6 @@ static unsigned int prescale_table[] =
0xe9400 /* 15dB */
};
#endif
#endif
static unsigned char fliptable[] =
{
@ -796,6 +794,46 @@ void mpeg_prev(void)
#endif
}
#ifndef ARCHOS_RECORDER
int current_volume=0; /* all values in tenth of dB */
int current_treble=0;
int current_bass=0;
int current_balance=0;
/* convert tenth of dB volume to register value */
static int tenthdb2reg(int db) {
if (db < -540)
return (db + 780) / 30;
else
return (db + 660) / 15;
}
void set_prescaled_volume(void)
{
int prescale;
int l, r;
prescale = MAX(current_bass, current_treble);
if (prescale < 0)
prescale = 0; /* no need to prescale if we don't boost
bass or treble */
mas_writereg(MAS_REG_KPRESCALE, prescale_table[prescale/10]);
/* gain up the analog volume to compensate the prescale reduction gain */
r = l = current_volume + prescale;
/* balance */
if (current_balance >= 0)
l -= current_balance;
else
r += current_balance;
dac_volume(tenthdb2reg(l), tenthdb2reg(r), false);
}
#endif
void mpeg_sound_set(int setting, int value)
{
#ifdef SIMULATOR
@ -813,7 +851,11 @@ void mpeg_sound_set(int setting, int value)
mas_codec_writereg(0x10, tmp & 0xff00);
#else
tmp = 0x38 * value / 100;
dac_volume(tmp, tmp, false);
/* store volume in tenth of dB */
current_volume = ( tmp < 0x08 ? tmp*30 - 780 : tmp*15 - 660 );
set_prescaled_volume();
#endif
break;
@ -823,6 +865,8 @@ void mpeg_sound_set(int setting, int value)
mas_codec_writereg(0x14, tmp & 0xff00);
#else
mas_writereg(MAS_REG_KBASS, bass_table[value]);
current_bass = (value-15) * 10;
set_prescaled_volume();
#endif
break;
@ -832,6 +876,8 @@ void mpeg_sound_set(int setting, int value)
mas_codec_writereg(0x15, tmp & 0xff00);
#else
mas_writereg(MAS_REG_KTREBLE, treble_table[value]);
current_treble = (value-15) * 10;
set_prescaled_volume();
#endif
break;
}