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Performance improvement in limiter, about 2%

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git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22735 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Jeffrey Goode 2009-09-19 00:12:02 +00:00
parent 293a4b62d7
commit b2aa2452e7
1 changed files with 10 additions and 13 deletions
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23
apps/dsp.c
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@ -1934,21 +1934,18 @@ static int limiter_process(int count, int32_t *buf[])
}
/* Implement the limiter: adjust gain of the outbound samples by the gain
* amounts in the gain steps array corresponding to the peak values. */
for (ch = 0; ch < AUDIO_DSP.data.num_channels; ch++)
for (i = 0; i < count; i++)
{
int32_t *d = buf[ch];
for (i = 0; i < count; i++)
if (out_buf_peak[i] > 0)
{
if (out_buf_peak[i] > 0)
{
gain_peak = (out_buf_peak[i] + 1) / 90;
gain_rem = (out_buf_peak[i] + 1) % 90;
gain = gain_steps[gain_peak];
if ((gain_peak < 48) && (gain_rem > 0))
gain -= gain_rem * ((gain_steps[gain_peak] -
gain_steps[gain_peak + 1]) / 90);
d[i] = FRACMUL_SHL(d[i], gain, 3);
}
gain_peak = (out_buf_peak[i] + 1) / 90;
gain_rem = (out_buf_peak[i] + 1) % 90;
gain = gain_steps[gain_peak];
if ((gain_peak < 48) && (gain_rem > 0))
gain -= gain_rem * ((gain_steps[gain_peak] -
gain_steps[gain_peak + 1]) / 90);
for (ch = 0; ch < AUDIO_DSP.data.num_channels; ch++)
buf[ch][i] = FRACMUL_SHL(buf[ch][i], gain, 3);
}
}
return count;