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unroll some code in FLAC__plugin_common_apply_gain()

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This commit is contained in:
Josh Coalson 2002-11-01 06:15:46 +00:00
parent 83bf6157e7
commit 2f5de01321
1 changed files with 134 additions and 0 deletions
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134
src/plugin_common/replaygain_synthesis.c
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@ -372,8 +372,10 @@ PLUGIN_COMMON_API int FLAC__plugin_common_apply_gain(FLAC__byte *data_out, FLAC_
FLAC__byte * const start = data_out;
const unsigned samples = wide_samples * channels;
#ifdef FLAC__PLUGIN_COMMON__DONT_UNROLL
const unsigned dither_twiggle = channels - 1;
unsigned dither_source = 0;
#endif
unsigned i;
int coeff;
double sample;
@ -386,6 +388,10 @@ PLUGIN_COMMON_API int FLAC__plugin_common_apply_gain(FLAC__byte *data_out, FLAC_
FLAC__ASSERT(target_bps < 32);
FLAC__ASSERT((target_bps & 7) == 0);
#ifdef FLAC__PLUGIN_COMMON__DONT_UNROLL
/*
* This flavor handles 1 or 2 channels with the same code
*/
coeff = 0;
for(i = 0; i < samples; i++, coeff++) {
sample = (double)input[i] * multi_scale;
@ -432,6 +438,134 @@ PLUGIN_COMMON_API int FLAC__plugin_common_apply_gain(FLAC__byte *data_out, FLAC_
data_out += target_bps/8;
}
#else
/*
* This flavor has optimized versions for 1 or 2 channels
*/
if(channels == 2) {
FLAC__int64 val64;
FLAC__int32 val32;
coeff = 0;
for(i = 0; i < samples; ) {
sample = (double)input[i] * multi_scale;
if(hard_limit) {
/* hard 6dB limiting */
if(sample < -0.5)
sample = tanh((sample + 0.5) / (1-0.5)) * (1-0.5) - 0.5;
else if(sample > 0.5)
sample = tanh((sample - 0.5) / (1-0.5)) * (1-0.5) + 0.5;
}
sample *= 2147483647.f;
val64 = dither_output_(dither_context, do_dithering, noise_shaping, coeff, sample, 0) / conv_factor;
val32 = (FLAC__int32)val64;
if(val64 >= -hard_clip_factor)
val32 = (FLAC__int32)(-(hard_clip_factor+1));
else if(val64 < hard_clip_factor)
val32 = (FLAC__int32)hard_clip_factor;
switch(target_bps) {
case 8:
data_out[0] = val32 ^ 0x80;
break;
case 24:
data_out[2] = (FLAC__byte)(val32 >> 16);
/* fall through */
case 16:
data_out[1] = (FLAC__byte)(val32 >> 8);
data_out[0] = (FLAC__byte)val32;
}
data_out += target_bps/8;
i++;
sample = (double)input[i] * multi_scale;
if(hard_limit) {
/* hard 6dB limiting */
if(sample < -0.5)
sample = tanh((sample + 0.5) / (1-0.5)) * (1-0.5) - 0.5;
else if(sample > 0.5)
sample = tanh((sample - 0.5) / (1-0.5)) * (1-0.5) + 0.5;
}
sample *= 2147483647.f;
val64 = dither_output_(dither_context, do_dithering, noise_shaping, coeff, sample, 1) / conv_factor;
val32 = (FLAC__int32)val64;
if(val64 >= -hard_clip_factor)
val32 = (FLAC__int32)(-(hard_clip_factor+1));
else if(val64 < hard_clip_factor)
val32 = (FLAC__int32)hard_clip_factor;
switch(target_bps) {
case 8:
data_out[0] = val32 ^ 0x80;
break;
case 24:
data_out[2] = (FLAC__byte)(val32 >> 16);
/* fall through */
case 16:
data_out[1] = (FLAC__byte)(val32 >> 8);
data_out[0] = (FLAC__byte)val32;
}
data_out += target_bps/8;
i++;
coeff++;
if(coeff >= 32)
coeff = 0;
}
}
else {
FLAC__int64 val64;
FLAC__int32 val32;
coeff = 0;
for(i = 0; i < samples; i++, coeff++) {
if(coeff >= 32)
coeff = 0;
sample = (double)input[i] * multi_scale;
if(hard_limit) {
/* hard 6dB limiting */
if(sample < -0.5)
sample = tanh((sample + 0.5) / (1-0.5)) * (1-0.5) - 0.5;
else if(sample > 0.5)
sample = tanh((sample - 0.5) / (1-0.5)) * (1-0.5) + 0.5;
}
sample *= 2147483647.f;
val64 = dither_output_(dither_context, do_dithering, noise_shaping, coeff, sample, 0) / conv_factor;
val32 = (FLAC__int32)val64;
if(val64 >= -hard_clip_factor)
val32 = (FLAC__int32)(-(hard_clip_factor+1));
else if(val64 < hard_clip_factor)
val32 = (FLAC__int32)hard_clip_factor;
switch(target_bps) {
case 8:
data_out[0] = val32 ^ 0x80;
break;
case 24:
data_out[2] = (FLAC__byte)(val32 >> 16);
/* fall through */
case 16:
data_out[1] = (FLAC__byte)(val32 >> 8);
data_out[0] = (FLAC__byte)val32;
}
data_out += target_bps/8;
}
}
#endif
return data_out - start;
}