ref: ceb1f19afffc8a17eb132a5ee2f8ff58dd5803b1
dir: /src/helpers/resample.inc/
/* _______ ____ __ ___ ___
* \ _ \ \ / \ / \ \ / / ' ' '
* | | \ \ | | || | \/ | . .
* | | | | | | || ||\ /| |
* | | | | | | || || \/ | | ' ' '
* | | | | | | || || | | . .
* | |_/ / \ \__// || | |
* /_______/ynamic \____/niversal /__\ /____\usic /| . . ibliotheque
* / \
* / . \
* resample.inc - Resampling helper template. / / \ \
* | < / \_
* By Bob and entheh. | \/ /\ /
* \_ / > /
* In order to find a good trade-off between | \ / /
* speed and accuracy in this code, some tests | ' /
* were carried out regarding the behaviour of \__/
* long long ints with gcc. The following code
* was tested:
*
* int a, b, c;
* c = ((long long)a * b) >> 16;
*
* DJGPP GCC Version 3.0.3 generated the following assembly language code for
* the multiplication and scaling, leaving the 32-bit result in EAX.
*
* movl -8(%ebp), %eax ; read one int into EAX
* imull -4(%ebp) ; multiply by the other; result goes in EDX:EAX
* shrdl $16, %edx, %eax ; shift EAX right 16, shifting bits in from EDX
*
* Note that a 32*32->64 multiplication is performed, allowing for high
* accuracy. On the Pentium 2 and above, shrdl takes two cycles (generally),
* so it is a minor concern when four multiplications are being performed
* (the cubic resampler). On the Pentium MMX and earlier, it takes four or
* more cycles, so this method is unsuitable for use in the low-quality
* resamplers.
*
* Since "long long" is a gcc-specific extension, we use LONG_LONG instead,
* defined in dumb.h. We may investigate later what code MSVC generates, but
* if it seems too slow then we suggest you use a good compiler.
*
* FIXME: these comments are somewhat out of date now.
*/
void dumb_reset_resampler(DUMB_RESAMPLER *resampler, SRCTYPE *src,
int src_channels, long pos, long start, long end,
int quality) {
int i;
resampler->src = src;
resampler->pos = pos;
resampler->subpos = 0;
resampler->start = start;
resampler->end = end;
resampler->dir = 1;
resampler->pickup = NULL;
resampler->pickup_data = NULL;
if (quality < 0) {
resampler->quality = 0;
} else if (quality > DUMB_RQ_N_LEVELS - 1) {
resampler->quality = DUMB_RQ_N_LEVELS - 1;
} else {
resampler->quality = quality;
}
for (i = 0; i < src_channels * 3; i++)
resampler->X[i] = 0;
resampler->overshot = -1;
resampler->fir_resampler_ratio = 0;
resampler_clear(resampler->fir_resampler[0]);
resampler_clear(resampler->fir_resampler[1]);
resampler_set_quality(resampler->fir_resampler[0], resampler->quality);
resampler_set_quality(resampler->fir_resampler[1], resampler->quality);
}
DUMB_RESAMPLER *dumb_start_resampler(SRCTYPE *src, int src_channels, long pos,
long start, long end, int quality) {
DUMB_RESAMPLER *resampler = malloc(sizeof(*resampler));
if (!resampler)
return NULL;
dumb_reset_resampler(resampler, src, src_channels, pos, start, end,
quality);
return resampler;
}
#define UPDATE_VOLUME(pvol, vol) \
{ \
if (pvol) { \
vol##r += vol##d; \
if ((vol##d < 0 && vol##r <= vol##t) || \
(vol##d > 0 && vol##r >= vol##t)) { \
pvol->volume = pvol->target; \
if (pvol->declick_stage == 0 || pvol->declick_stage >= 3) \
pvol->declick_stage++; \
pvol = NULL; \
vol = vol##t * vol##m; \
} else { \
vol = vol##r * vol##m; \
} \
} \
}
/* Create mono source resampler. */
#define SUFFIX2 _1
#define SRC_CHANNELS 1
#define DIVIDE_BY_SRC_CHANNELS(x) (x)
#define COPYSRC(dstarray, dstindex, srcarray, srcindex) \
(dstarray)[dstindex] = (srcarray)[srcindex]
#define COPYSRC2(dstarray, dstindex, condition, srcarray, srcindex) \
(dstarray)[dstindex] = condition ? (srcarray)[srcindex] : 0
#define MONO_DEST_VOLUME_PARAMETERS DUMB_VOLUME_RAMP_INFO *volume
#define MONO_DEST_VOLUME_VARIABLES vol, volr, vold, volt, volm
#define MONO_DEST_VOLUME_ZEROS 0
#define SET_MONO_DEST_VOLUME_VARIABLES \
{ \
if (volume) { \
volr = volume->volume; \
vold = volume->delta; \
volt = volume->target; \
volm = volume->mix; \
vol = volr * volm; \
if (volr == volt) \
volume = NULL; \
} else { \
vol = 0; \
volr = 0; \
vold = 0; \
volt = 0; \
volm = 0; \
} \
}
#define RETURN_MONO_DEST_VOLUME_VARIABLES \
if (volume) \
volume->volume = volr
#define MONO_DEST_VOLUMES_ARE_ZERO (vol == 0 && volt == 0)
#define POKE_FIR(offset) \
{ \
resampler_write_sample_float(resampler->fir_resampler[0], \
FIR(x[offset])); \
}
#define MONO_DEST_PEEK_FIR \
*dst = resampler_get_sample_float(resampler->fir_resampler[0]) * vol * \
16777216.0f
#define MONO_DEST_MIX_FIR \
{ \
*dst++ += resampler_get_sample_float(resampler->fir_resampler[0]) * \
vol * 16777216.0f; \
UPDATE_VOLUME(volume, vol); \
}
#define ADVANCE_FIR resampler_remove_sample(resampler->fir_resampler[0], 1)
#define STEREO_DEST_PEEK_FIR \
{ \
float sample = \
resampler_get_sample_float(resampler->fir_resampler[0]); \
*dst++ = sample * lvol * 16777216.0f; \
*dst++ = sample * rvol * 16777216.0f; \
}
#define STEREO_DEST_MIX_FIR \
{ \
float sample = \
resampler_get_sample_float(resampler->fir_resampler[0]); \
*dst++ += sample * lvol * 16777216.0f; \
*dst++ += sample * rvol * 16777216.0f; \
UPDATE_VOLUME(volume_left, lvol); \
UPDATE_VOLUME(volume_right, rvol); \
}
#include "resamp2.inc"
/* Create stereo source resampler. */
#define SUFFIX2 _2
#define SRC_CHANNELS 2
#define DIVIDE_BY_SRC_CHANNELS(x) ((x) >> 1)
#define COPYSRC(dstarray, dstindex, srcarray, srcindex) \
{ \
(dstarray)[(dstindex)*2] = (srcarray)[(srcindex)*2]; \
(dstarray)[(dstindex)*2 + 1] = (srcarray)[(srcindex)*2 + 1]; \
}
#define COPYSRC2(dstarray, dstindex, condition, srcarray, srcindex) \
{ \
if (condition) { \
(dstarray)[(dstindex)*2] = (srcarray)[(srcindex)*2]; \
(dstarray)[(dstindex)*2 + 1] = (srcarray)[(srcindex)*2 + 1]; \
} else { \
(dstarray)[(dstindex)*2] = 0; \
(dstarray)[(dstindex)*2 + 1] = 0; \
} \
}
#define MONO_DEST_VOLUME_PARAMETERS \
DUMB_VOLUME_RAMP_INFO *volume_left, DUMB_VOLUME_RAMP_INFO *volume_right
#define MONO_DEST_VOLUME_VARIABLES \
lvol, lvolr, lvold, lvolt, lvolm, rvol, rvolr, rvold, rvolt, rvolm
#define MONO_DEST_VOLUME_ZEROS 0, 0
#define SET_MONO_DEST_VOLUME_VARIABLES \
{ \
if (volume_left) { \
lvolr = volume_left->volume; \
lvold = volume_left->delta; \
lvolt = volume_left->target; \
lvolm = volume_left->mix; \
lvol = lvolr * lvolm; \
if (lvolr == lvolt) \
volume_left = NULL; \
} else { \
lvol = 0; \
lvolr = 0; \
lvold = 0; \
lvolt = 0; \
lvolm = 0; \
} \
if (volume_right) { \
rvolr = volume_right->volume; \
rvold = volume_right->delta; \
rvolt = volume_right->target; \
rvolm = volume_right->mix; \
rvol = rvolr * rvolm; \
if (rvolr == rvolt) \
volume_right = NULL; \
} else { \
rvol = 0; \
rvolr = 0; \
rvold = 0; \
rvolt = 0; \
rvolm = 0; \
} \
}
#define RETURN_MONO_DEST_VOLUME_VARIABLES \
{ \
if (volume_left) \
volume_left->volume = lvolr; \
if (volume_right) \
volume_right->volume = rvolr; \
}
#define MONO_DEST_VOLUMES_ARE_ZERO \
(lvol == 0 && lvolt == 0 && rvol == 0 && rvolt == 0)
#define POKE_FIR(offset) \
{ \
resampler_write_sample_float(resampler->fir_resampler[0], \
FIR(x[(offset)*2 + 0])); \
resampler_write_sample_float(resampler->fir_resampler[1], \
FIR(x[(offset)*2 + 1])); \
}
#define MONO_DEST_PEEK_FIR \
{ \
*dst = \
(resampler_get_sample_float(resampler->fir_resampler[0]) * lvol + \
resampler_get_sample_float(resampler->fir_resampler[1]) * rvol) * \
16777216.0f; \
}
#define MONO_DEST_MIX_FIR \
{ \
*dst++ += \
(resampler_get_sample_float(resampler->fir_resampler[0]) * lvol + \
resampler_get_sample_float(resampler->fir_resampler[1]) * rvol) * \
16777216.0f; \
UPDATE_VOLUME(volume_left, lvol); \
UPDATE_VOLUME(volume_right, rvol); \
}
#define ADVANCE_FIR \
{ \
resampler_remove_sample(resampler->fir_resampler[0], 1); \
resampler_remove_sample(resampler->fir_resampler[1], 1); \
}
#define STEREO_DEST_PEEK_FIR \
{ \
*dst++ = resampler_get_sample_float(resampler->fir_resampler[0]) * \
lvol * 16777216.0f; \
*dst++ = resampler_get_sample_float(resampler->fir_resampler[1]) * \
rvol * 16777216.0f; \
}
#define STEREO_DEST_MIX_FIR \
{ \
*dst++ += resampler_get_sample_float(resampler->fir_resampler[0]) * \
lvol * 16777216.0f; \
*dst++ += resampler_get_sample_float(resampler->fir_resampler[1]) * \
rvol * 16777216.0f; \
UPDATE_VOLUME(volume_left, lvol); \
UPDATE_VOLUME(volume_right, rvol); \
}
#include "resamp2.inc"
void dumb_end_resampler(DUMB_RESAMPLER *resampler) {
if (resampler)
free(resampler);
}
#undef FIR
#undef SRCBITS
#undef SRCTYPE
#undef SUFFIX