Cog/Frameworks/Dumb/dumb/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 * FIXME: these comments are somewhat out of date now.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; \
		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; \
		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; \
		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