Initial import of libFLAC from flac-1.1.2.tar.gz

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@5983 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 430 insertions, 0 deletions

diff --git a/apps/codecs/libFLAC/lpc.c b/apps/codecs/libFLAC/lpc.c
new file mode 100644
index 0000000..b846db5
--- /dev/null
+++ b/apps/codecs/libFLAC/lpc.c
@@ -0,0 +1,430 @@
+/* libFLAC - Free Lossless Audio Codec library
+ * Copyright (C) 2000,2001,2002,2003,2004,2005  Josh Coalson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of the Xiph.org Foundation nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <math.h>
+#include "FLAC/assert.h"
+#include "FLAC/format.h"
+#include "private/bitmath.h"
+#include "private/lpc.h"
+#if defined DEBUG || defined FLAC__OVERFLOW_DETECT || defined FLAC__OVERFLOW_DETECT_VERBOSE
+#include <stdio.h>
+#endif
+
+#ifndef FLAC__INTEGER_ONLY_LIBRARY
+
+#ifndef M_LN2
+/* math.h in VC++ doesn't seem to have this (how Microsoft is that?) */
+#define M_LN2 0.69314718055994530942
+#endif
+
+void FLAC__lpc_compute_autocorrelation(const FLAC__real data[], unsigned data_len, unsigned lag, FLAC__real autoc[])
+{
+	/* a readable, but slower, version */
+#if 0
+	FLAC__real d;
+	unsigned i;
+
+	FLAC__ASSERT(lag > 0);
+	FLAC__ASSERT(lag <= data_len);
+
+	while(lag--) {
+		for(i = lag, d = 0.0; i < data_len; i++)
+			d += data[i] * data[i - lag];
+		autoc[lag] = d;
+	}
+#endif
+
+	/*
+	 * this version tends to run faster because of better data locality
+	 * ('data_len' is usually much larger than 'lag')
+	 */
+	FLAC__real d;
+	unsigned sample, coeff;
+	const unsigned limit = data_len - lag;
+
+	FLAC__ASSERT(lag > 0);
+	FLAC__ASSERT(lag <= data_len);
+
+	for(coeff = 0; coeff < lag; coeff++)
+		autoc[coeff] = 0.0;
+	for(sample = 0; sample <= limit; sample++) {
+		d = data[sample];
+		for(coeff = 0; coeff < lag; coeff++)
+			autoc[coeff] += d * data[sample+coeff];
+	}
+	for(; sample < data_len; sample++) {
+		d = data[sample];
+		for(coeff = 0; coeff < data_len - sample; coeff++)
+			autoc[coeff] += d * data[sample+coeff];
+	}
+}
+
+void FLAC__lpc_compute_lp_coefficients(const FLAC__real autoc[], unsigned max_order, FLAC__real lp_coeff[][FLAC__MAX_LPC_ORDER], FLAC__double error[])
+{
+	unsigned i, j;
+	FLAC__double r, err, ref[FLAC__MAX_LPC_ORDER], lpc[FLAC__MAX_LPC_ORDER];
+
+	FLAC__ASSERT(0 < max_order);
+	FLAC__ASSERT(max_order <= FLAC__MAX_LPC_ORDER);
+	FLAC__ASSERT(autoc[0] != 0.0);
+
+	err = autoc[0];
+
+	for(i = 0; i < max_order; i++) {
+		/* Sum up this iteration's reflection coefficient. */
+		r = -autoc[i+1];
+		for(j = 0; j < i; j++)
+			r -= lpc[j] * autoc[i-j];
+		ref[i] = (r/=err);
+
+		/* Update LPC coefficients and total error. */
+		lpc[i]=r;
+		for(j = 0; j < (i>>1); j++) {
+			FLAC__double tmp = lpc[j];
+			lpc[j] += r * lpc[i-1-j];
+			lpc[i-1-j] += r * tmp;
+		}
+		if(i & 1)
+			lpc[j] += lpc[j] * r;
+
+		err *= (1.0 - r * r);
+
+		/* save this order */
+		for(j = 0; j <= i; j++)
+			lp_coeff[i][j] = (FLAC__real)(-lpc[j]); /* negate FIR filter coeff to get predictor coeff */
+		error[i] = err;
+	}
+}
+
+int FLAC__lpc_quantize_coefficients(const FLAC__real lp_coeff[], unsigned order, unsigned precision, FLAC__int32 qlp_coeff[], int *shift)
+{
+	unsigned i;
+	FLAC__double d, cmax = -1e32;
+	FLAC__int32 qmax, qmin;
+	const int max_shiftlimit = (1 << (FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN-1)) - 1;
+	const int min_shiftlimit = -max_shiftlimit - 1;
+
+	FLAC__ASSERT(precision > 0);
+	FLAC__ASSERT(precision >= FLAC__MIN_QLP_COEFF_PRECISION);
+
+	/* drop one bit for the sign; from here on out we consider only |lp_coeff[i]| */
+	precision--;
+	qmax = 1 << precision;
+	qmin = -qmax;
+	qmax--;
+
+	for(i = 0; i < order; i++) {
+		if(lp_coeff[i] == 0.0)
+			continue;
+		d = fabs(lp_coeff[i]);
+		if(d > cmax)
+			cmax = d;
+	}
+redo_it:
+	if(cmax <= 0.0) {
+		/* => coefficients are all 0, which means our constant-detect didn't work */
+		return 2;
+	}
+	else {
+		int log2cmax;
+
+		(void)frexp(cmax, &log2cmax);
+		log2cmax--;
+		*shift = (int)precision - log2cmax - 1;
+
+		if(*shift < min_shiftlimit || *shift > max_shiftlimit) {
+#if 0
+			/*@@@ this does not seem to help at all, but was not extensively tested either: */
+			if(*shift > max_shiftlimit)
+				*shift = max_shiftlimit;
+			else
+#endif
+				return 1;
+		}
+	}
+
+	if(*shift >= 0) {
+		for(i = 0; i < order; i++) {
+			qlp_coeff[i] = (FLAC__int32)floor((FLAC__double)lp_coeff[i] * (FLAC__double)(1 << *shift));
+
+			/* double-check the result */
+			if(qlp_coeff[i] > qmax || qlp_coeff[i] < qmin) {
+#ifdef FLAC__OVERFLOW_DETECT
+				fprintf(stderr,"FLAC__lpc_quantize_coefficients: compensating for overflow, qlp_coeff[%u]=%d, lp_coeff[%u]=%f, cmax=%f, precision=%u, shift=%d, q=%f, f(q)=%f\n", i, qlp_coeff[i], i, lp_coeff[i], cmax, precision, *shift, (FLAC__double)lp_coeff[i] * (FLAC__double)(1 << *shift), floor((FLAC__double)lp_coeff[i] * (FLAC__double)(1 << *shift)));
+#endif
+				cmax *= 2.0;
+				goto redo_it;
+			}
+		}
+	}
+	else { /* (*shift < 0) */
+		const int nshift = -(*shift);
+#ifdef DEBUG
+		fprintf(stderr,"FLAC__lpc_quantize_coefficients: negative shift = %d\n", *shift);
+#endif
+		for(i = 0; i < order; i++) {
+			qlp_coeff[i] = (FLAC__int32)floor((FLAC__double)lp_coeff[i] / (FLAC__double)(1 << nshift));
+
+			/* double-check the result */
+			if(qlp_coeff[i] > qmax || qlp_coeff[i] < qmin) {
+#ifdef FLAC__OVERFLOW_DETECT
+				fprintf(stderr,"FLAC__lpc_quantize_coefficients: compensating for overflow, qlp_coeff[%u]=%d, lp_coeff[%u]=%f, cmax=%f, precision=%u, shift=%d, q=%f, f(q)=%f\n", i, qlp_coeff[i], i, lp_coeff[i], cmax, precision, *shift, (FLAC__double)lp_coeff[i] / (FLAC__double)(1 << nshift), floor((FLAC__double)lp_coeff[i] / (FLAC__double)(1 << nshift)));
+#endif
+				cmax *= 2.0;
+				goto redo_it;
+			}
+		}
+	}
+
+	return 0;
+}
+
+void FLAC__lpc_compute_residual_from_qlp_coefficients(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
+{
+#ifdef FLAC__OVERFLOW_DETECT
+	FLAC__int64 sumo;
+#endif
+	unsigned i, j;
+	FLAC__int32 sum;
+	const FLAC__int32 *history;
+
+#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
+	fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
+	for(i=0;i<order;i++)
+		fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
+	fprintf(stderr,"\n");
+#endif
+	FLAC__ASSERT(order > 0);
+
+	for(i = 0; i < data_len; i++) {
+#ifdef FLAC__OVERFLOW_DETECT
+		sumo = 0;
+#endif
+		sum = 0;
+		history = data;
+		for(j = 0; j < order; j++) {
+			sum += qlp_coeff[j] * (*(--history));
+#ifdef FLAC__OVERFLOW_DETECT
+			sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
+#if defined _MSC_VER
+			if(sumo > 2147483647I64 || sumo < -2147483648I64)
+				fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%I64d\n",i,j,qlp_coeff[j],*history,sumo);
+#else
+			if(sumo > 2147483647ll || sumo < -2147483648ll)
+				fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%lld\n",i,j,qlp_coeff[j],*history,sumo);
+#endif
+#endif
+		}
+		*(residual++) = *(data++) - (sum >> lp_quantization);
+	}
+
+	/* Here's a slower but clearer version:
+	for(i = 0; i < data_len; i++) {
+		sum = 0;
+		for(j = 0; j < order; j++)
+			sum += qlp_coeff[j] * data[i-j-1];
+		residual[i] = data[i] - (sum >> lp_quantization);
+	}
+	*/
+}
+
+void FLAC__lpc_compute_residual_from_qlp_coefficients_wide(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[])
+{
+	unsigned i, j;
+	FLAC__int64 sum;
+	const FLAC__int32 *history;
+
+#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
+	fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
+	for(i=0;i<order;i++)
+		fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
+	fprintf(stderr,"\n");
+#endif
+	FLAC__ASSERT(order > 0);
+
+	for(i = 0; i < data_len; i++) {
+		sum = 0;
+		history = data;
+		for(j = 0; j < order; j++)
+			sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history));
+#ifdef FLAC__OVERFLOW_DETECT
+		if(FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32) {
+			fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, sum=%lld\n", i, sum >> lp_quantization);
+			break;
+		}
+		if(FLAC__bitmath_silog2_wide((FLAC__int64)(*data) - (sum >> lp_quantization)) > 32) {
+			fprintf(stderr,"FLAC__lpc_compute_residual_from_qlp_coefficients_wide: OVERFLOW, i=%u, data=%d, sum=%lld, residual=%lld\n", i, *data, sum >> lp_quantization, (FLAC__int64)(*data) - (sum >> lp_quantization));
+			break;
+		}
+#endif
+		*(residual++) = *(data++) - (FLAC__int32)(sum >> lp_quantization);
+	}
+}
+
+#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */
+
+void FLAC__lpc_restore_signal(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
+{
+#ifdef FLAC__OVERFLOW_DETECT
+	FLAC__int64 sumo;
+#endif
+	unsigned i, j;
+	FLAC__int32 sum;
+	const FLAC__int32 *history;
+
+#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
+	fprintf(stderr,"FLAC__lpc_restore_signal: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
+	for(i=0;i<order;i++)
+		fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
+	fprintf(stderr,"\n");
+#endif
+	FLAC__ASSERT(order > 0);
+
+	for(i = 0; i < data_len; i++) {
+#ifdef FLAC__OVERFLOW_DETECT
+		sumo = 0;
+#endif
+		sum = 0;
+		history = data;
+		for(j = 0; j < order; j++) {
+			sum += qlp_coeff[j] * (*(--history));
+#ifdef FLAC__OVERFLOW_DETECT
+			sumo += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*history);
+#if defined _MSC_VER
+			if(sumo > 2147483647I64 || sumo < -2147483648I64)
+				fprintf(stderr,"FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%I64d\n",i,j,qlp_coeff[j],*history,sumo);
+#else
+			if(sumo > 2147483647ll || sumo < -2147483648ll)
+				fprintf(stderr,"FLAC__lpc_restore_signal: OVERFLOW, i=%u, j=%u, c=%d, d=%d, sumo=%lld\n",i,j,qlp_coeff[j],*history,sumo);
+#endif
+#endif
+		}
+		*(data++) = *(residual++) + (sum >> lp_quantization);
+	}
+
+	/* Here's a slower but clearer version:
+	for(i = 0; i < data_len; i++) {
+		sum = 0;
+		for(j = 0; j < order; j++)
+			sum += qlp_coeff[j] * data[i-j-1];
+		data[i] = residual[i] + (sum >> lp_quantization);
+	}
+	*/
+}
+
+void FLAC__lpc_restore_signal_wide(const FLAC__int32 residual[], unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 data[])
+{
+	unsigned i, j;
+	FLAC__int64 sum;
+	const FLAC__int32 *history;
+
+#ifdef FLAC__OVERFLOW_DETECT_VERBOSE
+	fprintf(stderr,"FLAC__lpc_restore_signal_wide: data_len=%d, order=%u, lpq=%d",data_len,order,lp_quantization);
+	for(i=0;i<order;i++)
+		fprintf(stderr,", q[%u]=%d",i,qlp_coeff[i]);
+	fprintf(stderr,"\n");
+#endif
+	FLAC__ASSERT(order > 0);
+
+	for(i = 0; i < data_len; i++) {
+		sum = 0;
+		history = data;
+		for(j = 0; j < order; j++)
+			sum += (FLAC__int64)qlp_coeff[j] * (FLAC__int64)(*(--history));
+#ifdef FLAC__OVERFLOW_DETECT
+		if(FLAC__bitmath_silog2_wide(sum >> lp_quantization) > 32) {
+			fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, sum=%lld\n", i, sum >> lp_quantization);
+			break;
+		}
+		if(FLAC__bitmath_silog2_wide((FLAC__int64)(*residual) + (sum >> lp_quantization)) > 32) {
+			fprintf(stderr,"FLAC__lpc_restore_signal_wide: OVERFLOW, i=%u, residual=%d, sum=%lld, data=%lld\n", i, *residual, sum >> lp_quantization, (FLAC__int64)(*residual) + (sum >> lp_quantization));
+			break;
+		}
+#endif
+		*(data++) = *(residual++) + (FLAC__int32)(sum >> lp_quantization);
+	}
+}
+
+#ifndef FLAC__INTEGER_ONLY_LIBRARY
+
+FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample(FLAC__double lpc_error, unsigned total_samples)
+{
+	FLAC__double error_scale;
+
+	FLAC__ASSERT(total_samples > 0);
+
+	error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;
+
+	return FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error, error_scale);
+}
+
+FLAC__double FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(FLAC__double lpc_error, FLAC__double error_scale)
+{
+	if(lpc_error > 0.0) {
+		FLAC__double bps = (FLAC__double)0.5 * log(error_scale * lpc_error) / M_LN2;
+		if(bps >= 0.0)
+			return bps;
+		else
+			return 0.0;
+	}
+	else if(lpc_error < 0.0) { /* error should not be negative but can happen due to inadequate floating-point resolution */
+		return 1e32;
+	}
+	else {
+		return 0.0;
+	}
+}
+
+unsigned FLAC__lpc_compute_best_order(const FLAC__double lpc_error[], unsigned max_order, unsigned total_samples, unsigned bits_per_signal_sample)
+{
+	unsigned order, best_order;
+	FLAC__double best_bits, tmp_bits, error_scale;
+
+	FLAC__ASSERT(max_order > 0);
+	FLAC__ASSERT(total_samples > 0);
+
+	error_scale = 0.5 * M_LN2 * M_LN2 / (FLAC__double)total_samples;
+
+	best_order = 0;
+	best_bits = FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error[0], error_scale) * (FLAC__double)total_samples;
+
+	for(order = 1; order < max_order; order++) {
+		tmp_bits = FLAC__lpc_compute_expected_bits_per_residual_sample_with_error_scale(lpc_error[order], error_scale) * (FLAC__double)(total_samples - order) + (FLAC__double)(order * bits_per_signal_sample);
+		if(tmp_bits < best_bits) {
+			best_order = order;
+			best_bits = tmp_bits;
+		}
+	}
+
+	return best_order+1; /* +1 since index of lpc_error[] is order-1 */
+}
+
+#endif /* !defined FLAC__INTEGER_ONLY_LIBRARY */