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-rw-r--r--arm-hybrid-22k/lib_src/eas_math.c312
1 files changed, 156 insertions, 156 deletions
diff --git a/arm-hybrid-22k/lib_src/eas_math.c b/arm-hybrid-22k/lib_src/eas_math.c
index 12d788e..dc85051 100644
--- a/arm-hybrid-22k/lib_src/eas_math.c
+++ b/arm-hybrid-22k/lib_src/eas_math.c
@@ -1,13 +1,13 @@
-/*----------------------------------------------------------------------------
- *
- * File:
- * eas_math.c
- *
- * Contents and purpose:
- * Contains common math routines for the various audio engines.
- *
- *
- * Copyright Sonic Network Inc. 2005
+/*----------------------------------------------------------------------------
+ *
+ * File:
+ * eas_math.c
+ *
+ * Contents and purpose:
+ * Contains common math routines for the various audio engines.
+ *
+ *
+ * Copyright Sonic Network Inc. 2005
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -20,149 +20,149 @@
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
- *
- *----------------------------------------------------------------------------
- * Revision Control:
- * $Revision: 586 $
- * $Date: 2007-03-08 20:33:04 -0800 (Thu, 08 Mar 2007) $
- *----------------------------------------------------------------------------
-*/
-
-#include "eas.h"
-#include "eas_math.h"
-
-/* anything less than this converts to a fraction too small to represent in 32-bits */
-#define MIN_CENTS -18000
-
-/*----------------------------------------------------------------------------
- * EAS_Calculate2toX()
- *----------------------------------------------------------------------------
- * Purpose:
- * Calculate 2^x
- *
- * Inputs:
- * nCents - measured in cents
- * psEASData - pointer to overall EAS data structure
- *
- * Outputs:
- * nResult - int.frac result (where frac has NUM_DENTS_FRAC_BITS)
- *
- * Side Effects:
- *
- *----------------------------------------------------------------------------
-*/
-EAS_I32 EAS_Calculate2toX (EAS_I32 nCents)
-{
- EAS_I32 nDents;
- EAS_I32 nExponentInt, nExponentFrac;
- EAS_I32 nTemp1, nTemp2;
- EAS_I32 nResult;
-
- /* check for minimum value */
- if (nCents < MIN_CENTS)
- return 0;
-
- /* for the time being, convert cents to dents */
- nDents = FMUL_15x15(nCents, CENTS_TO_DENTS);
-
- nExponentInt = GET_DENTS_INT_PART(nDents);
- nExponentFrac = GET_DENTS_FRAC_PART(nDents);
-
- /*
- implement 2^(fracPart) as a power series
- */
- nTemp1 = GN2_TO_X2 + MULT_DENTS_COEF(nExponentFrac, GN2_TO_X3);
- nTemp2 = GN2_TO_X1 + MULT_DENTS_COEF(nExponentFrac, nTemp1);
- nTemp1 = GN2_TO_X0 + MULT_DENTS_COEF(nExponentFrac, nTemp2);
-
- /*
- implement 2^(intPart) as
- a left shift for intPart >= 0 or
- a left shift for intPart < 0
- */
- if (nExponentInt >= 0)
- {
- /* left shift for positive exponents */
- /*lint -e{703} <avoid multiply for performance>*/
- nResult = nTemp1 << nExponentInt;
- }
- else
- {
- /* right shift for negative exponents */
- nExponentInt = -nExponentInt;
- nResult = nTemp1 >> nExponentInt;
- }
-
- return nResult;
-}
-
-/*----------------------------------------------------------------------------
- * EAS_LogToLinear16()
- *----------------------------------------------------------------------------
- * Purpose:
- * Transform log value to linear gain multiplier using piece-wise linear
- * approximation
- *
- * Inputs:
- * nGain - log scale value in 20.10 format. Even though gain is normally
- * stored in 6.10 (16-bit) format we use 32-bit numbers here to eliminate
- * the need for saturation checking when combining gain values.
- *
- * Outputs:
- * Returns a 16-bit linear value approximately equal to 2^(nGain/1024)
- *
- * Side Effects:
- *
- *----------------------------------------------------------------------------
-*/
-EAS_U16 EAS_LogToLinear16 (EAS_I32 nGain)
-{
- EAS_INT nExp;
- EAS_U16 nTemp;
-
- /* bias to positive */
- nGain += 32767;
-
- /* check for infinite attenuation */
- if (nGain < 0)
- return 0;
-
- /* extract the exponent */
- nExp = 31 - (nGain >> 10);
-
- /* check for maximum output */
- if (nExp < 0)
- return 0x7fff;
-
- /* extract mantissa and restore implied 1 bit */
- nTemp = (EAS_U16)((((nGain & 0x3ff) << 4) | 0x4000) >> nExp);
-
- /* use shift to approximate power-of-2 operation */
- return nTemp;
-}
-
-/*----------------------------------------------------------------------------
- * EAS_VolumeToGain()
- *----------------------------------------------------------------------------
- * Purpose:
- * Transform volume control in 1dB increments to gain multiplier
- *
- * Inputs:
- * volume - 100 = 0dB, 99 = -1dB, 0 = -inf
- *
- * Outputs:
- * Returns a 16-bit linear value
- *----------------------------------------------------------------------------
-*/
-EAS_I16 EAS_VolumeToGain (EAS_INT volume)
-{
- /* check for limits */
- if (volume <= 0)
- return 0;
- if (volume >= 100)
- return 0x7fff;
-
- /*lint -e{702} use shift instead of division */
- return (EAS_I16) EAS_Calculate2toX((((volume - EAS_MAX_VOLUME) * 204099) >> 10) - 1);
-}
-
+ *
+ *----------------------------------------------------------------------------
+ * Revision Control:
+ * $Revision: 586 $
+ * $Date: 2007-03-08 20:33:04 -0800 (Thu, 08 Mar 2007) $
+ *----------------------------------------------------------------------------
+*/
+
+#include "eas.h"
+#include "eas_math.h"
+
+/* anything less than this converts to a fraction too small to represent in 32-bits */
+#define MIN_CENTS -18000
+
+/*----------------------------------------------------------------------------
+ * EAS_Calculate2toX()
+ *----------------------------------------------------------------------------
+ * Purpose:
+ * Calculate 2^x
+ *
+ * Inputs:
+ * nCents - measured in cents
+ * psEASData - pointer to overall EAS data structure
+ *
+ * Outputs:
+ * nResult - int.frac result (where frac has NUM_DENTS_FRAC_BITS)
+ *
+ * Side Effects:
+ *
+ *----------------------------------------------------------------------------
+*/
+EAS_I32 EAS_Calculate2toX (EAS_I32 nCents)
+{
+ EAS_I32 nDents;
+ EAS_I32 nExponentInt, nExponentFrac;
+ EAS_I32 nTemp1, nTemp2;
+ EAS_I32 nResult;
+
+ /* check for minimum value */
+ if (nCents < MIN_CENTS)
+ return 0;
+
+ /* for the time being, convert cents to dents */
+ nDents = FMUL_15x15(nCents, CENTS_TO_DENTS);
+
+ nExponentInt = GET_DENTS_INT_PART(nDents);
+ nExponentFrac = GET_DENTS_FRAC_PART(nDents);
+
+ /*
+ implement 2^(fracPart) as a power series
+ */
+ nTemp1 = GN2_TO_X2 + MULT_DENTS_COEF(nExponentFrac, GN2_TO_X3);
+ nTemp2 = GN2_TO_X1 + MULT_DENTS_COEF(nExponentFrac, nTemp1);
+ nTemp1 = GN2_TO_X0 + MULT_DENTS_COEF(nExponentFrac, nTemp2);
+
+ /*
+ implement 2^(intPart) as
+ a left shift for intPart >= 0 or
+ a left shift for intPart < 0
+ */
+ if (nExponentInt >= 0)
+ {
+ /* left shift for positive exponents */
+ /*lint -e{703} <avoid multiply for performance>*/
+ nResult = nTemp1 << nExponentInt;
+ }
+ else
+ {
+ /* right shift for negative exponents */
+ nExponentInt = -nExponentInt;
+ nResult = nTemp1 >> nExponentInt;
+ }
+
+ return nResult;
+}
+
+/*----------------------------------------------------------------------------
+ * EAS_LogToLinear16()
+ *----------------------------------------------------------------------------
+ * Purpose:
+ * Transform log value to linear gain multiplier using piece-wise linear
+ * approximation
+ *
+ * Inputs:
+ * nGain - log scale value in 20.10 format. Even though gain is normally
+ * stored in 6.10 (16-bit) format we use 32-bit numbers here to eliminate
+ * the need for saturation checking when combining gain values.
+ *
+ * Outputs:
+ * Returns a 16-bit linear value approximately equal to 2^(nGain/1024)
+ *
+ * Side Effects:
+ *
+ *----------------------------------------------------------------------------
+*/
+EAS_U16 EAS_LogToLinear16 (EAS_I32 nGain)
+{
+ EAS_INT nExp;
+ EAS_U16 nTemp;
+
+ /* bias to positive */
+ nGain += 32767;
+
+ /* check for infinite attenuation */
+ if (nGain < 0)
+ return 0;
+
+ /* extract the exponent */
+ nExp = 31 - (nGain >> 10);
+
+ /* check for maximum output */
+ if (nExp < 0)
+ return 0x7fff;
+
+ /* extract mantissa and restore implied 1 bit */
+ nTemp = (EAS_U16)((((nGain & 0x3ff) << 4) | 0x4000) >> nExp);
+
+ /* use shift to approximate power-of-2 operation */
+ return nTemp;
+}
+
+/*----------------------------------------------------------------------------
+ * EAS_VolumeToGain()
+ *----------------------------------------------------------------------------
+ * Purpose:
+ * Transform volume control in 1dB increments to gain multiplier
+ *
+ * Inputs:
+ * volume - 100 = 0dB, 99 = -1dB, 0 = -inf
+ *
+ * Outputs:
+ * Returns a 16-bit linear value
+ *----------------------------------------------------------------------------
+*/
+EAS_I16 EAS_VolumeToGain (EAS_INT volume)
+{
+ /* check for limits */
+ if (volume <= 0)
+ return 0;
+ if (volume >= 100)
+ return 0x7fff;
+
+ /*lint -e{702} use shift instead of division */
+ return (EAS_I16) EAS_Calculate2toX((((volume - EAS_MAX_VOLUME) * 204099) >> 10) - 1);
+}
+
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