Create local copy of Opus v1.1.2

webrtc/modules/audio_coding/codecs/opus/opus/src/silk/Inlines.h

+/***********************************************************************
+Copyright (c) 2006-2011, Skype Limited. All rights reserved.
+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 Internet Society, IETF or IETF Trust, nor the
+names of specific 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 COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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+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.
+***********************************************************************/
+
+/*! \file silk_Inlines.h
+ *  \brief silk_Inlines.h defines OPUS_INLINE signal processing functions.
+ */
+
+#ifndef SILK_FIX_INLINES_H
+#define SILK_FIX_INLINES_H
+
+#ifdef  __cplusplus
+extern "C"
+{
+#endif
+
+/* count leading zeros of opus_int64 */
+static OPUS_INLINE opus_int32 silk_CLZ64( opus_int64 in )
+{
+    opus_int32 in_upper;
+
+    in_upper = (opus_int32)silk_RSHIFT64(in, 32);
+    if (in_upper == 0) {
+        /* Search in the lower 32 bits */
+        return 32 + silk_CLZ32( (opus_int32) in );
+    } else {
+        /* Search in the upper 32 bits */
+        return silk_CLZ32( in_upper );
+    }
+}
+
+/* get number of leading zeros and fractional part (the bits right after the leading one */
+static OPUS_INLINE void silk_CLZ_FRAC(
+    opus_int32 in,            /* I  input                               */
+    opus_int32 *lz,           /* O  number of leading zeros             */
+    opus_int32 *frac_Q7       /* O  the 7 bits right after the leading one */
+)
+{
+    opus_int32 lzeros = silk_CLZ32(in);
+
+    * lz = lzeros;
+    * frac_Q7 = silk_ROR32(in, 24 - lzeros) & 0x7f;
+}
+
+/* Approximation of square root                                          */
+/* Accuracy: < +/- 10%  for output values > 15                           */
+/*           < +/- 2.5% for output values > 120                          */
+static OPUS_INLINE opus_int32 silk_SQRT_APPROX( opus_int32 x )
+{
+    opus_int32 y, lz, frac_Q7;
+
+    if( x <= 0 ) {
+        return 0;
+    }
+
+    silk_CLZ_FRAC(x, &lz, &frac_Q7);
+
+    if( lz & 1 ) {
+        y = 32768;
+    } else {
+        y = 46214;        /* 46214 = sqrt(2) * 32768 */
+    }
+
+    /* get scaling right */
+    y >>= silk_RSHIFT(lz, 1);
+
+    /* increment using fractional part of input */
+    y = silk_SMLAWB(y, y, silk_SMULBB(213, frac_Q7));
+
+    return y;
+}
+
+/* Divide two int32 values and return result as int32 in a given Q-domain */
+static OPUS_INLINE opus_int32 silk_DIV32_varQ(   /* O    returns a good approximation of "(a32 << Qres) / b32" */
+    const opus_int32     a32,               /* I    numerator (Q0)                  */
+    const opus_int32     b32,               /* I    denominator (Q0)                */
+    const opus_int       Qres               /* I    Q-domain of result (>= 0)       */
+)
+{
+    opus_int   a_headrm, b_headrm, lshift;
+    opus_int32 b32_inv, a32_nrm, b32_nrm, result;
+
+    silk_assert( b32 != 0 );
+    silk_assert( Qres >= 0 );
+
+    /* Compute number of bits head room and normalize inputs */
+    a_headrm = silk_CLZ32( silk_abs(a32) ) - 1;
+    a32_nrm = silk_LSHIFT(a32, a_headrm);                                       /* Q: a_headrm                  */
+    b_headrm = silk_CLZ32( silk_abs(b32) ) - 1;
+    b32_nrm = silk_LSHIFT(b32, b_headrm);                                       /* Q: b_headrm                  */
+
+    /* Inverse of b32, with 14 bits of precision */
+    b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) );   /* Q: 29 + 16 - b_headrm        */
+
+    /* First approximation */
+    result = silk_SMULWB(a32_nrm, b32_inv);                                     /* Q: 29 + a_headrm - b_headrm  */
+
+    /* Compute residual by subtracting product of denominator and first approximation */
+    /* It's OK to overflow because the final value of a32_nrm should always be small */
+    a32_nrm = silk_SUB32_ovflw(a32_nrm, silk_LSHIFT_ovflw( silk_SMMUL(b32_nrm, result), 3 ));  /* Q: a_headrm   */
+
+    /* Refinement */
+    result = silk_SMLAWB(result, a32_nrm, b32_inv);                             /* Q: 29 + a_headrm - b_headrm  */
+
+    /* Convert to Qres domain */
+    lshift = 29 + a_headrm - b_headrm - Qres;
+    if( lshift < 0 ) {
+        return silk_LSHIFT_SAT32(result, -lshift);
+    } else {
+        if( lshift < 32){
+            return silk_RSHIFT(result, lshift);
+        } else {
+            /* Avoid undefined result */
+            return 0;
+        }
+    }
+}
+
+/* Invert int32 value and return result as int32 in a given Q-domain */
+static OPUS_INLINE opus_int32 silk_INVERSE32_varQ(   /* O    returns a good approximation of "(1 << Qres) / b32" */
+    const opus_int32     b32,                   /* I    denominator (Q0)                */
+    const opus_int       Qres                   /* I    Q-domain of result (> 0)        */
+)
+{
+    opus_int   b_headrm, lshift;
+    opus_int32 b32_inv, b32_nrm, err_Q32, result;
+
+    silk_assert( b32 != 0 );
+    silk_assert( Qres > 0 );
+
+    /* Compute number of bits head room and normalize input */
+    b_headrm = silk_CLZ32( silk_abs(b32) ) - 1;
+    b32_nrm = silk_LSHIFT(b32, b_headrm);                                       /* Q: b_headrm                */
+
+    /* Inverse of b32, with 14 bits of precision */
+    b32_inv = silk_DIV32_16( silk_int32_MAX >> 2, silk_RSHIFT(b32_nrm, 16) );   /* Q: 29 + 16 - b_headrm    */
+
+    /* First approximation */
+    result = silk_LSHIFT(b32_inv, 16);                                          /* Q: 61 - b_headrm            */
+
+    /* Compute residual by subtracting product of denominator and first approximation from one */
+    err_Q32 = silk_LSHIFT( ((opus_int32)1<<29) - silk_SMULWB(b32_nrm, b32_inv), 3 );        /* Q32                        */
+
+    /* Refinement */
+    result = silk_SMLAWW(result, err_Q32, b32_inv);                             /* Q: 61 - b_headrm            */
+
+    /* Convert to Qres domain */
+    lshift = 61 - b_headrm - Qres;
+    if( lshift <= 0 ) {
+        return silk_LSHIFT_SAT32(result, -lshift);
+    } else {
+        if( lshift < 32){
+            return silk_RSHIFT(result, lshift);
+        }else{
+            /* Avoid undefined result */
+            return 0;
+        }
+    }
+}
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif /* SILK_FIX_INLINES_H */