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Diffstat (limited to 'media/libstagefright/codecs/amrnb/common/src/norm_s.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrnb/common/src/norm_s.cpp | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/common/src/norm_s.cpp b/media/libstagefright/codecs/amrnb/common/src/norm_s.cpp new file mode 100644 index 0000000..8cdcdb8 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/common/src/norm_s.cpp @@ -0,0 +1,242 @@ +/* ------------------------------------------------------------------ + * Copyright (C) 1998-2009 PacketVideo + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * 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. + * ------------------------------------------------------------------- + */ +/**************************************************************************************** +Portions of this file are derived from the following 3GPP standard: + + 3GPP TS 26.073 + ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec + Available from http://www.3gpp.org + +(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC) +Permission to distribute, modify and use this file under the standard license +terms listed above has been obtained from the copyright holder. +****************************************************************************************/ +/* + + Pathname: ./gsm-amr/c/src/norm_s.c + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Created separate file for the norm_s function. Sync'ed up + with the current template and fixed tabs. + + Description: Updated input/output definition and module description to + be the same as the equivalent assembly file (norm_s.asm). + + Description: Updated definition of var1 to be the same as that in the + assembly file (norm_s.asm). + + Description: Removed conditional code that updates WMOPS counter + + Who: Date: + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + var1 = 16 bit signed integer of type Word16, whose value falls + in the range: 0x8000 <= var1 <= 0x7fff + + Local Stores/Buffers/Pointers Needed: + None + + Global Stores/Buffers/Pointers Needed: + None + + Outputs: + var_out = number of left shifts need to normalize var1 (Word16) + + Pointers and Buffers Modified: + None + + Local Stores Modified: + None + + Global Stores Modified: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function produces the number of left shifts needed to normalize the 16 + bit variable var1 for positive values on the interval with minimum of 0x4000 + and maximum of 0x7fff, and for negative values on the interval with minimum + of 0x8000 and maximum of 0xc000. Note that when var1 is zero, the resulting + output var_out is set to zero. + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + [1] basicop2.c, ETS Version 2.0.0, February 8, 1999 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +Word16 norm_s (Word16 var1) +{ + Word16 var_out; + + if (var1 == 0) + { + var_out = 0; + } + else + { + if (var1 == (Word16) 0xffff) + { + var_out = 15; + } + else + { + if (var1 < 0) + { + var1 = ~var1; + } + for (var_out = 0; var1 < 0x4000; var_out++) + { + var1 <<= 1; + } + } + } + +#if (WMOPS) + multiCounter[currCounter].norm_s++; +#endif + return (var_out); +} + +------------------------------------------------------------------------------ + RESOURCES USED + When the code is written for a specific target processor the + the resources used should be documented below. + + STACK USAGE: [stack count for this module] + [variable to represent + stack usage for each subroutine called] + + where: [stack usage variable] = stack usage for [subroutine + name] (see [filename].ext) + + DATA MEMORY USED: x words + + PROGRAM MEMORY USED: x words + + CLOCK CYCLES: [cycle count equation for this module] + [variable + used to represent cycle count for each subroutine + called] + + where: [cycle count variable] = cycle count for [subroutine + name] (see [filename].ext) + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ +#include "basic_op.h" + +/*---------------------------------------------------------------------------- +; MACROS +; Define module specific macros here +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; DEFINES +; Include all pre-processor statements here. Include conditional +; compile variables also. +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL FUNCTION DEFINITIONS +; Function Prototype declaration +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; LOCAL STORE/BUFFER/POINTER DEFINITIONS +; Variable declaration - defined here and used outside this module +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; EXTERNAL FUNCTION REFERENCES +; Declare functions defined elsewhere and referenced in this module +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES +; Declare variables used in this module but defined elsewhere +----------------------------------------------------------------------------*/ + +/*---------------------------------------------------------------------------- +; FUNCTION CODE +----------------------------------------------------------------------------*/ +#if !( defined(PV_ARM_V5) || defined(PV_ARM_GCC_V5) ) + +Word16 norm_s(register Word16 var1) +{ + /*---------------------------------------------------------------------------- + ; Define all local variables + ----------------------------------------------------------------------------*/ + + register Word16 var_out = 0; + + /*---------------------------------------------------------------------------- + ; Function body here + ----------------------------------------------------------------------------*/ + + if (var1) + { + Word16 y = var1 - (var1 < 0); + var1 = y ^(y >> 15); + + while (!(0x4000 & var1)) + { + var_out++; + if ((0x2000 & var1)) + { + break; + } + var_out++; + if ((0x1000 & var1)) + { + break; + } + var_out++; + if ((0x0800 & var1)) + { + break; + } + var_out++; + var1 <<= 4; + } + } + + /*---------------------------------------------------------------------------- + ; Return nothing or data or data pointer + ----------------------------------------------------------------------------*/ + return (var_out); +} + +#endif |