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Diffstat (limited to 'media/libstagefright/codecs/amrnb/common/src/shr_r.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrnb/common/src/shr_r.cpp | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrnb/common/src/shr_r.cpp b/media/libstagefright/codecs/amrnb/common/src/shr_r.cpp new file mode 100644 index 0000000..6656f93 --- /dev/null +++ b/media/libstagefright/codecs/amrnb/common/src/shr_r.cpp @@ -0,0 +1,226 @@ +/* ------------------------------------------------------------------ + * 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/shr_r.c + +------------------------------------------------------------------------------ + REVISION HISTORY + + Description: Created separate file for the shr_r function. Sync'ed up + with the current template and fixed tabs. + + Description: Passing around pOverflow as per EPOC changes. + + Who: Date: + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + Inputs: + var1 = 16 bit short signed integer (Word16) whose value falls in + the range : 0xffff 8000 <= var1 <= 0x0000 7fff. + var2 = 16 bit short signed integer (Word16) whose value falls in + the range : 0xffff 8000 <= var2 <= 0x0000 7fff. + + Local Stores/Buffers/Pointers Needed: + None + + Global Stores/Buffers/Pointers Needed: + None + + Outputs: + var_out = shifted input w/ rounding (Word16) + + Pointers and Buffers Modified: + None + + Local Stores Modified: + None + + Global Stores Modified: + None + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + This function arithmetically shifts the 16 bit input var1 right var2 positions + with rounding. If var2 is negative, arithmetically shift var1 left by + -var2 with rounding. Saturate the result in case of underflows or + overflows. + + - If var2 is greater than zero : + if (sub(shl(shr(var1,var2),1),shr(var1,sub(var2,1)))) + is equal to zero + then + shr_r(var1,var2) = shr(var1,var2) + else + shr_r(var1,var2) = add(shr(var1,var2),1) + - If var2 is less than or equal to zero : + shr_r(var1,var2) = shr(var1,var2). + +------------------------------------------------------------------------------ + REQUIREMENTS + + None + +------------------------------------------------------------------------------ + REFERENCES + + [1] basicop2.c, ETS Version 2.0.0, February 8, 1999 + +------------------------------------------------------------------------------ + PSEUDO-CODE + +Word16 shr_r (Word16 var1, Word16 var2) +{ + Word16 var_out; + + if (var2 > 15) + { + var_out = 0; + } + else + { + var_out = shr (var1, var2); +#if (WMOPS) + multiCounter[currCounter].shr--; +#endif + + if (var2 > 0) + { + if ((var1 & ((Word16) 1 << (var2 - 1))) != 0) + { + var_out++; + } + } + } +#if (WMOPS) + multiCounter[currCounter].shr_r++; +#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 +----------------------------------------------------------------------------*/ +Word16 shr_r(register Word16 var1, register Word16 var2, Flag *pOverflow) +{ + /*---------------------------------------------------------------------------- + ; Define all local variables + ----------------------------------------------------------------------------*/ + Word16 var_out; + + /*---------------------------------------------------------------------------- + ; Function body here + ----------------------------------------------------------------------------*/ + if (var2 > 15) + { + var_out = 0; + } + else + { + var_out = shr(var1, var2, pOverflow); + if (var2 > 0) + { + if ((var1 & ((Word16) 1 << (var2 - 1))) != 0) + { + var_out++; + } + } + } + + /*---------------------------------------------------------------------------- + ; Return nothing or data or data pointer + ----------------------------------------------------------------------------*/ + return (var_out); +} |