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Diffstat (limited to 'media/libstagefright/codecs/amrwb/src/deemphasis_32.cpp')
| -rw-r--r-- | media/libstagefright/codecs/amrwb/src/deemphasis_32.cpp | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/amrwb/src/deemphasis_32.cpp b/media/libstagefright/codecs/amrwb/src/deemphasis_32.cpp new file mode 100644 index 0000000..b80555b --- /dev/null +++ b/media/libstagefright/codecs/amrwb/src/deemphasis_32.cpp @@ -0,0 +1,166 @@ +/* ------------------------------------------------------------------ + * 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 26.173 + ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec + Available from http://www.3gpp.org + +(C) 2007, 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. +****************************************************************************************/ +/* +------------------------------------------------------------------------------ + + + + Filename: deemphasis_32.cpp + + Date: 05/08/2004 + +------------------------------------------------------------------------------ + REVISION HISTORY + + + Description: + +------------------------------------------------------------------------------ + INPUT AND OUTPUT DEFINITIONS + + int16 x_hi[], (i) : input signal (bit31..16) + int16 x_lo[], (i) : input signal (bit15..4) + int16 y[], (o) : output signal (x16) + int16 mu, (i) Q15 : deemphasis factor + int16 L, (i) : vector size + int16 * mem (i/o) : memory (y[-1]) + +------------------------------------------------------------------------------ + FUNCTION DESCRIPTION + + 32-bits filtering through 1/(1-mu z^-1) + +------------------------------------------------------------------------------ + REQUIREMENTS + + +------------------------------------------------------------------------------ + REFERENCES + +------------------------------------------------------------------------------ + PSEUDO-CODE + + Deemphasis H(z) = 1/(1 - 0.68z^(-1)) where mu = 0.67999 in Q15 + +------------------------------------------------------------------------------ +*/ + + +/*---------------------------------------------------------------------------- +; INCLUDES +----------------------------------------------------------------------------*/ + +#include "pv_amr_wb_type_defs.h" +#include "pvamrwbdecoder_basic_op.h" +#include "pvamrwb_math_op.h" +#include "pvamrwbdecoder_acelp.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 +----------------------------------------------------------------------------*/ + +void deemphasis_32( + int16 x_hi[], /* (i) : input signal (bit31..16) */ + int16 x_lo[], /* (i) : input signal (bit15..4) */ + int16 y[], /* (o) : output signal (x16) */ + int16 mu, /* (i) Q15 : deemphasis factor */ + int16 L, /* (i) : vector size */ + int16 * mem /* (i/o) : memory (y[-1]) */ +) +{ + int16 i; + int32 L_tmp; + int16 lo, hi; + + L_tmp = ((int32)x_hi[0]) << 16; + L_tmp += ((int32)x_lo[0]) << 4; + L_tmp = shl_int32(L_tmp, 3); + + L_tmp = fxp_mac_16by16(*mem, mu, L_tmp), + + L_tmp = shl_int32(L_tmp, 1); /* saturation can occur here */ + y[0] = amr_wb_round(L_tmp); + + lo = x_lo[1]; + hi = x_hi[1]; + for (i = 1; i < L - 1; i++) + { + L_tmp = ((int32)hi) << 16; + L_tmp += ((int32)lo) << 4; + L_tmp = shl_int32(L_tmp, 3); + L_tmp = fxp_mac_16by16(y[i - 1], mu, L_tmp), + L_tmp = shl_int32(L_tmp, 1); /* saturation can occur here */ + y[i] = amr_wb_round(L_tmp); + lo = x_lo[i+1]; + hi = x_hi[i+1]; + } + L_tmp = ((int32)hi) << 16; + L_tmp += ((int32)lo) << 4; + L_tmp = shl_int32(L_tmp, 3); + L_tmp = fxp_mac_16by16(y[i - 1], mu, L_tmp), + L_tmp = shl_int32(L_tmp, 1); /* saturation can occur here */ + y[i] = amr_wb_round(L_tmp); + + *mem = y[L - 1]; + + return; +} + |