188 lines
5.8 KiB
C++
188 lines
5.8 KiB
C++
/* ------------------------------------------------------------------
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* Copyright (C) 1998-2009 PacketVideo
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
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* express or implied.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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* -------------------------------------------------------------------
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*/
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/*
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------------------------------------------------------------------------------
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PacketVideo Corp.
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MP3 Decoder Library
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Filename: pvmp3_poly_phase_synthesis.cpp
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Date: 09/21/2007
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------------------------------------------------------------------------------
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REVISION HISTORY
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Description:
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------------------------------------------------------------------------------
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INPUT AND OUTPUT DEFINITIONS
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Input
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tmp3dec_chan *pChVars, decoder state structure per channel
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int32 numChannels, number of channels
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e_equalization equalizerType, equalization mode
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int16 *outPcm pointer to the PCM output data
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Output
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int16 *outPcm pointer to the PCM output data
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------------------------------------------------------------------------------
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FUNCTION DESCRIPTION
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polyphase synthesis
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Each time the subband samples for all 32 polyphase subbands of one
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channel have been calculated, they can be applied to the synthesis
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subband filter and 32 consecutive audio samples can be calculated
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------------------------------------------------------------------------------
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REQUIREMENTS
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------------------------------------------------------------------------------
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REFERENCES
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[1] ISO MPEG Audio Subgroup Software Simulation Group (1996)
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ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension
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------------------------------------------------------------------------------
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PSEUDO-CODE
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------------------------------------------------------------------------------
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*/
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/*----------------------------------------------------------------------------
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; INCLUDES
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----------------------------------------------------------------------------*/
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#include "pvmp3_poly_phase_synthesis.h"
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#include "pvmp3_polyphase_filter_window.h"
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#include "pv_mp3dec_fxd_op.h"
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#include "pvmp3_dec_defs.h"
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#include "pvmp3_dct_16.h"
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#include "pvmp3_equalizer.h"
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#include "mp3_mem_funcs.h"
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/*----------------------------------------------------------------------------
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; MACROS
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; Define module specific macros here
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; DEFINES
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; Include all pre-processor statements here. Include conditional
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; compile variables also.
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; LOCAL FUNCTION DEFINITIONS
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; Function Prototype declaration
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; LOCAL STORE/BUFFER/POINTER DEFINITIONS
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; Variable declaration - defined here and used outside this module
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; EXTERNAL FUNCTION REFERENCES
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; Declare functions defined elsewhere and referenced in this module
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
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; Declare variables used in this module but defined elsewhere
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----------------------------------------------------------------------------*/
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/*----------------------------------------------------------------------------
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; FUNCTION CODE
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----------------------------------------------------------------------------*/
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void pvmp3_poly_phase_synthesis(tmp3dec_chan *pChVars,
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int32 numChannels,
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e_equalization equalizerType,
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int16 *outPcm)
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{
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/*
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* Equalizer
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*/
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pvmp3_equalizer(pChVars->circ_buffer,
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equalizerType,
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pChVars->work_buf_int32);
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int16 * ptr_out = outPcm;
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for (int32 band = 0; band < FILTERBANK_BANDS; band += 2)
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{
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int32 *inData = &pChVars->circ_buffer[544 - (band<<5)];
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/*
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* DCT 32
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*/
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pvmp3_split(&inData[16]);
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pvmp3_dct_16(&inData[16], 0);
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pvmp3_dct_16(inData, 1); // Even terms
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pvmp3_merge_in_place_N32(inData);
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pvmp3_polyphase_filter_window(inData,
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ptr_out,
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numChannels);
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inData -= SUBBANDS_NUMBER;
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/*
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* DCT 32
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*/
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pvmp3_split(&inData[16]);
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pvmp3_dct_16(&inData[16], 0);
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pvmp3_dct_16(inData, 1); // Even terms
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pvmp3_merge_in_place_N32(inData);
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pvmp3_polyphase_filter_window(inData,
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ptr_out + (numChannels << 5),
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numChannels);
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ptr_out += (numChannels << 6);
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inData -= SUBBANDS_NUMBER;
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}/* end band loop */
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pv_memmove(&pChVars->circ_buffer[576],
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pChVars->circ_buffer,
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480*sizeof(*pChVars->circ_buffer));
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}
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