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/* ------------------------------------------------------------------
* 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.
* -------------------------------------------------------------------
*/
/*
------------------------------------------------------------------------------
PacketVideo Corp.
MP3 Decoder Library
Filename: pvmp3_poly_phase_synthesis.cpp
Date: 09/21/2007
------------------------------------------------------------------------------
REVISION HISTORY
Description:
------------------------------------------------------------------------------
INPUT AND OUTPUT DEFINITIONS
Input
tmp3dec_chan *pChVars, decoder state structure per channel
int32 numChannels, number of channels
e_equalization equalizerType, equalization mode
int16 *outPcm pointer to the PCM output data
Output
int16 *outPcm pointer to the PCM output data
------------------------------------------------------------------------------
FUNCTION DESCRIPTION
polyphase synthesis
Each time the subband samples for all 32 polyphase subbands of one
channel have been calculated, they can be applied to the synthesis
subband filter and 32 consecutive audio samples can be calculated
------------------------------------------------------------------------------
REQUIREMENTS
------------------------------------------------------------------------------
REFERENCES
[1] ISO MPEG Audio Subgroup Software Simulation Group (1996)
ISO 13818-3 MPEG-2 Audio Decoder - Lower Sampling Frequency Extension
------------------------------------------------------------------------------
PSEUDO-CODE
------------------------------------------------------------------------------
*/
/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "pvmp3_poly_phase_synthesis.h"
#include "pvmp3_polyphase_filter_window.h"
#include "pv_mp3dec_fxd_op.h"
#include "pvmp3_dec_defs.h"
#include "pvmp3_dct_16.h"
#include "pvmp3_equalizer.h"
#include "mp3_mem_funcs.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 pvmp3_poly_phase_synthesis(tmp3dec_chan *pChVars,
int32 numChannels,
e_equalization equalizerType,
int16 *outPcm)
{
/*
* Equalizer
*/
pvmp3_equalizer(pChVars->circ_buffer,
equalizerType,
pChVars->work_buf_int32);
int16 * ptr_out = outPcm;
for (int32 band = 0; band < FILTERBANK_BANDS; band += 2)
{
int32 *inData = &pChVars->circ_buffer[544 - (band<<5)];
/*
* DCT 32
*/
pvmp3_split(&inData[16]);
pvmp3_dct_16(&inData[16], 0);
pvmp3_dct_16(inData, 1); // Even terms
pvmp3_merge_in_place_N32(inData);
pvmp3_polyphase_filter_window(inData,
ptr_out,
numChannels);
inData -= SUBBANDS_NUMBER;
/*
* DCT 32
*/
pvmp3_split(&inData[16]);
pvmp3_dct_16(&inData[16], 0);
pvmp3_dct_16(inData, 1); // Even terms
pvmp3_merge_in_place_N32(inData);
pvmp3_polyphase_filter_window(inData,
ptr_out + (numChannels << 5),
numChannels);
ptr_out += (numChannels << 6);
inData -= SUBBANDS_NUMBER;
}/* end band loop */
pv_memmove(&pChVars->circ_buffer[576],
pChVars->circ_buffer,
480*sizeof(*pChVars->circ_buffer));
}
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