| /* ------------------------------------------------------------------ |
| * 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)); |
| |
| } |
| |
| |
| |