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Diffstat (limited to 'media/libstagefright/codecs/mp3dec/src/pvmp3_poly_phase_synthesis.cpp')
| -rw-r--r-- | media/libstagefright/codecs/mp3dec/src/pvmp3_poly_phase_synthesis.cpp | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/mp3dec/src/pvmp3_poly_phase_synthesis.cpp b/media/libstagefright/codecs/mp3dec/src/pvmp3_poly_phase_synthesis.cpp new file mode 100644 index 0000000..33c8e61 --- /dev/null +++ b/media/libstagefright/codecs/mp3dec/src/pvmp3_poly_phase_synthesis.cpp @@ -0,0 +1,187 @@ +/* ------------------------------------------------------------------ + * 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)); + +} + + + |