/* ------------------------------------------------------------------ * 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_dequantize_sample.cpp Functions: power_1_third pvmp3_dequantize_sample Date: 09/21/2007 ------------------------------------------------------------------------------ REVISION HISTORY Description: ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS power_1_third int32 power_1_third( int32 xx) Input int32 xx, int32 in the [0, 8192] range Returns int32 xx^(1/3) int32 Q26 number representing the 1/3 power of the input ------------------------------------------------------------------------------ INPUT AND OUTPUT DEFINITIONS pvmp3_dequantize_sample Input int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], mp3ScaleFactors *scalefac, scale factor structure struct gr_info_s *gr_info, granule structure informatiom mp3Header *info mp3 header info Returns int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], dequantize output as (.)^(4/3) ------------------------------------------------------------------------------ FUNCTION DESCRIPTION dequantize sample ------------------------------------------------------------------------------ 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 "pv_mp3dec_fxd_op.h" #include "pvmp3_dec_defs.h" #include "pvmp3_dequantize_sample.h" #include "pvmp3_normalize.h" #include "mp3_mem_funcs.h" #include "pvmp3_tables.h" /*---------------------------------------------------------------------------- ; MACROS ; Define module specific macros here ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; DEFINES ; Include all pre-processor statements here. Include conditional ; compile variables also. ----------------------------------------------------------------------------*/ #define Q30_fmt(a)(int32(double(0x40000000)*a)) #define Q29_fmt(a)(int32(double(0x20000000)*a)) /*---------------------------------------------------------------------------- ; LOCAL FUNCTION DEFINITIONS ; Function Prototype declaration ----------------------------------------------------------------------------*/ /*---------------------------------------------------------------------------- ; LOCAL STORE/BUFFER/POINTER DEFINITIONS ; Variable declaration - defined here and used outside this module ----------------------------------------------------------------------------*/ const int32 pretab[22] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 3, 3, 3, 2, 0}; const int32 pow_2_1_fourth[4] = { Q30_fmt(1.0), Q30_fmt(1.18920711500272), Q30_fmt(1.41421356237310), Q30_fmt(1.68179283050743) }; const int32 two_cubic_roots[7] = { Q29_fmt(0), Q29_fmt(1.25992104989487), Q29_fmt(1.58740105196820), Q29_fmt(2.00000000000000), Q29_fmt(2.51984209978975), Q29_fmt(3.17480210393640), Q29_fmt(3.99999999999999) }; /*---------------------------------------------------------------------------- ; 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 ----------------------------------------------------------------------------*/ int32 power_1_third(int32 xx) { if (xx <= 512) { return (power_one_third[xx] >> 1); } else { if (xx >> 15) { return 0x7FFFFFFF; /* saturate any value over 32767 */ } else { int32 x = xx; int32 m = 22 - pvmp3_normalize(xx); xx >>= m; xx = (power_one_third[xx]) + (((power_one_third[xx+1] - power_one_third[xx]) >> m) * (x & ((1 << m) - 1))); return (fxp_mul32_Q30(xx, two_cubic_roots[m])); } } } /*---------------------------------------------------------------------------- ; FUNCTION CODE ----------------------------------------------------------------------------*/ void pvmp3_dequantize_sample(int32 is[SUBBANDS_NUMBER*FILTERBANK_BANDS], mp3ScaleFactors *scalefac, granuleInfo *gr_info, int32 used_freq_lines, mp3Header *info) { int32 ss; int32 cb = 0; int32 global_gain; int32 sfreq = info->sampling_frequency + info->version_x + (info->version_x << 1); /* apply formula per block type */ if (gr_info->window_switching_flag && (gr_info->block_type == 2)) { int32 next_cb_boundary; int32 cb_begin = 0; int32 cb_width = 0; int32 mixstart = 8; /* added 2003/08/21 efs */ if (info->version_x != MPEG_1) { mixstart = 6; /* different value in MPEG2 LSF */ } if (gr_info->mixed_block_flag) { next_cb_boundary = mp3_sfBandIndex[sfreq].l[1]; /* LONG blocks: 0,1,3 */ } else { next_cb_boundary = mp3_sfBandIndex[sfreq].s[1] * 3; /* pure SHORT block */ cb_width = 0; } global_gain = gr_info->global_gain; int32 two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; global_gain = 12 + (global_gain >> 2); for (ss = 0 ; ss < used_freq_lines ; ss++) { if (ss == next_cb_boundary) { cb++; /* critical band counter */ if (gr_info->mixed_block_flag) { if (next_cb_boundary == mp3_sfBandIndex[sfreq].l[mixstart]) { next_cb_boundary = mp3_sfBandIndex[sfreq].s[4] * 3; cb_begin = mp3_sfBandIndex[sfreq].s[3] * 3; cb_width = 3; cb = 3; } else if (ss < mp3_sfBandIndex[sfreq].l[mixstart]) { next_cb_boundary = mp3_sfBandIndex[sfreq].l[cb+1]; } else { next_cb_boundary = mp3_sfBandIndex[sfreq].s[cb+1] * 3; cb_width = cb; cb_begin = mp3_sfBandIndex[sfreq].s[cb] * 3; } if (ss < 2*FILTERBANK_BANDS) { /* 1st 2 subbands of switched blocks */ global_gain = (gr_info->global_gain); global_gain -= (1 + gr_info->scalefac_scale) * (scalefac->l[cb] + gr_info->preflag * pretab[cb]) << 1; two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; global_gain = 12 + (global_gain >> 2); } } else { next_cb_boundary = mp3_sfBandIndex[sfreq].s[cb+1] * 3; cb_width = cb; cb_begin = mp3_sfBandIndex[sfreq].s[cb] * 3; } } /* end-if ( ss == next_cb_boundary) */ /* Do long/short dependent scaling operations. */ if ((gr_info->mixed_block_flag == 0) || (gr_info->mixed_block_flag && (ss >= 2*FILTERBANK_BANDS))) { int32 temp2 = fxp_mul32_Q32((ss - cb_begin) << 16, mp3_shortwindBandWidths[sfreq][cb_width]); temp2 = (temp2 + 1) >> 15; global_gain = (gr_info->global_gain); global_gain -= gr_info->subblock_gain[temp2] << 3; global_gain -= (1 + gr_info->scalefac_scale) * (scalefac->s[temp2][cb] << 1); two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; global_gain = 12 + (global_gain >> 2); } /* * xr[sb][ss] = 2^(global_gain/4) */ /* Scale quantized value. */ /* 0 < abs(is[ss]) < 8192 */ int32 tmp = fxp_mul32_Q30((is[ss] << 16), power_1_third(pv_abs(is[ ss]))); tmp = fxp_mul32_Q30(tmp, two_raise_one_fourth); if (global_gain < 0) { int32 temp = - global_gain; if (temp < 32) { is[ss] = (tmp >> temp); } else { is[ss] = 0; } } else { is[ss] = (tmp << global_gain); } } /* for (ss=0 ; ss < used_freq_lines ; ss++) */ } else { for (cb = 0 ; cb < 22 ; cb++) { /* Compute overall (global) scaling. */ global_gain = (gr_info->global_gain); global_gain -= (1 + gr_info->scalefac_scale) * (scalefac->l[cb] + gr_info->preflag * pretab[cb]) << 1; int32 two_raise_one_fourth = pow_2_1_fourth[global_gain&0x3]; global_gain = 12 + (global_gain >> 2); /* * xr[sb][ss] = 2^(global_gain/4) */ /* Scale quantized value. */ if (used_freq_lines >= mp3_sfBandIndex[sfreq].l[cb+1]) { if (global_gain <= 0) { global_gain = - global_gain; if (global_gain < 32) { for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < mp3_sfBandIndex[sfreq].l[cb+1]; ss += 2) { int32 tmp = is[ss]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; } tmp = is[ss+1]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss+1] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; } } } else { pv_memset(&is[ mp3_sfBandIndex[sfreq].l[cb]], 0, (mp3_sfBandIndex[sfreq].l[cb+1] - mp3_sfBandIndex[sfreq].l[cb])*sizeof(*is)); } } else { for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < mp3_sfBandIndex[sfreq].l[cb+1]; ss += 2) { int32 tmp = is[ss]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) << global_gain; } tmp = is[ss+1]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss+1] = fxp_mul32_Q30(tmp, two_raise_one_fourth) << global_gain; } } } } else { if (global_gain <= 0) { global_gain = - global_gain; if (global_gain < 32) { for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < used_freq_lines; ss += 2) { int32 tmp = is[ss]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; } tmp = is[ss+1]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss+1] = fxp_mul32_Q30(tmp, two_raise_one_fourth) >> global_gain; } } } else { pv_memset(&is[ mp3_sfBandIndex[sfreq].l[cb]], 0, (mp3_sfBandIndex[sfreq].l[cb+1] - mp3_sfBandIndex[sfreq].l[cb])*sizeof(*is)); } } else { for (ss = mp3_sfBandIndex[sfreq].l[cb]; ss < used_freq_lines; ss++) { int32 tmp = is[ss]; if (tmp) { tmp = fxp_mul32_Q30((tmp << 16), power_1_third(pv_abs(tmp))); is[ss] = fxp_mul32_Q30(tmp, two_raise_one_fourth) << global_gain; } } } cb = 22; // force breaking out of the loop } /* if ( used_freq_lines >= mp3_sfBandIndex[sfreq].l[cb+1]) */ } /* for (cb=0 ; cb < 22 ; cb++) */ } /* if (gr_info->window_switching_flag && (gr_info->block_type == 2)) */ pv_memset(&is[used_freq_lines], 0, (FILTERBANK_BANDS*SUBBANDS_NUMBER - used_freq_lines)*sizeof(*is)); }