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