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