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/* ------------------------------------------------------------------
* 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.
* -------------------------------------------------------------------
*/
/*
Pathname: huffspec_fxp.c
Funtions:
huffspec_fxp
------------------------------------------------------------------------------
REVISION HISTORY
Description: Modified from original shareware code
Description: Modified to pass variables by reference to eliminate use
of global variables.
Description: (1) Modified to keep in-line with PV standards
(2) Eliminated "continue" in if(sect_cb==ZERO_HCB||...)
Description: (1) Use SectInfo *pSect
(2) Convert 'Real' to 'Int32', float -> fixed-point
(3) move BITS *pInputStream to second parameter
(4) pass in quantSpec and tmp_spec, scratch shared with hufffac
(5) pass in FrameInfo *pLongFrameInfo, eliminate only_long_info
Description: (1) Eliminate parameter Hcb *book, because of eliminating
function 'hufftab.c', Hcb hcbbook defined as a
const structure in 'hcbtables.h'.
(2) Replace three nested 'for' loops with a for-while loop in
the rescaling part.
(3) Change esc_iquant-> esc_iquant_fxp, call esc_iquant_fxp()
by sfb
Description: Cleaned up include files.
Description: Correct definition of stack variable "scale".
It was defined as Int, but it receives an UInt value,
this present a problem when Int is 16 bits and
the sign bit is not interpreted correctly. This does not
shows for 32-bit implementations. This problem manifest itself
as a flipping sign on some spectral coefficients (the ones
multiplied by 0x8000).
Description: Typecast b_low and b_high to 32-bits before multiplication, this
assures propoer compilation on a 16-bit platform (TI-C55x)
Description: Modified to speed up decode_huff_cw
Description: pass codebook index to decode_huff_cw, delete pointer to Huffman
structure
Description: keep memset to quantSpec, remove memset to temp_spec
Description: Modified per review comments
Description: Use Binary tree search in decode_huff_cw_binary
Description: Modified per review comments
(1) delete unused codes
Description: (1) Change the interface to decode huffman codeword.
(2) Move the scaling inside the inverse quantization.
(3) Change scaling factor accuracy to 10 bits.
Description:
(1) delete unused variable max_fac
Description: Addresses of huffman tables are now found by means of a
switch statement, this solve linking problem when using the
/ropi option (Read-only position independent) for some
compilers
Who: Date: MM/DD/YYYY
Description:
------------------------------------------------------------------------------
INPUT AND OUTPUT DEFINITIONS
Inputs:
pFrameInfo = ptr to structure that holds Information of current Frame,
type FrameInfo
pInputStream = ptr to structure of bitstream, type BITS
nsect = number of sections in current Frame, at fs = 44.1 kHz,
range [0, 49] long block, [0,112] short blocks. type Int
pSect = ptr to structure that holds section codebook and boundary
type SectInfo
factors[] = array that contains scalefactors for each sfb, type Int16
coef[] = array that holds inverse quantized coefs, Int32 QFormat.
quantSpec[] = array that holds quantized spectral coefs, type Int
tmp_spec[] = temporary buffer to hold the de-interleaved coefs.
pLongFrameInfo = ptr to structure that holds long frame info
Local Stores/Buffers/Pointers Needed:
exptable = array contains the Q15 format data for 2^0, 2^0.25, 2^0.5,
and 2^0.75, type const Int.
Global Stores/Buffers/Pointers Needed:
None
Outputs:
return 0 if decoding properly.
Pointers and Buffers Modified:
pInputStream read codeword index and/or sign bits and/or ESC value
coef contains the newly inverse quantized 1024 spec coefs,
type Int32 Q-format from esc_iquant()
quantSpec contains decoded quantized 1024 spec coefs, type Int
tmp_spec contains the de-interleaved version of quantSpec
qFormat contains Q-Format for each scalefactor band
Local Stores Modified:
None
Global Stores Modified:
None
------------------------------------------------------------------------------
FUNCTION DESCRIPTION
This function first reads the section info (codebook and boundary), then
decode the spectral coefficients if a spectral codebook is used.
If necessary, get the sign bits, ESC value or the NEC_pulse data. In case of
short window sequences, the decoded data is de-interleaved before
multiplied by scalefactors.
------------------------------------------------------------------------------
REQUIREMENTS
This function should set the content of the array 'coef' with the inverse
quantized and rescaled value of spectral coefficients.
------------------------------------------------------------------------------
REFERENCES
(1) MPEG-2 NBC Audio Decoder
"This software module was originally developed by AT&T, Dolby
Laboratories, Fraunhofer Gesellschaft IIS in the course of development
of the MPEG-2 NBC/MPEG-4 Audio standard ISO/IEC 13818-7, 14496-1,2 and
3. This software module is an implementation of a part of one or more
MPEG-2 NBC/MPEG-4 Audio tools as specified by the MPEG-2 NBC/MPEG-4
Audio standard. ISO/IEC gives users of the MPEG-2 NBC/MPEG-4 Audio
standards free license to this software module or modifications thereof
for use in hardware or software products claiming conformance to the
MPEG-2 NBC/MPEG-4 Audio standards. Those intending to use this software
module in hardware or software products are advised that this use may
infringe existing patents. The original developer of this software
module and his/her company, the subsequent editors and their companies,
and ISO/IEC have no liability for use of this software module or
modifications thereof in an implementation. Copyright is not released
for non MPEG-2 NBC/MPEG-4 Audio conforming products.The original
developer retains full right to use the code for his/her own purpose,
assign or donate the code to a third party and to inhibit third party
from using the code for non MPEG-2 NBC/MPEG-4 Audio conforming products.
This copyright notice must be included in all copies or derivative
works."
Copyright(c)1996.
(2) ISO/IEC 14496-3: 1999(E)
Subpart (4) p56 (spectral_data() parsing and decoding)
p26 (Syntax of spectral_data())
p74-78 (decoding: unpack_idx, get_sign_bits,
getescape, pulse_nc, deinterleave)
p72 (inverse quantization: esc_iquant)
------------------------------------------------------------------------------
PSEUDO-CODE
------------------------------------------------------------------------------
RESOURCES USED
When the code is written for a specific target processor the
the resources used should be documented below.
STACK USAGE: [stack count for this module] + [variable to represent
stack usage for each subroutine called]
where: [stack usage variable] = stack usage for [subroutine
name] (see [filename].ext)
DATA MEMORY USED: x words
PROGRAM MEMORY USED: x words
CLOCK CYCLES: [cycle count equation for this module] + [variable
used to represent cycle count for each subroutine
called]
where: [cycle count variable] = cycle count for [subroutine
name] (see [filename].ext)
------------------------------------------------------------------------------
*/
/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "pv_audio_type_defs.h"
#include "aac_mem_funcs.h"
#include "esc_iquant_scaling.h"
#include "huffman.h"
#include "unpack_idx.h"
#include "pulse_nc.h"
#include "iquant_table.h"
#include "e_huffmanconst.h"
#include "pv_normalize.h"
/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; DEFINES
; Include all pre-processor statements here. Include conditional
; compile variables also.
----------------------------------------------------------------------------*/
#define ORDER (3)
/*
* Format the table is stored in.
*/
#define QTABLE (27)
/*
* Number of bits for data in a signed 32 bit integer.
*/
#define SIGNED32BITS (31)
/*
* Round up value for intermediate values obtained from the table
*/
#define ROUND_UP (( ((UInt32) 1) << (QTABLE) )-1)
/*----------------------------------------------------------------------------
; LOCAL FUNCTION DEFINITIONS
; Function Prototype declaration
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL STORE/BUFFER/POINTER DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/
const UInt16 exptable[4] =
{
0, /* (2^0.00)<<15 (Q10), use zero to signal no scaling required! */
19485, /* (2^0.25)<<15 */
23171, /* (2^0.50)<<15 */
27555 /* (2^0.75)<<15 */
};
/*----------------------------------------------------------------------------
; 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
----------------------------------------------------------------------------*/
Int huffspec_fxp(
FrameInfo *pFrameInfo,
BITS *pInputStream,
Int nsect,
SectInfo *pSectInfo,
Int factors[],
Int32 coef[],
Int16 quantSpec[],
Int16 tmp_spec[],
const FrameInfo *pLongFrameInfo,
PulseInfo *pPulseInfo,
Int qFormat[])
{
/*----------------------------------------------------------------------------
; Define all local variables
----------------------------------------------------------------------------*/
const Hcb *pHcb;
Int i;
Int sfb;
Int idx_count;
Int sect_cb; /* section codebook */
Int dim;
Int idx;
Int stop_idx; /* index of 1st coef in next sfb */
Int sect_start; /* start index of sfb in one section*/
Int sect_end; /* index of 1st sfb in next section */
Int *pSfbStart;
Int *pSfb;
Int16 *pQuantSpec; /* probably could be short */
Int max = 0;
/* rescaling parameters */
Int nsfb;
Int tot_sfb;
Int fac;
Int32 *pCoef; /* ptr to coef[], inverse quantized coefs */
UInt16 scale;
Int power_scale_div_4;
Int sfbWidth;
void (*pUnpack_idx)(
Int16 quant_spec[],
Int codeword_indx,
const Hcb *pHuffCodebook,
BITS *pInputStream,
Int *max);
Int(*pDec_huff_tab)(BITS *) = NULL;
UInt32 temp;
Int binaryDigits, QFormat;
/*----------------------------------------------------------------------------
; Function body here
----------------------------------------------------------------------------*/
sect_start = 0;
stop_idx = 0;
/* pSfb: ptr to array that holds stop index of each sfb */
pSfbStart = pFrameInfo->frame_sfb_top;
if (pSfbStart == NULL)
{
return (-1); /* error condition */
}
pSfb = pSfbStart;
/* decoding spectral values section by section */
for (i = nsect; i > 0; i--)
{
/* read the codebook and section length */
sect_cb = pSectInfo->sect_cb; /* codebook */
if ((sect_cb > 15) || (sect_cb < 0))
{
return (-1); /* error condition */
}
sect_end = pSectInfo->sect_end; /* # of sfbs */
if (sect_end < 0)
{
return (-1); /* error condition */
}
pSectInfo++;
/* sect_cb sect_cb - 1
* ZERO_HCB 1111b
* 1 0000b
* 2 0001b
* 3 0010b
* 4 0011b
* 5 0100b
* 6 0101b
* 7 0110b
* 8 0111b
* 9 1000b
* 10 1001b
* 11 1010b
* 12 1011b
* NOISE_HCB 1100b
* INTENSITY_HCB2 1101b
* INTENSITY_HCB 1110b
* if ( ((sect_cb - 1) & 0xC) == 0xC ) is identical to
* if !((sect_cb == ZERO_HCB) || (sect_cb == NOISE_HCB) ||
* (sec_cb == INTENSITY_HCB) || (sect_cb==INTENSITY_HCB2) )
* use this compare scheme to speed up the execution
*/
if (((sect_cb - 1) & 0xC) != 0xC)
{
/* decode spec in one section */
if (sect_cb > BY4BOOKS)
{
dim = DIMENSION_2; /* set codebook dimension */
}
else
{
dim = DIMENSION_4;
}
pHcb = &hcbbook_binary[sect_cb];
if (sect_cb == ESCBOOK)
{
pUnpack_idx = &unpack_idx_esc;
}
else if (pHcb->signed_cb == FALSE)
{
pUnpack_idx = &unpack_idx_sgn;
}
else
{
pUnpack_idx = &unpack_idx;
}
switch (sect_cb)
{
case 1:
pDec_huff_tab = decode_huff_cw_tab1;
break;
case 2:
pDec_huff_tab = decode_huff_cw_tab2;
break;
case 3:
pDec_huff_tab = decode_huff_cw_tab3;
break;
case 4:
pDec_huff_tab = decode_huff_cw_tab4;
break;
case 5:
pDec_huff_tab = decode_huff_cw_tab5;
break;
case 6:
pDec_huff_tab = decode_huff_cw_tab6;
break;
case 7:
pDec_huff_tab = decode_huff_cw_tab7;
break;
case 8:
pDec_huff_tab = decode_huff_cw_tab8;
break;
case 9:
pDec_huff_tab = decode_huff_cw_tab9;
break;
case 10:
pDec_huff_tab = decode_huff_cw_tab10;
break;
case 11:
pDec_huff_tab = decode_huff_cw_tab11;
break;
default:
return (-1); /* error condition */
}
/* move ptr to first sfb of current section */
pQuantSpec = quantSpec + stop_idx;
/* step through all sfbs in current section */
for (sfb = sect_start; sfb < sect_end; sfb++)
{
idx_count = *pSfb - stop_idx;
stop_idx = *pSfb++;
/* decode all coefs for one sfb */
while ((idx_count > 0) && (idx_count < 1024))
{
idx = (*pDec_huff_tab)(pInputStream);
(*pUnpack_idx)(pQuantSpec,
idx,
pHcb,
pInputStream,
&max); /* unpack idx -> coefs */
pQuantSpec += dim;
idx_count -= dim;
} /* while(idx_count) */
} /* for (sfb=sect_start) */
}
else
{
/* current section uses ZERO_HCB, NOISE_HCB, etc */
/* move sfb pointer to the start sfb of next section */
pSfb = pSfbStart + sect_end;
/* number of coefs in current section */
idx_count = *(pSfb - 1) - stop_idx;
if ((idx_count > 1024) || (idx_count < 0))
{
return (-1); /* error condition */
}
/*
* This memset is necessary in terms of (1) net savings in total
* MIPS and (2) accurate Q-Formats for fft_rx2
* In case a scalefactor band uses ZERO_HCB, all coefficients of
* that sfb should be zeros. Without this call to memset, the
* coefficients for a ZERO_HCB sfb are the "leftovers" of the
* previous frame, which may not have all zero values. This leads
* to a drastical increase in the cycles consumed by esc_iquant_fxp
* and fft_rx2, which is the most "expensive" function of the
* library.
* This memset also guarantees the Q_Format for sfbs with all zero
* coefficients will be set properly.
* Profiling data on ARM and TMS320C55x proves that there is a net
* gain in total MIPS if a memset is called here.
*/
pv_memset(&quantSpec[stop_idx],
0,
idx_count * sizeof(quantSpec[0]));
/*
* This memset is called because pQuantSpec points to tmp_spec
* after deinterleaving
*/
pv_memset(&tmp_spec[stop_idx],
0,
idx_count * sizeof(tmp_spec[0]));
/* stop_idx is the index of the 1st coef of next section */
stop_idx = *(pSfb - 1);
}/* if (sect_cb) */
sect_start = sect_end;
} /* for (i=nsect) */
/* noisless coding reconstruction */
if (pFrameInfo->islong != FALSE)
{
if (pPulseInfo->pulse_data_present == 1)
{
pulse_nc(quantSpec,
pPulseInfo,
pLongFrameInfo,
&max); /* add pulse data */
}
pQuantSpec = quantSpec;
}
else
{
deinterleave(quantSpec,
tmp_spec,
pFrameInfo);
pQuantSpec = tmp_spec;
}
/* inverse quantization, Q_format: Int32 */
/* rescaling */
/* what we can do here is assuming that we already know maxInput for each band, we have to go
though each one of them for re-quant and scaling, and pick the right qFormat to apply to
all spectral coeffs.*/
if ((max < 0) || (max > 8192)) /* (8192>>ORDER) == 1024 is the inverseQuantTable size */
{
return (-1); /* error condition */
}
else
{
/* Get (max/SPACING) ^ (1/3), in Q Format */
temp = inverseQuantTable[(max >> ORDER) + 1];
}
/* Round up before shifting down to Q0 */
temp += ROUND_UP;
/* shift down to Q0 and multiply by 2 (FACTOR) in one step */
temp >>= (QTABLE - 1);
/* Now get max ^ (4/3) in Q0 */
temp *= max;
binaryDigits = 31 - pv_normalize(temp);
/* Prevent negative shifts caused by low maximums. */
if (binaryDigits < (SIGNED32BITS - QTABLE))
{
binaryDigits = SIGNED32BITS - QTABLE;
}
QFormat = SIGNED32BITS - binaryDigits;
/********************/
tot_sfb = 0;
nsfb = pFrameInfo->sfb_per_win[0];
pCoef = coef;
for (i = pFrameInfo->num_win; i > 0; i--)
{
stop_idx = 0;
for (sfb = 0; sfb < nsfb; sfb++)
{
sfbWidth = pFrameInfo->win_sfb_top[0][sfb] - stop_idx;
if ((sfbWidth < 0) || (sfbWidth > 1024))
{
return (-1); /* error condition */
}
stop_idx += sfbWidth;
fac = factors[tot_sfb] - SF_OFFSET;
scale = exptable[fac & 0x3];
power_scale_div_4 = fac >> 2;
power_scale_div_4++;
qFormat[tot_sfb] = QFormat;
esc_iquant_scaling(pQuantSpec,
pCoef,
sfbWidth,
QFormat,
scale,
max);
pQuantSpec += sfbWidth;
qFormat[tot_sfb] -= power_scale_div_4;
pCoef += sfbWidth;
tot_sfb++;
} /* for (sfb) */
} /* for (i) */
/*----------------------------------------------------------------------------
; Return status
----------------------------------------------------------------------------*/
return SUCCESS;
} /* huffspec_fxp */
|