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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.
* -------------------------------------------------------------------
*/
/*
------------------------------------------------------------------------------
PacketVideo Corp.
MP3 Decoder Library
Filename: pvmp3_get_scale_factors.cpp
Date: 09/21/2007
------------------------------------------------------------------------------
REVISION HISTORY
Description:
------------------------------------------------------------------------------
INPUT AND OUTPUT DEFINITIONS
Input
mp3ScaleFactors *scalefac,
mp3SideInfo *si, side info
int32 gr, granule
int32 ch, channel
tbits *pMainData bit stream
Returns
mp3ScaleFactors *scalefac, scale factors
------------------------------------------------------------------------------
FUNCTION DESCRIPTION
get scale factors
------------------------------------------------------------------------------
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_get_scale_factors.h"
#include "pvmp3_getbits.h"
#include "mp3_mem_funcs.h"
/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; DEFINES
; Include all pre-processor statements here. Include conditional
; compile variables also.
----------------------------------------------------------------------------*/
#define Qfmt_28(a)(int32(double(0x10000000)*a))
/*----------------------------------------------------------------------------
; LOCAL FUNCTION DEFINITIONS
; Function Prototype declaration
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL STORE/BUFFER/POINTER DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/
const int32 slen[2][16] =
{
{0, 0, 0, 0, 3, 1, 1, 1, 2, 2, 2, 3, 3, 3, 4, 4},
{0, 1, 2, 3, 0, 1, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3}
};
const struct
{
int32 l[5];
int32 s[3];
} sfbtable =
{
{0, 6, 11, 16, 21},
{0, 6, 12}
};
const int32 long_sfbtable[4] = { 6, 5, 5, 5};
/*----------------------------------------------------------------------------
; 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_get_scale_factors(mp3ScaleFactors *scalefac,
mp3SideInfo *si,
int32 gr,
int32 ch,
tmp3Bits *pMainData)
{
int32 sfb;
int32 i;
int32 window;
granuleInfo *gr_info = &(si->ch[ch].gran[gr]);
if (gr_info->window_switching_flag && (gr_info->block_type == 2))
{
if (gr_info->mixed_block_flag)
{ /* MIXED */
for (sfb = 0; sfb < 8; sfb++)
{
scalefac->l[sfb] = getNbits(pMainData, slen[0][gr_info->scalefac_compress]);
}
for (sfb = 3; sfb < 6; sfb++)
{
for (window = 0; window < 3; window++)
{
scalefac->s[window][sfb] = getNbits(pMainData, slen[0][gr_info->scalefac_compress]);
}
}
for (sfb = 6; sfb < 12; sfb++)
{
for (window = 0; window < 3; window++)
{
scalefac->s[window][sfb] = getNbits(pMainData, slen[1][gr_info->scalefac_compress]);
}
}
}
else
{ /* SHORT*/
for (i = 0; i < 2; i++)
{
for (sfb = sfbtable.s[i]; sfb < sfbtable.s[i+1]; sfb++)
{
for (window = 0; window < 3; window++)
{
scalefac->s[window][sfb] = getNbits(pMainData, slen[i][gr_info->scalefac_compress]);
}
}
}
}
scalefac->s[0][12] = 0; /* sfb = 12 win= 0 */
scalefac->s[1][12] = 0; /* sfb = 12 win= 1 */
scalefac->s[2][12] = 0; /* sfb = 12 win= 2 */
}
else
{ /* LONG types 0,1,3 */
int32 *ptr = &scalefac->l[0];
for (i = 0; i < 4; i++)
{
int32 tmp4 = long_sfbtable[i];
if ((si->ch[ch].scfsi[i] == 0) || (gr == 0))
{
int32 tmp1 = slen[(i>>1)][gr_info->scalefac_compress];
if (tmp1)
{
int32 tmp2 = tmp1 * tmp4;
uint32 tmp3 = getNbits(pMainData, tmp2);
tmp4 = 32 - tmp1;
for (; tmp2 > 0; tmp2 -= tmp1)
{
*(ptr++) = (tmp3 << (32 - tmp2)) >> tmp4;
}
}
else
{
for (sfb = tmp4; sfb != 0; sfb--)
{
*(ptr++) = 0;
}
}
}
else
{
ptr += tmp4;
}
}
scalefac->l[21] = 0;
scalefac->l[22] = 0;
}
}
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