media/libstagefright/codecs/aacdec/pulse_nc.cpp - third_party/android/platform/frameworks/av - Git at Google

 /* ------------------------------------------------------------------
  * 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: pulse_nc.c

 ------------------------------------------------------------------------------
  REVISION HISTORY

  Description:  Modified from original shareware code

  Description:  Modified to pass variables by reference to eliminate use
                of global variables.

  Description:  Modified to bring code in-line with PV standards.

  Description: Pass in max as input argument.

  Description: Went back to the if-statement to check for max.

  Who:                       Date:
  Description:

 ------------------------------------------------------------------------------
  INPUT AND OUTPUT DEFINITIONS

  Inputs:
     coef[]         =  Array of quantized spectral coefficents.
                       (Int [])

     pPulseInfo     =  Pointer to structure which contains noiseless
                       encoding info, includes information about the pulse data,
                       pulse amplitude, etc.
                       (const PulseInfo *)

     pLongFrameInfo =  Pointer to structure that holds information about
                       each group. (long block flag, number of windows,
                       scalefactor bands per group, etc.)

                       Variable is named (pLongFrameInfo) because this function
                       is only used for LONG windows.
                       (FrameInfo *)
     max             = Pointer to the maximum value of coef[]

  Local Stores/Buffers/Pointers Needed:
     None

  Global Stores/Buffers/Pointers Needed:
     None

  Outputs:
     None

  Pointers and Buffers Modified:
     coef[]  =  coefficient contents are modified by the encoded pulse

  Local Stores Modified:

  Global Stores Modified:

 ------------------------------------------------------------------------------
  FUNCTION DESCRIPTION

  This function adds pulses to defined ranges of coefficients in the window,
  for the case of LONG windows.  The pulses are unsigned, so
  negative coefficients subtract the pulse, and positive coefficients add it.
  (The ampltiude of the coefficient is always increased by the pulse)

  A maximum of 4 coefficients may be modified by a pulse, and these
  coefficients must all occur in the same scalefactor band.

  The number of pulse-encoded coefficients to be processed by this function
  is communicated to this function via pPulseInfo->number_pulse

  This value is equal to the actual number of pulses - 1.
  (e.g if pPulseInfo->number_pulse == 0, one pulse is assumed)
  This function must not be called if no pulse encoded data exists.
  The function assumes that at least one pulse exists.
 ------------------------------------------------------------------------------
  REQUIREMENTS

  This module shall correctly add transmitted pulse(s) to the correct
  coefficients in a LONG window.

 ------------------------------------------------------------------------------
  REFERENCES
  (1) ISO/IEC 14496-3:1999(E)
      Part 3
         Subpart 4.6.3.3 Decoding Process

  (2) 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.

 ------------------------------------------------------------------------------
  PSEUDO-CODE

     index = pLongFrameInfo->win_sfb_top[0][pPulseInfo->pulse_start_sfb];

     pPulseOffset = &(pPulseInfo->pulse_offset[0]);

     pPulseAmp    = &(pPulseInfo->pulse_amp[0]);

     pCoef        = &(Coef[index]);

     FOR (index = pPulseInfo->number_pulse; index >= 0; index--)

         pCoef   = pCoef + *(pPulseOffset);
         pPulseOffset = pPulseOffset + 1;

         IF (*pCoef > 0)
             *(pCoef) = *(pCoef) + *(pPulseAmp);
             pPulseAmp     = pPulseAmp + 1;
         ELSE
             *(pCoef) = *(pCoef) - *(pPulseAmp);
             pPulseAmp     = pPulseAmp + 1;
         ENDIF

     ENDFOR

 ------------------------------------------------------------------------------
  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 "s_frameinfo.h"
 #include "s_pulseinfo.h"
 #include "pulse_nc.h"

 /*----------------------------------------------------------------------------
 ; MACROS
 ; Define module specific macros here
 ----------------------------------------------------------------------------*/

 /*---------------------------------------------------------------------------
 ; DEFINES
 ; Include all pre-processor statements here. Include conditional
 ; compile variables also.
 ----------------------------------------------------------------------------*/

 /*----------------------------------------------------------------------------
 ; LOCAL FUNCTION DEFINITIONS
 ; Function Prototype declaration
 ----------------------------------------------------------------------------*/

 /*----------------------------------------------------------------------------
 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
 ; Variable declaration - defined here and used outside this module
 ----------------------------------------------------------------------------*/

 /*----------------------------------------------------------------------------
 ; 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 pulse_nc(
     Int16      coef[],
     const PulseInfo  *pPulseInfo,
     const FrameInfo  *pLongFrameInfo,
     Int      *max)
 {
     Int index;

     Int16 *pCoef;
     Int temp;

     const Int *pPulseOffset;
     const Int *pPulseAmp;

     /*--- Find the scalefactor band where pulse-encoded data starts ---*/

     if (pPulseInfo->pulse_start_sfb > 0)
     {
         index = pLongFrameInfo->win_sfb_top[0][pPulseInfo->pulse_start_sfb - 1];
     }
     else
     {
         index = 0;
     }

     /*-------------------------------------------------------------------------
       Each pulse index is stored as an offset from the previous pulse

       Example - here we have a sfb that is 20 coefficients in length:

       [0][1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]
       [ ][ ][ ][ ][ ][P][P][ ][ ][ ][  ][  ][  ][  ][  ][ P][  ][  ][  ][ P]

       The array pointed to by pPulseOffset == [5][1][9][4]

       pPulseAmp is of the same length as pPulseOffset, and contains
       an individual pulse amplitude for each coefficient.
     --------------------------------------------------------------------------*/

     pCoef        = &(coef[index]);

     pPulseOffset = &(pPulseInfo->pulse_offset[0]);

     pPulseAmp    = &(pPulseInfo->pulse_amp[0]);

     for (index = pPulseInfo->number_pulse; index > 0; index--)
     {
         pCoef  += *pPulseOffset++;

         temp = *pCoef;

         if (temp > 0)
         {
             temp += *(pPulseAmp++);
             *pCoef = (Int16)temp;
             if (temp > *max)
             {
                 *max = temp;
             }
         }
         else
         {
             temp -= *(pPulseAmp++);
             *pCoef = (Int16)temp;
             if (-temp > *max)
             {
                 *max = -temp;
             }
         }

     } /* for() */

     return;

 } /* pulse_nc */
	/* ------------------------------------------------------------------
	* 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: pulse_nc.c

	------------------------------------------------------------------------------
	REVISION HISTORY

	Description: Modified from original shareware code

	Description: Modified to pass variables by reference to eliminate use
	of global variables.

	Description: Modified to bring code in-line with PV standards.

	Description: Pass in max as input argument.

	Description: Went back to the if-statement to check for max.

	Who: Date:
	Description:

	------------------------------------------------------------------------------
	INPUT AND OUTPUT DEFINITIONS

	Inputs:
	coef[] = Array of quantized spectral coefficents.
	(Int [])

	pPulseInfo = Pointer to structure which contains noiseless
	encoding info, includes information about the pulse data,
	pulse amplitude, etc.
	(const PulseInfo *)

	pLongFrameInfo = Pointer to structure that holds information about
	each group. (long block flag, number of windows,
	scalefactor bands per group, etc.)

	Variable is named (pLongFrameInfo) because this function
	is only used for LONG windows.
	(FrameInfo *)
	max = Pointer to the maximum value of coef[]

	Local Stores/Buffers/Pointers Needed:
	None

	Global Stores/Buffers/Pointers Needed:
	None

	Outputs:
	None

	Pointers and Buffers Modified:
	coef[] = coefficient contents are modified by the encoded pulse

	Local Stores Modified:

	Global Stores Modified:

	------------------------------------------------------------------------------
	FUNCTION DESCRIPTION

	This function adds pulses to defined ranges of coefficients in the window,
	for the case of LONG windows. The pulses are unsigned, so
	negative coefficients subtract the pulse, and positive coefficients add it.
	(The ampltiude of the coefficient is always increased by the pulse)

	A maximum of 4 coefficients may be modified by a pulse, and these
	coefficients must all occur in the same scalefactor band.

	The number of pulse-encoded coefficients to be processed by this function
	is communicated to this function via pPulseInfo->number_pulse

	This value is equal to the actual number of pulses - 1.
	(e.g if pPulseInfo->number_pulse == 0, one pulse is assumed)
	This function must not be called if no pulse encoded data exists.
	The function assumes that at least one pulse exists.
	------------------------------------------------------------------------------
	REQUIREMENTS

	This module shall correctly add transmitted pulse(s) to the correct
	coefficients in a LONG window.

	------------------------------------------------------------------------------
	REFERENCES
	(1) ISO/IEC 14496-3:1999(E)
	Part 3
	Subpart 4.6.3.3 Decoding Process

	(2) 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.

	------------------------------------------------------------------------------
	PSEUDO-CODE

	index = pLongFrameInfo->win_sfb_top[0][pPulseInfo->pulse_start_sfb];

	pPulseOffset = &(pPulseInfo->pulse_offset[0]);

	pPulseAmp = &(pPulseInfo->pulse_amp[0]);

	pCoef = &(Coef[index]);

	FOR (index = pPulseInfo->number_pulse; index >= 0; index--)

	pCoef = pCoef + *(pPulseOffset);
	pPulseOffset = pPulseOffset + 1;

	IF (*pCoef > 0)
	(pCoef) = (pCoef) + *(pPulseAmp);
	pPulseAmp = pPulseAmp + 1;
	ELSE
	(pCoef) = (pCoef) - *(pPulseAmp);
	pPulseAmp = pPulseAmp + 1;
	ENDIF

	ENDFOR

	------------------------------------------------------------------------------
	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 "s_frameinfo.h"
	#include "s_pulseinfo.h"
	#include "pulse_nc.h"

	/*----------------------------------------------------------------------------
	; MACROS
	; Define module specific macros here
	----------------------------------------------------------------------------*/

	/*---------------------------------------------------------------------------
	; DEFINES
	; Include all pre-processor statements here. Include conditional
	; compile variables also.
	----------------------------------------------------------------------------*/

	/*----------------------------------------------------------------------------
	; LOCAL FUNCTION DEFINITIONS
	; Function Prototype declaration
	----------------------------------------------------------------------------*/

	/*----------------------------------------------------------------------------
	; LOCAL STORE/BUFFER/POINTER DEFINITIONS
	; Variable declaration - defined here and used outside this module
	----------------------------------------------------------------------------*/

	/*----------------------------------------------------------------------------
	; 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 pulse_nc(
	Int16 coef[],
	const PulseInfo *pPulseInfo,
	const FrameInfo *pLongFrameInfo,
	Int *max)
	{
	Int index;

	Int16 *pCoef;
	Int temp;

	const Int *pPulseOffset;
	const Int *pPulseAmp;

	/--- Find the scalefactor band where pulse-encoded data starts ---/

	if (pPulseInfo->pulse_start_sfb > 0)
	{
	index = pLongFrameInfo->win_sfb_top[0][pPulseInfo->pulse_start_sfb - 1];
	}
	else
	{
	index = 0;
	}

	/*-------------------------------------------------------------------------
	Each pulse index is stored as an offset from the previous pulse

	Example - here we have a sfb that is 20 coefficients in length:

	[0][1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]
	[ ][ ][ ][ ][ ][P][P][ ][ ][ ][ ][ ][ ][ ][ ][ P][ ][ ][ ][ P]

	The array pointed to by pPulseOffset == [5][1][9][4]

	pPulseAmp is of the same length as pPulseOffset, and contains
	an individual pulse amplitude for each coefficient.
	--------------------------------------------------------------------------*/

	pCoef = &(coef[index]);

	pPulseOffset = &(pPulseInfo->pulse_offset[0]);

	pPulseAmp = &(pPulseInfo->pulse_amp[0]);

	for (index = pPulseInfo->number_pulse; index > 0; index--)
	{
	pCoef += *pPulseOffset++;

	temp = *pCoef;

	if (temp > 0)
	{
	temp += *(pPulseAmp++);
	*pCoef = (Int16)temp;
	if (temp > *max)
	{
	*max = temp;
	}
	}
	else
	{
	temp -= *(pPulseAmp++);
	*pCoef = (Int16)temp;
	if (-temp > *max)
	{
	*max = -temp;
	}
	}

	} /* for() */

	return;

	} /* pulse_nc */