media/libstagefright/codecs/aacdec/sbr_get_header_data.cpp

/* ------------------------------------------------------------------
 * 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.
 * -------------------------------------------------------------------
 */
/*

 Filename: sbr_get_header_data.c

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


 Who:                                   Date: MM/DD/YYYY
 Description:

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

 Arguments:     h_sbr_header - handle to struct SBR_HEADER_DATA
                hBitBuf      - handle to struct BIT_BUFFER
                id_sbr       - SBR_ELEMENT_ID

 Return:        error status - 0 if ok


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

    Reads header data from bitstream

------------------------------------------------------------------------------
 REQUIREMENTS


------------------------------------------------------------------------------
 REFERENCES

SC 29 Software Copyright Licencing Disclaimer:

This software module was originally developed by
  Coding Technologies

and edited by
  -

in the course of development of the ISO/IEC 13818-7 and ISO/IEC 14496-3
standards for reference purposes and its performance may not have been
optimized. This software module is an implementation of one or more tools as
specified by the ISO/IEC 13818-7 and ISO/IEC 14496-3 standards.
ISO/IEC gives users free license to this software module or modifications
thereof for use in products claiming conformance to audiovisual and
image-coding related ITU Recommendations and/or ISO/IEC International
Standards. ISO/IEC gives users the same free license to this software module or
modifications thereof for research purposes and further ISO/IEC standardisation.
Those intending to use this software module in products are advised that its
use may infringe existing patents. ISO/IEC have no liability for use of this
software module or modifications thereof. Copyright is not released for
products that do not conform to audiovisual and image-coding related ITU
Recommendations and/or ISO/IEC International Standards.
The original developer retains full right to modify and use the code for its
own purpose, assign or donate the code to a third party and to inhibit third
parties from using the code for products that do not conform to audiovisual and
image-coding related ITU Recommendations and/or ISO/IEC International Standards.
This copyright notice must be included in all copies or derivative works.
Copyright (c) ISO/IEC 2002.

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

------------------------------------------------------------------------------
*/


/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/

#ifdef AAC_PLUS


#include    "sbr_get_header_data.h"
#include    "sbr_constants.h"
#include    "buf_getbits.h"
#include    "aac_mem_funcs.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
----------------------------------------------------------------------------*/

SBR_HEADER_STATUS sbr_get_header_data(SBR_HEADER_DATA   * h_sbr_header,
                                      BIT_BUFFER          * hBitBuf,
                                      SBR_SYNC_STATE     syncState)
{
    SBR_HEADER_DATA lastHeader;
    Int32 headerExtra1, headerExtra2;


    /* Copy header to temporary header */
    if (syncState == SBR_ACTIVE)
    {
        pv_memcpy(&lastHeader, h_sbr_header, sizeof(SBR_HEADER_DATA));
    }
    else
    {
        pv_memset((void *)&lastHeader, 0, sizeof(SBR_HEADER_DATA));
    }


    /* Read new header from bitstream */
    h_sbr_header->ampResolution   = buf_getbits(hBitBuf, SI_SBR_AMP_RES_BITS);
    h_sbr_header->startFreq       = buf_getbits(hBitBuf, SI_SBR_START_FREQ_BITS);
    h_sbr_header->stopFreq        = buf_getbits(hBitBuf, SI_SBR_STOP_FREQ_BITS);
    h_sbr_header->xover_band      = buf_getbits(hBitBuf, SI_SBR_XOVER_BAND_BITS);

    buf_getbits(hBitBuf, SI_SBR_RESERVED_BITS_HDR);

    headerExtra1    = buf_getbits(hBitBuf, SI_SBR_HEADER_EXTRA_1_BITS);
    headerExtra2    = buf_getbits(hBitBuf, SI_SBR_HEADER_EXTRA_2_BITS);

    /* handle extra header information */
    if (headerExtra1)
    {
        h_sbr_header->freqScale   = buf_getbits(hBitBuf, SI_SBR_FREQ_SCALE_BITS);
        h_sbr_header->alterScale  = buf_getbits(hBitBuf, SI_SBR_ALTER_SCALE_BITS);
        h_sbr_header->noise_bands = buf_getbits(hBitBuf, SI_SBR_NOISE_BANDS_BITS);
    }
    else
    { /* Set default values.*/
        h_sbr_header->freqScale   = SBR_FREQ_SCALE_DEFAULT;
        h_sbr_header->alterScale  = SBR_ALTER_SCALE_DEFAULT;
        h_sbr_header->noise_bands = SBR_NOISE_BANDS_DEFAULT;
    }


    if (headerExtra2)
    {
        h_sbr_header->limiterBands    = buf_getbits(hBitBuf, SI_SBR_LIMITER_BANDS_BITS);
        h_sbr_header->limiterGains    = buf_getbits(hBitBuf, SI_SBR_LIMITER_GAINS_BITS);
        h_sbr_header->interpolFreq    = buf_getbits(hBitBuf, SI_SBR_INTERPOL_FREQ_BITS);
        h_sbr_header->smoothingLength = buf_getbits(hBitBuf, SI_SBR_SMOOTHING_LENGTH_BITS);
    }
    else
    { /* Set default values.*/
        h_sbr_header->limiterBands    = SBR_LIMITER_BANDS_DEFAULT;
        h_sbr_header->limiterGains    = SBR_LIMITER_GAINS_DEFAULT;
        h_sbr_header->interpolFreq    = SBR_INTERPOL_FREQ_DEFAULT;
        h_sbr_header->smoothingLength = SBR_SMOOTHING_LENGTH_DEFAULT;
    }

    if (syncState == SBR_ACTIVE)
    {
        h_sbr_header->status = HEADER_OK;

        /* look for new settings */
        if (lastHeader.startFreq   != h_sbr_header->startFreq   ||
                lastHeader.stopFreq    != h_sbr_header->stopFreq    ||
                lastHeader.xover_band  != h_sbr_header->xover_band  ||
                lastHeader.freqScale   != h_sbr_header->freqScale   ||
                lastHeader.alterScale  != h_sbr_header->alterScale  ||
                lastHeader.noise_bands != h_sbr_header->noise_bands)
        {
            h_sbr_header->status = HEADER_RESET;
        }
    }
    else
    {
        h_sbr_header->status = HEADER_RESET;
    }

    return h_sbr_header->status;
}

#endif