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view libtwamr/q_gain_c.h @ 477:4c9222d95647

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libtwamr encoder: always emit frame->mode = mode; In the original implementation of amr_encode_frame(), the 'mode' member of the output struct was set to 0xFF if the output frame type is TX_NO_DATA. This design was made to mimic the mode field (16-bit word) being set to 0xFFFF (or -1) in 3GPP test sequence format - but nothing actually depends on this struct member being set in any way, and amr_frame_to_tseq() generates the needed 0xFFFF on its own, based on frame->type being equal to TX_NO_DATA. It is simpler and more efficient to always set frame->mode to the actual encoding mode in amr_encode_frame(), and this new behavior has already been documented in doc/AMR-library-API description in anticipation of the present change.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 18 May 2024 22:30:42 +0000
parents 3a25bdfad0d8
children
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/*
********************************************************************************
*
*      GSM AMR-NB speech codec   R98   Version 7.6.0   December 12, 2001
*                                R99   Version 3.3.0                
*                                REL-4 Version 4.1.0                
*
********************************************************************************
*
*      File             : q_gain_c.h
*      Purpose          : Scalar quantization of the innovative
*                       : codebook gain.
*
********************************************************************************
*/
#ifndef q_gain_c_h
#define q_gain_c_h "$Id $"
 
/*
********************************************************************************
*                         INCLUDE FILES
********************************************************************************
*/
#include "tw_amr.h"
#include "typedef.h"
#include "gc_pred.h"

/*
********************************************************************************
*                         DECLARATION OF PROTOTYPES
********************************************************************************
*/

/*--------------------------------------------------------------------------*
 * Function q_gain_code()                                                   *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~                                  *
 * Scalar quantization of the innovative codebook gain.                     *
 *                                                                          *
 * gc_pred() is used for MA prediction of the innovation energy             *
 *--------------------------------------------------------------------------*/
Word16 q_gain_code (        /* o  : quantization index,            Q0  */
    enum Mode mode,         /* i  : AMR mode                           */
    Word16 exp_gcode0,      /* i  : predicted CB gain (exponent),  Q0  */
    Word16 frac_gcode0,     /* i  : predicted CB gain (fraction),  Q15 */
    Word16 *gain,           /* i/o: quantized fixed codebook gain, Q1  */
    Word16 *qua_ener_MR122, /* o  : quantized energy error,        Q10 */
                            /*      (for MR122 MA predictor update)    */
    Word16 *qua_ener        /* o  : quantized energy error,        Q10 */
                            /*      (for other MA predictor update)    */
);
 
#endif