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 /***********************************************************************

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 ***********************************************************************/

 #ifdef HAVE_CONFIG_H

 #include "config.h"

 #endif

 #include "main.h"

 #include "stack_alloc.h"

 #include "PLC.h"

 /****************/

 /* Decode frame */

 /****************/

 opus_int silk_decode_frame(

     silk_decoder_state          *psDec,                         /* I/O  Pointer to Silk decoder state               */

     ec_dec                      *psRangeDec,                    /* I/O  Compressor data structure                   */

     opus_int16                  pOut[],                         /* O    Pointer to output speech frame              */

     opus_int32                  *pN,                            /* O    Pointer to size of output frame             */

     opus_int                    lostFlag,                       /* I    0: no loss, 1 loss, 2 decode fec            */

     opus_int                    condCoding                      /* I    The type of conditional coding to use       */

 )

 {

     VARDECL( silk_decoder_control, psDecCtrl );

     opus_int         L, mv_len, ret = 0;

     VARDECL( opus_int, pulses );

     SAVE_STACK;

     L = psDec->frame_length;

     ALLOC( psDecCtrl, 1, silk_decoder_control );

     ALLOC( pulses, (L + SHELL_CODEC_FRAME_LENGTH - 1) &

                    ~(SHELL_CODEC_FRAME_LENGTH - 1), opus_int );

     psDecCtrl->LTP_scale_Q14 = 0;

     /* Safety checks */

     silk_assert( L > 0 && L <= MAX_FRAME_LENGTH );

     if(   lostFlag == FLAG_DECODE_NORMAL ||

         ( lostFlag == FLAG_DECODE_LBRR && psDec->LBRR_flags[ psDec->nFramesDecoded ] == 1 ) )

     {

         /*********************************************/

         /* Decode quantization indices of side info  */

         /*********************************************/

         silk_decode_indices( psDec, psRangeDec, psDec->nFramesDecoded, lostFlag, condCoding );

         /*********************************************/

         /* Decode quantization indices of excitation */

         /*********************************************/

         silk_decode_pulses( psRangeDec, pulses, psDec->indices.signalType,

                 psDec->indices.quantOffsetType, psDec->frame_length );

         /********************************************/

         /* Decode parameters and pulse signal       */

         /********************************************/

         silk_decode_parameters( psDec, psDecCtrl, condCoding );

         /********************************************************/

         /* Run inverse NSQ                                      */

         /********************************************************/

         silk_decode_core( psDec, psDecCtrl, pOut, pulses );

         /********************************************************/

         /* Update PLC state                                     */

         /********************************************************/

         silk_PLC( psDec, psDecCtrl, pOut, 0 );

         psDec->lossCnt = 0;

         psDec->prevSignalType = psDec->indices.signalType;

         silk_assert( psDec->prevSignalType >= 0 && psDec->prevSignalType <= 2 );

         /* A frame has been decoded without errors */

         psDec->first_frame_after_reset = 0;

     } else {

         /* Handle packet loss by extrapolation */

         silk_PLC( psDec, psDecCtrl, pOut, 1 );

     }

     /*************************/

     /* Update output buffer. */

     /*************************/

     silk_assert( psDec->ltp_mem_length >= psDec->frame_length );

     mv_len = psDec->ltp_mem_length - psDec->frame_length;

     silk_memmove( psDec->outBuf, &psDec->outBuf[ psDec->frame_length ], mv_len * sizeof(opus_int16) );

     silk_memcpy( &psDec->outBuf[ mv_len ], pOut, psDec->frame_length * sizeof( opus_int16 ) );

     /****************************************************************/

     /* Ensure smooth connection of extrapolated and good frames     */

     /****************************************************************/

     silk_PLC_glue_frames( psDec, pOut, L );

     /************************************************/

     /* Comfort noise generation / estimation        */

     /************************************************/

     silk_CNG( psDec, psDecCtrl, pOut, L );

     /* Update some decoder state variables */

     psDec->lagPrev = psDecCtrl->pitchL[ psDec->nb_subfr - 1 ];

     /* Set output frame length */

     *pN = L;

     RESTORE_STACK;

     return ret;

 }