opus/silk/decode_frame.c

/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, (subject to the limitations in the disclaimer below)
are permitted provided that the following conditions are met:
- Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
- Neither the name of Skype Limited, nor the names of specific
contributors, may be used to endorse or promote products derived from
this software without specific prior written permission.
NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE GRANTED
BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS ''AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "main.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       */
)
{
    silk_decoder_control sDecCtrl;
    opus_int         L, mv_len, ret = 0;
    opus_int         pulses[ MAX_FRAME_LENGTH ];

    L = psDec->frame_length;
    sDecCtrl.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, &sDecCtrl, condCoding );

        /* Update length. Sampling frequency may have changed */
        L = psDec->frame_length;

        /********************************************************/
        /* Run inverse NSQ                                      */
        /********************************************************/
        silk_decode_core( psDec, &sDecCtrl, pOut, pulses );

        /********************************************************/
        /* Update PLC state                                     */
        /********************************************************/
        silk_PLC( psDec, &sDecCtrl, 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, &sDecCtrl, 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, &sDecCtrl, pOut, L );

    /* Update some decoder state variables */
    psDec->lagPrev = sDecCtrl.pitchL[ psDec->nb_subfr - 1 ];

    /* Set output frame length */
    *pN = L;

    return ret;
}