opus/silk/control_codec.c

/***********************************************************************
Copyright (c) 2006-2011, Skype Limited. All rights reserved.
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modification, are permitted provided that the following conditions
are met:
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names of specific contributors, may be used to endorse or promote
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permission.
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
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***********************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef FIXED_POINT
#include "main_FIX.h"
#define silk_encoder_state_Fxx      silk_encoder_state_FIX
#else
#include "main_FLP.h"
#define silk_encoder_state_Fxx      silk_encoder_state_FLP
#endif
#include "stack_alloc.h"
#include "tuning_parameters.h"
#include "pitch_est_defines.h"

static opus_int silk_setup_resamplers(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                        fs_kHz              /* I                        */
);

static opus_int silk_setup_fs(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                        fs_kHz,             /* I                        */
    opus_int                        PacketSize_ms       /* I                        */
);

static opus_int silk_setup_complexity(
    silk_encoder_state              *psEncC,            /* I/O                      */
    opus_int                        Complexity          /* I                        */
);

static OPUS_INLINE opus_int silk_setup_LBRR(
    silk_encoder_state              *psEncC,            /* I/O                      */
    const opus_int32                TargetRate_bps      /* I                        */
);


/* Control encoder */
opus_int silk_control_encoder(
    silk_encoder_state_Fxx          *psEnc,                                 /* I/O  Pointer to Silk encoder state                                               */
    silk_EncControlStruct           *encControl,                            /* I    Control structure                                                           */
    const opus_int32                TargetRate_bps,                         /* I    Target max bitrate (bps)                                                    */
    const opus_int                  allow_bw_switch,                        /* I    Flag to allow switching audio bandwidth                                     */
    const opus_int                  channelNb,                              /* I    Channel number                                                              */
    const opus_int                  force_fs_kHz
)
{
    opus_int   fs_kHz, ret = 0;

    psEnc->sCmn.useDTX                 = encControl->useDTX;
    psEnc->sCmn.useCBR                 = encControl->useCBR;
    psEnc->sCmn.API_fs_Hz              = encControl->API_sampleRate;
    psEnc->sCmn.maxInternal_fs_Hz      = encControl->maxInternalSampleRate;
    psEnc->sCmn.minInternal_fs_Hz      = encControl->minInternalSampleRate;
    psEnc->sCmn.desiredInternal_fs_Hz  = encControl->desiredInternalSampleRate;
    psEnc->sCmn.useInBandFEC           = encControl->useInBandFEC;
    psEnc->sCmn.nChannelsAPI           = encControl->nChannelsAPI;
    psEnc->sCmn.nChannelsInternal      = encControl->nChannelsInternal;
    psEnc->sCmn.allow_bandwidth_switch = allow_bw_switch;
    psEnc->sCmn.channelNb              = channelNb;

    if( psEnc->sCmn.controlled_since_last_payload != 0 && psEnc->sCmn.prefillFlag == 0 ) {
        if( psEnc->sCmn.API_fs_Hz != psEnc->sCmn.prev_API_fs_Hz && psEnc->sCmn.fs_kHz > 0 ) {
            /* Change in API sampling rate in the middle of encoding a packet */
            ret += silk_setup_resamplers( psEnc, psEnc->sCmn.fs_kHz );
        }
        return ret;
    }

    /* Beyond this point we know that there are no previously coded frames in the payload buffer */

    /********************************************/
    /* Determine internal sampling rate         */
    /********************************************/
    fs_kHz = silk_control_audio_bandwidth( &psEnc->sCmn, encControl );
    if( force_fs_kHz ) {
       fs_kHz = force_fs_kHz;
    }
    /********************************************/
    /* Prepare resampler and buffered data      */
    /********************************************/
    ret += silk_setup_resamplers( psEnc, fs_kHz );

    /********************************************/
    /* Set internal sampling frequency          */
    /********************************************/
    ret += silk_setup_fs( psEnc, fs_kHz, encControl->payloadSize_ms );

    /********************************************/
    /* Set encoding complexity                  */
    /********************************************/
    ret += silk_setup_complexity( &psEnc->sCmn, encControl->complexity  );

    /********************************************/
    /* Set packet loss rate measured by farend  */
    /********************************************/
    psEnc->sCmn.PacketLoss_perc = encControl->packetLossPercentage;

    /********************************************/
    /* Set LBRR usage                           */
    /********************************************/
    ret += silk_setup_LBRR( &psEnc->sCmn, TargetRate_bps );

    psEnc->sCmn.controlled_since_last_payload = 1;

    return ret;
}

static opus_int silk_setup_resamplers(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                         fs_kHz              /* I                        */
)
{
    opus_int   ret = SILK_NO_ERROR;
    SAVE_STACK;

    if( psEnc->sCmn.fs_kHz != fs_kHz || psEnc->sCmn.prev_API_fs_Hz != psEnc->sCmn.API_fs_Hz )
    {
        if( psEnc->sCmn.fs_kHz == 0 ) {
            /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
            ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, fs_kHz * 1000, 1 );
        } else {
            VARDECL( opus_int16, x_buf_API_fs_Hz );
            VARDECL( silk_resampler_state_struct, temp_resampler_state );
#ifdef FIXED_POINT
            opus_int16 *x_bufFIX = psEnc->x_buf;
#else
            VARDECL( opus_int16, x_bufFIX );
            opus_int32 new_buf_samples;
#endif
            opus_int32 api_buf_samples;
            opus_int32 old_buf_samples;
            opus_int32 buf_length_ms;

            buf_length_ms = silk_LSHIFT( psEnc->sCmn.nb_subfr * 5, 1 ) + LA_SHAPE_MS;
            old_buf_samples = buf_length_ms * psEnc->sCmn.fs_kHz;

#ifndef FIXED_POINT
            new_buf_samples = buf_length_ms * fs_kHz;
            ALLOC( x_bufFIX, silk_max( old_buf_samples, new_buf_samples ),
                   opus_int16 );
            silk_float2short_array( x_bufFIX, psEnc->x_buf, old_buf_samples );
#endif

            /* Initialize resampler for temporary resampling of x_buf data to API_fs_Hz */
            ALLOC( temp_resampler_state, 1, silk_resampler_state_struct );
            ret += silk_resampler_init( temp_resampler_state, silk_SMULBB( psEnc->sCmn.fs_kHz, 1000 ), psEnc->sCmn.API_fs_Hz, 0 );

            /* Calculate number of samples to temporarily upsample */
            api_buf_samples = buf_length_ms * silk_DIV32_16( psEnc->sCmn.API_fs_Hz, 1000 );

            /* Temporary resampling of x_buf data to API_fs_Hz */
            ALLOC( x_buf_API_fs_Hz, api_buf_samples, opus_int16 );
            ret += silk_resampler( temp_resampler_state, x_buf_API_fs_Hz, x_bufFIX, old_buf_samples );

            /* Initialize the resampler for enc_API.c preparing resampling from API_fs_Hz to fs_kHz */
            ret += silk_resampler_init( &psEnc->sCmn.resampler_state, psEnc->sCmn.API_fs_Hz, silk_SMULBB( fs_kHz, 1000 ), 1 );

            /* Correct resampler state by resampling buffered data from API_fs_Hz to fs_kHz */
            ret += silk_resampler( &psEnc->sCmn.resampler_state, x_bufFIX, x_buf_API_fs_Hz, api_buf_samples );

#ifndef FIXED_POINT
            silk_short2float_array( psEnc->x_buf, x_bufFIX, new_buf_samples);
#endif
        }
    }

    psEnc->sCmn.prev_API_fs_Hz = psEnc->sCmn.API_fs_Hz;

    RESTORE_STACK;
    return ret;
}

static opus_int silk_setup_fs(
    silk_encoder_state_Fxx          *psEnc,             /* I/O                      */
    opus_int                        fs_kHz,             /* I                        */
    opus_int                        PacketSize_ms       /* I                        */
)
{
    opus_int ret = SILK_NO_ERROR;

    /* Set packet size */
    if( PacketSize_ms != psEnc->sCmn.PacketSize_ms ) {
        if( ( PacketSize_ms !=  10 ) &&
            ( PacketSize_ms !=  20 ) &&
            ( PacketSize_ms !=  40 ) &&
            ( PacketSize_ms !=  60 ) ) {
            ret = SILK_ENC_PACKET_SIZE_NOT_SUPPORTED;
        }
        if( PacketSize_ms <= 10 ) {
            psEnc->sCmn.nFramesPerPacket = 1;
            psEnc->sCmn.nb_subfr = PacketSize_ms == 10 ? 2 : 1;
            psEnc->sCmn.frame_length = silk_SMULBB( PacketSize_ms, fs_kHz );
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
            if( psEnc->sCmn.fs_kHz == 8 ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
            }
        } else {
            psEnc->sCmn.nFramesPerPacket = silk_DIV32_16( PacketSize_ms, MAX_FRAME_LENGTH_MS );
            psEnc->sCmn.nb_subfr = MAX_NB_SUBFR;
            psEnc->sCmn.frame_length = silk_SMULBB( 20, fs_kHz );
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
            if( psEnc->sCmn.fs_kHz == 8 ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF;
            }
        }
        psEnc->sCmn.PacketSize_ms  = PacketSize_ms;
        psEnc->sCmn.TargetRate_bps = 0;         /* trigger new SNR computation */
    }

    /* Set internal sampling frequency */
    silk_assert( fs_kHz == 8 || fs_kHz == 12 || fs_kHz == 16 );
    silk_assert( psEnc->sCmn.nb_subfr == 2 || psEnc->sCmn.nb_subfr == 4 );
    if( psEnc->sCmn.fs_kHz != fs_kHz ) {
        /* reset part of the state */
        silk_memset( &psEnc->sShape,               0, sizeof( psEnc->sShape ) );
        silk_memset( &psEnc->sCmn.sNSQ,            0, sizeof( psEnc->sCmn.sNSQ ) );
        silk_memset( psEnc->sCmn.prev_NLSFq_Q15,   0, sizeof( psEnc->sCmn.prev_NLSFq_Q15 ) );
        silk_memset( &psEnc->sCmn.sLP.In_LP_State, 0, sizeof( psEnc->sCmn.sLP.In_LP_State ) );
        psEnc->sCmn.inputBufIx                  = 0;
        psEnc->sCmn.nFramesEncoded              = 0;
        psEnc->sCmn.TargetRate_bps              = 0;     /* trigger new SNR computation */

        /* Initialize non-zero parameters */
        psEnc->sCmn.prevLag                     = 100;
        psEnc->sCmn.first_frame_after_reset     = 1;
        psEnc->sShape.LastGainIndex             = 10;
        psEnc->sCmn.sNSQ.lagPrev                = 100;
        psEnc->sCmn.sNSQ.prev_gain_Q16          = 65536;
        psEnc->sCmn.prevSignalType              = TYPE_NO_VOICE_ACTIVITY;

        psEnc->sCmn.fs_kHz = fs_kHz;
        if( psEnc->sCmn.fs_kHz == 8 ) {
            if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_NB_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_NB_iCDF;
            }
        } else {
            if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_iCDF;
            } else {
                psEnc->sCmn.pitch_contour_iCDF = silk_pitch_contour_10_ms_iCDF;
            }
        }
        if( psEnc->sCmn.fs_kHz == 8 || psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->sCmn.predictLPCOrder = MIN_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_NB_MB;
        } else {
            psEnc->sCmn.predictLPCOrder = MAX_LPC_ORDER;
            psEnc->sCmn.psNLSF_CB  = &silk_NLSF_CB_WB;
        }
        psEnc->sCmn.subfr_length   = SUB_FRAME_LENGTH_MS * fs_kHz;
        psEnc->sCmn.frame_length   = silk_SMULBB( psEnc->sCmn.subfr_length, psEnc->sCmn.nb_subfr );
        psEnc->sCmn.ltp_mem_length = silk_SMULBB( LTP_MEM_LENGTH_MS, fs_kHz );
        psEnc->sCmn.la_pitch       = silk_SMULBB( LA_PITCH_MS, fs_kHz );
        psEnc->sCmn.max_pitch_lag  = silk_SMULBB( 18, fs_kHz );
        if( psEnc->sCmn.nb_subfr == MAX_NB_SUBFR ) {
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS, fs_kHz );
        } else {
            psEnc->sCmn.pitch_LPC_win_length = silk_SMULBB( FIND_PITCH_LPC_WIN_MS_2_SF, fs_kHz );
        }
        if( psEnc->sCmn.fs_kHz == 16 ) {
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform8_iCDF;
        } else if( psEnc->sCmn.fs_kHz == 12 ) {
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform6_iCDF;
        } else {
            psEnc->sCmn.pitch_lag_low_bits_iCDF = silk_uniform4_iCDF;
        }
    }

    /* Check that settings are valid */
    silk_assert( ( psEnc->sCmn.subfr_length * psEnc->sCmn.nb_subfr ) == psEnc->sCmn.frame_length );

    return ret;
}

static opus_int silk_setup_complexity(
    silk_encoder_state              *psEncC,            /* I/O                      */
    opus_int                        Complexity          /* I                        */
)
{
    opus_int ret = 0;

    /* Set encoding complexity */
    silk_assert( Complexity >= 0 && Complexity <= 10 );
    if( Complexity < 1 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MIN_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.8, 16 );
        psEncC->pitchEstimationLPCOrder         = 6;
        psEncC->shapingLPCOrder                 = 12;
        psEncC->la_shape                        = 3 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 1;
        psEncC->useInterpolatedNLSFs            = 0;
        psEncC->NLSF_MSVQ_Survivors             = 2;
        psEncC->warping_Q16                     = 0;
    } else if( Complexity < 2 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.76, 16 );
        psEncC->pitchEstimationLPCOrder         = 8;
        psEncC->shapingLPCOrder                 = 14;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 1;
        psEncC->useInterpolatedNLSFs            = 0;
        psEncC->NLSF_MSVQ_Survivors             = 3;
        psEncC->warping_Q16                     = 0;
    } else if( Complexity < 3 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MIN_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.8, 16 );
        psEncC->pitchEstimationLPCOrder         = 6;
        psEncC->shapingLPCOrder                 = 12;
        psEncC->la_shape                        = 3 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 2;
        psEncC->useInterpolatedNLSFs            = 0;
        psEncC->NLSF_MSVQ_Survivors             = 2;
        psEncC->warping_Q16                     = 0;
    } else if( Complexity < 4 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.76, 16 );
        psEncC->pitchEstimationLPCOrder         = 8;
        psEncC->shapingLPCOrder                 = 14;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 2;
        psEncC->useInterpolatedNLSFs            = 0;
        psEncC->NLSF_MSVQ_Survivors             = 4;
        psEncC->warping_Q16                     = 0;
    } else if( Complexity < 6 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.74, 16 );
        psEncC->pitchEstimationLPCOrder         = 10;
        psEncC->shapingLPCOrder                 = 16;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 2;
        psEncC->useInterpolatedNLSFs            = 1;
        psEncC->NLSF_MSVQ_Survivors             = 6;
        psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
    } else if( Complexity < 8 ) {
        psEncC->pitchEstimationComplexity       = SILK_PE_MID_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.72, 16 );
        psEncC->pitchEstimationLPCOrder         = 12;
        psEncC->shapingLPCOrder                 = 20;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = 3;
        psEncC->useInterpolatedNLSFs            = 1;
        psEncC->NLSF_MSVQ_Survivors             = 8;
        psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
    } else {
        psEncC->pitchEstimationComplexity       = SILK_PE_MAX_COMPLEX;
        psEncC->pitchEstimationThreshold_Q16    = SILK_FIX_CONST( 0.7, 16 );
        psEncC->pitchEstimationLPCOrder         = 16;
        psEncC->shapingLPCOrder                 = 24;
        psEncC->la_shape                        = 5 * psEncC->fs_kHz;
        psEncC->nStatesDelayedDecision          = MAX_DEL_DEC_STATES;
        psEncC->useInterpolatedNLSFs            = 1;
        psEncC->NLSF_MSVQ_Survivors             = 16;
        psEncC->warping_Q16                     = psEncC->fs_kHz * SILK_FIX_CONST( WARPING_MULTIPLIER, 16 );
    }

    /* Do not allow higher pitch estimation LPC order than predict LPC order */
    psEncC->pitchEstimationLPCOrder = silk_min_int( psEncC->pitchEstimationLPCOrder, psEncC->predictLPCOrder );
    psEncC->shapeWinLength          = SUB_FRAME_LENGTH_MS * psEncC->fs_kHz + 2 * psEncC->la_shape;
    psEncC->Complexity              = Complexity;

    silk_assert( psEncC->pitchEstimationLPCOrder <= MAX_FIND_PITCH_LPC_ORDER );
    silk_assert( psEncC->shapingLPCOrder         <= MAX_SHAPE_LPC_ORDER      );
    silk_assert( psEncC->nStatesDelayedDecision  <= MAX_DEL_DEC_STATES       );
    silk_assert( psEncC->warping_Q16             <= 32767                    );
    silk_assert( psEncC->la_shape                <= LA_SHAPE_MAX             );
    silk_assert( psEncC->shapeWinLength          <= SHAPE_LPC_WIN_MAX        );

    return ret;
}

static OPUS_INLINE opus_int silk_setup_LBRR(
    silk_encoder_state          *psEncC,            /* I/O                      */
    const opus_int32            TargetRate_bps      /* I                        */
)
{
    opus_int   LBRR_in_previous_packet, ret = SILK_NO_ERROR;
    opus_int32 LBRR_rate_thres_bps;

    LBRR_in_previous_packet = psEncC->LBRR_enabled;
    psEncC->LBRR_enabled = 0;
    if( psEncC->useInBandFEC && psEncC->PacketLoss_perc > 0 ) {
        if( psEncC->fs_kHz == 8 ) {
            LBRR_rate_thres_bps = LBRR_NB_MIN_RATE_BPS;
        } else if( psEncC->fs_kHz == 12 ) {
            LBRR_rate_thres_bps = LBRR_MB_MIN_RATE_BPS;
        } else {
            LBRR_rate_thres_bps = LBRR_WB_MIN_RATE_BPS;
        }
        LBRR_rate_thres_bps = silk_SMULWB( silk_MUL( LBRR_rate_thres_bps, 125 - silk_min( psEncC->PacketLoss_perc, 25 ) ), SILK_FIX_CONST( 0.01, 16 ) );

        if( TargetRate_bps > LBRR_rate_thres_bps ) {
            /* Set gain increase for coding LBRR excitation */
            if( LBRR_in_previous_packet == 0 ) {
                /* Previous packet did not have LBRR, and was therefore coded at a higher bitrate */
                psEncC->LBRR_GainIncreases = 7;
            } else {
                psEncC->LBRR_GainIncreases = silk_max_int( 7 - silk_SMULWB( (opus_int32)psEncC->PacketLoss_perc, SILK_FIX_CONST( 0.4, 16 ) ), 2 );
            }
            psEncC->LBRR_enabled = 1;
        }
    }

    return ret;
}