path: root/src_common/SKP_Silk_enc_API.c

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#include "SKP_Silk_define.h"
#include "SKP_Silk_SDK_API.h"
#include "SKP_Silk_control.h"
#include "SKP_Silk_typedef.h"
#include "SKP_Silk_structs.h"
#include "SKP_Silk_tuning_parameters.h"
#if FIXED_POINT
#include "SKP_Silk_main_FIX.h"
#define SKP_Silk_encoder_state_Fxx      SKP_Silk_encoder_state_FIX
#define SKP_Silk_encode_frame_Fxx       SKP_Silk_encode_frame_FIX
#else
#include "SKP_Silk_main_FLP.h"
#define SKP_Silk_encoder_state_Fxx      SKP_Silk_encoder_state_FLP
#define SKP_Silk_encode_frame_Fxx       SKP_Silk_encode_frame_FLP
#endif

/* Encoder Super Struct */
typedef struct {
    SKP_Silk_encoder_state_Fxx          state_Fxx[ ENCODER_NUM_CHANNELS ];
    stereo_state                        sStereo;
    SKP_int32                           nBitsExceeded;
    SKP_int                             nChannels;
    SKP_int                             timeSinceSwitchAllowed_ms;
    SKP_int                             allowBandwidthSwitch;
} SKP_Silk_encoder;

/****************************************/
/* Encoder functions                    */
/****************************************/

SKP_int SKP_Silk_SDK_Get_Encoder_Size( SKP_int32 *encSizeBytes )
{
    SKP_int ret = SKP_SILK_NO_ERROR;
    
    *encSizeBytes = sizeof( SKP_Silk_encoder );
    
    return ret;
}

/*************************/
/* Init or Reset encoder */
/*************************/
SKP_int SKP_Silk_SDK_InitEncoder(
    void                            *encState,          /* I/O: State                                           */
    SKP_SILK_SDK_EncControlStruct   *encStatus          /* O:   Control structure                               */
)
{
    SKP_Silk_encoder *psEnc;
    SKP_int n, ret = SKP_SILK_NO_ERROR;

    psEnc = (SKP_Silk_encoder *)encState;
    
    /* Reset encoder */
    for( n = 0; n < ENCODER_NUM_CHANNELS; n++ ) {
        if( ret += SKP_Silk_init_encoder( &psEnc->state_Fxx[ n ] ) ) {
            SKP_assert( 0 );
        }
    }
    SKP_memset( &psEnc->sStereo, 0, sizeof( psEnc->sStereo ) );

    psEnc->nBitsExceeded = 0;
    psEnc->nChannels = 1;

    /* Read control structure */
    if( ret += SKP_Silk_SDK_QueryEncoder( encState, encStatus ) ) {
        SKP_assert( 0 );
    }

    return ret;
}

/***************************************/
/* Read control structure from encoder */
/***************************************/
SKP_int SKP_Silk_SDK_QueryEncoder(
    const void *encState,                       /* I:   State Vector                                    */
    SKP_SILK_SDK_EncControlStruct *encStatus    /* O:   Control Structure                               */
)
{
    SKP_Silk_encoder_state_Fxx *state_Fxx;
    SKP_int ret = SKP_SILK_NO_ERROR;

    state_Fxx = ((SKP_Silk_encoder *)encState)->state_Fxx;

    encStatus->API_sampleRate            = state_Fxx->sCmn.API_fs_Hz;
    encStatus->maxInternalSampleRate     = state_Fxx->sCmn.maxInternal_fs_Hz;
    encStatus->minInternalSampleRate     = state_Fxx->sCmn.minInternal_fs_Hz;
    encStatus->desiredInternalSampleRate = state_Fxx->sCmn.desiredInternal_fs_Hz;
    encStatus->payloadSize_ms            = state_Fxx->sCmn.PacketSize_ms;
    encStatus->bitRate                   = state_Fxx->sCmn.TargetRate_bps;
    encStatus->packetLossPercentage      = state_Fxx->sCmn.PacketLoss_perc;
    encStatus->complexity                = state_Fxx->sCmn.Complexity;
    encStatus->useInBandFEC              = state_Fxx->sCmn.useInBandFEC;
    encStatus->useDTX                    = state_Fxx->sCmn.useDTX;
    encStatus->useCBR                    = state_Fxx->sCmn.useCBR;
    encStatus->internalSampleRate        = SKP_SMULBB( state_Fxx->sCmn.fs_kHz, 1000 );

    return ret;
}

/**************************/
/* Encode frame with Silk */
/**************************/
SKP_int SKP_Silk_SDK_Encode( 
    void                                *encState,      /* I/O: State                                           */
    SKP_SILK_SDK_EncControlStruct       *encControl,    /* I:   Control structure                               */
    const SKP_int16                     *samplesIn,     /* I:   Speech sample input vector                      */
    SKP_int                             nSamplesIn,     /* I:   Number of samples in input vector               */
    ec_enc                              *psRangeEnc,    /* I/O  Compressor data structure                       */
    SKP_int32                           *nBytesOut,     /* I/O: Number of bytes in payload (input: Max bytes)   */
    const SKP_int                       prefillFlag     /* I:   Flag to indicate prefilling buffers; no coding  */
)
{
    SKP_int   n, i, nBits, flags, tmp_payloadSize_ms, tmp_complexity, MS_predictorIx = 0, ret = 0;
    SKP_int   nSamplesToBuffer, nBlocksOf10ms, nSamplesFromInput = 0;
    SKP_int   speech_act_thr_for_switch_Q8;
    SKP_int32 TargetRate_bps, channelRate_bps, LBRR_symbol;
    SKP_Silk_encoder *psEnc = ( SKP_Silk_encoder * )encState;
    SKP_int16 buf[ MAX_FRAME_LENGTH_MS * MAX_API_FS_KHZ ];

    /* Check values in encoder control structure */
    if( ( ret = check_control_input( encControl ) != 0 ) ) {
        SKP_assert( 0 );
        return ret;
    }

    if( encControl->nChannels > psEnc->nChannels ) {
        /* Mono -> Stereo transition: init state of second channel and stereo state */
        SKP_memset( &psEnc->sStereo, 0, sizeof( psEnc->sStereo ) );
        ret += SKP_Silk_init_encoder( &psEnc->state_Fxx[ 1 ] );
    }
    psEnc->nChannels = encControl->nChannels;

    nBlocksOf10ms = SKP_DIV32( 100 * nSamplesIn, encControl->API_sampleRate );
    if( prefillFlag ) {
        /* Only accept input length of 10 ms */
        if( nBlocksOf10ms != 1 ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return ret;
        }
        /* Reset Encoder */
        for( n = 0; n < encControl->nChannels; n++ ) {
            if( ret = SKP_Silk_init_encoder( &psEnc->state_Fxx[ n ] ) ) {
                SKP_assert( 0 );
            }
        }
        tmp_payloadSize_ms = encControl->payloadSize_ms;
        encControl->payloadSize_ms = 10;
        tmp_complexity = encControl->complexity;
        encControl->complexity = 0;
        for( n = 0; n < encControl->nChannels; n++ ) {
            psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
            psEnc->state_Fxx[ n ].sCmn.prefillFlag = 1;
        }
    } else {
        /* Only accept input lengths that are a multiple of 10 ms */
        if( nBlocksOf10ms * encControl->API_sampleRate != 100 * nSamplesIn || nSamplesIn < 0 ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return ret;
        }
        /* Make sure no more than one packet can be produced */
        if( 1000 * (SKP_int32)nSamplesIn > encControl->payloadSize_ms * encControl->API_sampleRate ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return ret;
        }
    }

    TargetRate_bps = SKP_RSHIFT32( encControl->bitRate, encControl->nChannels - 1 );
    for( n = 0; n < encControl->nChannels; n++ ) {
        if( ( ret = SKP_Silk_control_encoder( &psEnc->state_Fxx[ n ], encControl, TargetRate_bps, psEnc->allowBandwidthSwitch ) ) != 0 ) {
            SKP_assert( 0 );
            return ret;
        }
    }
    SKP_assert( encControl->nChannels == 1 || psEnc->state_Fxx[ 0 ].sCmn.fs_kHz == psEnc->state_Fxx[ 1 ].sCmn.fs_kHz );

    /* Input buffering/resampling and encoding */
    while( 1 ) {
        nSamplesToBuffer  = psEnc->state_Fxx[ 0 ].sCmn.frame_length - psEnc->state_Fxx[ 0 ].sCmn.inputBufIx;
        nSamplesToBuffer  = SKP_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->state_Fxx[ 0 ].sCmn.fs_kHz );
        nSamplesFromInput = SKP_DIV32_16( nSamplesToBuffer * psEnc->state_Fxx[ 0 ].sCmn.API_fs_Hz, psEnc->state_Fxx[ 0 ].sCmn.fs_kHz * 1000 );
        /* Resample and write to buffer */
        if( encControl->nChannels == 2 ) {
            for( n = 0; n < nSamplesFromInput; n++ ) {
                buf[ n ] = samplesIn[ 2 * n ];
            }
            ret += SKP_Silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state, 
                &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx ], buf, nSamplesFromInput );
            psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;

            nSamplesToBuffer  = psEnc->state_Fxx[ 1 ].sCmn.frame_length - psEnc->state_Fxx[ 1 ].sCmn.inputBufIx;
            nSamplesToBuffer  = SKP_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->state_Fxx[ 1 ].sCmn.fs_kHz );
            for( n = 0; n < nSamplesFromInput; n++ ) {
                buf[ n ] = samplesIn[ 2 * n + 1 ];
            }
            ret += SKP_Silk_resampler( &psEnc->state_Fxx[ 1 ].sCmn.resampler_state, 
                &psEnc->state_Fxx[ 1 ].sCmn.inputBuf[ psEnc->state_Fxx[ 1 ].sCmn.inputBufIx ], buf, nSamplesFromInput );
            psEnc->state_Fxx[ 1 ].sCmn.inputBufIx += nSamplesToBuffer;
        } else {
            SKP_assert( encControl->nChannels == 1 );
            ret += SKP_Silk_resampler( &psEnc->state_Fxx[ 0 ].sCmn.resampler_state, 
                &psEnc->state_Fxx[ 0 ].sCmn.inputBuf[ psEnc->state_Fxx[ 0 ].sCmn.inputBufIx ], samplesIn, nSamplesFromInput );
            psEnc->state_Fxx[ 0 ].sCmn.inputBufIx += nSamplesToBuffer;
        }
        samplesIn  += nSamplesFromInput * encControl->nChannels;
        nSamplesIn -= nSamplesFromInput;

        /* Default */
        psEnc->allowBandwidthSwitch = 0;

        /* Silk encoder */
        if( psEnc->state_Fxx[ 0 ].sCmn.inputBufIx >= psEnc->state_Fxx[ 0 ].sCmn.frame_length ) {
            /* Enough data in input buffer, so encode */
            SKP_assert( psEnc->state_Fxx[ 0 ].sCmn.inputBufIx == psEnc->state_Fxx[ 0 ].sCmn.frame_length );
            SKP_assert( encControl->nChannels == 1 || psEnc->state_Fxx[ 1 ].sCmn.inputBufIx == psEnc->state_Fxx[ 1 ].sCmn.frame_length );

            /* Deal with LBRR data */
            if( psEnc->state_Fxx[ 0 ].sCmn.nFramesAnalyzed == 0 && !prefillFlag ) {
                /* Create space at start of payload for VAD and FEC flags */
                SKP_uint8 iCDF[ 2 ] = { 0, 0 };
                iCDF[ 0 ] = 256 - SKP_RSHIFT( 256, ( psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket + 1 ) * encControl->nChannels );
                ec_enc_icdf( psRangeEnc, 0, iCDF, 8 );

                /* Encode any LBRR data from previous packet */
                /* Encode LBRR flags */
                for( n = 0; n < encControl->nChannels; n++ ) {
                    LBRR_symbol = 0;
                    for( i = 0; i < psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket; i++ ) {
                        LBRR_symbol |= SKP_LSHIFT( psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ], i );
                    }
                    psEnc->state_Fxx[ n ].sCmn.LBRR_flag = LBRR_symbol > 0 ? 1 : 0;
                    if( LBRR_symbol && psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket > 1 ) {
                        ec_enc_icdf( psRangeEnc, LBRR_symbol - 1, SKP_Silk_LBRR_flags_iCDF_ptr[ psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket - 2 ], 8 );
                    }
                }

                /* Code LBRR indices and excitation signals */
                for( i = 0; i < psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket; i++ ) {
                    for( n = 0; n < encControl->nChannels; n++ ) {                
                        if( psEnc->state_Fxx[ n ].sCmn.LBRR_flags[ i ] ) {
                            SKP_Silk_encode_indices( &psEnc->state_Fxx[ n ].sCmn, psRangeEnc, i, 1 );
                            SKP_Silk_encode_pulses( psRangeEnc, psEnc->state_Fxx[ n ].sCmn.indices_LBRR[i].signalType, psEnc->state_Fxx[ n ].sCmn.indices_LBRR[i].quantOffsetType, 
                                psEnc->state_Fxx[ n ].sCmn.pulses_LBRR[ i ], psEnc->state_Fxx[ n ].sCmn.frame_length );
                        }
                    }
                }

                /* Reset LBRR flags */
                for( n = 0; n < encControl->nChannels; n++ ) {                
                    SKP_memset( psEnc->state_Fxx[ n ].sCmn.LBRR_flags, 0, sizeof( psEnc->state_Fxx[ n ].sCmn.LBRR_flags ) );
                }
            }

            /* Convert Left/Right to Mid/Side */
            if( encControl->nChannels == 2 ) {
                SKP_Silk_stereo_LR_to_MS( &psEnc->sStereo, psEnc->state_Fxx[ 0 ].sCmn.inputBuf, psEnc->state_Fxx[ 1 ].sCmn.inputBuf, 
                    &MS_predictorIx, psEnc->state_Fxx[ 0 ].sCmn.fs_kHz, psEnc->state_Fxx[ 0 ].sCmn.frame_length );
                ec_enc_icdf( psRangeEnc, MS_predictorIx, SKP_Silk_stereo_predictor_iCDF, 8 );
            }


            /* Total target bits for packet */
            nBits = SKP_DIV32_16( SKP_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 );
            /* Subtract bits already used */
            nBits -= ec_tell( psRangeEnc );
            /* Divide by number of uncoded frames left in packet */
            nBits = SKP_DIV32_16( nBits, psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket - psEnc->state_Fxx[ 0 ].sCmn.nFramesAnalyzed );
            /* Convert to bits/second */
            if( encControl->payloadSize_ms == 10 ) {
                TargetRate_bps = SKP_SMULBB( nBits, 100 );
            } else {
                TargetRate_bps = SKP_SMULBB( nBits, 50 );
            }
            /* Subtract fraction of bits in excess of target in previous packets */
            TargetRate_bps -= SKP_DIV32_16( SKP_MUL( psEnc->nBitsExceeded, 1000 ), BITRESERVOIR_DECAY_TIME_MS );
            /* Don't exceed input bitrate */
            TargetRate_bps = SKP_min( TargetRate_bps, encControl->bitRate );

            /* Encode */
            for( n = 0; n < encControl->nChannels; n++ ) {
                /* For stereo coding, allocate 60% of the bitrate to mid and 40% to side */
                if( encControl->nChannels == 1 ) {
                    channelRate_bps = TargetRate_bps;
                } else if( n == 0 ) {
                    channelRate_bps = SKP_SMULWW( TargetRate_bps, SKP_FIX_CONST( 0.6, 16 ) );
                } else {
                    channelRate_bps = SKP_SMULWB( TargetRate_bps, SKP_FIX_CONST( 0.4, 16 ) );
                }
                SKP_Silk_control_SNR( &psEnc->state_Fxx[ n ].sCmn, channelRate_bps );
                //SKP_Silk_control_SNR( &psEnc->state_Fxx[ n ].sCmn, TargetRate_bps / 2 );
                if( ( ret = SKP_Silk_encode_frame_Fxx( &psEnc->state_Fxx[ n ], nBytesOut, psRangeEnc ) ) != 0 ) {
                    SKP_assert( 0 );
                }
                psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
                psEnc->state_Fxx[ n ].sCmn.inputBufIx = 0;
            }

            /* Insert VAD and FEC flags at beginning of bitstream */
            if( *nBytesOut > 0 ) {
                flags = 0;
                for( n = 0; n < encControl->nChannels; n++ ) {
                    for( i = 0; i < psEnc->state_Fxx[ n ].sCmn.nFramesPerPacket; i++ ) {
                        flags  = SKP_LSHIFT( flags, 1 );
                        flags |= psEnc->state_Fxx[ n ].sCmn.VAD_flags[ i ];
                    }
                    flags  = SKP_LSHIFT( flags, 1 );
                    flags |= psEnc->state_Fxx[ n ].sCmn.LBRR_flag;
                }
                ec_enc_patch_initial_bits( psRangeEnc, flags, ( psEnc->state_Fxx[ 0 ].sCmn.nFramesPerPacket + 1 ) * encControl->nChannels );

                /* Return zero bytes if DTXed */
                if( psEnc->state_Fxx[ 0 ].sCmn.inDTX && ( encControl->nChannels == 1 || psEnc->state_Fxx[ 1 ].sCmn.inDTX ) ) {
                    *nBytesOut = 0;
                }

                psEnc->nBitsExceeded += *nBytesOut * 8;
                psEnc->nBitsExceeded -= SKP_DIV32_16( SKP_MUL( encControl->bitRate, encControl->payloadSize_ms ), 1000 );
                psEnc->nBitsExceeded  = SKP_LIMIT( psEnc->nBitsExceeded, 0, 10000 );

                /* Update flag indicating if bandwidth switching is allowed */
                speech_act_thr_for_switch_Q8 = SKP_SMLAWB( SKP_FIX_CONST( SPEECH_ACTIVITY_DTX_THRES, 8 ), 
                    SKP_FIX_CONST( ( 1 - SPEECH_ACTIVITY_DTX_THRES ) / MAX_BANDWIDTH_SWITCH_DELAY_MS, 16 + 8 ), psEnc->timeSinceSwitchAllowed_ms );
                if( psEnc->state_Fxx[ 0 ].sCmn.speech_activity_Q8 < speech_act_thr_for_switch_Q8 ) {
                    psEnc->allowBandwidthSwitch = 1;
                    psEnc->timeSinceSwitchAllowed_ms = 0;
                } else {
                    psEnc->allowBandwidthSwitch = 0;
                    psEnc->timeSinceSwitchAllowed_ms += encControl->payloadSize_ms;
                }
            }

            if( nSamplesIn == 0 ) {
                break;
            }
        } else {
            break;
        }
    }

    encControl->allowBandwidthSwitch = psEnc->allowBandwidthSwitch;
    encControl->inWBmodeWithoutVariableLP = ( psEnc->state_Fxx[ 0 ].sCmn.fs_kHz == 16 ) && ( psEnc->state_Fxx[ 0 ].sCmn.sLP.mode == 0 );
    encControl->internalSampleRate = SKP_SMULBB( psEnc->state_Fxx[ 0 ].sCmn.fs_kHz, 1000 );
    if( prefillFlag ) {
        encControl->payloadSize_ms = tmp_payloadSize_ms;
        encControl->complexity = tmp_complexity;
        for( n = 0; n < encControl->nChannels; n++ ) {
            psEnc->state_Fxx[ n ].sCmn.controlled_since_last_payload = 0;
            psEnc->state_Fxx[ n ].sCmn.prefillFlag = 0;
        }
    }

    return ret;
}