Exemplo n.º 1
0
/* Decode a frame */
SKP_int SKP_Silk_SDK_Decode(
    void*                               decState,       /* I/O: State                                           */
    SKP_SILK_SDK_DecControlStruct*      decControl,     /* I/O: Control structure                               */
    SKP_int                             lostFlag,       /* I:   0: no loss, 1 loss                              */
    const SKP_uint8                     *inData,        /* I:   Encoded input vector                            */
    const SKP_int                       nBytesIn,       /* I:   Number of input Bytes                           */
    SKP_int16                           *samplesOut,    /* O:   Decoded output speech vector                    */
    SKP_int16                           *nSamplesOut    /* I/O: Number of samples (vector/decoded)              */
)
{
    SKP_int ret = 0, used_bytes, prev_fs_kHz;
    SKP_Silk_decoder_state *psDec;
    SKP_int16 samplesOutInternal[ MAX_API_FS_KHZ * FRAME_LENGTH_MS ];
    SKP_int16 *pSamplesOutInternal;

    psDec = (SKP_Silk_decoder_state *)decState;

    /* We need this buffer to have room for an internal frame */
    pSamplesOutInternal = samplesOut;
    if( psDec->fs_kHz * 1000 > decControl->API_sampleRate ) {
        pSamplesOutInternal = samplesOutInternal;
    }

    /**********************************/
    /* Test if first frame in payload */
    /**********************************/
    if( psDec->moreInternalDecoderFrames == 0 ) {
        /* First Frame in Payload */
        psDec->nFramesDecoded = 0;  /* Used to count frames in packet */
    }

    if( psDec->moreInternalDecoderFrames == 0 &&    /* First frame in packet    */
        lostFlag == 0 &&                            /* Not packet loss          */
        nBytesIn > MAX_ARITHM_BYTES ) {             /* Too long payload         */
            /* Avoid trying to decode a too large packet */
            lostFlag = 1;
            ret = SKP_SILK_DEC_PAYLOAD_TOO_LARGE;
    }
            
    /* Save previous sample frequency */
    prev_fs_kHz = psDec->fs_kHz;
    
    /* Call decoder for one frame */
    ret += SKP_Silk_decode_frame( psDec, pSamplesOutInternal, nSamplesOut, inData, nBytesIn, 
            lostFlag, &used_bytes );
    
    if( used_bytes ) { /* Only Call if not a packet loss */
        if( psDec->nBytesLeft > 0 && psDec->FrameTermination == SKP_SILK_MORE_FRAMES && psDec->nFramesDecoded < 5 ) {
            /* We have more frames in the Payload */
            psDec->moreInternalDecoderFrames = 1;
        } else {
            /* Last frame in Payload */
            psDec->moreInternalDecoderFrames = 0;
            psDec->nFramesInPacket = psDec->nFramesDecoded;
        
            /* Track inband FEC usage */
            if( psDec->vadFlag == VOICE_ACTIVITY ) {
                if( psDec->FrameTermination == SKP_SILK_LAST_FRAME ) {
                    psDec->no_FEC_counter++;
                    if( psDec->no_FEC_counter > NO_LBRR_THRES ) {
                        psDec->inband_FEC_offset = 0;
                    }
                } else if( psDec->FrameTermination == SKP_SILK_LBRR_VER1 ) {
                    psDec->inband_FEC_offset = 1; /* FEC info with 1 packet delay */
                    psDec->no_FEC_counter    = 0;
                } else if( psDec->FrameTermination == SKP_SILK_LBRR_VER2 ) {
                    psDec->inband_FEC_offset = 2; /* FEC info with 2 packets delay */
                    psDec->no_FEC_counter    = 0;
                }
            }
        }
    }

    if( MAX_API_FS_KHZ * 1000 < decControl->API_sampleRate ||
        8000       > decControl->API_sampleRate ) {
        ret = SKP_SILK_DEC_INVALID_SAMPLING_FREQUENCY;
        return( ret );
    }

    /* Resample if needed */
    if( psDec->fs_kHz * 1000 != decControl->API_sampleRate ) { 
        SKP_int16 samplesOut_tmp[ MAX_API_FS_KHZ * FRAME_LENGTH_MS ];
        SKP_assert( psDec->fs_kHz <= MAX_API_FS_KHZ );

        /* Copy to a tmp buffer as the resampling writes to samplesOut */
        SKP_memcpy( samplesOut_tmp, pSamplesOutInternal, *nSamplesOut * sizeof( SKP_int16 ) );

        /* (Re-)initialize resampler state when switching internal sampling frequency */
        if( prev_fs_kHz != psDec->fs_kHz || psDec->prev_API_sampleRate != decControl->API_sampleRate ) {
            ret = SKP_Silk_resampler_init( &psDec->resampler_state, SKP_SMULBB( psDec->fs_kHz, 1000 ), decControl->API_sampleRate );
        }

        /* Resample the output to API_sampleRate */
        ret += SKP_Silk_resampler( &psDec->resampler_state, samplesOut, samplesOut_tmp, *nSamplesOut );

        /* Update the number of output samples */
        *nSamplesOut = SKP_DIV32( ( SKP_int32 )*nSamplesOut * decControl->API_sampleRate, psDec->fs_kHz * 1000 );
    } else if( prev_fs_kHz * 1000 > decControl->API_sampleRate ) { 
        SKP_memcpy( samplesOut, pSamplesOutInternal, *nSamplesOut * sizeof( SKP_int16 ) );
    }

    psDec->prev_API_sampleRate = decControl->API_sampleRate;

    /* Copy all parameters that are needed out of internal structure to the control stucture */
    decControl->frameSize                 = (SKP_uint16)( decControl->API_sampleRate / 50 ) ;
    decControl->framesPerPacket           = ( SKP_int )psDec->nFramesInPacket;
    decControl->inBandFECOffset           = ( SKP_int )psDec->inband_FEC_offset;
    decControl->moreInternalDecoderFrames = ( SKP_int )psDec->moreInternalDecoderFrames;

    return ret;
}
Exemplo n.º 2
0
SKP_int SKP_Silk_SDK_Encode( 
    void                                *encState,      /* I/O: State                                           */
    SKP_Silk_EncodeControlStruct        *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   tmp_payloadSize_ms, tmp_complexity, ret = 0;
    SKP_int   nSamplesToBuffer, nBlocksOf10ms, nSamplesFromInput = 0;
    SKP_Silk_encoder_state_Fxx *psEnc = ( SKP_Silk_encoder_state_Fxx* )encState;

    ret = process_enc_control_struct( psEnc, encControl );

    nBlocksOf10ms = SKP_DIV32( 100 * nSamplesIn, psEnc->sCmn.API_fs_Hz );
    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 */
        if( ret = SKP_Silk_init_encoder_Fxx( psEnc ) ) {
            SKP_assert( 0 );
        }
        tmp_payloadSize_ms = encControl->payloadSize_ms;
        encControl->payloadSize_ms = 10;
        tmp_complexity = encControl->complexity;
        encControl->complexity = 0;
        ret = process_enc_control_struct( psEnc, encControl );
        psEnc->sCmn.prefillFlag = 1;
    } else {
        /* Only accept input lengths that are a multiple of 10 ms */
        if( nBlocksOf10ms * psEnc->sCmn.API_fs_Hz != 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 > psEnc->sCmn.PacketSize_ms * psEnc->sCmn.API_fs_Hz ) {
            ret = SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES;
            SKP_assert( 0 );
            return( ret );
        }
    }

    /* Input buffering/resampling and encoding */
    while( 1 ) {
        nSamplesToBuffer = psEnc->sCmn.frame_length - psEnc->sCmn.inputBufIx;
        if( psEnc->sCmn.API_fs_Hz == SKP_SMULBB( 1000, psEnc->sCmn.fs_kHz ) ) { 
            nSamplesToBuffer  = SKP_min_int( nSamplesToBuffer, nSamplesIn );
            nSamplesFromInput = nSamplesToBuffer;
            /* Copy to buffer */
            SKP_memcpy( &psEnc->sCmn.inputBuf[ psEnc->sCmn.inputBufIx ], samplesIn, nSamplesFromInput * sizeof( SKP_int16 ) );
        } else {  
            nSamplesToBuffer  = SKP_min( nSamplesToBuffer, 10 * nBlocksOf10ms * psEnc->sCmn.fs_kHz );
            nSamplesFromInput = SKP_DIV32_16( nSamplesToBuffer * psEnc->sCmn.API_fs_Hz, psEnc->sCmn.fs_kHz * 1000 );
            /* Resample and write to buffer */
            ret += SKP_Silk_resampler( &psEnc->sCmn.resampler_state, &psEnc->sCmn.inputBuf[ psEnc->sCmn.inputBufIx ], samplesIn, nSamplesFromInput );
        } 
        samplesIn              += nSamplesFromInput;
        nSamplesIn             -= nSamplesFromInput;
        psEnc->sCmn.inputBufIx += nSamplesToBuffer;

        /* Silk encoder */
        if( psEnc->sCmn.inputBufIx >= psEnc->sCmn.frame_length ) {
            SKP_assert( psEnc->sCmn.inputBufIx == psEnc->sCmn.frame_length );

            /* Enough data in input buffer, so encode */
            if( ( ret = SKP_Silk_encode_frame_Fxx( psEnc, nBytesOut, psRangeEnc ) ) != 0 ) {
                SKP_assert( 0 );
            }
            psEnc->sCmn.inputBufIx = 0;
            psEnc->sCmn.controlled_since_last_payload = 0;

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

    if( prefillFlag ) {
        encControl->payloadSize_ms = tmp_payloadSize_ms;
        encControl->complexity = tmp_complexity;
        ret = process_enc_control_struct( psEnc, encControl );
        psEnc->sCmn.prefillFlag = 0;
    }

    return ret;
}