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    names of specific contributors, may be used to endorse or promote
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//#ifdef HAVE_CONFIG_H
#include "../config.h"
//#endif

#include "main.h"
#include "tuning_parameters.h"

/* Control internal sampling rate */
opus_int silk_control_audio_bandwidth(
    silk_encoder_state          *psEncC,                        /* I/O  Pointer to Silk encoder state               */
    silk_EncControlStruct       *encControl                     /* I    Control structure                           */
) {
    opus_int   fs_kHz;
    opus_int   orig_kHz;
    opus_int32 fs_Hz;

    orig_kHz = psEncC->fs_kHz;
    /* Handle a bandwidth-switching reset where we need to be aware what the last sampling rate was. */
    if (orig_kHz == 0) {
        orig_kHz = psEncC->sLP.saved_fs_kHz;
    }
    fs_kHz = orig_kHz;
    fs_Hz = silk_SMULBB(fs_kHz, 1000);
    if (fs_Hz == 0) {
        /* Encoder has just been initialized */
        fs_Hz  = silk_min(psEncC->desiredInternal_fs_Hz, psEncC->API_fs_Hz);
        fs_kHz = silk_DIV32_16(fs_Hz, 1000);
    } else if (fs_Hz > psEncC->API_fs_Hz || fs_Hz > psEncC->maxInternal_fs_Hz || fs_Hz < psEncC->minInternal_fs_Hz) {
        /* Make sure internal rate is not higher than external rate or maximum allowed, or lower than minimum allowed */
        fs_Hz  = psEncC->API_fs_Hz;
        fs_Hz  = silk_min(fs_Hz, psEncC->maxInternal_fs_Hz);
        fs_Hz  = silk_max(fs_Hz, psEncC->minInternal_fs_Hz);
        fs_kHz = silk_DIV32_16(fs_Hz, 1000);
    } else {
        /* State machine for the internal sampling rate switching */
        if (psEncC->sLP.transition_frame_no >= TRANSITION_FRAMES) {
            /* Stop transition phase */
            psEncC->sLP.mode = 0;
        }
        if (psEncC->allow_bandwidth_switch || encControl->opusCanSwitch) {
            /* Check if we should switch down */
            if (silk_SMULBB(orig_kHz, 1000) > psEncC->desiredInternal_fs_Hz) {
                /* Switch down */
                if (psEncC->sLP.mode == 0) {
                    /* New transition */
                    psEncC->sLP.transition_frame_no = TRANSITION_FRAMES;

                    /* Reset transition filter state */
                    silk_memset(psEncC->sLP.In_LP_State, 0, sizeof(psEncC->sLP.In_LP_State));
                }
                if (encControl->opusCanSwitch) {
                    /* Stop transition phase */
                    psEncC->sLP.mode = 0;

                    /* Switch to a lower sample frequency */
                    fs_kHz = orig_kHz == 16 ? 12 : 8;
                } else {
                    if (psEncC->sLP.transition_frame_no <= 0) {
                        encControl->switchReady = 1;
                        /* Make room for redundancy */
                        encControl->maxBits -= encControl->maxBits * 5 / (encControl->payloadSize_ms + 5);
                    } else {
                        /* Direction: down (at double speed) */
                        psEncC->sLP.mode = -2;
                    }
                }
            } else
                /* Check if we should switch up */
                if (silk_SMULBB(orig_kHz, 1000) < psEncC->desiredInternal_fs_Hz) {
                    /* Switch up */
                    if (encControl->opusCanSwitch) {
                        /* Switch to a higher sample frequency */
                        fs_kHz = orig_kHz == 8 ? 12 : 16;

                        /* New transition */
                        psEncC->sLP.transition_frame_no = 0;

                        /* Reset transition filter state */
                        silk_memset(psEncC->sLP.In_LP_State, 0, sizeof(psEncC->sLP.In_LP_State));

                        /* Direction: up */
                        psEncC->sLP.mode = 1;
                    } else {
                        if (psEncC->sLP.mode == 0) {
                            encControl->switchReady = 1;
                            /* Make room for redundancy */
                            encControl->maxBits -= encControl->maxBits * 5 / (encControl->payloadSize_ms + 5);
                        } else {
                            /* Direction: up */
                            psEncC->sLP.mode = 1;
                        }
                    }
                } else {
                    if (psEncC->sLP.mode < 0) {
                        psEncC->sLP.mode = 1;
                    }
                }
        }
    }

    return fs_kHz;
}
