codec2_talkie/libcodec2-android/src/main/cpp/Codec2JNI.cpp

#include <jni.h>
#include <cstdlib>
#include "codec2/codec2_fdmdv.h"
#include "codec2/codec2.h"
#include "codec2/fsk.h"
#include "codec2/freedv_api.h"

namespace Java_com_ustadmobile_codec2_Codec2 {

    struct Context {
        struct CODEC2 *c2;
        short *buf; //raw audio data
        unsigned char *bits; //codec2 data
        int nsam; //nsam: number of samples per frame - e.g. raw (uncompressed) size = samples per frame
        int nbit;
        int nbyte;//size of one frame of codec2 data
    };

    struct ContextFsk {
        struct FSK *fsk;
        float *modBuf;
        unsigned char *modBits;
        short *demodBuf;
        COMP *demodCBuf;
        unsigned char *demodBits;
        int Nbits;
        int N;
        int Ts;
        int gain;
    };

    struct ContextFreedv {
        struct freedv *freeDv;
        short *speechSamples;
        short *modemSamples;
        short *rawDataSamples;
        unsigned char *rawData;
    };

    static Context *getContext(jlong jp) {
        auto p = (unsigned long) jp;
        Context *con;
        con = (Context *) p;
        return con;
    }

    static ContextFsk *getContextFsk(jlong jp) {
        auto p = (unsigned long) jp;
        ContextFsk *conFsk;
        conFsk = (ContextFsk *) p;
        return conFsk;
    }

    static ContextFreedv *getContextFreedv(jlong jp) {
        auto p = (unsigned long) jp;
        ContextFreedv *conFreedv;
        conFreedv = (ContextFreedv *) p;
        return conFreedv;
    }

    static jlong create(JNIEnv *env, jclass clazz, int mode) {
        struct Context *con;
        con = (struct Context *) malloc(sizeof(struct Context));
        struct CODEC2 *c;
        c = codec2_create(mode);
        con->c2 = c;
        con->nsam = codec2_samples_per_frame(c);
        con->nbit = codec2_bits_per_frame(con->c2);
        con->buf = (short*)malloc(con->nsam*sizeof(short));
        con->nbyte = (con->nbit +  7) / 8;
        con->bits = (unsigned char*)malloc(con->nbyte*sizeof(char));
        auto pv = (unsigned long) con;
        return pv;
    }

    static jlong fskCreate(JNIEnv *env, jclass clazz, int sampleFrequency, int symbolRate, int toneFreq, int toneSpacing, int gain) {
        struct ContextFsk *conFsk;
        conFsk = (struct ContextFsk *) malloc(sizeof(struct ContextFsk));
        struct FSK *fsk;
        fsk = fsk_create_hbr(sampleFrequency, symbolRate, MODE_2FSK, 8, FSK_DEFAULT_NSYM, toneFreq, toneSpacing);
        conFsk->fsk = fsk;

        conFsk->Nbits = fsk->Nbits;
        conFsk->N = fsk->N;
        conFsk->Ts = fsk->Ts;

        conFsk->modBuf = (float*)malloc(sizeof(float) * conFsk->N);
        conFsk->modBits = (uint8_t*)malloc(sizeof(uint8_t) * conFsk->Nbits);

        conFsk->demodCBuf = (COMP*)malloc(sizeof(COMP) * (fsk->N + 2 * fsk->Ts));
        conFsk->demodBits = (uint8_t*)malloc(sizeof(uint8_t) * fsk->Nbits);
        conFsk->demodBuf = (int16_t*)malloc(sizeof(short) * (fsk->N + 2 * fsk->Ts));

        conFsk->gain = gain;

        fsk_set_freq_est_limits(fsk, 500, sampleFrequency / 4);
        fsk_set_freq_est_alg(fsk, 0);

        return reinterpret_cast<jlong>(conFsk);
    }

    static jlong freedvCreate(JNIEnv *env, jclass clazz, int mode, jboolean isSquelchEnabled, jfloat squelchSnr, jlong framesPerBurst) {
        struct ContextFreedv *conFreedv;
        conFreedv = (struct ContextFreedv *) malloc(sizeof(struct ContextFreedv));
        conFreedv->freeDv = freedv_open(mode);
        // speech
        conFreedv->speechSamples = static_cast<short *>(malloc(
                freedv_get_n_max_speech_samples(conFreedv->freeDv) * sizeof(short)));
        conFreedv->modemSamples = static_cast<short *>(malloc(
                freedv_get_n_max_modem_samples(conFreedv->freeDv) * sizeof(short)));
        // data
        conFreedv->rawData = static_cast<unsigned char *>(malloc(
                freedv_get_bits_per_modem_frame(conFreedv->freeDv) / 8));
        conFreedv->rawDataSamples = static_cast<short *>(malloc(
                freedv_get_n_tx_modem_samples(conFreedv->freeDv) * sizeof(short)));
        // squelch
        if (isSquelchEnabled) {
            freedv_set_squelch_en(conFreedv->freeDv, isSquelchEnabled);
            freedv_set_snr_squelch_thresh(conFreedv->freeDv, squelchSnr);
        }
        // frames per single burst, 0 - not specified
        if (framesPerBurst > 0) {
            freedv_set_frames_per_burst(conFreedv->freeDv, framesPerBurst);
        }
        //freedv_set_tx_amp(conFreedv->freeDv, FSK_SCALE);
        return reinterpret_cast<jlong>(conFreedv);
    }

    static jint c2spf(JNIEnv *env, jclass clazz, jlong n) {
        Context *con = getContext(n);
        return con->nsam;
    }

    static jint c2bits(JNIEnv *env, jclass clazz, jlong n) {
        Context *con = getContext(n);
        return con->nbyte;
    }

    static jint fskDemodSamplesBufSize(JNIEnv * env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        return conFsk->N + 2 * conFsk->Ts;  // number of shorts
    }

    static jint fskDemodBitsBufSize(JNIEnv * env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        return conFsk->Nbits;
    }

    static jint fskModSamplesBufSize(JNIEnv * env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        return conFsk->N;
    }

    static jint fskModBitsBufSize(JNIEnv * env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        return conFsk->Nbits;
    }

    static jint fskSamplesPerSymbol(JNIEnv * env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        return conFsk->Ts;
    }

    static jint fskNin(JNIEnv * env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        return fsk_nin(conFsk->fsk);
    }

    static jint freedvGetMaxSpeechSamples(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_get_n_max_speech_samples(conFreedv->freeDv);
    }

    static jint freedvGetMaxModemSamples(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_get_n_max_modem_samples(conFreedv->freeDv);
    }

    static jint freedvGetNSpeechSamples(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_get_n_speech_samples(conFreedv->freeDv);
    }

    static jint freedvGetNomModemSamples(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_get_n_nom_modem_samples(conFreedv->freeDv);
    }

    static jint freedvGetBitsPerModemFrame(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_get_bits_per_modem_frame(conFreedv->freeDv);
    }

    static jint freedvGetNTxSamples(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_get_n_tx_modem_samples(conFreedv->freeDv);
    }

    static jint freedvNin(JNIEnv * env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        return freedv_nin(conFreedv->freeDv);
    }

    static jint destroy(JNIEnv *env, jclass clazz, jlong n) {
        Context *con = getContext(n);
        codec2_destroy(con->c2);
        free(con->bits);
        free(con->buf);
        free(con);
        return 0;
    }

    static jint fskDestroy(JNIEnv *env, jclass clazz, jlong n) {
        ContextFsk *conFsk = getContextFsk(n);
        fsk_destroy(conFsk->fsk);
        free(conFsk->demodBuf);
        free(conFsk->demodBits);
        free(conFsk->demodCBuf);
        free(conFsk->modBits);
        free(conFsk->modBuf);
        free(conFsk);
        return 0;
    }

    static jint freedvDestroy(JNIEnv *env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        freedv_close(conFreedv->freeDv);
        free(conFreedv->modemSamples);
        free(conFreedv->speechSamples);
        free(conFreedv->rawDataSamples);
        free(conFreedv->rawData);
        free(conFreedv);
        return 0;
    }

    static jlong encode(JNIEnv *env, jclass clazz, jlong n, jshortArray inputBuffer, jcharArray outputBits) {
        Context *con = getContext(n);
        jshort *jbuf = env->GetShortArrayElements(inputBuffer, nullptr);
        for (int i = 0; i < con->nsam; i++) {
            auto v = (short) jbuf[i];
            con->buf[i] = v;
        }
        env->ReleaseShortArrayElements(inputBuffer, jbuf, 0);

        codec2_encode(con->c2, con->bits, con->buf);

        jchar *jbits = env->GetCharArrayElements(outputBits, nullptr);
        for (int i = 0; i < con->nbyte; i++) {
            jbits[i] = con->bits[i];
        }
        env->ReleaseCharArrayElements(outputBits, jbits, 0);
        return 0;
    }

    static jlong fskModulate(JNIEnv *env, jclass clazz, jlong n, jshortArray outputSamples, jbyteArray inputBits) {
        ContextFsk *conFsk = getContextFsk(n);
        int inputBitsSize = env->GetArrayLength(inputBits);
        env->GetByteArrayRegion(inputBits, 0, inputBitsSize, reinterpret_cast<jbyte*>(conFsk->modBits));
        fsk_mod(conFsk->fsk, conFsk->modBuf, conFsk->modBits, inputBitsSize);
        jshort *jOutBuf = env->GetShortArrayElements(outputSamples, nullptr);
        for (int i = 0; i < conFsk->N; i++) {
            jOutBuf[i] = (int16_t)(conFsk->modBuf[i] * conFsk->gain);
        }
        env->ReleaseShortArrayElements(outputSamples, jOutBuf, 0);
        return 0;
    }

    static jlong freedvTx(JNIEnv *env, jclass clazz, jlong n, jshortArray outputModemSamples, jshortArray inputSpeechSamples) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        int cntSpeechSamples = freedv_get_n_speech_samples(conFreedv->freeDv);
        env->GetShortArrayRegion(inputSpeechSamples, 0, cntSpeechSamples, conFreedv->speechSamples);
        int cntModemSamples = freedv_get_n_nom_modem_samples(conFreedv->freeDv);
        freedv_tx(conFreedv->freeDv, conFreedv->modemSamples, conFreedv->speechSamples);
        env->SetShortArrayRegion(outputModemSamples, 0, cntModemSamples, conFreedv->modemSamples);
        return cntModemSamples;
    }

    static jlong freedvRawDataTx(JNIEnv *env, jclass clazz, jlong n, jshortArray outputModemSamples, jbyteArray inputData) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        int cntBytes = freedv_get_bits_per_modem_frame(conFreedv->freeDv) / 8;
        env->GetByteArrayRegion(inputData, 0, cntBytes,
                                reinterpret_cast<jbyte *>(conFreedv->rawData));
        uint16_t crc16 = freedv_gen_crc16(conFreedv->rawData, cntBytes - 2);
        conFreedv->rawData[cntBytes-2] = crc16 >> 8;
        conFreedv->rawData[cntBytes-1] = crc16 & 0xff;
        freedv_rawdatatx(conFreedv->freeDv, conFreedv->rawDataSamples, conFreedv->rawData);
        int cntSamples = freedv_get_n_tx_modem_samples(conFreedv->freeDv);
        env->SetShortArrayRegion(outputModemSamples, 0, cntSamples, conFreedv->rawDataSamples);
        return cntSamples;
    }

    static jlong freedvRawDataPreambleTx(JNIEnv *env, jclass clazz, jlong n, jshortArray outputModemSamples) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        int cntSamples = freedv_rawdatapreambletx(conFreedv->freeDv, conFreedv->rawDataSamples);
        env->SetShortArrayRegion(outputModemSamples, 0, cntSamples, conFreedv->rawDataSamples);
        return cntSamples;
    }

    static jlong freedvRawDataPostambleTx(JNIEnv *env, jclass clazz, jlong n, jshortArray outputModemSamples) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        int cntSamples = freedv_rawdatapostambletx(conFreedv->freeDv, conFreedv->rawDataSamples);
        env->SetShortArrayRegion(outputModemSamples, 0, cntSamples, conFreedv->rawDataSamples);
        return cntSamples;
    }

    static jfloat freedvGetModemStat(JNIEnv *env, jclass clazz, jlong n) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        float snr;
        freedv_get_modem_stats(conFreedv->freeDv, NULL, &snr);
        return snr;
    }

    static jlong decode(JNIEnv *env, jclass clazz, jlong n, jshortArray outputSamples, jbyteArray inputBits) {
        Context *con = getContext(n);
        env->GetByteArrayRegion(inputBits, 0, con->nbyte, reinterpret_cast<jbyte*>(con->bits));
        codec2_decode_ber(con->c2, con->buf, con->bits, 0.0);
        env->SetShortArrayRegion(outputSamples, 0, con->nsam, con->buf);
        return 0;
    }

    static jlong fskDemodulate(JNIEnv * env, jclass clazz, jlong n, jshortArray inputSamples, jbyteArray outputBits) {
        ContextFsk *conFsk = getContextFsk(n);
        env->GetShortArrayRegion(inputSamples, 0, conFsk->N, reinterpret_cast<jshort*>(conFsk->demodBuf));
        for(int i = 0; i < fsk_nin(conFsk->fsk); i++){
            conFsk->demodCBuf[i].real = ((float)conFsk->demodBuf[i]) / conFsk->gain;
            conFsk->demodCBuf[i].imag = 0.0;
        }
        fsk_demod(conFsk->fsk, conFsk->demodBits, conFsk->demodCBuf);
        env->SetByteArrayRegion(outputBits, 0, conFsk->Nbits, reinterpret_cast<const jbyte *>(conFsk->demodBits));
        return 0;
    }

    static jlong freedvRx(JNIEnv *env, jclass clazz, jlong n, jshortArray outputSpeechSamples, jshortArray inputModemSamples) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        int nin = freedv_nin(conFreedv->freeDv);
        env->GetShortArrayRegion(inputModemSamples, 0, nin, conFreedv->speechSamples);
        int cntRead = freedv_rx(conFreedv->freeDv, conFreedv->modemSamples, conFreedv->speechSamples);
        env->SetShortArrayRegion(outputSpeechSamples, 0, cntRead, conFreedv->modemSamples);
        return cntRead;
    }

    static jlong freedvRawDataRx(JNIEnv *env, jclass clazz, jlong n, jbyteArray outputRawData, jshortArray inputModemSamples) {
        ContextFreedv *conFreedv = getContextFreedv(n);
        int nin = freedv_nin(conFreedv->freeDv);
        env->GetShortArrayRegion(inputModemSamples, 0, nin, conFreedv->rawDataSamples);
        int cntRead = freedv_rawdatarx(conFreedv->freeDv, conFreedv->rawData, conFreedv->rawDataSamples);
        env->SetByteArrayRegion(outputRawData, 0, cntRead,
                                reinterpret_cast<const jbyte *>(conFreedv->rawData));
        return cntRead;
    }

    static JNINativeMethod method_table[] = {
        // codec2
        {"create", "(I)J",                      (void *) create},
        {"getSamplesPerFrame", "(J)I",          (void *) c2spf},
        {"getBitsSize", "(J)I",                 (void *) c2bits},
        {"destroy", "(J)I",                     (void *) destroy},
        {"encode", "(J[S[C)J",                  (void *) encode},
        {"decode", "(J[S[B)J",                  (void *) decode},
        // fsk
        {"fskCreate", "(IIIII)J",               (void *) fskCreate},
        {"fskDestroy", "(J)I",                  (void *) fskDestroy},
        {"fskModulate", "(J[S[B)J",             (void *) fskModulate},
        {"fskDemodulate", "(J[S[B)J",           (void *) fskDemodulate},
        {"fskDemodBitsBufSize", "(J)I",         (void *) fskDemodBitsBufSize},
        {"fskModSamplesBufSize", "(J)I",        (void *) fskModSamplesBufSize},
        {"fskDemodSamplesBufSize", "(J)I",      (void *) fskDemodSamplesBufSize},
        {"fskModBitsBufSize", "(J)I",           (void *) fskModBitsBufSize},
        {"fskSamplesPerSymbol", "(J)I",         (void *) fskSamplesPerSymbol},
        {"fskNin", "(J)I",                      (void *) fskNin},
        // freedv
        {"freedvCreate", "(IZFJ)J",             (void *)freedvCreate},
        {"freedvDestroy", "(J)I",               (void *)freedvDestroy},
        {"freedvGetMaxSpeechSamples", "(J)I",   (void *)freedvGetMaxSpeechSamples},
        {"freedvGetMaxModemSamples", "(J)I",    (void *)freedvGetMaxModemSamples},
        {"freedvGetNSpeechSamples", "(J)I",     (void *)freedvGetNSpeechSamples},
        {"freedvGetNomModemSamples", "(J)I",    (void *)freedvGetNomModemSamples},
        {"freedvNin", "(J)I",                   (void *)freedvNin},
        {"freedvTx", "(J[S[S)J",                (void *)freedvTx},
        {"freedvRx", "(J[S[S)J",                (void *)freedvRx},
        {"freedvGetModemStat", "(J)F",          (void *)freedvGetModemStat},
        // freedv raw data
        {"freedvRawDataRx", "(J[B[S)J",         (void*)freedvRawDataRx},
        {"freedvRawDataTx", "(J[S[B)J",         (void*)freedvRawDataTx},
        {"freedvRawDataPreambleTx", "(J[S)J",   (void*)freedvRawDataPreambleTx},
        {"freedvRawDataPostambleTx", "(J[S)J",  (void*)freedvRawDataPostambleTx},
        {"freedvGetBitsPerModemFrame", "(J)I",  (void*)freedvGetBitsPerModemFrame},
        {"freedvGetNTxSamples", "(J)I",         (void*)freedvGetNTxSamples}
    };
}

using namespace Java_com_ustadmobile_codec2_Codec2;

extern "C" jint JNI_OnLoad(JavaVM *vm, void *reserved) {
    JNIEnv *env;
    if (vm->GetEnv(reinterpret_cast<void **>(&env), JNI_VERSION_1_6) != JNI_OK) {
        return JNI_ERR;
    } else {
        jclass clazz = env->FindClass("com/ustadmobile/codec2/Codec2");
        if (clazz) {
            jint ret = env->RegisterNatives(clazz, method_table,
                                            sizeof(method_table) / sizeof(method_table[0]));
            env->DeleteLocalRef(clazz);
            return ret == 0 ? JNI_VERSION_1_6 : JNI_ERR;
        } else {
            return JNI_ERR;
        }
    }
}