speex jni包装使用起来轻松

Question

你好，结合速度和写jni包装非常难，所以我希望大家可以添加包装，以便其他人可以轻松使用。我的包装如下：

    #include <jni.h>

#include <string.h>
#include <unistd.h>

#include <speex/speex.h>

static int codec_open = 0;

static int dec_frame_size;
static int enc_frame_size;

static SpeexBits ebits, dbits;
void *enc_state;
void *dec_state;

static JavaVM *gJavaVM;

extern "C"
JNIEXPORT jint JNICALL Java_com_audio_Speex_open
  (JNIEnv *env, jobject obj, jint compression) {
    int tmp;

    if (codec_open++ != 0)
        return (jint)0;

    speex_bits_init(&ebits);
    speex_bits_init(&dbits);

    enc_state = speex_encoder_init(&speex_nb_mode);
    dec_state = speex_decoder_init(&speex_nb_mode);
    tmp = compression;
    speex_encoder_ctl(enc_state, SPEEX_SET_QUALITY, &tmp);
    speex_encoder_ctl(enc_state, SPEEX_GET_FRAME_SIZE, &enc_frame_size);
    speex_decoder_ctl(dec_state, SPEEX_GET_FRAME_SIZE, &dec_frame_size);

    return (jint)0;
}

extern "C"
JNIEXPORT jint Java_com_audio_Speex_encode
    (JNIEnv *env, jobject obj, jshortArray lin, jint offset, jbyteArray encoded, jint size) {

    jshort buffer[enc_frame_size];
    jbyte output_buffer[enc_frame_size];
    int nsamples = (size-1)/enc_frame_size + 1;
    int i, tot_bytes = 0;

    if (!codec_open)
        return 0;

    speex_bits_reset(&ebits);

    for (i = 0; i < nsamples; i++) {
        env->GetShortArrayRegion(lin, offset + i*enc_frame_size, enc_frame_size, buffer);
        speex_encode_int(enc_state, buffer, &ebits);
    }
    //env->GetShortArrayRegion(lin, offset, enc_frame_size, buffer);
    //speex_encode_int(enc_state, buffer, &ebits);

    tot_bytes = speex_bits_write(&ebits, (char *)output_buffer,
                     enc_frame_size);
    env->SetByteArrayRegion(encoded, 0, tot_bytes,
                output_buffer);

    return (jint)tot_bytes;
}

extern "C"
JNIEXPORT jint JNICALL Java_com_audio_Speex_decode
    (JNIEnv *env, jobject obj, jbyteArray encoded, jshortArray lin, jint size) {

    jbyte buffer[dec_frame_size];
    jshort output_buffer[dec_frame_size];
    jsize encoded_length = size;

    if (!codec_open)
        return 0;

    env->GetByteArrayRegion(encoded, 0, encoded_length, buffer);
    speex_bits_read_from(&dbits, (char *)buffer, encoded_length);
    speex_decode_int(dec_state, &dbits, output_buffer);
    env->SetShortArrayRegion(lin, 0, dec_frame_size,
                 output_buffer);

    return (jint)dec_frame_size;
}

extern "C"
JNIEXPORT jint JNICALL Java_com_audio_getFrameSize
    (JNIEnv *env, jobject obj) {

    if (!codec_open)
        return 0;
    return (jint)enc_frame_size;

}

extern "C"
JNIEXPORT void JNICALL Java_com_audio_Speex_close
    (JNIEnv *env, jobject obj) {

    if (--codec_open != 0)
        return;

    speex_bits_destroy(&ebits);
    speex_bits_destroy(&dbits);
    speex_decoder_destroy(dec_state);
    speex_encoder_destroy(enc_state);
}

java：

public native int open(int compression);  
public native int getFrameSize();  
public native int decode(byte encoded[], short lin[], int size);  
public native int encode(short lin[], int offset, byte encoded[], int size);  
public native void close();