Question

Can anybody help me on how to use speex or jspeex in android?

I have searched a lot but could not able to find anywhere.There are many issues regarding this in code.google.com/android but none have answered it. Here also this question did not got a good response as my another question regarding this is Decoding speex encoded byte array in Android. So If you know something about this then Please provide me information regarding this.

I need to encode and decode bytearray of audio file using this codec.

I have tried Android-ndk and got encoding done, but getting a problem in decoding the byte array. Is there any other alternative to achieve this?

EDIT

my encoding Functions in native c file are as follow:

#include <jni.h>
#include "speex/speex.h"

#define FRAME_SIZE 320

int nbBytes;
/*Holds the state of the encoder*/
void *state;
void *decod_state;


/*Holds bits so they can be read and written to by the Speex routines*/

SpeexBits decod_bits;
SpeexBits bits;
int i, tmp;

void Java_com_mycom_speex_SpeexEncodingActivity_init(JNIEnv * env, jobject jobj) {
   /*Create a new encoder state in narrowband mode*/
   state = speex_encoder_init(&speex_wb_mode);

   /*Set the quality to 8*/
   tmp=8;
   speex_encoder_ctl(state, SPEEX_SET_QUALITY, &tmp);

   /*Initialization of the structure that holds the bits*/
   speex_bits_init(&bits);
}

jbyteArray Java_com_mycom_speex_SpeexEncodingActivity_encode(JNIEnv * env, jobject jobj, jshortArray inputData) {
        jbyteArray ret;

        jshort * inputArrayElements = (*env)->GetShortArrayElements(env, inputData, 0);

        /*Flush all the bits in the struct so we can encode a new frame*/
        speex_bits_reset(&bits);

        /*Encode the frame*/
        speex_encode_int(state, inputArrayElements, &bits);
        /*Copy the bits to an array of char that can be written*/
        nbBytes = speex_bits_nbytes(&bits);

        ret = (jbyteArray) ((*env)->NewByteArray(env, nbBytes));
        jbyte * arrayElements = (*env)->GetByteArrayElements(env, ret, 0);

        speex_bits_write(&bits, arrayElements, nbBytes);

        (*env)->ReleaseShortArrayElements(env, inputData, inputArrayElements, JNI_ABORT);
        (*env)->ReleaseByteArrayElements(env, ret, arrayElements, 0);
        return ret;
}

now for decoding i am sending the converted short array to decode function as follow:

void Java_com_mycom_speex_SpeexEncodingActivity_initDecode(JNIEnv * env,
        jobject jobj) {

    decod_state = speex_decoder_init(&speex_wb_mode);

    tmp = 1;
    speex_decoder_ctl(decod_state, SPEEX_SET_ENH, &tmp);

    /*Initialization of the structure that holds the bits*/
    speex_bits_init(&decod_bits);
}

jshortArray Java_com_mycom_speex_SpeexEncodingActivity_decode(JNIEnv * env,
        jobject jobj, jshortArray inputData) {



    jshort * inputArrayElements = (*env)->GetShortArrayElements(env, inputData,
            0);

    /*Flush all the bits in the struct so we can decode a new frame*/
    speex_bits_reset(&decod_bits);
    /*Copy the bits to an array of char that can be written*/
    nbBytes = speex_bits_nbytes(&decod_bits);
    speex_bits_read_from(&decod_bits,inputArrayElements, nbBytes); // here it requires char * in second argument
    /*Decode the frame*/
    speex_decode_int(decod_state, &decod_bits, inputArrayElements);
    (*env)->ReleaseShortArrayElements(env, encodedData, inputArrayElements,
            JNI_ABORT);
    return inputArrayElements;
}

my Encoding functions are working fine the example is provided on the blog A JNI Wrapper for Speex on Android

Another attempt to decoding by passing char array and returning short array is as follow:

jshortArray Java_com_mycom_speex_SpeexEncodingActivity_decode(JNIEnv * env,
        jobject jobj, jcharArray inputCharData) {

    jshortArray ret;
    jchar * inputArrayElements = (*env)->GetCharArrayElements(env,
            inputCharData, 0);
    /*Flush all the bits in the struct so we can decode a new frame*/
    speex_bits_reset(&decod_bits);
    /*Copy the bits to an array of char that can be written*/
    nbBytes = speex_bits_nbytes(&decod_bits);
    ret = (jshortArray)((*env)->NewShortArray(env, nbBytes));
    jshort * arrayElements = (*env)->GetShortArrayElements(env, ret, 0);

    speex_bits_read_from(&decod_bits,(char *) inputArrayElements, nbBytes);
    /*Decode the frame*/
    speex_decode_int(decod_state, &decod_bits, arrayElements);

    (*env)->ReleaseCharArrayElements(env, inputCharData, inputArrayElements,
            JNI_ABORT);
    (*env)->ReleaseShortArrayElements(env, ret, arrayElements, 0);
    return ret;
}

the result is

Returned empty array of short if i return ret and if i return arrayElements it 
gives an error Fatal signal 11 (SIGSEGV) at 0x00000018 (code=1)

Answer 1

speex_bits_reset do following in its body:

bits->nbBits=0;

and speex_bits_nbytes returns ((bits->nbBits+7)>>3);
So if you call speex_bits_nbytes right after speex_bits_reset, you always receive 0. So you must call speex_bits_read_from before array allocation:

/*Flush all the bits in the struct so we can decode a new frame*/
speex_bits_reset(&decod_bits);

/*Read bits in decod_bits struct from java array*/
speex_bits_read_from(&decod_bits,(char *) inputArrayElements, nbBytes);

/*Copy the bits to an array of char that can be written*/
nbBytes = speex_bits_nbytes(&decod_bits);
ret = (jshortArray)((*env)->NewShortArray(env, nbBytes));
jshort * arrayElements = (*env)->GetShortArrayElements(env, ret, 0);

/*Decode the frame*/
speex_decode_int(decod_state, &decod_bits, arrayElements);

(*env)->ReleaseCharArrayElements(env, inputCharData, inputArrayElements,
        JNI_ABORT);
(*env)->ReleaseShortArrayElements(env, ret, arrayElements, 0);
return ret;