android中的speex支持

  • Z时代
  • 2024-01-10
  • 分类：问答

有人可以帮助我

我进行了很多搜索，但找不到任何地方。code.google.com/

android中与此相关的问题很多，但都没有答案。这里的这个问题也没有得到很好的回答，因为我对此的另一个问题是Android中的解码speex编码的字节数组。因此，如果您对此有所了解，请向我提供有关此信息。

我需要使用此编解码器对音频文件的字节数组进行编码和解码。

我已经尝试过Android-ndk并完成了编码，但是 遇到了

还有其他替代方法可以做到这一点吗？

我在本机c文件中的编码函数如下：

#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;
}

现在进行解码，我将转换后的短数组发送给 

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;
}

我的编码功能运行良好，该示例在博客上提供。Android上用于Speex的JNI包装器

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;
}

结果是

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)

回答：

speex_bits_reset在其主体中执行以下操作：

bits->nbBits=0;

speex_bits_nbytes返回（（bits-> nbBits + 7）>> 3）;

因此，如果在speex_bits_reset之后立即调用speex_bits_nbytes，则始终会收到0。因此，必须在分配数组之前调用speex_bits_read_from：

/*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;

以上是 android中的speex支持 的全部内容， 来源链接： utcz.com/qa/408961.html

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