Silk编解码在android实现

Silk编解码是Skype向第三方开发人员和硬件制造商提供免版税认证(RF)的Silk宽带音频编码器。Skype已将其开源，可以访问http://developer.skype.com/silk获取最新动向。SILK Codec是一个语音和音频编解码算法, 对于音频带宽、网络带宽和算法复杂度都具有很好的弹性。支持4种采样率：8KHz、12KHz、16KHz、24KHz；三种复杂度：低、中、高。编码码率在 6~40kbps（不同采样率具有不同的码率范围）以及还支持VAD、DTX、FEC等模块，感觉还是比较全面。最重要的一点是提供了定点C代码，非常有利于向ARM、DSP移植和优化。这一篇主要参考了pjsip中的silk实现。

1、获取silk源码（http://developer.skype.com/silk）

2、创建新的android工程，并创建jni文件夹。

3、将silk源码拷贝到jni目录

4、在jni目录下新增Android.mk文件，编辑内容如下：

LOCAL_PATH := $(call my-dir)
 
include $(CLEAR_VARS)
SILK     := silk
LOCAL_MODULE    := silkcommon
LOCAL_SRC_FILES :=  $(SILK)/src/SKP_Silk_A2NLSF.c 
	$(SILK)/src/SKP_Silk_CNG.c 
	$(SILK)/src/SKP_Silk_HP_variable_cutoff_FIX.c 
	$(SILK)/src/SKP_Silk_LBRR_reset.c 
	$(SILK)/src/SKP_Silk_LPC_inv_pred_gain.c 
	$(SILK)/src/SKP_Silk_LPC_stabilize.c 
	$(SILK)/src/SKP_Silk_LPC_synthesis_filter.c 
	$(SILK)/src/SKP_Silk_LPC_synthesis_order16.c 
	$(SILK)/src/SKP_Silk_LP_variable_cutoff.c 
	$(SILK)/src/SKP_Silk_LSF_cos_table.c 
	$(SILK)/src/SKP_Silk_LTP_analysis_filter_FIX.c 
	$(SILK)/src/SKP_Silk_LTP_scale_ctrl_FIX.c 
	$(SILK)/src/SKP_Silk_MA.c 
	$(SILK)/src/SKP_Silk_NLSF2A.c 
	$(SILK)/src/SKP_Silk_NLSF2A_stable.c 
	$(SILK)/src/SKP_Silk_NLSF_MSVQ_decode.c 
	$(SILK)/src/SKP_Silk_NLSF_MSVQ_encode_FIX.c 
	$(SILK)/src/SKP_Silk_NLSF_VQ_rate_distortion_FIX.c 
	$(SILK)/src/SKP_Silk_NLSF_VQ_sum_error_FIX.c 
	$(SILK)/src/SKP_Silk_NLSF_VQ_weights_laroia.c 
	$(SILK)/src/SKP_Silk_NLSF_stabilize.c 
	$(SILK)/src/SKP_Silk_NSQ.c 
	$(SILK)/src/SKP_Silk_NSQ_del_dec.c 
	$(SILK)/src/SKP_Silk_PLC.c 
	$(SILK)/src/SKP_Silk_VAD.c 
	$(SILK)/src/SKP_Silk_VQ_nearest_neighbor_FIX.c 
	$(SILK)/src/SKP_Silk_allpass_int.c 
	$(SILK)/src/SKP_Silk_ana_filt_bank_1.c 
	$(SILK)/src/SKP_Silk_apply_sine_window.c 
	$(SILK)/src/SKP_Silk_array_maxabs.c 
	$(SILK)/src/SKP_Silk_autocorr.c 
	$(SILK)/src/SKP_Silk_biquad.c 
	$(SILK)/src/SKP_Silk_biquad_alt.c 
	$(SILK)/src/SKP_Silk_burg_modified.c 
	$(SILK)/src/SKP_Silk_bwexpander.c 
	$(SILK)/src/SKP_Silk_bwexpander_32.c 
	$(SILK)/src/SKP_Silk_code_signs.c 
	$(SILK)/src/SKP_Silk_control_codec_FIX.c 
	$(SILK)/src/SKP_Silk_corrMatrix_FIX.c 
	$(SILK)/src/SKP_Silk_create_init_destroy.c 
	$(SILK)/src/SKP_Silk_dec_API.c 
	$(SILK)/src/SKP_Silk_decode_core.c 
	$(SILK)/src/SKP_Silk_decode_frame.c 
	$(SILK)/src/SKP_Silk_decode_indices_v4.c 
	$(SILK)/src/SKP_Silk_decode_parameters.c 
	$(SILK)/src/SKP_Silk_decode_parameters_v4.c 
	$(SILK)/src/SKP_Silk_decode_pulses.c 
	$(SILK)/src/SKP_Silk_decoder_set_fs.c 
	$(SILK)/src/SKP_Silk_detect_SWB_input.c 
	$(SILK)/src/SKP_Silk_enc_API.c 
	$(SILK)/src/SKP_Silk_encode_frame_FIX.c 
	$(SILK)/src/SKP_Silk_encode_parameters.c 
	$(SILK)/src/SKP_Silk_encode_parameters_v4.c 
	$(SILK)/src/SKP_Silk_encode_pulses.c 
	$(SILK)/src/SKP_Silk_find_LPC_FIX.c 
	$(SILK)/src/SKP_Silk_find_LTP_FIX.c 
	$(SILK)/src/SKP_Silk_find_pitch_lags_FIX.c 
	$(SILK)/src/SKP_Silk_find_pred_coefs_FIX.c 
	$(SILK)/src/SKP_Silk_gain_quant.c 
	$(SILK)/src/SKP_Silk_init_encoder_FIX.c 
	$(SILK)/src/SKP_Silk_inner_prod_aligned.c 
	$(SILK)/src/SKP_Silk_interpolate.c 
	$(SILK)/src/SKP_Silk_k2a.c 
	$(SILK)/src/SKP_Silk_k2a_Q16.c 
	$(SILK)/src/SKP_Silk_lin2log.c 
	$(SILK)/src/SKP_Silk_log2lin.c 
	$(SILK)/src/SKP_Silk_lowpass_int.c 
	$(SILK)/src/SKP_Silk_lowpass_short.c 
	$(SILK)/src/SKP_Silk_noise_shape_analysis_FIX.c 
	$(SILK)/src/SKP_Silk_pitch_analysis_core.c 
	$(SILK)/src/SKP_Silk_pitch_est_tables.c 
	$(SILK)/src/SKP_Silk_prefilter_FIX.c 
	$(SILK)/src/SKP_Silk_process_NLSFs_FIX.c 
	$(SILK)/src/SKP_Silk_process_gains_FIX.c 
	$(SILK)/src/SKP_Silk_pulses_to_bytes.c 
	$(SILK)/src/SKP_Silk_quant_LTP_gains_FIX.c 
	$(SILK)/src/SKP_Silk_range_coder.c 
	$(SILK)/src/SKP_Silk_regularize_correlations_FIX.c 
	$(SILK)/src/SKP_Silk_resample_1_2.c 
	$(SILK)/src/SKP_Silk_resample_1_2_coarse.c 
	$(SILK)/src/SKP_Silk_resample_1_2_coarsest.c 
	$(SILK)/src/SKP_Silk_resample_1_3.c 
	$(SILK)/src/SKP_Silk_resample_2_1_coarse.c 
	$(SILK)/src/SKP_Silk_resample_2_3.c 
	$(SILK)/src/SKP_Silk_resample_2_3_coarse.c 
	$(SILK)/src/SKP_Silk_resample_2_3_coarsest.c 
	$(SILK)/src/SKP_Silk_resample_2_3_rom.c 
	$(SILK)/src/SKP_Silk_resample_3_1.c 
	$(SILK)/src/SKP_Silk_resample_3_2.c 
	$(SILK)/src/SKP_Silk_resample_3_2_rom.c 
	$(SILK)/src/SKP_Silk_resample_3_4.c 
	$(SILK)/src/SKP_Silk_resample_4_3.c 
	$(SILK)/src/SKP_Silk_residual_energy16_FIX.c 
	$(SILK)/src/SKP_Silk_residual_energy_FIX.c 
	$(SILK)/src/SKP_Silk_scale_copy_vector16.c 
	$(SILK)/src/SKP_Silk_scale_vector.c 
	$(SILK)/src/SKP_Silk_schur.c 
	$(SILK)/src/SKP_Silk_schur64.c 
	$(SILK)/src/SKP_Silk_shell_coder.c 
	$(SILK)/src/SKP_Silk_sigm_Q15.c 
	$(SILK)/src/SKP_Silk_solve_LS_FIX.c 
	$(SILK)/src/SKP_Silk_sort.c 
	$(SILK)/src/SKP_Silk_sum_sqr_shift.c 
	$(SILK)/src/SKP_Silk_tables_LTP.c 
	$(SILK)/src/SKP_Silk_tables_NLSF_CB0_10.c 
	$(SILK)/src/SKP_Silk_tables_NLSF_CB0_16.c 
	$(SILK)/src/SKP_Silk_tables_NLSF_CB1_10.c 
	$(SILK)/src/SKP_Silk_tables_NLSF_CB1_16.c 
	$(SILK)/src/SKP_Silk_tables_gain.c 
	$(SILK)/src/SKP_Silk_tables_other.c 
	$(SILK)/src/SKP_Silk_tables_pitch_lag.c 
	$(SILK)/src/SKP_Silk_tables_pulses_per_block.c 
	$(SILK)/src/SKP_Silk_tables_sign.c 
	$(SILK)/src/SKP_Silk_tables_type_offset.c
	
LOCAL_ARM_MODE := arm
LOCAL_CFLAGS = -O3 
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(SILK)/src $(LOCAL_PATH)/$(SILK)/interface
include $(BUILD_STATIC_LIBRARY)


include $(CLEAR_VARS)
LOCAL_MODULE    := silk8_jni
LOCAL_SRC_FILES := silk8_jni.cpp 
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(SILK)/src $(LOCAL_PATH)/$(SILK)/interface
LOCAL_CFLAGS = -O3 
LOCAL_STATIC_LIBRARIES :=  silkcommon
LOCAL_ARM_MODE := arm
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE    := silk16_jni
LOCAL_SRC_FILES := silk16_jni.cpp 
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(SILK)/src $(LOCAL_PATH)/$(SILK)/interface
LOCAL_CFLAGS = -O3 
LOCAL_STATIC_LIBRARIES :=  silkcommon
LOCAL_ARM_MODE := arm
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE    := silk24_jni
LOCAL_SRC_FILES := silk24_jni.cpp 
LOCAL_C_INCLUDES += $(LOCAL_PATH)/$(SILK)/src $(LOCAL_PATH)/$(SILK)/interface
LOCAL_CFLAGS = -O3 
LOCAL_STATIC_LIBRARIES :=  silkcommon
LOCAL_ARM_MODE := arm
LOCAL_LDLIBS := -L$(SYSROOT)/usr/lib -llog
include $(BUILD_SHARED_LIBRARY)

5、创建JNI包装类silk8_jni.cpp、silk16_jni.cpp、silk24_jni.cpp，用来调用Silk中的C代码函数，编辑内容如下

silk8_jni.cpp:

#include <jni.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

/* Define codec specific settings */
#define MAX_BYTES_ENC_PER_FRAME     250 // Equals peak bitrate of 100 kbps 
#define MAX_BYTES_DEC_PER_FRAME     1024

#define MAX_INPUT_FRAMES        5
#define MAX_LBRR_DELAY          2
#define MAX_FRAME_LENGTH        480

#define	MAX_FRAME			160

#include <android/log.h> 

#define LOG_TAG "silk" // text for log tag 

#include "SKP_Silk_SDK_API.h"
#include "SKP_Silk_SigProc_FIX.h"

#undef DEBUG_SILK8

// the header length of the RTP frame (must skip when en/decoding)
#define	RTP_HDR_SIZE	12

static int codec_open = 0;

static JavaVM *gJavaVM;
const char *kInterfacePath = "org/sipdroid/pjlib/silk8";

/* encoder parameters */

    SKP_int32 encSizeBytes;
    void      *psEnc;

    /* default settings */
    SKP_int   fs_kHz = 8;
    SKP_int   targetRate_bps = 20000;
    SKP_int   packetSize_ms = 20;
    SKP_int   frameSizeReadFromFile_ms = 20;
    SKP_int   packetLoss_perc = 0, smplsSinceLastPacket;
    SKP_int   INBandFec_enabled = 0, DTX_enabled = 0, quiet = 0;
    SKP_SILK_SDK_EncControlStruct encControl; // Struct for input to encoder
        

/* decoder parameters */

    jbyte payloadToDec[    MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES * ( MAX_LBRR_DELAY + 1 ) ];
    jshort out[ ( MAX_FRAME_LENGTH << 1 ) * MAX_INPUT_FRAMES ], *outPtr;
    SKP_int32 decSizeBytes;
    void      *psDec;
    SKP_SILK_SDK_DecControlStruct DecControl;

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK8_open
  (JNIEnv *env, jobject obj, jint compression) {
	int ret;

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

	/* Set the samplingrate that is requested for the output */
    DecControl.sampleRate = 8000;
		
    /* Create decoder */
    ret = SKP_Silk_SDK_Get_Decoder_Size( &decSizeBytes );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_Get_Decoder_Size returned %d", ret );		
    }
#ifdef DEBUG_SILK8
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "### INIT Decoder decSizeBytes = %d
", decSizeBytes); 		
#endif	
    psDec = malloc( decSizeBytes );

    /* Reset decoder */
    ret = SKP_Silk_SDK_InitDecoder( psDec );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_InitDecoder returned %d", ret );	
    }


    /* Create Encoder */
    ret = SKP_Silk_SDK_Get_Encoder_Size( &encSizeBytes );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_Get_Encoder_Size returned %d", ret );	
    }
#ifdef DEBUG_SILK8
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "### INIT Encoder encSizeBytes = %d
", encSizeBytes); 		
#endif		
    psEnc = malloc( encSizeBytes );
    
    /* Reset Encoder */
    ret = SKP_Silk_SDK_InitEncoder( psEnc, &encControl );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_InitEncoder returned %d", ret );	
	}
    
    /* Set Encoder parameters */
    encControl.sampleRate           = fs_kHz * 1000;
    encControl.packetSize           = packetSize_ms * fs_kHz;
    encControl.packetLossPercentage = packetLoss_perc;
    encControl.useInBandFEC         = INBandFec_enabled;
    encControl.useDTX               = DTX_enabled;
    encControl.complexity           = compression;
    encControl.bitRate              = targetRate_bps;		
	
	return (jint)0;
}

void Print_Decode_Error_Msg(int errcode) {
	switch (errcode) {
		case SKP_SILK_DEC_WRONG_SAMPLING_FREQUENCY:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Output sampling frequency lower than internal decoded sampling frequency
", errcode);
			break;
		case SKP_SILK_DEC_PAYLOAD_TOO_LARGE:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Payload size exceeded the maximum allowed 1024 bytes
", errcode); 
			break;
		case SKP_SILK_DEC_PAYLOAD_ERROR:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Payload has bit errors
", errcode); 
			break;			
	}
}

void Print_Encode_Error_Msg(int errcode) {
	switch (errcode) {
		case SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Input length is not a multiplum of 10 ms, or length is longer than the packet length
", errcode);
			break;
		case SKP_SILK_ENC_FS_NOT_SUPPORTED:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Sampling frequency not 8000, 12000, 16000 or 24000 Hertz 
", errcode); 
			break;
		case SKP_SILK_ENC_PACKET_SIZE_NOT_SUPPORTED:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Packet size not 20, 40, 60, 80 or 100 ms
", errcode); 
			break;			
		case SKP_SILK_ENC_PAYLOAD_BUF_TOO_SHORT:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Allocated payload buffer too short 
", errcode);
			break;
		case SKP_SILK_ENC_WRONG_LOSS_RATE:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Loss rate not between 0 and 100 percent
", errcode); 
			break;
		case SKP_SILK_ENC_WRONG_COMPLEXITY_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Complexity setting not valid, use 0, 1 or 2
", errcode); 
			break;		
		case SKP_SILK_ENC_WRONG_INBAND_FEC_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Inband FEC setting not valid, use 0 or 1
", errcode);
			break;
		case SKP_SILK_ENC_WRONG_DTX_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
DTX setting not valid, use 0 or 1
", errcode); 
			break;
		case SKP_SILK_ENC_INTERNAL_ERROR:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Internal encoder error
", errcode); 
			break;				
	}
}

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK8_encode
    (JNIEnv *env, jobject obj, jshortArray lin, jint offset, jbyteArray encoded, jint size) {

    jbyte	  enc_payload[ MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES ];
    jshort    in[ MAX_FRAME_LENGTH * MAX_INPUT_FRAMES ];	
	int ret,i,frsz=MAX_FRAME;
	SKP_int16 nBytes;
	unsigned int lin_pos = 0;
	
	if (!codec_open)
		return 0;
		
#ifdef DEBUG_SILK8
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "encoding frame size: %d	offset: %d
", size, offset); 		
#endif


	for (i = 0; i < size; i+=MAX_FRAME) {
#ifdef DEBUG_SILK8
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "encoding frame size: %d	offset: %d i: %d
", size, offset, i); 		
#endif
			
		env->GetShortArrayRegion(lin, offset + i,frsz, in);
        /* max payload size */
        nBytes = MAX_BYTES_ENC_PER_FRAME * MAX_INPUT_FRAMES;

        ret = SKP_Silk_SDK_Encode( psEnc, &encControl, in, (SKP_int16)frsz, (SKP_uint8 *)enc_payload, &nBytes );
        if( ret ) {
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!! SKP_Silk_Encode returned: %d
", ret);
			Print_Encode_Error_Msg(ret);				
            break;
        }
#ifdef DEBUG_SILK8
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"Enocded nBytes: %d
", nBytes); 		
#endif		
        /* Write payload */		
		env->SetByteArrayRegion(encoded, RTP_HDR_SIZE+ lin_pos, nBytes, enc_payload);
		lin_pos += nBytes;
	}
#ifdef DEBUG_SILK8
	__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
        "encoding **END** frame size: %d	offset: %d i: %d lin_pos: %d
", size, offset, i, lin_pos);
#endif		

    return (jint)lin_pos;
}

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK8_decode
    (JNIEnv *env, jobject obj, jbyteArray encoded, jshortArray lin, jint size) {

    jbyte buffer [MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES * ( MAX_LBRR_DELAY + 1 ) ];
    jshort output_buffer[( MAX_FRAME_LENGTH << 1 ) * MAX_INPUT_FRAMES ];
//	SKP_int16	*outPtr;

	int ret;
	SKP_int16 len;
//	int	tot_len,frames;

	if (!codec_open)
		return 0;

#ifdef DEBUG_SILK8		
	__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
        "##### BEGIN DECODE ********  decoding frame size: %d
", size); 	
#endif

	env->GetByteArrayRegion(encoded, RTP_HDR_SIZE, size, buffer);

//	outPtr = output_buffer;
//    tot_len = 0;
//	frames = 0;

//	do {
		ret = SKP_Silk_SDK_Decode( psDec, &DecControl, 0,(SKP_uint8 *) buffer, size, output_buffer,&len );
		if( ret ) {
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!! SKP_Silk_SDK_Decode returned: %d
", ret); 	
			Print_Decode_Error_Msg(ret);
		}
#ifdef DEBUG_SILK8		
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
			"##### DECODED length: %d
	 Frame #: %d", len); 	
#endif
//		frames++;
//		outPtr  += len;
//		tot_len += len;		
	
//	} while( DecControl.moreInternalDecoderFrames );

	env->SetShortArrayRegion(lin, 0, len,output_buffer);
	return (jint)len;
}

extern "C"
JNIEXPORT void JNICALL Java_com_trunkbow_silk_SILK8_close
    (JNIEnv *env, jobject obj) {

	if (--codec_open != 0)
		return;
    /* Free decoder */
    free( psDec );
    /* Free Encoder */
    free( psEnc );
}

silk_16.cpp:

#include <jni.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

/* Define codec specific settings */
#define MAX_BYTES_ENC_PER_FRAME     250 // Equals peak bitrate of 100 kbps 
#define MAX_BYTES_DEC_PER_FRAME     1024

#define MAX_INPUT_FRAMES        5
#define MAX_LBRR_DELAY          2
#define MAX_FRAME_LENGTH        480

#define	MAX_FRAME			320

#include <android/log.h> 

#define LOG_TAG "silk" // text for log tag 

#include "SKP_Silk_SDK_API.h"
#include "SKP_Silk_SigProc_FIX.h"

#undef DEBUG_SILK16

// the header length of the RTP frame (must skip when en/decoding)
#define	RTP_HDR_SIZE	12

static int codec_open = 0;

static JavaVM *gJavaVM;
const char *kInterfacePath = "org/sipdroid/pjlib/silk16";

/* encoder parameters */

    SKP_int32 encSizeBytes;
    void      *psEnc;

    /* default settings */
    SKP_int   fs_kHz = 16;
    SKP_int   targetRate_bps = 20000;
    SKP_int   packetSize_ms = 20;
    SKP_int   frameSizeReadFromFile_ms = 20;
    SKP_int   packetLoss_perc = 0, smplsSinceLastPacket;
    SKP_int   INBandFec_enabled = 0, DTX_enabled = 0, quiet = 0;
    SKP_SILK_SDK_EncControlStruct encControl; // Struct for input to encoder
        

/* decoder parameters */

    jbyte payloadToDec[    MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES * ( MAX_LBRR_DELAY + 1 ) ];
    jshort out[ ( MAX_FRAME_LENGTH << 1 ) * MAX_INPUT_FRAMES ], *outPtr;
    SKP_int32 decSizeBytes;
    void      *psDec;
    SKP_SILK_SDK_DecControlStruct DecControl;

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK16_open
  (JNIEnv *env, jobject obj, jint compression) {
	int ret;

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

	/* Set the samplingrate that is requested for the output */
    DecControl.sampleRate = 16000;
		
    /* Create decoder */
    ret = SKP_Silk_SDK_Get_Decoder_Size( &decSizeBytes );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_Get_Decoder_Size returned %d", ret );		
    }
#ifdef DEBUG_SILK16
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "### INIT Decoder decSizeBytes = %d
", decSizeBytes); 		
#endif	
    psDec = malloc( decSizeBytes );

    /* Reset decoder */
    ret = SKP_Silk_SDK_InitDecoder( psDec );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_InitDecoder returned %d", ret );	
    }


    /* Create Encoder */
    ret = SKP_Silk_SDK_Get_Encoder_Size( &encSizeBytes );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_Get_Encoder_Size returned %d", ret );	
    }
#ifdef DEBUG_SILK16
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "### INIT Encoder encSizeBytes = %d
", encSizeBytes); 		
#endif		
    psEnc = malloc( encSizeBytes );
    
    /* Reset Encoder */
    ret = SKP_Silk_SDK_InitEncoder( psEnc, &encControl );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_InitEncoder returned %d", ret );	
	}
    
    /* Set Encoder parameters */
    encControl.sampleRate           = fs_kHz * 1000;
    encControl.packetSize           = packetSize_ms * fs_kHz;
    encControl.packetLossPercentage = packetLoss_perc;
    encControl.useInBandFEC         = INBandFec_enabled;
    encControl.useDTX               = DTX_enabled;
    encControl.complexity           = compression;
    encControl.bitRate              = targetRate_bps;		
	
	return (jint)0;
}

void Print_Decode_Error_Msg(int errcode) {
	switch (errcode) {
		case SKP_SILK_DEC_WRONG_SAMPLING_FREQUENCY:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Output sampling frequency lower than internal decoded sampling frequency
", errcode);
			break;
		case SKP_SILK_DEC_PAYLOAD_TOO_LARGE:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Payload size exceeded the maximum allowed 1024 bytes
", errcode); 
			break;
		case SKP_SILK_DEC_PAYLOAD_ERROR:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Payload has bit errors
", errcode); 
			break;			
	}
}

void Print_Encode_Error_Msg(int errcode) {
	switch (errcode) {
		case SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Input length is not a multiplum of 10 ms, or length is longer than the packet length
", errcode);
			break;
		case SKP_SILK_ENC_FS_NOT_SUPPORTED:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Sampling frequency not 8000, 12000, 16000 or 24000 Hertz 
", errcode); 
			break;
		case SKP_SILK_ENC_PACKET_SIZE_NOT_SUPPORTED:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Packet size not 20, 40, 60, 80 or 100 ms
", errcode); 
			break;			
		case SKP_SILK_ENC_PAYLOAD_BUF_TOO_SHORT:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Allocated payload buffer too short 
", errcode);
			break;
		case SKP_SILK_ENC_WRONG_LOSS_RATE:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Loss rate not between 0 and 100 percent
", errcode); 
			break;
		case SKP_SILK_ENC_WRONG_COMPLEXITY_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Complexity setting not valid, use 0, 1 or 2
", errcode); 
			break;		
		case SKP_SILK_ENC_WRONG_INBAND_FEC_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Inband FEC setting not valid, use 0 or 1
", errcode);
			break;
		case SKP_SILK_ENC_WRONG_DTX_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
DTX setting not valid, use 0 or 1
", errcode); 
			break;
		case SKP_SILK_ENC_INTERNAL_ERROR:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Internal encoder error
", errcode); 
			break;				
	}
}

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK16_encode
    (JNIEnv *env, jobject obj, jshortArray lin, jint offset, jbyteArray encoded, jint size) {

    jbyte	  enc_payload[ MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES ];
    jshort    in[ MAX_FRAME_LENGTH * MAX_INPUT_FRAMES ];	
	int ret,i,frsz=MAX_FRAME;
	SKP_int16 nBytes;
	unsigned int lin_pos = 0;
	
	if (!codec_open)
		return 0;
		
#ifdef DEBUG_SILK16
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "encoding frame size: %d	offset: %d
", size, offset); 		
#endif


	for (i = 0; i < size; i+=MAX_FRAME) {
#ifdef DEBUG_SILK16
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "encoding frame size: %d	offset: %d i: %d
", size, offset, i); 		
#endif
			
		env->GetShortArrayRegion(lin, offset + i,frsz, in);
        /* max payload size */
        nBytes = MAX_BYTES_ENC_PER_FRAME * MAX_INPUT_FRAMES;

        ret = SKP_Silk_SDK_Encode( psEnc, &encControl, in, (SKP_int16)frsz, (SKP_uint8 *)enc_payload, &nBytes );
        if( ret ) {
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!! SKP_Silk_Encode returned: %d
", ret);
			Print_Encode_Error_Msg(ret);					
            break;
        }
#ifdef DEBUG_SILK16
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"Enocded nBytes: %d
", nBytes); 		
#endif		
        /* Write payload */		
		env->SetByteArrayRegion(encoded, RTP_HDR_SIZE+ lin_pos, nBytes, enc_payload);
		lin_pos += nBytes;
	}
#ifdef DEBUG_SILK16
	__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
        "encoding **END** frame size: %d	offset: %d i: %d lin_pos: %d
", size, offset, i, lin_pos);
#endif		

    return (jint)lin_pos;
}

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK16_decode
    (JNIEnv *env, jobject obj, jbyteArray encoded, jshortArray lin, jint size) {

    jbyte buffer [MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES * ( MAX_LBRR_DELAY + 1 ) ];
    jshort output_buffer[( MAX_FRAME_LENGTH << 1 ) * MAX_INPUT_FRAMES ];
//	SKP_int16	*outPtr;

	int ret;
	SKP_int16 len;
//	int	tot_len,frames;

	if (!codec_open)
		return 0;

#ifdef DEBUG_SILK16		
	__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
        "##### BEGIN DECODE ********  decoding frame size: %d
", size); 	
#endif

	env->GetByteArrayRegion(encoded, RTP_HDR_SIZE, size, buffer);

//	outPtr = output_buffer;
//    tot_len = 0;
//	frames = 0;

//	do {
		ret = SKP_Silk_SDK_Decode( psDec, &DecControl, 0,(SKP_uint8 *) buffer, size, output_buffer,&len );
		if( ret ) {
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!! SKP_Silk_SDK_Decode returned: %d
", ret); 	
			Print_Decode_Error_Msg(ret);
		}
#ifdef DEBUG_SILK16		
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
			"##### DECODED length: %d
	 Frame #: %d", len); 	
#endif
//		frames++;
//		outPtr  += len;
//		tot_len += len;		
	
//	} while( DecControl.moreInternalDecoderFrames );

	env->SetShortArrayRegion(lin, 0, len,output_buffer);
	return (jint)len;
}

extern "C"
JNIEXPORT void JNICALL Java_com_trunkbow_silk_SILK16_close
    (JNIEnv *env, jobject obj) {

	if (--codec_open != 0)
		return;
    /* Free decoder */
    free( psDec );
    /* Free Encoder */
    free( psEnc );
}

silk24_jni.cpp

#include <jni.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>

/* Define codec specific settings */
#define MAX_BYTES_ENC_PER_FRAME     250 // Equals peak bitrate of 100 kbps 
#define MAX_BYTES_DEC_PER_FRAME     1024

#define MAX_INPUT_FRAMES        5
#define MAX_LBRR_DELAY          2
#define MAX_FRAME_LENGTH        480

#define	MAX_FRAME			480

#include <android/log.h> 

#define LOG_TAG "silk" // text for log tag 

#include "SKP_Silk_SDK_API.h"
#include "SKP_Silk_SigProc_FIX.h"

#undef DEBUG_SILK24

// the header length of the RTP frame (must skip when en/decoding)
#define	RTP_HDR_SIZE	12

static int codec_open = 0;

static JavaVM *gJavaVM;
const char *kInterfacePath = "org/sipdroid/pjlib/SILK24";

/* encoder parameters */

    SKP_int32 encSizeBytes;
    void      *psEnc;

    /* default settings */
    SKP_int   fs_kHz = 24;
    SKP_int   targetRate_bps = 20000;
    SKP_int   packetSize_ms = 20;
    SKP_int   frameSizeReadFromFile_ms = 20;
    SKP_int   packetLoss_perc = 0, smplsSinceLastPacket;
    SKP_int   INBandFec_enabled = 0, DTX_enabled = 0, quiet = 0;
    SKP_SILK_SDK_EncControlStruct encControl; // Struct for input to encoder
        

/* decoder parameters */

    jbyte payloadToDec[    MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES * ( MAX_LBRR_DELAY + 1 ) ];
    jshort out[ ( MAX_FRAME_LENGTH << 1 ) * MAX_INPUT_FRAMES ], *outPtr;
    SKP_int32 decSizeBytes;
    void      *psDec;
    SKP_SILK_SDK_DecControlStruct DecControl;

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK24_open
  (JNIEnv *env, jobject obj, jint compression) {
	int ret;

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

	/* Set the samplingrate that is requested for the output */
    DecControl.sampleRate = 24000;
		
    /* Create decoder */
    ret = SKP_Silk_SDK_Get_Decoder_Size( &decSizeBytes );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_Get_Decoder_Size returned %d", ret );		
    }
#ifdef DEBUG_SILK24
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "### INIT Decoder decSizeBytes = %d
", decSizeBytes); 		
#endif	
    psDec = malloc( decSizeBytes );

    /* Reset decoder */
    ret = SKP_Silk_SDK_InitDecoder( psDec );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_InitDecoder returned %d", ret );	
    }


    /* Create Encoder */
    ret = SKP_Silk_SDK_Get_Encoder_Size( &encSizeBytes );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_Get_Encoder_Size returned %d", ret );	
    }
#ifdef DEBUG_SILK24
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "### INIT Encoder encSizeBytes = %d
", encSizeBytes); 		
#endif		
    psEnc = malloc( encSizeBytes );
    
    /* Reset Encoder */
    ret = SKP_Silk_SDK_InitEncoder( psEnc, &encControl );
    if( ret ) {
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "
!!!!!!!! SKP_Silk_SDK_InitEncoder returned %d", ret );	
	}
    
    /* Set Encoder parameters */
    encControl.sampleRate           = fs_kHz * 1000;
    encControl.packetSize           = packetSize_ms * fs_kHz;
    encControl.packetLossPercentage = packetLoss_perc;
    encControl.useInBandFEC         = INBandFec_enabled;
    encControl.useDTX               = DTX_enabled;
    encControl.complexity           = compression;
    encControl.bitRate              = targetRate_bps;		
	
	return (jint)0;
}

void Print_Decode_Error_Msg(int errcode) {
	switch (errcode) {
		case SKP_SILK_DEC_WRONG_SAMPLING_FREQUENCY:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Output sampling frequency lower than internal decoded sampling frequency
", errcode);
			break;
		case SKP_SILK_DEC_PAYLOAD_TOO_LARGE:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Payload size exceeded the maximum allowed 1024 bytes
", errcode); 
			break;
		case SKP_SILK_DEC_PAYLOAD_ERROR:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Payload has bit errors
", errcode); 
			break;			
	}
}

void Print_Encode_Error_Msg(int errcode) {
	switch (errcode) {
		case SKP_SILK_ENC_INPUT_INVALID_NO_OF_SAMPLES:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Input length is not a multiplum of 10 ms, or length is longer than the packet length
", errcode);
			break;
		case SKP_SILK_ENC_FS_NOT_SUPPORTED:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Sampling frequency not 8000, 12000, 16000 or 24000 Hertz 
", errcode); 
			break;
		case SKP_SILK_ENC_PACKET_SIZE_NOT_SUPPORTED:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Packet size not 20, 40, 60, 80 or 100 ms
", errcode); 
			break;			
		case SKP_SILK_ENC_PAYLOAD_BUF_TOO_SHORT:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Allocated payload buffer too short 
", errcode);
			break;
		case SKP_SILK_ENC_WRONG_LOSS_RATE:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Loss rate not between 0 and 100 percent
", errcode); 
			break;
		case SKP_SILK_ENC_WRONG_COMPLEXITY_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Complexity setting not valid, use 0, 1 or 2
", errcode); 
			break;		
		case SKP_SILK_ENC_WRONG_INBAND_FEC_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Inband FEC setting not valid, use 0 or 1
", errcode);
			break;
		case SKP_SILK_ENC_WRONG_DTX_SETTING:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
DTX setting not valid, use 0 or 1
", errcode); 
			break;
		case SKP_SILK_ENC_INTERNAL_ERROR:
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!!!!! Decode_Error_Message: %d
Internal encoder error
", errcode); 
			break;				
	}
}

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK24_encode
    (JNIEnv *env, jobject obj, jshortArray lin, jint offset, jbyteArray encoded, jint size) {

    jbyte	  enc_payload[ MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES ];
    jshort    in[ MAX_FRAME_LENGTH * MAX_INPUT_FRAMES ];	
	int ret,i,frsz=MAX_FRAME;
	SKP_int16 nBytes;
	unsigned int lin_pos = 0;
	
	if (!codec_open)
		return 0;
		
#ifdef DEBUG_SILK24
    __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "encoding frame size: %d	offset: %d
", size, offset); 		
#endif


	for (i = 0; i < size; i+=MAX_FRAME) {
#ifdef DEBUG_SILK24
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
            "encoding frame size: %d	offset: %d i: %d
", size, offset, i); 		
#endif
			
		env->GetShortArrayRegion(lin, offset + i,frsz, in);
        /* max payload size */
        nBytes = MAX_BYTES_ENC_PER_FRAME * MAX_INPUT_FRAMES;

        ret = SKP_Silk_SDK_Encode( psEnc, &encControl, in, (SKP_int16)frsz, (SKP_uint8 *)enc_payload, &nBytes );
        if( ret ) {
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!! SKP_Silk_Encode returned: %d
", ret);
			Print_Encode_Error_Msg(ret);				
            break;
        }
#ifdef DEBUG_SILK24
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"Enocded nBytes: %d
", nBytes); 		
#endif		
        /* Write payload */		
		env->SetByteArrayRegion(encoded, RTP_HDR_SIZE+ lin_pos, nBytes, enc_payload);
		lin_pos += nBytes;
	}
#ifdef DEBUG_SILK24
	__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
        "encoding **END** frame size: %d	offset: %d i: %d lin_pos: %d
", size, offset, i, lin_pos);
#endif		

    return (jint)lin_pos;
}

extern "C"
JNIEXPORT jint JNICALL Java_com_trunkbow_silk_SILK24_decode
    (JNIEnv *env, jobject obj, jbyteArray encoded, jshortArray lin, jint size) {

    jbyte buffer [MAX_BYTES_DEC_PER_FRAME * MAX_INPUT_FRAMES * ( MAX_LBRR_DELAY + 1 ) ];
    jshort output_buffer[( MAX_FRAME_LENGTH << 1 ) * MAX_INPUT_FRAMES ];
//	SKP_int16	*outPtr;

	int ret;
	SKP_int16 len;
//	int	tot_len,frames;

	if (!codec_open)
		return 0;

#ifdef DEBUG_SILK24		
	__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
        "##### BEGIN DECODE ********  decoding frame size: %d
", size); 	
#endif

	env->GetByteArrayRegion(encoded, RTP_HDR_SIZE, size, buffer);

//	outPtr = output_buffer;
//    tot_len = 0;
//	frames = 0;

//	do {
		ret = SKP_Silk_SDK_Decode( psDec, &DecControl, 0,(SKP_uint8 *) buffer, size, output_buffer,&len );
		if( ret ) {
			__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
				"!!!!!!!! SKP_Silk_SDK_Decode returned: %d
", ret); 	
			Print_Decode_Error_Msg(ret);
		}
#ifdef DEBUG_SILK24		
		__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, 
			"##### DECODED length: %d
	 Frame #: %d", len); 	
#endif
//		frames++;
//		outPtr  += len;
//		tot_len += len;		
	
//	} while( DecControl.moreInternalDecoderFrames );

	env->SetShortArrayRegion(lin, 0, len,output_buffer);
	return (jint)len;
}

extern "C"
JNIEXPORT void JNICALL Java_com_trunkbow_silk_SILK24_close
    (JNIEnv *env, jobject obj) {

	if (--codec_open != 0)
		return;
    /* Free decoder */
    free( psDec );
    /* Free Encoder */
    free( psEnc );
}

6、在Java层创建Speex工具类，内容如下：

Silk8.java：

class SILK8{   
	/* 
	 *                 | fs (Hz) | BR (kbps)
	 * ----------------+---------+---------
	 * Narrowband	   | 8000    | 6 -20
	 * Mediumband      | 12000   | 7 -25
	 * Wideband        | 16000   | 8 -30
	 * Super Wideband  | 24000   | 12 -40
	 *
	 * Table 1: fs specifies the audio sampling frequency in Hertz (Hz); BR
	 * specifies the adaptive bit rate range in kilobits per second (kbps).
	 * 
	 * Complexity can be scaled to optimize for CPU resources in real-time,
	 * mostly in trade-off to network bit rate. 0 is least CPU demanding and
	 * highest bit rate. 
	 */
	private static final int DEFAULT_COMPLEXITY = 0;
	
	void load() {
		 System.loadLibrary("silk8_jni");
	}  
 
	public native int open(int compression);
	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();
}

Silk16.java：

class SILK16 { 
	/* 
	 *                 | fs (Hz) | BR (kbps)
	 * ----------------+---------+---------
	 * Narrowband	   | 8000    | 6 -20
	 * Mediumband      | 12000   | 7 -25
	 * Wideband        | 16000   | 8 -30
	 * Super Wideband  | 24000   | 12 -40
	 *
	 * Table 1: fs specifies the audio sampling frequency in Hertz (Hz); BR
	 * specifies the adaptive bit rate range in kilobits per second (kbps).
	 * 
	 * Complexity can be scaled to optimize for CPU resources in real-time,
	 * mostly in trade-off to network bit rate. 0 is least CPU demanding and
	 * highest bit rate. 
	 */
	private static final int DEFAULT_COMPLEXITY = 0;


	void load() {
		System.loadLibrary("silk16_jni");
	}  
 
	public native int open(int compression);
	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();

}

Silk24.java：

class SILK24  { 
	/* 
	 *                 | fs (Hz) | BR (kbps)
	 * ----------------+---------+---------
	 * Narrowband	   | 8000    | 6 -20
	 * Mediumband      | 12000   | 7 -25
	 * Wideband        | 16000   | 8 -30
	 * Super Wideband  | 24000   | 12 -40
	 *
	 * Table 1: fs specifies the audio sampling frequency in Hertz (Hz); BR
	 * specifies the adaptive bit rate range in kilobits per second (kbps).
	 * 
	 * Complexity can be scaled to optimize for CPU resources in real-time,
	 * mostly in trade-off to network bit rate. 0 is least CPU demanding and
	 * highest bit rate. 
	 */
	private static final int DEFAULT_COMPLEXITY = 0;

	void load() {
		System.loadLibrary("silk24_jni");
	}  
 
	public native int open(int compression);
	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();

}

7、使用cygwin编译，生成so文件。
参考：http://developer.skype.com/silk
http://blog.csdn.net/wanggp_2007/article/details/5540686 Skype SILK vs. iLBC vs. Speex