Speex for Android

在Android开发中,需要录音并发送到对方设备上。这时问题来了,手机常会是GPRS、3G等方式上网,所以节省流量是非常关键的,使用Speex来压缩音频文件,可以将音频压文件小数倍。

1.去Speex官网下载最新Speex源码

2.创建一个新的应用(我创建的应用名为Audio),并创建一个jni目录($project/jni)。

3.把speex源码目录下的libspeex和include目录及其子目录文件全部拷贝到$project/jni目录下($project/jni/libspeex and $project/jni/include)。

4.在jni目录下新增Android.mk文件,编辑内容如下

 

[plain] view plaincopy
 
  1. LOCAL_PATH := $(call my-dir) 
  2.  
  3.  
  4. include $(CLEAR_VARS) 
  5.   
  6. LOCAL_MODULE    := libspeex 
  7. LOCAL_CFLAGS = -DFIXED_POINT -DUSE_KISS_FFT -DEXPORT="" -UHAVE_CONFIG_H 
  8. LOCAL_C_INCLUDES := $(LOCAL_PATH)/include 
  9.   
  10. LOCAL_SRC_FILES :=  \ 
  11. ./speex_jni.cpp \ 
  12. ./libspeex/bits.c \ 
  13. ./libspeex/buffer.c \ 
  14. ./libspeex/cb_search.c \ 
  15. ./libspeex/exc_10_16_table.c \ 
  16. ./libspeex/exc_10_32_table.c \ 
  17. ./libspeex/exc_20_32_table.c \ 
  18. ./libspeex/exc_5_256_table.c \ 
  19. ./libspeex/exc_5_64_table.c \ 
  20. ./libspeex/exc_8_128_table.c \ 
  21. ./libspeex/fftwrap.c \ 
  22. ./libspeex/filterbank.c \ 
  23. ./libspeex/filters.c \ 
  24. ./libspeex/gain_table.c \ 
  25. ./libspeex/gain_table_lbr.c \ 
  26. ./libspeex/hexc_10_32_table.c \ 
  27. ./libspeex/hexc_table.c \ 
  28. ./libspeex/high_lsp_tables.c \ 
  29. ./libspeex/jitter.c \ 
  30. ./libspeex/kiss_fft.c \ 
  31. ./libspeex/kiss_fftr.c \ 
  32. ./libspeex/lpc.c \ 
  33. ./libspeex/lsp.c \ 
  34. ./libspeex/lsp_tables_nb.c \ 
  35. ./libspeex/ltp.c \ 
  36. ./libspeex/mdf.c \ 
  37. ./libspeex/modes.c \ 
  38. ./libspeex/modes_wb.c \ 
  39. ./libspeex/nb_celp.c \ 
  40. ./libspeex/preprocess.c \ 
  41. ./libspeex/quant_lsp.c \ 
  42. ./libspeex/resample.c \ 
  43. ./libspeex/sb_celp.c \ 
  44. ./libspeex/scal.c \ 
  45. ./libspeex/smallft.c \ 
  46. ./libspeex/speex.c \ 
  47. ./libspeex/speex_callbacks.c \ 
  48. ./libspeex/speex_header.c \ 
  49. ./libspeex/stereo.c \ 
  50. ./libspeex/vbr.c \ 
  51. ./libspeex/vq.c \ 
  52. ./libspeex/window.c 
  53.   
  54. include $(BUILD_SHARED_LIBRARY) 


5.在jni目录下新增Application.mk文件,编辑内容如下

 

 

[plain] view plaincopy
 
  1. APP_ABI := armeabi armeabi-v7a 


6.在$project/jni/include/speex/目录下新增speex_config_types.h文件,编辑内容如下

 

 

[cpp] view plaincopy
 
  1. #ifndef __SPEEX_TYPES_H__ 
  2. #define __SPEEX_TYPES_H__ 
  3. typedefshort spx_int16_t; 
  4. typedef unsigned short spx_uint16_t; 
  5. typedefint spx_int32_t; 
  6. typedef unsigned int spx_uint32_t; 
  7. #endif 

 

7.创建JNI包装类speex_jni.cpp,用来调用Speex中的C代码函数,编辑内容如下

 

[cpp] view plaincopy
 
  1. #include <jni.h> 
  2.  
  3. #include <string.h> 
  4. #include <unistd.h> 
  5.  
  6. #include <speex/speex.h> 
  7.  
  8. staticint codec_open = 0; 
  9.  
  10. staticint dec_frame_size; 
  11. staticint enc_frame_size; 
  12.  
  13. static SpeexBits ebits, dbits; 
  14. void *enc_state; 
  15. void *dec_state; 
  16.  
  17. static JavaVM *gJavaVM; 
  18.  
  19. extern"C" 
  20. JNIEXPORT jint JNICALL Java_com_audio_Speex_open 
  21.   (JNIEnv *env, jobject obj, jint compression) { 
  22.     int tmp; 
  23.  
  24.     if (codec_open++ != 0) 
  25.         return (jint)0; 
  26.  
  27.     speex_bits_init(&ebits); 
  28.     speex_bits_init(&dbits); 
  29.  
  30.     enc_state = speex_encoder_init(&speex_nb_mode); 
  31.     dec_state = speex_decoder_init(&speex_nb_mode); 
  32.     tmp = compression; 
  33.     speex_encoder_ctl(enc_state, SPEEX_SET_QUALITY, &tmp); 
  34.     speex_encoder_ctl(enc_state, SPEEX_GET_FRAME_SIZE, &enc_frame_size); 
  35.     speex_decoder_ctl(dec_state, SPEEX_GET_FRAME_SIZE, &dec_frame_size); 
  36.  
  37.     return (jint)0; 
  38.  
  39. extern"C" 
  40. JNIEXPORT jint Java_com_audio_Speex_encode 
  41.     (JNIEnv *env, jobject obj, jshortArray lin, jint offset, jbyteArray encoded, jint size) { 
  42.  
  43.         jshort buffer[enc_frame_size]; 
  44.         jbyte output_buffer[enc_frame_size]; 
  45.     int nsamples = (size-1)/enc_frame_size + 1; 
  46.     int i, tot_bytes = 0; 
  47.  
  48.     if (!codec_open) 
  49.         return 0; 
  50.  
  51.     speex_bits_reset(&ebits); 
  52.  
  53.     for (i = 0; i < nsamples; i++) { 
  54.         env->GetShortArrayRegion(lin, offset + i*enc_frame_size, enc_frame_size, buffer); 
  55.         speex_encode_int(enc_state, buffer, &ebits); 
  56.     } 
  57.     //env->GetShortArrayRegion(lin, offset, enc_frame_size, buffer); 
  58.     //speex_encode_int(enc_state, buffer, &ebits); 
  59.  
  60.     tot_bytes = speex_bits_write(&ebits, (char *)output_buffer, 
  61.                      enc_frame_size); 
  62.     env->SetByteArrayRegion(encoded, 0, tot_bytes, 
  63.                 output_buffer); 
  64.  
  65.         return (jint)tot_bytes; 
  66.  
  67. extern"C" 
  68. JNIEXPORT jint JNICALL Java_com_audio_Speex_decode 
  69.     (JNIEnv *env, jobject obj, jbyteArray encoded, jshortArray lin, jint size) { 
  70.  
  71.         jbyte buffer[dec_frame_size]; 
  72.         jshort output_buffer[dec_frame_size]; 
  73.         jsize encoded_length = size; 
  74.  
  75.     if (!codec_open) 
  76.         return 0; 
  77.  
  78.     env->GetByteArrayRegion(encoded, 0, encoded_length, buffer); 
  79.     speex_bits_read_from(&dbits, (char *)buffer, encoded_length); 
  80.     speex_decode_int(dec_state, &dbits, output_buffer); 
  81.     env->SetShortArrayRegion(lin, 0, dec_frame_size, 
  82.                  output_buffer); 
  83.  
  84.     return (jint)dec_frame_size; 
  85.  
  86. extern"C" 
  87. JNIEXPORT jint JNICALL Java_com_audio_getFrameSize 
  88.     (JNIEnv *env, jobject obj) { 
  89.  
  90.     if (!codec_open) 
  91.         return 0; 
  92.     return (jint)enc_frame_size; 
  93.  
  94.  
  95. extern"C" 
  96. JNIEXPORT void JNICALL Java_com_audio_Speex_close 
  97.     (JNIEnv *env, jobject obj) { 
  98.  
  99.     if (--codec_open != 0) 
  100.         return
  101.  
  102.     speex_bits_destroy(&ebits); 
  103.     speex_bits_destroy(&dbits); 
  104.     speex_decoder_destroy(dec_state); 
  105.     speex_encoder_destroy(enc_state); 


8.在Java层创建Speex工具类,内容如下

 

 

[java] view plaincopy
 
  1. package com.audio; 
  2.  
  3. class Speex  { 
  4.  
  5.     /* quality
  6.      * 1 : 4kbps (very noticeable artifacts, usually intelligible)
  7.      * 2 : 6kbps (very noticeable artifacts, good intelligibility)
  8.      * 4 : 8kbps (noticeable artifacts sometimes)
  9.      * 6 : 11kpbs (artifacts usually only noticeable with headphones)
  10.      * 8 : 15kbps (artifacts not usually noticeable)
  11.      */ 
  12.     privatestaticfinalint DEFAULT_COMPRESSION = 8
  13.  
  14.     Speex() { 
  15.     } 
  16.  
  17.     publicvoid init() { 
  18.         load();  
  19.         open(DEFAULT_COMPRESSION); 
  20.     } 
  21.      
  22.     privatevoid load() { 
  23.         try
  24.             System.loadLibrary("speex"); 
  25.         } catch (Throwable e) { 
  26.             e.printStackTrace(); 
  27.         } 
  28.  
  29.     } 
  30.  
  31.     publicnativeint open(int compression); 
  32.     publicnativeint getFrameSize(); 
  33.     publicnativeint decode(byte encoded[], short lin[], int size); 
  34.     publicnativeint encode(short lin[], int offset, byte encoded[], int size); 
  35.     publicnativevoid close(); 
  36.      

 

9.打开cygwin工具,切换到项目目录(我项目是在F:\workspace\Audio),输入$NDK/ndk-build

cygwin工具的安装与配置,可以看这篇文章——使用NDK与环境搭建

 

 

会在项目中生成libs目录和libspeex.so文件,这就是Speex类中System.loadLibrary("speex");代码引用的,系统会根据操作系统由"speex"找到对应的动态库libspeex.so,Windows下是.dll文件,linux下是.so文件。

当前,我的项目结构如下图

posted @ 2014-06-01 14:27  疯子FK  阅读(1390)  评论(0编辑  收藏  举报