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

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1. LOCAL_PATH :=
   $(call my-dir)
2. include
   $(CLEAR_VARS)
3. LOCAL_MODULE   
   := libspeex


4. LOCAL_CFLAGS
   = -DFIXED_POINT -DUSE_KISS_FFT -DEXPORT="" -UHAVE_CONFIG_H


5. LOCAL_C_INCLUDES
   := $(LOCAL_PATH)/include
6. LOCAL_SRC_FILES
   :=  \


7. ./speex_jni.cpp
   \


8. ./libspeex/bits.c
   \


9. ./libspeex/buffer.c
   \


10. ./libspeex/cb_search.c
    \


11. ./libspeex/exc_10_16_table.c
    \


12. ./libspeex/exc_10_32_table.c
    \


13. ./libspeex/exc_20_32_table.c
    \


14. ./libspeex/exc_5_256_table.c
    \


15. ./libspeex/exc_5_64_table.c
    \


16. ./libspeex/exc_8_128_table.c
    \


17. ./libspeex/fftwrap.c
    \


18. ./libspeex/filterbank.c
    \


19. ./libspeex/filters.c
    \


20. ./libspeex/gain_table.c
    \


21. ./libspeex/gain_table_lbr.c
    \


22. ./libspeex/hexc_10_32_table.c
    \


23. ./libspeex/hexc_table.c
    \


24. ./libspeex/high_lsp_tables.c
    \


25. ./libspeex/jitter.c
    \


26. ./libspeex/kiss_fft.c
    \


27. ./libspeex/kiss_fftr.c
    \


28. ./libspeex/lpc.c
    \


29. ./libspeex/lsp.c
    \


30. ./libspeex/lsp_tables_nb.c
    \


31. ./libspeex/ltp.c
    \


32. ./libspeex/mdf.c
    \


33. ./libspeex/modes.c
    \


34. ./libspeex/modes_wb.c
    \


35. ./libspeex/nb_celp.c
    \


36. ./libspeex/preprocess.c
    \


37. ./libspeex/quant_lsp.c
    \


38. ./libspeex/resample.c
    \


39. ./libspeex/sb_celp.c
    \


40. ./libspeex/scal.c
    \


41. ./libspeex/smallft.c
    \


42. ./libspeex/speex.c
    \


43. ./libspeex/speex_callbacks.c
    \


44. ./libspeex/speex_header.c
    \


45. ./libspeex/stereo.c
    \


46. ./libspeex/vbr.c
    \


47. ./libspeex/vq.c
    \


48. ./libspeex/window.c
49. include
    $(BUILD_SHARED_LIBRARY)

5.在jni目录下新增Application.mk文件，编辑内容如下

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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

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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

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1. #include <jni.h>
2. #include <string.h>


3. #include <unistd.h>
4. #include <speex/speex.h>
5. staticint
   codec_open = 0;
6. staticint
   dec_frame_size;


7. staticint
   enc_frame_size;
8. static
   SpeexBits ebits, dbits;


9. void
   *enc_state;


10. void
    *dec_state;
11. static
    JavaVM *gJavaVM;
12. extern"C"


13. JNIEXPORT
    jint JNICALL Java_com_audio_Speex_open


14. (JNIEnv *env, jobject obj, jint compression) {


15. int
    tmp;
16. if
    (codec_open++ != 0)


17. return
    (jint)0;
18. speex_bits_init(&ebits);


19. speex_bits_init(&dbits);
20. enc_state = speex_encoder_init(&speex_nb_mode);


21. dec_state = speex_decoder_init(&speex_nb_mode);


22. tmp = compression;


23. speex_encoder_ctl(enc_state, SPEEX_SET_QUALITY, &tmp);


24. speex_encoder_ctl(enc_state, SPEEX_GET_FRAME_SIZE, &enc_frame_size);


25. speex_decoder_ctl(dec_state, SPEEX_GET_FRAME_SIZE, &dec_frame_size);
26. return
    (jint)0;


27. }
28. extern"C"


29. JNIEXPORT
    jint Java_com_audio_Speex_encode


30. (JNIEnv *env, jobject obj, jshortArray lin, jint offset, jbyteArray encoded,
    jint size) {
31. jshort buffer[enc_frame_size];


32. jbyte output_buffer[enc_frame_size];


33. int
    nsamples = (size-1)/enc_frame_size + 1;


34. int
    i, tot_bytes = 0;
35. if
    (!codec_open)


36. return
    0;
37. speex_bits_reset(&ebits);
38. for
    (i = 0; i < nsamples; i++) {


39. env->GetShortArrayRegion(lin, offset + i*enc_frame_size, enc_frame_size,
    buffer);


40. speex_encode_int(enc_state, buffer, &ebits);


41. }


42. //env->GetShortArrayRegion(lin, offset, enc_frame_size,
    buffer);


43. //speex_encode_int(enc_state, buffer, &ebits);
44. tot_bytes = speex_bits_write(&ebits, (char
    *)output_buffer,


45. enc_frame_size);


46. env->SetByteArrayRegion(encoded, 0, tot_bytes,


47. output_buffer);
48. return
    (jint)tot_bytes;


49. }
50. extern"C"


51. JNIEXPORT
    jint JNICALL Java_com_audio_Speex_decode


52. (JNIEnv *env, jobject obj, jbyteArray encoded, jshortArray lin, jint size)
    {
53. jbyte buffer[dec_frame_size];


54. jshort output_buffer[dec_frame_size];


55. jsize encoded_length = size;
56. if
    (!codec_open)


57. return
    0;
58. env->GetByteArrayRegion(encoded, 0, encoded_length, buffer);


59. speex_bits_read_from(&dbits, (char
    *)buffer, encoded_length);


60. speex_decode_int(dec_state, &dbits, output_buffer);


61. env->SetShortArrayRegion(lin, 0, dec_frame_size,


62. output_buffer);
63. return
    (jint)dec_frame_size;


64. }
65. extern"C"


66. JNIEXPORT
    jint JNICALL Java_com_audio_getFrameSize


67. (JNIEnv *env, jobject obj) {
68. if
    (!codec_open)


69. return
    0;


70. return
    (jint)enc_frame_size;
71. }
72. extern"C"


73. JNIEXPORT
    void
    JNICALL Java_com_audio_Speex_close


74. (JNIEnv *env, jobject obj) {
75. if
    (--codec_open != 0)


76. return;
77. speex_bits_destroy(&ebits);


78. speex_bits_destroy(&dbits);


79. speex_decoder_destroy(dec_state);


80. speex_encoder_destroy(enc_state);


81. }

8.在Java层创建Speex工具类，内容如下

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1. package
   com.audio;
2. class
   Speex  {
3. /* quality


4. * 1 : 4kbps (very noticeable
   artifacts, usually intelligible)


5. * 2 : 6kbps (very noticeable
   artifacts, good intelligibility)


6. * 4 : 8kbps (noticeable artifacts
   sometimes)


7. * 6 : 11kpbs (artifacts usually only
   noticeable with headphones)


8. * 8 : 15kbps (artifacts not usually
   noticeable)


9. */


10. privatestaticfinalint
    DEFAULT_COMPRESSION = 8;
11. Speex() {


12. }
13. publicvoid
    init() {


14. load();


15. open(DEFAULT_COMPRESSION);


16. }
17. privatevoid
    load() {


18. try
    {


19. System.loadLibrary("speex");


20. } catch
    (Throwable e) {


21. e.printStackTrace();


22. }
23. }
24. publicnativeint
    open(int
    compression);


25. publicnativeint
    getFrameSize();


26. publicnativeint
    decode(byte
    encoded[], short
    lin[], int
    size);


27. publicnativeint
    encode(short
    lin[], int
    offset, byte
    encoded[], int
    size);


28. publicnativevoid
    close();
29. }

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

Speex for Android,布布扣,bubuko.com