Android 音頻開發 目錄
- Android音頻開發(1):音頻相關知識
- Android音頻開發(2):使用AudioRecord錄制pcm格式音頻
- Android音頻開發(3):使用AudioRecord實作錄音的暫停和恢複
- Android音頻開發(4):PCM轉WAV格式音頻
- Android音頻開發(5):Mp3的錄制 - 編譯Lame源碼
- Android音頻開發(6):Mp3的錄制 - 使用Lame實時錄制MP3格式音頻
- Android音頻開發(7):音樂可視化-FFT頻譜圖
項目位址
https://github.com/zhaolewei/ZlwAudioRecorder
編譯 so包
1.下載下傳lame
官網(科學上網): http://lame.sourceforge.net/download.php
lame-3.100:https://pan.baidu.com/s/1U77GAq1nn3bVXFMEhRyo8g
2.使用ndk-build編譯源碼
2.1 在任意位置建立如下的目錄結構:
![](https://img.laitimes.com/img/9ZDMuAjOiMmIsIjOiQnIsICM0ITMvw1dvwlMvwlM3VWaWV2Zh1WaDdTJwlmc0N3LcRnbllmcv1yb0VXYvwlMyd2bNV2Zh1Wa-QTZwM2MwYTYzYDZ0QTZyYWLwAzNzUjM08CXzV2Zh1WafRWYvxGc19CXvlmL1h2cuFWaq5ycldWYtlWLkF2bsBXdvw1LcpDc0RHaiojIsJye.jpg)
檔案夾名稱随意,與.mk 檔案中路徑一緻即可
2.2 解壓下載下傳好的lame源碼
解壓後将其
/lame-3.100/libmp3lame/
目錄中.c和.h檔案和
/lame-3.100//include/
中的 lame.h拷貝到/jni/lame-3.100_libmp3lame中
3.100版本 有42個檔案
2.3 修改部分檔案
- 删除fft.c檔案的47行的
#include "vector/lame_intrin.h"
- 删除set_get.h檔案的24行的
#include <lame.h>
- 将util.h檔案的570行的
替換為extern ieee754_float32_t fast_log2(ieee754_float32_t x);
extern float fast_log2(float x);
2.4 編寫Mp3Encoder.c 和 Mp3Encoder.h 對接java代碼
2.4.1 Mp3Encoder.c
- 注意修改包名
#include "lame-3.100_libmp3lame/lame.h"
#include "Mp3Encoder.h"
static lame_global_flags *glf = NULL;
//TODO這裡包名要與java中對接檔案的路徑一緻(這裡是路徑是com.zlw.main.recorderlib.recorder.mp3,java檔案: Mp3Encoder.java),下同
JNIEXPORT void JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_init(
JNIEnv *env, jclass cls, jint inSamplerate, jint outChannel,
jint outSamplerate, jint outBitrate, jint quality) {
if (glf != NULL) {
lame_close(glf);
glf = NULL;
}
glf = lame_init();
lame_set_in_samplerate(glf, inSamplerate);
lame_set_num_channels(glf, outChannel);
lame_set_out_samplerate(glf, outSamplerate);
lame_set_brate(glf, outBitrate);
lame_set_quality(glf, quality);
lame_init_params(glf);
}
JNIEXPORT jint JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_encode(
JNIEnv *env, jclass cls, jshortArray buffer_l, jshortArray buffer_r,
jint samples, jbyteArray mp3buf) {
jshort* j_buffer_l = (*env)->GetShortArrayElements(env, buffer_l, NULL);
jshort* j_buffer_r = (*env)->GetShortArrayElements(env, buffer_r, NULL);
const jsize mp3buf_size = (*env)->GetArrayLength(env, mp3buf);
jbyte* j_mp3buf = (*env)->GetByteArrayElements(env, mp3buf, NULL);
int result = lame_encode_buffer(glf, j_buffer_l, j_buffer_r,
samples, j_mp3buf, mp3buf_size);
(*env)->ReleaseShortArrayElements(env, buffer_l, j_buffer_l, 0);
(*env)->ReleaseShortArrayElements(env, buffer_r, j_buffer_r, 0);
(*env)->ReleaseByteArrayElements(env, mp3buf, j_mp3buf, 0);
return result;
}
JNIEXPORT jint JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_flush(
JNIEnv *env, jclass cls, jbyteArray mp3buf) {
const jsize mp3buf_size = (*env)->GetArrayLength(env, mp3buf);
jbyte* j_mp3buf = (*env)->GetByteArrayElements(env, mp3buf, NULL);
int result = lame_encode_flush(glf, j_mp3buf, mp3buf_size);
(*env)->ReleaseByteArrayElements(env, mp3buf, j_mp3buf, 0);
return result;
}
JNIEXPORT void JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_close(
JNIEnv *env, jclass cls) {
lame_close(glf);
glf = NULL;
}
2.4.2 Mp3Encoder.h
- 注意修改包名
/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
#ifndef _Included_Mp3Encoder
#define _Included_Mp3Encoder
#ifdef __cplusplus
extern "C" {
#endif
/*
* Class: com.zlw.main.recorderlib.recorder.mp3.Mp3Encoder
* Method: init
*/
JNIEXPORT void JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_init
(JNIEnv *, jclass, jint, jint, jint, jint, jint);
JNIEXPORT jint JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_encode
(JNIEnv *, jclass, jshortArray, jshortArray, jint, jbyteArray);
JNIEXPORT jint JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_flush
(JNIEnv *, jclass, jbyteArray);
JNIEXPORT void JNICALL Java_com_zlw_main_recorderlib_recorder_mp3_Mp3Encoder_close
(JNIEnv *, jclass);
#ifdef __cplusplus
}
#endif
#endif
2.5 編寫Android.mk 和Application.mk
- 路徑與建立的目錄應當一緻
2.5.1 Android.mk
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LAME_LIBMP3_DIR := lame-3.100_libmp3lame
LOCAL_MODULE := mp3lame
LOCAL_SRC_FILES :=\
$(LAME_LIBMP3_DIR)/bitstream.c \
$(LAME_LIBMP3_DIR)/fft.c \
$(LAME_LIBMP3_DIR)/id3tag.c \
$(LAME_LIBMP3_DIR)/mpglib_interface.c \
$(LAME_LIBMP3_DIR)/presets.c \
$(LAME_LIBMP3_DIR)/quantize.c \
$(LAME_LIBMP3_DIR)/reservoir.c \
$(LAME_LIBMP3_DIR)/tables.c \
$(LAME_LIBMP3_DIR)/util.c \
$(LAME_LIBMP3_DIR)/VbrTag.c \
$(LAME_LIBMP3_DIR)/encoder.c \
$(LAME_LIBMP3_DIR)/gain_analysis.c \
$(LAME_LIBMP3_DIR)/lame.c \
$(LAME_LIBMP3_DIR)/newmdct.c \
$(LAME_LIBMP3_DIR)/psymodel.c \
$(LAME_LIBMP3_DIR)/quantize_pvt.c \
$(LAME_LIBMP3_DIR)/set_get.c \
$(LAME_LIBMP3_DIR)/takehiro.c \
$(LAME_LIBMP3_DIR)/vbrquantize.c \
$(LAME_LIBMP3_DIR)/version.c \
MP3Encoder.c
include $(BUILD_SHARED_LIBRARY)
2.5.2 Application.mk
- 若隻需要編譯armeabi的so包可将其他删除
APP_ABI := armeabi armeabi-v7a arm64-v8a x86 x86_64 mips mips64
APP_MODULES := mp3lame
APP_CFLAGS += -DSTDC_HEADERS
APP_PLATFORM := android-21
編譯
到達這一步,所有的檔案都已經準備好了
在指令行中切換到jni目錄中,執行ndk-build開始編譯
若果不能識别ndk-build指令 需要配置下環境變量