Android多媒体之LAME MP3录音转换

1、有编译JNI的环境，NDK，Android环境

2、下载LAME源码进行编辑
下载地址

3、在android环境中如何导入Lame的源码进行编译  http://developer.samsung.com/technical-doc/view.do?v=T000000090点击打开链接

4、JNI的代码

#include <stdio.h>
#include <stdlib.h>
#include <jni.h>
#include <android/log.h>
#include "libmp3lame/lame.h"

#define LOG_TAG "LAME ENCODER"
#define LOGD(format, args...)  __android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, format, ##args);
#define BUFFER_SIZE 8192
#define be_short(s) ((short) ((unsigned short) (s) << 8) | ((unsigned short) (s) >> 8))

lame_t lame;

int read_samples(FILE *input_file, short *input) {
int nb_read;
nb_read = fread(input, 1, sizeof(short), input_file) / sizeof(short);

int i = 0;
while (i < nb_read) {
input[i] = be_short(input[i]);
i++;
}

return nb_read;
}

void Java_com_samsung_sample_lame4android_LameActivity_initEncoder(JNIEnv *env,
jobject jobj, jint in_num_channels, jint in_samplerate, jint in_brate,
jint in_mode, jint in_quality) {
lame = lame_init();

LOGD("Init parameters:");
lame_set_num_channels(lame, in_num_channels);
LOGD("Number of channels: %d", in_num_channels);
lame_set_in_samplerate(lame, in_samplerate);
LOGD("Sample rate: %d", in_samplerate);
lame_set_brate(lame, in_brate);
LOGD("Bitrate: %d", in_brate);
lame_set_mode(lame, in_mode);
LOGD("Mode: %d", in_mode);
lame_set_quality(lame, in_quality);
LOGD("Quality: %d", in_quality);

int res = lame_init_params(lame);
LOGD("Init returned: %d", res);
}

void Java_com_samsung_sample_lame4android_LameActivity_destroyEncoder(
JNIEnv *env, jobject jobj) {
int res = lame_close(lame);
LOGD("Deinit returned: %d", res);
}

void Java_com_samsung_sample_lame4android_LameActivity_encodeFile(JNIEnv *env,
jobject jobj, jstring in_source_path, jstring in_target_path) {
const char *source_path, *target_path;
source_path = (*env)->GetStringUTFChars(env, in_source_path, NULL);
target_path = (*env)->GetStringUTFChars(env, in_target_path, NULL);

FILE *input_file, *output_file;
input_file = fopen(source_path, "rb");
output_file = fopen(target_path, "wb");

short input[BUFFER_SIZE];
char output[BUFFER_SIZE];
int nb_read = 0;
int nb_write = 0;
int nb_total = 0;

LOGD("Encoding started");
while (nb_read = read_samples(input_file, input)) {
nb_write = lame_encode_buffer(lame, input, input, nb_read, output,
BUFFER_SIZE);
fwrite(output, nb_write, 1, output_file);
nb_total += nb_write;
}
LOGD("Encoded %d bytes", nb_total);

nb_write = lame_encode_flush(lame, output, BUFFER_SIZE);
fwrite(output, nb_write, 1, output_file);
LOGD("Flushed %d bytes", nb_write);

fclose(input_file);
fclose(output_file);
}

5、参考资料

http://ikinglai.blog.51cto.com/6220785/1228730 

https://github.com/telescreen/AndroidMp3Recorder

http://wenku.baidu.com/view/70cebd3e580216fc700afd51?from_page=view&from_mod=download

下载源码