cmake_minimum_required(VERSION 3.4.1)
# file(GLOB SOURCE src/main/cpp/*.cpp)
file(GLOB SOURCE ${CMAKE_SOURCE_DIR}/*.cpp)
add_library( # Sets the name of the library.
neplayer
SHARED
${SOURCE})
find_library( # Sets the name of the path variable.
log-lib
log)
# include_directories(src/main/cpp/include)
include_directories(${CMAKE_SOURCE_DIR}/include)
set(my_lib_path ${CMAKE_SOURCE_DIR}/../../../libs/${CMAKE_ANDROID_ARCH_ABI})
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -L${my_lib_path}")
# message(WARNING "cmake_source_dir = ${CMAKE_SOURCE_DIR}") #E:/AndroidWangYiCloud/NDKWorkspace/NeVideoDecodeSync/app/src/main/cpp
target_link_libraries( # Specifies the target library.
neplayer
# avcodec avfilter avformat avutil swresample swscale
avfilter avformat avcodec avutil swresample swscale
${log-lib}
android #系统库,在 D:\AndroidDev\AndroidStudio\sdk\ndk-bundle\platforms\android-21\arch-arm\usr\lib
z
OpenSLES)#include <jni.h>
#include <string>
#include <android/log.h>
#define LOGI(FORMAT,...) __android_log_print(ANDROID_LOG_INFO, "sty", FORMAT, ##__VA_ARGS__);
#define LOGE(FORMAT,...) __android_log_print(ANDROID_LOG_ERROR, "sty", FORMAT, ## __VA_ARGS__);
#define MAX_AUDIO_FRME_SIZE 48000 * 4
extern "C" {
//封装格式
#include <libavformat/avformat.h>
//解码
#include <libavcodec/avcodec.h>
//缩放
#include <libswscale/swscale.h>
//重采样
#include <libswresample/swresample.h>
}
extern "C"
JNIEXPORT void JNICALL
Java_com_sty_ne_audio_decodesync_AudioPlayer_sound(JNIEnv *env, jobject thiz, jstring input_,
jstring output_) {
const char* input = env->GetStringUTFChars(input_, 0);
const char* output = env->GetStringUTFChars(output_, 0);
avformat_network_init();
//总上下文
AVFormatContext* formatContext = avformat_alloc_context();
//打开音频文件
if(avformat_open_input(&formatContext, input, NULL, NULL) != 0) {
LOGI("%s", "无法打开音频文件");
return;
}
//获取输入文件信息
if(avformat_find_stream_info(formatContext, NULL) < 0) {
LOGI("%s", "无法获取输入文件信息");
return;
}
//音频时长（单位：微妙us，转换为秒需要除以1000000）
int audio_stream_idx = -1;
for(int i = 0; i < formatContext->nb_streams; i++){
if(formatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO){
audio_stream_idx = i;
break;
}
}
//解码器参数
AVCodecParameters* codecpar = formatContext->streams[audio_stream_idx]->codecpar;
//找到解码器
AVCodec* dec = avcodec_find_decoder(codecpar->codec_id);
//创建上下文（packet->frame）
AVCodecContext* codecContext = avcodec_alloc_context3(dec);
avcodec_parameters_to_context(codecContext, codecpar);
//打开解码器
avcodec_open2(codecContext, dec, NULL);
//转换上下文（frame->audio统一格式）
SwrContext* swrContext = swr_alloc();
//输入参数
AVSampleFormat in_sample = codecContext->sample_fmt;
//输入采样率
int in_sample_rate = codecContext->sample_rate;
//输入声道布局
uint64_t in_ch_layout = codecContext->channel_layout;
//输出参数（固定的）
//输出采样格式
AVSampleFormat out_sample = AV_SAMPLE_FMT_S16;
//输出采样
int out_sample_rate = 44100;
//输出声道布局
uint64_t out_ch_layout = AV_CH_LAYOUT_STEREO;
swr_alloc_set_opts(swrContext, out_ch_layout, out_sample, out_sample_rate,
in_ch_layout, in_sample, in_sample_rate, 0, NULL);
//初始化转换器其他的默认参数
swr_init(swrContext);
uint8_t *out_buffer = static_cast<uint8_t *>(av_malloc(2 * 44100));
FILE* fp_pcm = fopen(output, "wb");
//读取包 压缩数据 转换过程参考：show/packet_to_frame.png
AVPacket* packet = av_packet_alloc();
int count = 0;
while (av_read_frame(formatContext, packet) >=0) {
avcodec_send_packet(codecContext, packet);
//解压缩数据 未压缩
AVFrame* frame = av_frame_alloc();
int ret = avcodec_receive_frame(codecContext, frame);
if(ret == AVERROR(EAGAIN)) {
continue;
}else if(ret < 0) {
LOGE("解码完成");
char buf[1024];
av_strerror(ret, buf, 1024);
LOGE("ERROR INFO: %s", buf);
break;
}
if(packet->stream_index != audio_stream_idx) {
continue;
}
LOGE("正在解码%d", count++);
// frame->audio统一格式 转换过程可参考：show/frame_to_audio.png
swr_convert(swrContext, &out_buffer, 2 * 44100, (const uint8_t **)frame->data, frame->nb_samples);
//out_buffer->file
int out_channel_nb = av_get_channel_layout_nb_channels(out_ch_layout);
//缓冲区的大小
int out_buffer_size = av_samples_get_buffer_size(NULL, out_channel_nb, frame->nb_samples,
out_sample, 1);
//字节：最小1字节 像素：最小4字节
fwrite(out_buffer, 1, out_buffer_size, fp_pcm);
}
fclose(fp_pcm);
av_free(out_buffer);
swr_free(&swrContext);
avcodec_close(codecContext);
avformat_close_input(&formatContext);
env->ReleaseStringUTFChars(input_, input);
env->ReleaseStringUTFChars(output_, output);
}
public class MainActivity extends AppCompatActivity {
private static final int MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE = 1;
private static final String FILE_DIR= Environment.getExternalStorageDirectory() + File.separator
+ "sty" + File.separator; // /storage/emulated/0/sty/
private Button btnStart;
private AudioPlayer audioPlayer;
private String inputStr;
private String outputStr;
static {
System.loadLibrary("neplayer");
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initView();
requestPermission();
}
private void initView() {
btnStart = findViewById(R.id.btn_start);
btnStart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
decodeAudio();
}
});
}
private void decodeAudio() {
new Thread(new Runnable() {
@Override
public void run() {
audioPlayer = new AudioPlayer();
inputStr = new File(FILE_DIR, "xpg.mp3").getAbsolutePath();
outputStr = new File(FILE_DIR, "out.pcm").getAbsolutePath();
audioPlayer.sound(inputStr, outputStr);
}
}).start();
}
private void requestPermission() {
if(ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED){
if(ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)){
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
}else {
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
}
}
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
switch (requestCode) {
case MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE: {
if(grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED){
Log.i("sty", "onRequestPermissionResult granted");
}else {
Log.i("sty", "onRequestPermissionResult denied");
showWarningDialog();
}
break;
}
default:
break;
}
}
private void showWarningDialog() {
AlertDialog dialog = new AlertDialog.Builder(this)
.setTitle("警告")
.setMessage("请前往设置->应用—>PermissionDemo->权限中打开相关权限，否则功能无法正常使用！")
.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
//finish();
}
}).show();
}
}虽然代码终于是编译通过了，但是安装到真机后，点击“开始解码”按钮生成的文件为0kb。单步调试后发现
int ret = avcodec_receive_frame(codecContext, frame); 这一步的返回值为-23，百思不得其解。于是添加如下代码：
char buf[1024];
av_strerror(ret, buf, 1024);
LOGE("ERROR INFO: %s", buf); 输出的结果为invalid argument，后经仔细检查，发现是漏掉了打开解码器的方法：
avcodec_open2(codecContext, dec, NULL);，加上之后才解决了问题。
在此获取一种解析错误原因，然后根据原因找错误的解决问题的思路。
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