之前 写了Android中怎么引入FFMmpeg的例子 。
本编文章将会写一个简单的demo实现ffmpeg拉去rtsp流并在界面中打印前五个字节
懒得往下细看的可以点击这里下载工程 基于andorid studio
实际效果下图：
android 用ffmpeg 拉取rtsp流 解出h264数据
看下目录结构：
很简单 应用进去之后有一个主界面MainActivity 主界面有一个按钮点击一下进入一个新的界面会显示解封装的h264数据的包的大小 和前5个字节
MainActivity内容如下：
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package com.qmcy.demux;
import androidx.appcompat.app.AppCompatActivity;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.qmcy.demux.databinding.ActivityMainBinding;
public class MainActivity extends AppCompatActivity {
// Used to load the 'demux' library on application startup.
static {
System.loadLibrary("demux");
}
private ActivityMainBinding binding;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = ActivityMainBinding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
// Example of a call to a native method
TextView tv = binding.sampleText;
tv.setText(GetVersion());
Button rtsp = (Button)findViewById(R.id.rtsp);
rtsp.setOnClickListener(new View.OnClickListener(){
@Override
public void onClick(View v)
{
Intent intent = new Intent(MainActivity.this,FFDemuxActivity.class);
startActivity(intent);
}
});
}
/**
* A native method that is implemented by the 'demux' native library,
* which is packaged with this application.
*/
public native String stringFromJNI();
public native String GetVersion();
}FFDemuxActivity代码如下：
package com.qmcy.demux;
import android.Manifest;
import android.content.pm.PackageManager;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceHolder;
import android.view.View;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
public class FFDemuxActivity extends AppCompatActivity implements FFDemuxJava.EventCallback{
private static final String TAG = "FFDemuxActivity";
private static final String[] REQUEST_PERMISSIONS = {
Manifest.permission.WRITE_EXTERNAL_STORAGE,
};
private static final int PERMISSION_REQUEST_CODE = 1;
private FFDemuxJava m_demuxer = null;
private EditText editText;
private boolean mIsTouch = false;
private final String mVideoPath = "rtsp://uer:[email protected]:554/Streaming/Channels/101";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.demux);
editText = findViewById(R.id.output);
m_demuxer = new FFDemuxJava();
m_demuxer.addEventCallback(this);
m_demuxer.init(mVideoPath);
m_demuxer.Start();
}
@Override
protected void onResume() {
super.onResume();
if (!hasPermissionsGranted(REQUEST_PERMISSIONS)) {
ActivityCompat.requestPermissions(this, REQUEST_PERMISSIONS, PERMISSION_REQUEST_CODE);
}
if(m_demuxer != null)
m_demuxer.Start();
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
if (requestCode == PERMISSION_REQUEST_CODE) {
if (!hasPermissionsGranted(REQUEST_PERMISSIONS)) {
Toast.makeText(this, "We need the permission: WRITE_EXTERNAL_STORAGE", Toast.LENGTH_SHORT).show();
}
} else {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
@Override
protected void onPause() {
super.onPause();
if(m_demuxer != null)
{
}
}
@Override
protected void onDestroy() {
m_demuxer.unInit();
super.onDestroy();
}
@Override
public void onPacketEvent(byte[] data) {
Log.d(TAG, "onPacketEvent() called with: size = [" + data.length+ "]"+"["+data[0]+" "+data[1]+" "+data[2]+" "+data[3]+" "+data[4]+" "+data[5]+"]");
String str = "onPacketEvent() called with: size = [" + data.length+ "]"+"["+data[0]+" "+data[1]+" "+data[2]+" "+data[3]+" "+data[4]+" "+data[5]+"]";
runOnUiThread(new Runnable() {
@Override
public void run() {
editText.setText(str);
}
});
}
@Override
public void onMessageEvent(final int msgType, final float msgValue) {
Log.d(TAG, "onPlayerEvent() called with: msgType = [" + msgType + "], msgValue = [" + msgValue + "]");
runOnUiThread(new Runnable() {
@Override
public void run() {
switch (msgType) {
case 1:
break;
default:
break;
}
}
});
}
protected boolean hasPermissionsGranted(String[] permissions) {
for (String permission : permissions) {
if (ActivityCompat.checkSelfPermission(this, permission)
!= PackageManager.PERMISSION_GRANTED) {
return false;
}
}
return true;
}
}
FFDemuxJava代码如下：
package com.qmcy.demux;
import android.view.Surface;
public class FFDemuxJava {
static {
System.loadLibrary("demux");
}
private long m_handle = 0;
private EventCallback mEventCallback = null;
public void init(String url) {
m_handle = native_Init(url);
}
public void Start() {
native_Start(m_handle);
}
public void stop() {
native_Stop(m_handle);
}
public void unInit() {
native_UnInit(m_handle);
}
public void addEventCallback(EventCallback callback) {
mEventCallback = callback;
}
private void playerEventCallback(int msgType, float msgValue) {
if(mEventCallback != null)
mEventCallback.onMessageEvent(msgType, msgValue);
}
private void packetEventCallback(byte[]data) {
if(mEventCallback != null)
mEventCallback.onPacketEvent(data);
}
private native long native_Init(String url);
private native void native_Start(long playerHandle);
private native void native_Stop(long playerHandle);
private native void native_UnInit(long playerHandle);
public interface EventCallback {
void onMessageEvent(int msgType, float msgValue);
void onPacketEvent(byte []data);
}
}
然后C++部分的代码 核心的在FFDemux.cpp中
//
// Created by Administrator on 2022/4/14/014.
//
#include "FFDemux.h"
FFDemux::FFDemux() {
}
FFDemux::~FFDemux() {
//UnInit();
}
void FFDemux::Start() {
if(m_Thread == nullptr) {
StartThread();
} else {
std::unique_lock lock(m_Mutex);
m_DecoderState = STATE_DEMUXING;
m_Cond.notify_all();
}
}
void FFDemux::Stop() {
LOGCATE("FFDemux::Stop2222");
std::unique_lock lock(m_Mutex);
m_DecoderState = STATE_STOP;
m_Cond.notify_all();
}
int FFDemux::Init(const char *url) {
strcpy(m_Url,url);
return 0;
}
void FFDemux::UnInit() {
if(m_Thread) {
Stop();
m_Thread->join();
delete m_Thread;
m_Thread = nullptr;
}
}
int FFDemux::InitDemux() {
int result = -1;
do {
//1.创建封装格式上下文
m_AVFormatContext = avformat_alloc_context();
//2.打开文件
if(avformat_open_input(&m_AVFormatContext, m_Url, NULL, NULL) != 0)
{
LOGCATE("FFDemux::InitDemux avformat_open_input fail.");
break;
}
//3.获取音视频流信息
if(avformat_find_stream_info(m_AVFormatContext, NULL) < 0) {
LOGCATE("FFDemux::InitDemux avformat_find_stream_info fail.");
break;
}
//4.获取音视频流索引
for(int i=0; i < m_AVFormatContext->nb_streams; i++) {
if(m_AVFormatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
m_StreamIndex = i;
break;
}
}
if(m_StreamIndex == -1) {
LOGCATE("FFDemux::InitFFDecoder Fail to find stream index.");
break;
}
AVDictionary *pAVDictionary = nullptr;
av_dict_set(&pAVDictionary, "buffer_size", "1024000", 0);
av_dict_set(&pAVDictionary, "stimeout", "20000000", 0);
av_dict_set(&pAVDictionary, "max_delay", "30000000", 0);
av_dict_set(&pAVDictionary, "rtsp_transport", "tcp", 0);
result = 0;
m_Packet = av_packet_alloc();
} while (false);
if(result != 0 && m_MsgContext && m_MsgCallback)
m_MsgCallback(m_MsgContext, MSG_DECODER_INIT_ERROR, 0);
return result;
}
void FFDemux::StartThread() {
// m_Thread = new thread(DoAVDecoding, this);
m_Thread = new thread(DoDemux, this);
}
void FFDemux::DemuxLoop() {
{
std::unique_lock lock(m_Mutex);
m_DecoderState = STATE_DEMUXING;
lock.unlock();
}
for(;;) {
LOGCATE("111111111111111111111111111 m_DecoderState =%d", m_DecoderState);
if(m_DecoderState == STATE_STOP) {
break;
}
if(DecodeOnePacket() != 0) {
//解码结束，暂停解码器
std::unique_lock lock(m_Mutex);
m_DecoderState = STATE_ERROR;
}
}
}
int FFDemux::DecodeOnePacket() {
int result = av_read_frame(m_AVFormatContext, m_Packet);
while(result == 0) {
if(m_DecoderState == STATE_STOP)
{
LOGCATE("111111111111111111111111111 m_DecoderState is stop");
break;
}
if(m_Packet->stream_index == m_StreamIndex) {
OnReceivePacket(m_Packet);
//LOGCATE("111111111111111111111111111 BaseDecoder::DecodeOnePacket_Ex packet size =%d", m_Packet->size);
//判断一个 packet 是否解码完成
}
av_packet_unref(m_Packet);
result = av_read_frame(m_AVFormatContext, m_Packet);
}
__EXIT:
av_packet_unref(m_Packet);
return result;
}
void FFDemux::DoDemux(FFDemux *demux) {
LOGCATE("FFDemux::DoDemux");
do {
if(demux->InitDemux() != 0) {
break;
}
demux->DemuxLoop();
} while (false);
demux->DeInitDemux();
}
void FFDemux::DeInitDemux() {
LOGCATE("FFDemux::DeInitDemux");
if(m_Packet != nullptr) {
av_packet_free(&m_Packet);
m_Packet = nullptr;
}
if(m_AVFormatContext != nullptr) {
avformat_close_input(&m_AVFormatContext);
avformat_free_context(m_AVFormatContext);
m_AVFormatContext = nullptr;
}
}
void FFDemux::OnReceivePacket(AVPacket *packet) {
if(m_MsgContext && m_MsgCallback)
m_PacketCallback(m_MsgContext, packet->data,packet->size);
} FFBridge充当cpp和java之间的桥梁 封装了一层
//
// Created by Administrator on 2022/4/14/014.
//
#include "FFBridge.h"
void FFBridge::Init(JNIEnv *jniEnv, jobject obj, char *url) {
jniEnv->GetJavaVM(&m_JavaVM);
m_JavaObj = jniEnv->NewGlobalRef(obj);
m_demux = new FFDemux();
m_demux->Init(url);
m_demux->SetMessageCallback(this, PostMessage);
m_demux->SetPacketCallback(this, PostPacket);
}
void FFBridge::Start() {
LOGCATE("FFBridge::Start");
if(m_demux)
m_demux->Start();
}
void FFBridge::UnInit() {
LOGCATE("FFBridge::UnInit");
if(m_demux) {
Stop();
delete m_demux;
m_demux = nullptr;
}
bool isAttach = false;
GetJNIEnv(&isAttach)->DeleteGlobalRef(m_JavaObj);
if(isAttach)
GetJavaVM()->DetachCurrentThread();
}
void FFBridge::Stop() {
LOGCATE("FFBridge::Stop");
if(m_demux)
{
m_demux->UnInit();
}
}
JNIEnv *FFBridge::GetJNIEnv(bool *isAttach) {
JNIEnv *env;
int status;
if (nullptr == m_JavaVM) {
LOGCATE("FFBridge::GetJNIEnv m_JavaVM == nullptr");
return nullptr;
}
*isAttach = false;
status = m_JavaVM->GetEnv((void **)&env, JNI_VERSION_1_4);
if (status != JNI_OK) {
status = m_JavaVM->AttachCurrentThread(&env, nullptr);
if (status != JNI_OK) {
LOGCATE("FFBridge::GetJNIEnv failed to attach current thread");
return nullptr;
}
*isAttach = true;
}
return env;
}
jobject FFBridge::GetJavaObj() {
return m_JavaObj;
}
JavaVM *FFBridge::GetJavaVM() {
return m_JavaVM;
}
void FFBridge::PostMessage(void *context, int msgType, float msgCode) {
if(context != nullptr)
{
FFBridge *player = static_cast(context);
bool isAttach = false;
JNIEnv *env = player->GetJNIEnv(&isAttach);
// LOGCATE("FFBridge::PostMessage env=%p", env);
if(env == nullptr)
return;
jobject javaObj = player->GetJavaObj();
jmethodID mid = env->GetMethodID(env->GetObjectClass(javaObj), JAVA_MESSAGE_EVENT_CALLBACK_API_NAME, "(IF)V");
env->CallVoidMethod(javaObj, mid, msgType, msgCode);
if(isAttach)
player->GetJavaVM()->DetachCurrentThread();
}
}
void FFBridge::PostPacket(void *context, uint8_t *buf,int size) {
if(context != nullptr)
{
FFBridge *player = static_cast(context);
bool isAttach = false;
JNIEnv *env = player->GetJNIEnv(&isAttach);
//LOGCATE("FFBridge::PostPacket env=%p", env);
if(env == nullptr)
return;
jobject javaObj = player->GetJavaObj();
jbyteArray array1 = env->NewByteArray(size);
env->SetByteArrayRegion(array1,0,size,(jbyte*)buf);
jmethodID mid = env->GetMethodID(env->GetObjectClass(javaObj), JAVA_PACKET_EVENT_CALLBACK_API_NAME, "([B)V");
env->CallVoidMethod(javaObj, mid, array1);
env->DeleteLocalRef(array1);
if(isAttach)
player->GetJavaVM()->DetachCurrentThread();
}
}
然后native 代码都在native-lib.cpp中
#include
#include
#include "FFBridge.h"
extern "C"
{
#include
#include
#include
#include
#include
#include
#include
#include
};
extern "C" JNIEXPORT jstring JNICALL
Java_com_qmcy_demux_MainActivity_stringFromJNI(
JNIEnv* env,
jobject /* this */) {
std::string hello = "Hello from C++";
return env->NewStringUTF(hello.c_str());
}
extern "C" JNIEXPORT jstring JNICALL
Java_com_qmcy_demux_MainActivity_GetVersion(
JNIEnv* env,
jobject /* this */) {
char strBuffer[1024 * 4] = {0};
strcat(strBuffer, "libavcodec : ");
strcat(strBuffer, AV_STRINGIFY(LIBAVCODEC_VERSION));
strcat(strBuffer, "\nlibavformat : ");
strcat(strBuffer, AV_STRINGIFY(LIBAVFORMAT_VERSION));
strcat(strBuffer, "\nlibavutil : ");
strcat(strBuffer, AV_STRINGIFY(LIBAVUTIL_VERSION));
strcat(strBuffer, "\nlibavfilter : ");
strcat(strBuffer, AV_STRINGIFY(LIBAVFILTER_VERSION));
strcat(strBuffer, "\nlibswresample : ");
strcat(strBuffer, AV_STRINGIFY(LIBSWRESAMPLE_VERSION));
strcat(strBuffer, "\nlibswscale : ");
strcat(strBuffer, AV_STRINGIFY(LIBSWSCALE_VERSION));
strcat(strBuffer, "\navcodec_configure : \n");
strcat(strBuffer, avcodec_configuration());
strcat(strBuffer, "\navcodec_license : ");
strcat(strBuffer, avcodec_license());
//LOGCATE("GetFFmpegVersion\n%s", strBuffer);
return env->NewStringUTF(strBuffer);
}
extern "C" JNIEXPORT jlong JNICALL Java_com_qmcy_demux_FFDemuxJava_native_1Init
(JNIEnv *env, jobject obj, jstring jurl)
{
const char* url = env->GetStringUTFChars(jurl, nullptr);
FFBridge *bridge = new FFBridge();
bridge->Init(env, obj, const_cast(url));
env->ReleaseStringUTFChars(jurl, url);
return reinterpret_cast(bridge);
}
extern "C"
JNIEXPORT void JNICALL Java_com_qmcy_demux_FFDemuxJava_native_1Start
(JNIEnv *env, jobject obj, jlong handle)
{
if(handle != 0)
{
FFBridge *bridge = reinterpret_cast(handle);
bridge->Start();
}
}
extern "C"
JNIEXPORT void JNICALL Java_com_qmcy_demux_FFDemuxJava_native_1Stop
(JNIEnv *env, jobject obj, jlong handle)
{
if(handle != 0)
{
FFBridge *bridge = reinterpret_cast(handle);
bridge->Stop();
}
}
extern "C"
JNIEXPORT void JNICALL Java_com_qmcy_demux_FFDemuxJava_native_1UnInit
(JNIEnv *env, jobject obj, jlong handle)
{
if(handle != 0)
{
FFBridge *bridge = reinterpret_cast(handle);
bridge->UnInit();
delete bridge;
}
} 一直从事的都是 c/c++的开发 对于java的知识 还停留在大学阶段所学的阶段
更别谈android了 很早的几年前 也写过一个简单的手机控制蓝牙的android app 但是那会还是 2015年左右 那会用的还是eclipse 还没有android studio这个ide 。
差别还是蛮大的
参考了csdn的另一位博主 字节流动 的 代码 做个入门阶段的demo
一些容错处理没处理好 ，毕竟只是个demo。
通过这个demo 了解下 JNI 以及Java C++ 如何交互
以及回调函数怎么处理 等等。
ffmpeg -rtsp_transport tcp -i rtsp://uer:[email protected]:554/Streaming/Channels/101 -vcodec copy -an -f flv rtmp://192.168.0.209:1935/live/0
欢迎分享，转载请注明来源：内存溢出
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