android调用ffmpeg解析rtsp协议的视频流

文章目录 一、背景二、解析rtsp数据1、C层功能代码2、jni层的定义3、app层的调用 三、源码下载

一、背景

本demo主要介绍android调用ffmpeg中的接口解析rtsp协议的视频流（不解析音频），得到yuv数据，把yuv转bitmap在android设备上显示，涉及到打开视频、解封装、解码、回调yuv数据。学习记录帖，C语言小白，不足的地方请指正，多谢！

二、解析rtsp数据 1、C层功能代码

Decoder.h

#ifndef DECODERTSP_DECODER_H #define DECODERTSP_DECODER_H #include <thread> #include "include/jniLog.h" extern "C" { #include <libavutil/time.h> #include <libavcodec/avcodec.h> #include <libavcodec/packet.h> #include <libavutil/imgutils.h> #include <libswscale/swscale.h> #include <libavformat/avformat.h> #include <libswscale/swscale.h> #include <libavutil/opt.h> #include <functional> }; using namespace std; // 定义一个回调函数类型（typedef 用于为已有的数据类型创建一个别名） typedef std::function<void(uint8_t *buf, int size)> Callback; // 解析rtsp视频流 int ReadFrameAndDecoder(const char *url,Callback callback); void DoStop(); #endif //DECODERTSP_DECODER_H

Decoder.cpp

#include "include/Decoder.h" #include "include/jniLog.h" bool isStop = false; int ReadFrameAndDecoder(const char* m_Url,Callback callback){ char url[100] = {0}; strcpy(url,m_Url); AVFormatContext *pFormatCtx = avformat_alloc_context(); AVDictionary *options = NULL; av_dict_set(&options, "buffer_size", "1024000", 0);// 设置缓冲区大小 av_dict_set(&options, "stimeout", "20000000", 0); av_dict_set(&options, "max_delay", "30000000", 0); // av_dict_set(&options, "rtsp_transport", "tcp", 0); //使用 TCP 传输 LOGI("ReadFrameAndDecoder:url = %s",url); if (avformat_open_input(&pFormatCtx, url, NULL, NULL) != 0) // 打开视频文件 return -1; if (avformat_find_stream_info(pFormatCtx, NULL) < 0) // 查找视频流 return -2; //视频解码，需要找到视频对应的AVStream所在pFormatCtx->streams的索引位置 int video_stream_idx = -1; for (int i = 0; i < pFormatCtx->nb_streams; i++) { //根据类型判断，是否是视频流 if (pFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) { video_stream_idx = i; break; } } //只有知道视频的编码方式，才能够根据编码方式去找到解码器 //获取视频流中的编解码上下文 AVCodecContext *pCodecCtx = avcodec_alloc_context3(NULL);; avcodec_parameters_to_context(pCodecCtx, pFormatCtx->streams[video_stream_idx]->codecpar); // AVDISCARD_NONKEY; // 丢弃非关键帧(如B帧) // AVDISCARD_NONINTRA; // 丢弃所有非帧内编码的帧(这个参数不会灰屏) // AVDISCARD_NONREF // 丢弃所有非参考帧 // AVDISCARD_BIDIR // 丢弃所有双向预测帧 // AVDISCARD_DEFAULT // pCodecCtx->skip_frame = AVDISCARD_NONKEY; //4.根据编解码上下文中的编码id查找对应的解码 //AVCodec *pCodec = const_cast<AVCodec *>(avcodec_find_decoder(pCodecCtx->codec_id)); AVCodec *pCodec = const_cast<AVCodec *>(avcodec_find_decoder(AV_CODEC_ID_HEVC)); if (pCodec == NULL) return -3; // 打开解码器 if (avcodec_open2(pCodecCtx, pCodec, NULL) < 0) return -4; // 设置参数(不缓冲，低延时) // av_opt_set(pCodecCtx->priv_data, "tune", "zerolatency", 0); // pCodecCtx->flags |= AV_CODEC_FLAG_LOW_DELAY; // 分配视频帧(装载解码后的数据) AVFrame *pFrame = av_frame_alloc(); AVPacket packet; // 读取视频帧(解码前的数据包) while (av_read_frame(pFormatCtx, &packet) >= 0 && !isStop) { if (packet.stream_index == video_stream_idx) { int got_picture; // 向解码器输入数据包 got_picture = avcodec_send_packet(pCodecCtx, &packet); if (got_picture < 0) { LOGI("got_picture = %d", got_picture); continue; } while (got_picture == 0) { // 从解码器获取帧 返回值 -11：数据包不足？ got_picture = avcodec_receive_frame(pCodecCtx, pFrame); //此时，pFrame中的数据就是YUV数据 if(got_picture == 0){ // 计算 frame 的数据大小 int data_size = av_image_get_buffer_size(AV_PIX_FMT_YUV420P, pFrame->width, pFrame->height, 1); if (data_size < 0) { LOGE("Could not calculate buffer size"); return -5; } // 分配内存来存储 byte[] uint8_t *buffer = (uint8_t *)av_malloc(data_size * sizeof(uint8_t)); if (!buffer) { LOGE("Could not allocate memory for buffer"); return -6; } // 将 AVFrame 的数据复制到 buffer 中 int ret = av_image_copy_to_buffer(buffer, data_size, (const uint8_t * const *)pFrame->data, pFrame->linesize, AV_PIX_FMT_YUV420P, pFrame->width, pFrame->height, 1); if (ret < 0) { LOGE("Could not copy image data to buffer"); av_free(buffer); return -7; } if (callback){ callback(buffer,data_size * sizeof(uint8_t)); } // 释放 buffer av_free(buffer); }else{ LOGI("avcodec_receive_frame # got_picture = %d", got_picture); } } } av_packet_unref(&packet); } // 释放资源 av_frame_free(&pFrame); avcodec_close(pCodecCtx); avformat_close_input(&pFormatCtx); return 0; } void DoStop(){ isStop = true; } 2、jni层的定义

native-lib.cpp

#include <jni.h> #include <string> #include <include/jniLog.h> #include "include/Decoder.h" extern "C" JNIEXPORT jint JNICALL Java_com_hisign_decodertsp_DecodeLib_native_1readAndDecode(JNIEnv *env, jobject thiz, jstring rtsp_url) { // TODO: implement native_readAndDecode() const char *url = env->GetStringUTFChars(rtsp_url, nullptr); LOGI("url = %s", url); // java层的回调函数 jmethodID mid = env->GetMethodID(env->GetObjectClass(thiz), "packetEventCallback", "([B)V"); if(!mid){ LOGI("StartRestAndDecodePackage, mid is null"); } // 获取java层的回调函数 Callback dataCallback = [&env, &mid, &thiz](uint8_t *buf, int size){ // todo 通过jni调用java层返回数据 if(mid != nullptr){ jbyteArray array1 = env->NewByteArray(size); env->SetByteArrayRegion(array1,0,size,(jbyte*)buf); env->CallVoidMethod(thiz, mid, array1); env->DeleteLocalRef(array1); } }; int ret = ReadFrameAndDecoder(url,dataCallback); LOGI("ReadFrameAndDecoder ret = %d",ret); env->ReleaseStringUTFChars(rtsp_url, url); return 0; } extern "C" JNIEXPORT jint JNICALL Java_com_hisign_decodertsp_DecodeLib_native_1Stop(JNIEnv *env, jobject thiz) { // TODO: implement native_Stop() DoStop(); return 0; } 3、app层的调用 public class DecodeLib { static { System.loadLibrary("decodertsp"); } private EventCallback mEventCallback = null; // 开始解码 public void start(String url) { native_readAndDecode(url); } public void stop() { native_Stop(); } public void addEventCallback(EventCallback callback) { mEventCallback = callback; } // 被native层回调 private void packetEventCallback(byte[] data) { if (mEventCallback != null) mEventCallback.onReceiveData(data); } // 测试读取视频帧并解码 private native int native_readAndDecode(String rtsp_url); private native int native_Stop(); /** * 返回yuv数据 */ public interface EventCallback { void onReceiveData(byte[] yuv); } }

MainActivity.java

public class MainActivity extends AppCompatActivity { private final static String KEY_IP = "KEY_IP"; private static int width = 1920; private static int height = 1080; private ActivityMainBinding binding; private DecodeLib decodeLib; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); binding = ActivityMainBinding.inflate(getLayoutInflater()); setContentView(binding.getRoot()); decodeLib = new DecodeLib(); String ip = SPUtils.getInstance().getString(KEY_IP); binding.etIp.setText(ip); binding.btnStart.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { String ip = binding.etIp.getText().toString(); if(TextUtils.isEmpty(ip)){ Toast.makeText(MainActivity.this, "please input ip!", Toast.LENGTH_SHORT).show(); return; } SPUtils.getInstance().put(KEY_IP,ip); String url = "rtsp://"+ip+":554/livestream/0"; new Thread(){ public void run(){ startRtsp(url); } }.start(); KeyboardUtils.hideSoftInput(MainActivity.this); } }); binding.btnStop.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { decodeLib.stop(); } }); } private void startRtsp(String url){ decodeLib.addEventCallback(new DecodeLib.EventCallback() { @Override public void onReceiveData(byte[] yuv) { // todo 这里显示图片 runOnUiThread(new Runnable() { @Override public void run() { Bitmap bmp = YuvToBitmapConverter.i420ToBitmap(yuv, width, height); if(bmp != null){ binding.img.setImageBitmap(bmp); } } }); } }); decodeLib.start(url); } } 三、源码下载

download.csdn.net/download/dami_lixm/90408495?spm=1001.2014.3001.5503