ffmpeg 5.0.1版本用C++写一个在vs2019编译通过的rtsp播放器

好的，我可以为您提供一个简单的基于FFmpeg的RTSP播放器示例。

首先，您需要下载FFmpeg的最新版本，并将其添加到您的VS2019项目中。在项目属性中添加以下包含目录和库目录：

包含目录：`<FFmpeg目录>/include`
库目录：`<FFmpeg目录>/lib`

然后，您需要在项目中添加以下库文件：

avcodec.lib
avformat.lib
avutil.lib
swscale.lib

接下来，您可以使用以下代码创建一个简单的RTSP播放器：

#include <iostream>
#include <string>
#include <opencv2/opencv.hpp>

extern "C" {
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libavutil/imgutils.h>
#include <libswscale/swscale.h>
}

using namespace std;
using namespace cv;

int main(int argc, char* argv[])
{
    av_register_all();
    avformat_network_init();

    AVFormatContext* pFormatCtx = nullptr;
    AVCodecContext* pCodecCtx = nullptr;
    AVCodec* pCodec = nullptr;
    AVPacket* packet = nullptr;

    int videoStream = -1;
    int frameFinished = 0;

    string url = "rtsp://<your_rtsp_url>";

    if (avformat_open_input(&pFormatCtx, url.c_str(), nullptr, nullptr) != 0) {
        cerr << "Failed to open input stream." << endl;
        return -1;
    }

    if (avformat_find_stream_info(pFormatCtx, nullptr) < 0) {
        cerr << "Failed to find stream information." << endl;
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    for (int i = 0; i < pFormatCtx->nb_streams; i++) {
        if (pFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            videoStream = i;
            break;
        }
    }

    if (videoStream == -1) {
        cerr << "Failed to find video stream." << endl;
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    pCodec = avcodec_find_decoder(pFormatCtx->streams[videoStream]->codecpar->codec_id);
    if (pCodec == nullptr) {
        cerr << "Failed to find decoder." << endl;
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    pCodecCtx = avcodec_alloc_context3(pCodec);
    if (pCodecCtx == nullptr) {
        cerr << "Failed to allocate codec context." << endl;
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    if (avcodec_parameters_to_context(pCodecCtx, pFormatCtx->streams[videoStream]->codecpar) < 0) {
        cerr << "Failed to copy codec parameters to context." << endl;
        avcodec_free_context(&pCodecCtx);
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    if (avcodec_open2(pCodecCtx, pCodec, nullptr) < 0) {
        cerr << "Failed to open codec." << endl;
        avcodec_free_context(&pCodecCtx);
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    packet = av_packet_alloc();
    if (packet == nullptr) {
        cerr << "Failed to allocate packet." << endl;
        avcodec_free_context(&pCodecCtx);
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    AVFrame* pFrame = av_frame_alloc();
    AVFrame* pFrameRGB = av_frame_alloc();
    if (pFrame == nullptr || pFrameRGB == nullptr) {
        cerr << "Failed to allocate frames." << endl;
        av_packet_free(&packet);
        avcodec_free_context(&pCodecCtx);
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    int numBytes = av_image_get_buffer_size(AV_PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height, 1);
    uint8_t* buffer = (uint8_t*)av_malloc(numBytes * sizeof(uint8_t));
    av_image_fill_arrays(pFrameRGB->data, pFrameRGB->linesize, buffer, AV_PIX_FMT_RGB24, pCodecCtx->width, pCodecCtx->height, 1);

    struct SwsContext* swsCtx = sws_getContext(pCodecCtx->width, pCodecCtx->height, pCodecCtx->pix_fmt, pCodecCtx->width, pCodecCtx->height, AV_PIX_FMT_RGB24, SWS_BILINEAR, nullptr, nullptr, nullptr);
    if (swsCtx == nullptr) {
        cerr << "Failed to create sws context." << endl;
        av_frame_free(&pFrame);
        av_frame_free(&pFrameRGB);
        av_packet_free(&packet);
        avcodec_free_context(&pCodecCtx);
        avformat_close_input(&pFormatCtx);
        return -1;
    }

    while (av_read_frame(pFormatCtx, packet) >= 0) {
        if (packet->stream_index == videoStream) {
            if (avcodec_send_packet(pCodecCtx, packet) < 0) {
                cerr << "Failed to send packet to decoder." << endl;
                break;
            }

            while (avcodec_receive_frame(pCodecCtx, pFrame) >= 0) {
                sws_scale(swsCtx, pFrame->data, pFrame->linesize, 0, pCodecCtx->height, pFrameRGB->data, pFrameRGB->linesize);

                Mat img(pCodecCtx->height, pCodecCtx->width, CV_8UC3, pFrameRGB->data[0]);
                imshow("RTSP Player", img);
                waitKey(1);

                av_frame_unref(pFrame);
            }
        }

        av_packet_unref(packet);
    }

    sws_freeContext(swsCtx);
    av_frame_free(&pFrame);
    av_frame_free(&pFrameRGB);
    av_packet_free(&packet);
    avcodec_free_context(&pCodecCtx);
    avformat_close_input(&pFormatCtx);

    return 0;
}

请将`<your_rtsp_url>`替换为您要播放的RTSP URL。您还需要安装OpenCV库，因为该示例使用OpenCV显示视频帧。

希望这可以帮助你开始。