qt c++中ffmpeg推流无法拉流

为了在Qt C++中使用FFmpeg进行推流和拉流，您需要遵循以下步骤：

1.安装FFmpeg库并确保其在系统路径中。

2.在Qt项目中包含FFmpeg头文件和库文件。

3.使用FFmpeg API编写推流和拉流代码。

以下是一个简单的Qt C++程序，演示如何使用FFmpeg进行推流和拉流：

#include <QCoreApplication>
#include <QDebug>
#include <QThread>
#include <QTimer>

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

// 推流
void pushStream()
{
    AVFormatContext *outFormatCtx = NULL;
    AVOutputFormat *outFormat = NULL;
    AVStream *videoStream = NULL;
    AVCodecContext *codecCtx = NULL;
    AVCodec *codec = NULL;
    AVFrame *frame = NULL;
    AVPacket pkt;
    int ret = 0;

    // 初始化FFmpeg
    av_register_all();
    avformat_network_init();

    // 打开输出流
    ret = avformat_alloc_output_context2(&outFormatCtx, NULL, "rtsp", "rtsp://localhost:8554/zyx");
    if (ret < 0) {
        qDebug() << "Error: avformat_alloc_output_context2 failed";
        return;
    }

    outFormat = outFormatCtx->oformat;

    // 添加视频流
    videoStream = avformat_new_stream(outFormatCtx, NULL);
    if (!videoStream) {
        qDebug() << "Error: avformat_new_stream failed";
        return;
    }

    codecCtx = videoStream->codec;
    codecCtx->codec_id = outFormat->video_codec;
    codecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
    codecCtx->pix_fmt = AV_PIX_FMT_YUV420P;
    codecCtx->width = 800;
    codecCtx->height = 600;
    codecCtx->time_base.num = 1;
    codecCtx->time_base.den = 25;

    codec = avcodec_find_encoder(codecCtx->codec_id);
    if (!codec) {
        qDebug() << "Error: avcodec_find_encoder failed";
        return;
    }

    ret = avcodec_open2(codecCtx, codec, NULL);
    if (ret < 0) {
        qDebug() << "Error: avcodec_open2 failed";
        return;
    }

    frame = av_frame_alloc();
    frame->format = codecCtx->pix_fmt;
    frame->width = codecCtx->width;
    frame->height = codecCtx->height;
    ret = av_image_alloc(frame->data, frame->linesize, codecCtx->width, codecCtx->height, codecCtx->pix_fmt, 32);
    if (ret < 0) {
        qDebug() << "Error: av_image_alloc failed";
        return;
    }

    // 打开输出流
    ret = avio_open(&outFormatCtx->pb, "rtsp://localhost:8554/zyx", AVIO_FLAG_WRITE);
    if (ret < 0) {
        qDebug() << "Error: avio_open failed";
        return;
    }

    ret = avformat_write_header(outFormatCtx, NULL);
    if (ret < 0) {
        qDebug() << "Error: avformat_write_header failed";
        return;
    }

    // 推流
    for (int i = 0; i < 100; i++) {
        av_init_packet(&pkt);
        pkt.data = NULL;
        pkt.size = 0;

        // 生成测试图像
        for (int y = 0; y < codecCtx->height; y++) {
            for (int x = 0; x < codecCtx->width; x++) {
                frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
            }
        }

        frame->pts = i;
        ret = avcodec_send_frame(codecCtx, frame);
        if (ret < 0) {
            qDebug() << "Error: avcodec_send_frame failed";
            return;
        }

        ret = avcodec_receive_packet(codecCtx, &pkt);
        if (ret < 0) {
            qDebug() << "Error: avcodec_receive_packet failed";
            return;
        }

        pkt.stream_index = videoStream->index;
        ret = av_interleaved_write_frame(outFormatCtx, &pkt);
        if (ret < 0) {
            qDebug() << "Error: av_interleaved_write_frame failed";
            return;
        }

        av_packet_unref(&pkt);
    }

    av_write_trailer(outFormatCtx);

    avcodec_close(codecCtx);
    avio_close(outFormatCtx->pb);
    avformat_free_context(outFormatCtx);
    av_frame_free(&frame);
}

// 拉流
void pullStream()
{
    AVFormatContext *inFormatCtx = NULL;
    AVCodecContext *codecCtx = NULL;
    AVCodec *codec = NULL;
    AVFrame *frame = NULL;
    AVPacket pkt;
    int ret = 0;

    // 初始化FFmpeg
    av_register_all();
    avformat_network_init();

    // 打开输入流
    ret = avformat_open_input(&inFormatCtx, "rtsp://localhost:8554/zyx", NULL, NULL);
    if (ret < 0) {
        qDebug() << "Error: avformat_open_input failed";
        return;
    }

    ret = avformat_find_stream_info(inFormatCtx, NULL);
    if (ret < 0) {
        qDebug() << "Error: avformat_find_stream_info failed";
        return;
    }

    // 查找视频流
    int videoStreamIndex = -1;
    for (int i = 0; i < inFormatCtx->nb_streams; i++) {
        if (inFormatCtx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            videoStreamIndex = i;
            break;
        }
    }

    if (videoStreamIndex == -1) {
        qDebug() << "Error: video stream not found";
        return;
    }

    codecCtx = avcodec_alloc_context3(NULL);
    if (!codecCtx) {
        qDebug() << "Error: avcodec_alloc_context3 failed";
        return;
    }

    ret = avcodec_parameters_to_context(codecCtx, inFormatCtx->streams[videoStreamIndex]->codecpar);
    if (ret < 0) {
        qDebug() << "Error: avcodec_parameters_to_context failed";
        return;
    }

    codec = avcodec_find_decoder(codecCtx->codec_id);
    if (!codec) {
        qDebug() << "Error: avcodec_find_decoder failed";
        return;
    }

    ret = avcodec_open2(codecCtx, codec, NULL);
    if (ret < 0) {
        qDebug() << "Error: avcodec_open2 failed";
        return;
    }

    frame = av_frame_alloc();

    // 拉流
    while (true) {
        ret = av_read_frame(inFormatCtx, &pkt);
        if (ret < 0) {
            qDebug() << "Error: av_read_frame failed";
            break;
        }

        if (pkt.stream_index == videoStreamIndex) {
            ret = avcodec_send_packet(codecCtx, &pkt);
            if (ret < 0) {
                qDebug() << "Error: avcodec_send_packet failed";
                break;
            }

            while (ret >= 0) {
                ret = avcodec_receive_frame(codecCtx, frame);
                if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
                    break;
                } else if (ret < 0) {
                    qDebug() << "Error: avcodec_receive_frame failed";
                    break;
                }

                // 在UI界面播放视频数据
                // ...

                av_frame_unref(frame);
            }
        }

        av_packet_unref(&pkt);
    }

    avcodec_close(codecCtx);
    avformat_close_input(&inFormatCtx);
    av_frame_free(&frame);
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    // 推流
    QThread pushThread;
    QObject::connect(&pushThread, &QThread::started, [](){
        pushStream();
    });
    pushThread.start();

    // 拉流
    QTimer pullTimer;
    QObject::connect(&pullTimer, &QTimer::timeout, [](){
        pullStream();
    });
    pullTimer.start(1000);

    return a.exec();
}