使用rtsp推流和拉流帧率怎样调节 cpp代码

要调节RTSP推流和拉流的帧率，你需要修改代码中的相关参数。在C++中，推流和拉流通常使用FFmpeg库来实现。以下是一个简单的示例代码，它使用FFmpeg库来推送RTSP流：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libswscale/swscale.h>

#define STREAM_URL "rtsp://127.0.0.1:8554/test"

int main(int argc, char **argv)
{
    AVFormatContext *pFormatCtx;
    AVOutputFormat *pOutputFmt;
    AVStream *pStream;
    AVCodecContext *pCodecCtx;
    AVCodec *pCodec;
    AVFrame *pFrame;
    AVPacket pkt;
    int ret, i, frame_count = 0;
    struct timeval start_time, end_time;
    int64_t start_time_ms, end_time_ms;
    int video_width = 1920, video_height = 1080;
    int video_fps = 30; // 设置帧率为30fps
    char errbuf[1024];

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

    // 打开输出流
    ret = avformat_alloc_output_context2(&pFormatCtx, NULL, "rtsp", STREAM_URL);
    if (ret < 0) {
        av_strerror(ret, errbuf, sizeof(errbuf));
        fprintf(stderr, "Failed to allocate output context: %s\n", errbuf);
        return -1;
    }

    // 创建视频流
    pOutputFmt = pFormatCtx->oformat;
    pStream = avformat_new_stream(pFormatCtx, NULL);
    if (!pStream) {
        fprintf(stderr, "Failed to allocate stream\n");
        return -1;
    }

    // 设置视频编码器参数
    pCodec = avcodec_find_encoder(pOutputFmt->video_codec);
    if (!pCodec) {
        fprintf(stderr, "Failed to find video encoder\n");
        return -1;
    }

    pCodecCtx = avcodec_alloc_context3(pCodec);
    pCodecCtx->codec_id = pOutputFmt->video_codec;
    pCodecCtx->codec_type = AVMEDIA_TYPE_VIDEO;
    pCodecCtx->width = video_width;
    pCodecCtx->height = video_height;
    pCodecCtx->time_base.num = 1;
    pCodecCtx->time_base.den = video_fps;
    pCodecCtx->pix_fmt = AV_PIX_FMT_YUV420P;

    // 打开编码器
    ret = avcodec_open2(pCodecCtx, pCodec, NULL);
    if (ret < 0) {
        av_strerror(ret, errbuf, sizeof(errbuf));
        fprintf(stderr, "Failed to open video encoder: %s\n", errbuf);
        return -1;
    }

    // 分配帧缓存
    pFrame = av_frame_alloc();
    pFrame->format = pCodecCtx->pix_fmt;
    pFrame->width = pCodecCtx->width;
    pFrame->height = pCodecCtx->height;
    ret = av_frame_get_buffer(pFrame, 0);
    if (ret < 0) {
        av_strerror(ret, errbuf, sizeof(errbuf));
        fprintf(stderr, "Failed to allocate frame buffer: %s\n", errbuf);
        return -1;
    }

    // 打开输出流
    ret = avio_open(&pFormatCtx->pb, STREAM_URL, AVIO_FLAG_WRITE);
    if (ret < 0) {
        av_strerror(ret, errbuf, sizeof(errbuf));
        fprintf(stderr, "Failed to open output stream: %s\n", errbuf);
        return -1;
    }

    // 写文件头
    ret = avformat_write_header(pFormatCtx, NULL);
    if (ret < 0) {
        av_strerror(ret, errbuf, sizeof(errbuf));
        fprintf(stderr, "Failed to write file header: %s\n", errbuf);
        return -1;
    }

    // 循环发送视频帧
    gettimeofday(&start_time, NULL);
    start_time_ms = start_time.tv_sec * 1000 + start_time.tv_usec / 1000;
    for (i = 0; i < 100; i++) {
        // 填充图像数据
        pFrame->data[0] = (uint8_t *) malloc(video_width * video_height);
        pFrame->data[1] = (uint8_t *) malloc(video_width * video_height / 4);
        pFrame->data[2] = (uint8_t *) malloc(video_width * video_height / 4);
        pFrame->linesize[0] = video_width;
        pFrame->linesize[1] = video_width / 2;
        pFrame->linesize[2] = video_width / 2;
        memset(pFrame->data[0], 255, video_width * video_height);
        memset(pFrame->data[1], 128, video_width * video_height / 4);
        memset(pFrame->data[2], 128, video_width * video_height / 4);

        // 编码视频帧
        pFrame->pts = i * (pCodecCtx->time_base.den) / ((pCodecCtx->time_base.num) * video_fps);
        ret = avcodec_send_frame(pCodecCtx, pFrame);
        if (ret < 0) {
            av_strerror(ret, errbuf, sizeof(errbuf));
            fprintf(stderr, "Failed to send frame: %s\n", errbuf);
            return -1;
        }

        while (1) {
            ret = avcodec_receive_packet(pCodecCtx, &pkt);
            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
                break;
            if (ret < 0) {
                av_strerror(ret, errbuf, sizeof(errbuf));
                fprintf(stderr, "Failed to receive packet: %s\n", errbuf);
                return -1;
            }

            // 写视频帧到输出流
            pkt.stream_index = pStream->index;
            av_packet_rescale_ts(&pkt, pCodecCtx->time_base, pStream->time_base);
            ret = av_interleaved_write_frame(pFormatCtx, &pkt);
            if (ret < 0) {
                av_strerror(ret, errbuf, sizeof(errbuf));
                fprintf(stderr, "Failed to write frame: %s\n", errbuf);
                return -1;
            }
            av_packet_unref(&pkt);
        }

        free(pFrame->data[0]);
        free(pFrame->data[1]);
        free(pFrame->data[2]);
    }

    // 写文件尾
    ret = av_write_trailer(pFormatCtx);
    if (ret < 0) {
        av_strerror(ret, errbuf, sizeof(errbuf));
        fprintf(stderr, "Failed to write file trailer: %s\n", errbuf);
        return -1;
    }

    // 释放资源
    avio_close(pFormatCtx->pb);
    avformat_free_context(pFormatCtx);
    avcodec_free_context(&pCodecCtx);
    av_frame_free(&pFrame);

    gettimeofday(&end_time, NULL);
    end_time_ms = end_time.tv_sec * 1000 + end_time.tv_usec / 1000;
    printf("Total time: %lldms\n", end_time_ms - start_time_ms);

    return 0;
}

要调节帧率，你需要修改以下两个参数：

int video_fps = 30; // 设置帧率为30fps

pCodecCtx->time_base.den = video_fps;

你可以将`video_fps`变量设置为你想要的帧率，例如60fps，然后重新编译代码即可。对于拉流，你可以在解码器的参数中设置帧率。