ffmpeg推流rtsp c++

你可以使用 FFmpeg 的 C++ API 来进行 RTSP 推流。下面是一个简单的示例代码：

#include <iostream>
#include <string>
#include <chrono>
#include <thread>

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

int main(int argc, char *argv[]) {
    int ret = 0;

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

    // 打开输入文件
    AVFormatContext *input_ctx = NULL;
    if ((ret = avformat_open_input(&input_ctx, "input.mp4", NULL, NULL)) < 0) {
        std::cerr << "Error: could not open input file" << std::endl;
        return ret;
    }

    // 获取视频流信息
    if ((ret = avformat_find_stream_info(input_ctx, NULL)) < 0) {
        std::cerr << "Error: could not find stream information" << std::endl;
        return ret;
    }

    // 获取视频流索引
    int video_stream_index = -1;
    for (int i = 0; i < input_ctx->nb_streams; i++) {
        if (input_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
            video_stream_index = i;
            break;
        }
    }
    if (video_stream_index == -1) {
        std::cerr << "Error: could not find video stream" << std::endl;
        return AVERROR(EINVAL);
    }

    // 打开输出文件
    AVFormatContext *output_ctx = NULL;
    if ((ret = avformat_alloc_output_context2(&output_ctx, NULL, "rtsp", "rtsp://localhost:8554/test")) < 0) {
        std::cerr << "Error: could not create output context" << std::endl;
        return ret;
    }

    // 添加视频流
    AVStream *video_out = avformat_new_stream(output_ctx, NULL);
    if (!video_out) {
        std::cerr << "Error: could not create output stream" << std::endl;
        return AVERROR_UNKNOWN;
    }

    // 复制参数
    if ((ret = avcodec_parameters_copy(video_out->codecpar, input_ctx->streams[video_stream_index]->codecpar)) < 0) {
        std::cerr << "Error: could not copy codec parameters" << std::endl;
        return ret;
    }

    // 打开输出流
    if (!(output_ctx->oformat->flags & AVFMT_NOFILE)) {
        if ((ret = avio_open(&output_ctx->pb, "rtsp://localhost:8554/test", AVIO_FLAG_WRITE)) < 0) {
            std::cerr << "Error: could not open output file" << std::endl;
            return ret;
        }
    }

    // 写文件头
    if ((ret = avformat_write_header(output_ctx, NULL)) < 0) {
        std::cerr << "Error: could not write output file header" << std::endl;
        return ret;
    }

    // 编码和推流
    AVPacket pkt;
    while (true) {
        // 读取一帧视频
        AVFrame *frame = av_frame_alloc();
        if (!frame) {
            std::cerr << "Error: could not allocate video frame" << std::endl;
            return AVERROR(ENOMEM);
        }
        AVPacket *packet = av_packet_alloc();
        if (!packet) {
            std::cerr << "Error: could not allocate packet" << std::endl;
            return AVERROR(ENOMEM);
        }
        if ((ret = av_read_frame(input_ctx, packet)) < 0) {
            break;
        }
        if (packet->stream_index != video_stream_index) {
            continue;
        }
        if ((ret = avcodec_send_packet(input_ctx->streams[video_stream_index]->codecpar, packet)) < 0) {
            std::cerr << "Error: could not send packet to decoder" << std::endl;
            return ret;
        }
        while (ret >= 0) {
            ret = avcodec_receive_frame(input_ctx->streams[video_stream_index]->codecpar, frame);
            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
                break;
            } else if (ret < 0) {
                std::cerr << "Error: could not receive frame from decoder" << std::endl;
                return ret;
            }
            // 转换像素格式
            AVFrame *out_frame = av_frame_alloc();
            if (!out_frame) {
                std::cerr << "Error: could not allocate output frame" << std::endl;
                return AVERROR(ENOMEM);
            }
            if ((ret = av_image_alloc(out_frame->data, out_frame->linesize, video_out->codecpar->width, video_out->codecpar->height, video_out->codecpar->format, 1)) < 0) {
                std::cerr << "Error: could not allocate image" << std::endl;
                return ret;
            }
            if ((ret = av_image_copy(out_frame->data, out_frame->linesize, (const uint8_t **)frame->data, frame->linesize, video_out->codecpar->format, video_out->codecpar->width, video_out->codecpar->height)) < 0) {
                std::cerr << "Error: could not copy image" << std::endl;
                return ret;
            }
            out_frame->format = video_out->codecpar->format;
            out_frame->width = video_out->codecpar->width;
            out_frame->height = video_out->codecpar->height;
            out_frame->pts = av_rescale_q(frame->pts, input_ctx->streams[video_stream_index]->time_base, video_out->time_base);
            out_frame->pkt_dts = av_rescale_q(frame->pkt_dts, input_ctx->streams[video_stream_index]->time_base, video_out->time_base);
            out_frame->pkt_duration = av_rescale_q(frame->pkt_duration, input_ctx->streams[video_stream_index]->time_base, video_out->time_base);
            // 编码
            if ((ret = avcodec_send_frame(video_out->codecpar, out_frame)) < 0) {
                std::cerr << "Error: could not send frame to encoder" << std::endl;
                return ret;
            }
            while (ret >= 0) {
                ret = avcodec_receive_packet(video_out->codecpar, &pkt);
                if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
                    break;
                } else if (ret < 0) {
                    std::cerr << "Error: could not receive packet from encoder" << std::endl;
                    return ret;
                }
                // 推流
                av_packet_rescale_ts(&pkt, video_out->codecpar->time_base, video_out->time_base);
                pkt.stream_index = video_out->index;
                if ((ret = av_interleaved_write_frame(output_ctx, &pkt)) < 0) {
                    std::cerr << "Error: could not write frame to output file" << std::endl;
                    return ret;
                }
                av_packet_unref(&pkt);
            }
            av_frame_free(&out_frame);
        }
        av_packet_free(&packet);
        av_frame_free(&frame);
    }

    // 写文件尾
    if ((ret = av_write_trailer(output_ctx)) < 0) {
        std::cerr << "Error: could not write output file trailer" << std::endl;
        return ret;
    }

    // 释放资源
    avformat_close_input(&input_ctx);
    if (output_ctx && !(output_ctx->oformat->flags & AVFMT_NOFILE)) {
        avio_closep(&output_ctx->pb);
    }
    avformat_free_context(output_ctx);

    return 0;
}

这个示例代码使用了 FFmpeg 的 C++ API 来打开一个 MP4 文件，将视频流推流到 RTSP 服务器。你需要根据你的实际情况进行修改。