ffmpeg rtsp 源码

这里提供一个简单的基于FFmpeg的RTSP客户端示例代码，你可以根据自己的需求进行修改和扩展：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libavformat/avformat.h>

int main(int argc, char **argv) {
    if (argc < 2) {
        printf("Usage: %s rtsp_url\n", argv[0]);
        return -1;
    }

    int ret;
    AVFormatContext *fmt_ctx = NULL;
    AVDictionary *opts = NULL;

    // 设置连接选项
    av_dict_set(&opts, "rtsp_transport", "tcp", 0);
    av_dict_set(&opts, "stimeout", "5000000", 0);

    // 打开 RTSP 流
    if ((ret = avformat_open_input(&fmt_ctx, argv[1], NULL, &opts)) < 0) {
        printf("Could not open input stream.\n");
        return -1;
    }

    // 查找流信息
    if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) {
        printf("Failed to retrieve input stream information.\n");
        return -1;
    }

    // 打印流信息
    av_dump_format(fmt_ctx, 0, argv[1], 0);

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

    if (video_stream_index == -1) {
        printf("Could not find video stream.\n");
        return -1;
    }

    // 获取视频解码器
    AVCodecParameters *codec_params = fmt_ctx->streams[video_stream_index]->codecpar;
    AVCodec *codec = avcodec_find_decoder(codec_params->codec_id);

    if (codec == NULL) {
        printf("Unsupported codec.\n");
        return -1;
    }

    // 初始化解码器上下文
    AVCodecContext *codec_ctx = avcodec_alloc_context3(codec);

    if ((ret = avcodec_parameters_to_context(codec_ctx, codec_params)) < 0) {
        printf("Failed to copy codec parameters to decoder context.\n");
        return -1;
    }

    if ((ret = avcodec_open2(codec_ctx, codec, NULL)) < 0) {
        printf("Failed to open codec.\n");
        return -1;
    }

    // 创建视频帧和数据包
    AVFrame *frame = av_frame_alloc();
    AVPacket *packet = av_packet_alloc();

    if (frame == NULL || packet == NULL) {
        printf("Failed to allocate frame and packet.\n");
        return -1;
    }

    // 读取视频帧
    while (av_read_frame(fmt_ctx, packet) >= 0) {
        if (packet->stream_index != video_stream_index) {
            continue;
        }

        if ((ret = avcodec_send_packet(codec_ctx, packet)) < 0) {
            printf("Error sending a packet to the decoder.\n");
            break;
        }

        while (ret >= 0) {
            ret = avcodec_receive_frame(codec_ctx, frame);

            if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF) {
                break;
            } else if (ret < 0) {
                printf("Error during decoding.\n");
                break;
            }

            // 处理视频帧数据
            printf("Video frame: width=%d, height=%d, format=%d\n", frame->width, frame->height, frame->format);
        }

        av_packet_unref(packet);
    }

    av_packet_free(&packet);
    av_frame_free(&frame);
    avcodec_free_context(&codec_ctx);
    avformat_close_input(&fmt_ctx);
    av_dict_free(&opts);

    return 0;
}

这个程序可以从 RTSP URL 指定的网络摄像头或视频服务器中，读取视频流数据并进行解码，然后输出解码后的视频帧信息。你可以根据需要，将这个程序集成到你的应用中。