C# h264视频推送类

您可以使用 C# 中的 FFmpeg 库来实现 H264 视频推送。FFmpeg 是一个跨平台的多媒体解决方案，可以实现音视频的编解码、转码、播放等功能。

以下是使用 FFmpeg 实现 H264 视频推送的示例代码：

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using FFmpeg.AutoGen;

namespace H264Pusher
{
    class Program
    {
        static void Main(string[] args)
        {
            // 初始化 FFmpeg 库
            ffmpeg.av_register_all();
            ffmpeg.avformat_network_init();

            // 创建输出流的 AVFormatContext 对象
            AVFormatContext* outputContext = null;
            string outputUrl = "rtmp://example.com/live/stream";
            int ret = ffmpeg.avformat_alloc_output_context2(&outputContext, null, "flv", outputUrl);
            if (ret < 0)
            {
                Console.WriteLine("Failed to allocate output context: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                return;
            }

            // 添加视频流
            AVStream* videoStream = ffmpeg.avformat_new_stream(outputContext, null);
            if (videoStream == null)
            {
                Console.WriteLine("Failed to create video stream");
                return;
            }

            // 设置视频流参数
            AVCodecParameters* codecParams = videoStream->codecpar;
            codecParams->codec_id = AVCodecID.AV_CODEC_ID_H264;
            codecParams->codec_type = AVMediaType.AVMEDIA_TYPE_VIDEO;
            codecParams->width = 1920; // 视频宽度
            codecParams->height = 1080; // 视频高度
            codecParams->format = (int)AVPixelFormat.AV_PIX_FMT_YUV420P; // 像素格式
            codecParams->bit_rate = 2000000; // 码率
            codecParams->profile = FF_PROFILE_H264_HIGH; // H264 Profile
            codecParams->level = 41; // H264 Level

            // 初始化视频编码器
            AVCodec* codec = ffmpeg.avcodec_find_encoder(codecParams->codec_id);
            if (codec == null)
            {
                Console.WriteLine("Failed to find codec");
                return;
            }
            AVCodecContext* codecContext = ffmpeg.avcodec_alloc_context3(codec);
            if (codecContext == null)
            {
                Console.WriteLine("Failed to allocate codec context");
                return;
            }
            ret = ffmpeg.avcodec_parameters_to_context(codecContext, codecParams);
            if (ret < 0)
            {
                Console.WriteLine("Failed to copy codec parameters to context: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                return;
            }
            ret = ffmpeg.avcodec_open2(codecContext, codec, null);
            if (ret < 0)
            {
                Console.WriteLine("Failed to open codec: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                return;
            }

            // 打开输出流
            ret = ffmpeg.avio_open2(&outputContext->pb, outputUrl, AVIO_FLAG_WRITE, null, null);
            if (ret < 0)
            {
                Console.WriteLine("Failed to open output stream: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                return;
            }

            // 写入文件头
            ret = ffmpeg.avformat_write_header(outputContext, null);
            if (ret < 0)
            {
                Console.WriteLine("Failed to write output header: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                return;
            }

            // 将视频帧编码并写入输出流
            AVFrame* frame = ffmpeg.av_frame_alloc();
            byte[] yuvData = new byte[codecParams->width * codecParams->height * 3 / 2]; // YUV数据
            int frameCount = 0;
            Stopwatch stopwatch = Stopwatch.StartNew();
            while (stopwatch.ElapsedMilliseconds < 30000) // 推流30秒钟
            {
                // 生成一帧随机的 YUV 数据
                for (int i = 0; i < yuvData.Length; i++)
                {
                    yuvData[i] = (byte)(i + frameCount);
                }

                // 将 YUV 数据填充到 AVFrame 中
                ffmpeg.av_image_fill_arrays(frame->data, frame->linesize, yuvData, codecParams->format, codecParams->width, codecParams->height, 1);

                // 将 AVFrame 编码为 H264 格式
                AVPacket packet;
                ffmpeg.av_init_packet(&packet);
                packet.data = null;
                packet.size = 0;
                ret = ffmpeg.avcodec_send_frame(codecContext, frame);
                if (ret < 0)
                {
                    Console.WriteLine("Failed to send frame to codec: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                    return;
                }
                while (ret >= 0)
                {
                    ret = ffmpeg.avcodec_receive_packet(codecContext, &packet);
                    if (ret == AVERROR.AVERROR_EAGAIN || ret == AVERROR.AVERROR_EOF)
                    {
                        break;
                    }
                    else if (ret < 0)
                    {
                        Console.WriteLine("Failed to receive packet from codec: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                        return;
                    }

                    // 将编码后的数据写入输出流
                    ret = ffmpeg.av_write_frame(outputContext, &packet);
                    if (ret < 0)
                    {
                        Console.WriteLine("Failed to write packet to output stream: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                        return;
                    }
                    ffmpeg.av_packet_unref(&packet);
                }

                frameCount++;
            }

            // 写入文件尾
            ret = ffmpeg.av_write_trailer(outputContext);
            if (ret < 0)
            {
                Console.WriteLine("Failed to write output trailer: " + Marshal.PtrToStringAnsi(ffmpeg.av_err2str(ret)));
                return;
            }

            // 释放资源
            ffmpeg.avformat_free_context(outputContext);
            ffmpeg.avcodec_free_context(&codecContext);
            ffmpeg.av_frame_free(&frame);
        }
    }
}

以上代码仅供参考，具体实现需要根据您的实际需求进行调整。