.net core Docker 容器添加ffmpeg 获取视频信息和截图

最近在处理上传视频，需要获取视频信息和截图，这里就需要用到ffmpeg;

由于我的项目是在docker compose中运行调试，所以ffmpeg也需要在docker中能调用；

网上找到的方法在Dockerfile中安装ffmpeg；

.net core 运行的docker容器可以理解为一个安装了.net core runtime的轻量型linux，所以我们要在docker中调用ffmpeg,就需要在这个linux中安装ffmpeg;

下面是我的Dockerfile 重点是前面的两个RUN 命令，复制这两个RUN 到Dockerfile就可以。(因为我还需要处理Excel所以使用了NPOI，这个linux下也是要安装libgdiplus才能运行；)

FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base

RUN sed -i 's/deb.debian.org/mirrors.ustc.edu.cn/g' /etc/apt/sources.list \
    && apt-get update \
    && apt-get install -y ffmpeg \
    && apt-get clean && apt-get autoclean && apt-get autoremove \
    && rm -rf /var/lib/apt/lists/*

RUN apt-get update && apt-get install -y libgdiplus libc6-dev && ln -s /usr/lib/libgdiplus.so /usr/lib/gdiplus.dll
WORKDIR /app
EXPOSE 80
EXPOSE 443

FROM mcr.microsoft.com/dotnet/core/sdk:3.1-buster AS build
WORKDIR /src
COPY ["test/test.csproj", "test/"]
RUN dotnet restore "test/test.csproj"
COPY . .
WORKDIR "/src/test"
RUN dotnet build "test.csproj" -c Release -o /app/build

FROM build AS publish
RUN dotnet publish "test.csproj" -c Release -o /app/publish

FROM base AS final
WORKDIR /app
COPY --from=publish /app/publish .
VOLUME /app/wwwroot
ENTRYPOINT ["dotnet", "test.dll"]

然后就可以使用ffmpeg 命令了，我这里适配和window和linux 程序；

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace test.Ffmpeg
{
    public static class FfmpegHelper
    {
        private static System.Diagnostics.ProcessStartInfo cmdFfmpeg;
        private static System.Diagnostics.ProcessStartInfo cmdFfprobe;
        static FfmpegHelper()
        {

            if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
            {
                string ffmpegPath = "/usr/bin/ffmpeg";
                string ffprobePath = "/usr/bin/ffprobe";
                cmdFfmpeg = new System.Diagnostics.ProcessStartInfo(ffmpegPath);
                cmdFfprobe = new System.Diagnostics.ProcessStartInfo(ffprobePath);
            }
            else if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
            {
                string ffmpegPath = AppDomain.CurrentDomain.BaseDirectory+ "Ffmpeg\\ffmpeg.exe";
                string ffprobePath = AppDomain.CurrentDomain.BaseDirectory + "Ffmpeg\\ffprobe.exe";
                cmdFfmpeg = new System.Diagnostics.ProcessStartInfo(ffmpegPath);
                cmdFfprobe = new System.Diagnostics.ProcessStartInfo(ffprobePath);

            }
            else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
            {
                string ffmpegPath = "/usr/bin/ffmpeg";
                string ffprobePath = "/usr/bin/ffprobe";
                cmdFfmpeg = new System.Diagnostics.ProcessStartInfo(ffmpegPath);
                cmdFfprobe = new System.Diagnostics.ProcessStartInfo(ffprobePath);
            }

            cmdFfmpeg.RedirectStandardError = false; // 输出错误
            cmdFfmpeg.RedirectStandardOutput = true; //输出打印
            cmdFfmpeg.UseShellExecute = false; //使用Shell
            cmdFfmpeg.CreateNoWindow = true;  //创建黑窗

            cmdFfprobe.RedirectStandardError = false; //set false
            cmdFfprobe.RedirectStandardOutput = true;
            cmdFfprobe.UseShellExecute = false; //set true
            cmdFfprobe.CreateNoWindow = true;  //don't need the black window
        }

        /// <summary>
        /// 获取视频信息
        /// </summary>
        /// <param name="path"></param>
        public static async Task<VideoInfoModel> GetVideoInfo(string path)
        {
            try
            {
                string command = $"-i {path} -print_format json -show_format -show_streams -show_data";
                cmdFfprobe.Arguments = command;

                System.Diagnostics.Process cmd = new System.Diagnostics.Process();
                cmd.StartInfo = cmdFfprobe;
                cmd.Start();

                string InfoStr = await cmd.StandardOutput.ReadToEndAsync();
                cmd.WaitForExit();

                VideoInfoModel resp = JsonConvert.DeserializeObject<VideoInfoModel>(InfoStr);
                return resp;
            }
            catch (Exception)
            {
                return null;
            }

        }
        /// <summary>
        /// 视频截图
        /// </summary>
        /// <param name="path"></param>
        /// <param name="outPath"></param>
        public static void VideoScreenshot(string path,string outPath)
        {
            string command = $"-i {path} -y -q:v 7 -f image2 -t 0.001 {outPath}";

            cmdFfmpeg.Arguments = command;

            System.Diagnostics.Process cmd = new System.Diagnostics.Process();
            cmd.StartInfo = cmdFfmpeg;
            cmd.Start();
            cmd.WaitForExit();

        }
    }
}