Basic multiplatform (#218)

* Make GetPlatformId() return null on unknown platforms so static ffmpeg ctor won't fail on those.
calling ffmpeg.XXXX functions won't work on unknown platforms, but data structures are available for direct DLLIMPORT calls

* .gitignore for JetBrains Rider

* additional .NET6.0 target framework and better OS detection on those systems

.gitignore

@@ -105,5 +105,9 @@ UpgradeLog*.XML
 
 *.stackdump
 
+# JetBrains Rider
+.idea/
+*.sln.iml
+
 # Local 
 /FFmpeg.AutoGen.Example/frame.*.jpg

FFmpeg.AutoGen/FFmpeg.AutoGen.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
  <PropertyGroup>
- <TargetFrameworks>netstandard2.1;netstandard2.0;net472;net45</TargetFrameworks>
+ <TargetFrameworks>net6.0;netstandard2.1;netstandard2.0;net472;net45</TargetFrameworks>
  <GeneratePackageOnBuild Condition=" $(Configuration) == 'Release' ">true</GeneratePackageOnBuild>
  <Description>FFmpeg auto generated unsafe bindings for C#/.NET and Mono.</Description>
  </PropertyGroup>

FFmpeg.AutoGen/FFmpeg.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Runtime.InteropServices;
 using FFmpeg.AutoGen.Native;
 
 namespace FFmpeg.AutoGen
@@ -38,11 +39,23 @@ static ffmpeg()
  {
  GetOrLoadLibrary = libraryName => LoadLibrary(libraryName, true);
 
+#if NET
+ //BSD has #define EAGAIN 35 in errno.h, other OS have EAGAIN 11. Apple is based on BSD 
+ bool bsdStyleErrno =
+ OperatingSystem.IsFreeBSD()
+ || OperatingSystem.IsMacCatalyst()
+ || OperatingSystem.IsMacOS()
+ || OperatingSystem.IsIOS()
+ || OperatingSystem.IsTvOS()
+ || OperatingSystem.IsWatchOS();
+ EAGAIN = bsdStyleErrno ? 35 : 11;
+#else
  EAGAIN = LibraryLoader.GetPlatformId() switch
  {
  PlatformID.MacOSX => 35,
  _ => 11
  };
+#endif
  }
 
  /// <summary>

FFmpeg.AutoGen/Native/LibraryLoader.cs

@@ -4,7 +4,7 @@
 
 namespace FFmpeg.AutoGen.Native
 {
- public delegate PlatformID GetPlatformId();
+ public delegate PlatformID? GetPlatformId();
 
  public delegate string GetNativeLibraryName(string libraryName, int version);
 
@@ -16,11 +16,23 @@ static LibraryLoader()
  {
 #if NET45 || NET40
  return Environment.OSVersion.Platform;
+#elif NET
+ if (OperatingSystem.IsWindows())
+ return PlatformID.Win32NT;
+ if (OperatingSystem.IsMacCatalyst()
+ || OperatingSystem.IsMacOS()
+ || OperatingSystem.IsIOS()
+ || OperatingSystem.IsTvOS()
+ || OperatingSystem.IsWatchOS())
+ return PlatformID.MacOSX; // all share similar .dylib calling style. But only static libs on iOS store apps!
+ if (OperatingSystem.IsAndroid() || OperatingSystem.IsFreeBSD() || OperatingSystem.IsLinux())
+ return PlatformID.Unix;
+ return null;
 #else
  if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows)) return PlatformID.Win32NT;
  if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux)) return PlatformID.Unix;
  if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX)) return PlatformID.MacOSX;
- throw new PlatformNotSupportedException();
+ return null;
 #endif
  };