Simplify FFmpeg detection code

MediaBrowser.MediaEncoding/Encoder/EncoderValidator.cs

@@ -100,20 +100,6 @@ namespace MediaBrowser.MediaEncoding.Encoder
             { "libpostproc", new Version(55, 1) }
         };
 
-        // This lookup table is to be maintained with the following command line:
-        // $ ffmpeg -version | perl -ne ' print "$1=$2.$3," if /^(lib\w+)\s+(\d+)\.\s*(\d+)/'
-        private static readonly IReadOnlyDictionary<string, Version> _ffmpegVersionMap = new Dictionary<string, Version>
-        {
-            { "libavutil=56.51,libavcodec=58.91,libavformat=58.45,libavdevice=58.10,libavfilter=7.85,libswscale=5.7,libswresample=3.7,libpostproc=55.7,", new Version(4, 3) },
-            { "libavutil=56.31,libavcodec=58.54,libavformat=58.29,libavdevice=58.8,libavfilter=7.57,libswscale=5.5,libswresample=3.5,libpostproc=55.5,", new Version(4, 2) },
-            { "libavutil=56.22,libavcodec=58.35,libavformat=58.20,libavdevice=58.5,libavfilter=7.40,libswscale=5.3,libswresample=3.3,libpostproc=55.3,", new Version(4, 1) },
-            { "libavutil=56.14,libavcodec=58.18,libavformat=58.12,libavdevice=58.3,libavfilter=7.16,libswscale=5.1,libswresample=3.1,libpostproc=55.1,", new Version(4, 0) },
-            { "libavutil=55.78,libavcodec=57.107,libavformat=57.83,libavdevice=57.10,libavfilter=6.107,libswscale=4.8,libswresample=2.9,libpostproc=54.7,", new Version(3, 4) },
-            { "libavutil=55.58,libavcodec=57.89,libavformat=57.71,libavdevice=57.6,libavfilter=6.82,libswscale=4.6,libswresample=2.7,libpostproc=54.5,", new Version(3, 3) },
-            { "libavutil=55.34,libavcodec=57.64,libavformat=57.56,libavdevice=57.1,libavfilter=6.65,libswscale=4.2,libswresample=2.3,libpostproc=54.1,", new Version(3, 2) },
-            { "libavutil=54.31,libavcodec=56.60,libavformat=56.40,libavdevice=56.4,libavfilter=5.40,libswscale=3.1,libswresample=1.2,libpostproc=53.3,", new Version(2, 8) }
-        };
-
         private readonly ILogger _logger;
 
         private readonly string _encoderPath;
@@ -130,6 +116,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             Decoder
         }
 
+        // When changing this, also change the minimum library versions in _ffmpegMinimumLibraryVersions
         public static Version MinVersion { get; } = new Version(4, 0);
 
         public static Version MaxVersion { get; } = null;
@@ -227,28 +214,9 @@ namespace MediaBrowser.MediaEncoding.Encoder
             {
                 return new Version(match.Groups[1].Value);
             }
-            else
-            {
-                if (!TryGetFFmpegLibraryVersions(output, out string versionString, out IReadOnlyDictionary<string, Version> versionMap))
-                {
-                    _logger.LogError("No ffmpeg library versions found");
 
-                    return null;
-                }
-
-                // First try to lookup the full version string
-                if (_ffmpegVersionMap.TryGetValue(versionString, out Version version))
-                {
-                    return version;
-                }
+            var versionMap = GetFFmpegLibraryVersions(output);
 
-                // Then try to test for minimum library versions
-                return TestMinimumFFmpegLibraryVersions(versionMap);
-            }
-        }
-
-        private Version TestMinimumFFmpegLibraryVersions(IReadOnlyDictionary<string, Version> versionMap)
-        {
             var allVersionsValidated = true;
 
             foreach (var minimumVersion in _ffmpegMinimumLibraryVersions)
@@ -281,10 +249,8 @@ namespace MediaBrowser.MediaEncoding.Encoder
         /// </summary>
         /// <param name="output">The 'ffmpeg -version' output.</param>
         /// <returns>The library names and major.minor version numbers.</returns>
-        private static bool TryGetFFmpegLibraryVersions(string output, out string versionString, out IReadOnlyDictionary<string, Version> versionMap)
+        private static IReadOnlyDictionary<string, Version> GetFFmpegLibraryVersions(string output)
         {
-            var sb = new StringBuilder(144);
-
             var map = new Dictionary<string, Version>();
 
             foreach (Match match in Regex.Matches(
@@ -292,24 +258,14 @@ namespace MediaBrowser.MediaEncoding.Encoder
                 @"((?<name>lib\w+)\s+(?<major>[0-9]+)\.\s*(?<minor>[0-9]+))",
                 RegexOptions.Multiline))
             {
-                sb.Append(match.Groups["name"])
-                    .Append('=')
-                    .Append(match.Groups["major"])
-                    .Append('.')
-                    .Append(match.Groups["minor"])
-                    .Append(',');
-
-                var str = $"{match.Groups["major"]}.{match.Groups["minor"]}";
-
-                var version = Version.Parse(str);
+                var version = new Version(
+                    int.Parse(match.Groups["major"].Value),
+                    int.Parse(match.Groups["minor"].Value));
 
                 map.Add(match.Groups["name"].Value, version);
             }
 
-            versionString = sb.ToString();
-            versionMap = map;
-
-            return sb.Length > 0;
+            return map;
         }
 
         private IEnumerable<string> GetHwaccelTypes()

tests/Jellyfin.MediaEncoding.Tests/EncoderValidatorTests.cs

@@ -18,6 +18,7 @@ namespace Jellyfin.MediaEncoding.Tests
         }
 
         [Theory]
+        [InlineData(EncoderValidatorTestsData.FFmpegV431Output, true)]
         [InlineData(EncoderValidatorTestsData.FFmpegV43Output, true)]
         [InlineData(EncoderValidatorTestsData.FFmpegV421Output, true)]
         [InlineData(EncoderValidatorTestsData.FFmpegV42Output, true)]
@@ -34,6 +35,7 @@ namespace Jellyfin.MediaEncoding.Tests
         {
             public IEnumerator<object?[]> GetEnumerator()
             {
+                yield return new object?[] { EncoderValidatorTestsData.FFmpegV431Output, new Version(4, 3, 1) };
                 yield return new object?[] { EncoderValidatorTestsData.FFmpegV43Output, new Version(4, 3) };
                 yield return new object?[] { EncoderValidatorTestsData.FFmpegV421Output, new Version(4, 2, 1) };
                 yield return new object?[] { EncoderValidatorTestsData.FFmpegV42Output, new Version(4, 2) };

tests/Jellyfin.MediaEncoding.Tests/EncoderValidatorTestsData.cs

@@ -2,6 +2,18 @@ namespace Jellyfin.MediaEncoding.Tests
 {
     internal static class EncoderValidatorTestsData
     {
+        public const string FFmpegV431Output = @"ffmpeg version n4.3.1 Copyright (c) 2000-2020 the FFmpeg developers
+built with gcc 10.1.0 (GCC)
+configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-avisynth --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-librav1e --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-nvdec --enable-nvenc --enable-omx --enable-shared --enable-version3
+libavutil      56. 51.100 / 56. 51.100
+libavcodec     58. 91.100 / 58. 91.100
+libavformat    58. 45.100 / 58. 45.100
+libavdevice    58. 10.100 / 58. 10.100
+libavfilter     7. 85.100 /  7. 85.100
+libswscale      5.  7.100 /  5.  7.100
+libswresample   3.  7.100 /  3.  7.100
+libpostproc    55.  7.100 / 55.  7.100";
+
         public const string FFmpegV43Output = @"ffmpeg version 4.3 Copyright (c) 2000-2020 the FFmpeg developers
 built with gcc 7 (Ubuntu 7.5.0-3ubuntu1~18.04)
 configuration: --prefix=/usr/lib/jellyfin-ffmpeg --target-os=linux --disable-doc --disable-ffplay --disable-shared --disable-libxcb --disable-vdpau --disable-sdl2 --disable-xlib --enable-gpl --enable-version3 --enable-static --enable-libfontconfig --enable-fontconfig --enable-gmp --enable-gnutls --enable-libass --enable-libbluray --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-libopus --enable-libtheora --enable-libvorbis --enable-libwebp --enable-libx264 --enable-libx265 --enable-libzvbi --arch=amd64 --enable-amf --enable-nvenc --enable-nvdec --enable-vaapi --enable-opencl