1 files changed, 121 insertions, 0 deletions
diff --git a/src/Jellyfin.MediaEncoding.Keyframes/FfProbe/FfProbeKeyframeExtractor.cs b/src/Jellyfin.MediaEncoding.Keyframes/FfProbe/FfProbeKeyframeExtractor.cs
new file mode 100644
index 000000000..479e6ffdc
--- /dev/null
+++ b/src/Jellyfin.MediaEncoding.Keyframes/FfProbe/FfProbeKeyframeExtractor.cs
@@ -0,0 +1,121 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Globalization;
+using System.IO;
+
+namespace Jellyfin.MediaEncoding.Keyframes.FfProbe;
+
+/// <summary>
+/// FfProbe based keyframe extractor.
+/// </summary>
+public static class FfProbeKeyframeExtractor
+{
+    private const string DefaultArguments = "-fflags +genpts -v error -skip_frame nokey -show_entries format=duration -show_entries stream=duration -show_entries packet=pts_time,flags -select_streams v -of csv \"{0}\"";
+
+    /// <summary>
+    /// Extracts the keyframes using the ffprobe executable at the specified path.
+    /// </summary>
+    /// <param name="ffProbePath">The path to the ffprobe executable.</param>
+    /// <param name="filePath">The file path.</param>
+    /// <returns>An instance of <see cref="KeyframeData"/>.</returns>
+    public static KeyframeData GetKeyframeData(string ffProbePath, string filePath)
+    {
+        using var process = new Process
+        {
+            StartInfo = new ProcessStartInfo
+            {
+                FileName = ffProbePath,
+                Arguments = string.Format(CultureInfo.InvariantCulture, DefaultArguments, filePath),
+
+                CreateNoWindow = true,
+                UseShellExecute = false,
+                RedirectStandardOutput = true,
+
+                WindowStyle = ProcessWindowStyle.Hidden,
+                ErrorDialog = false,
+            },
+            EnableRaisingEvents = true
+        };
+
+        try
+        {
+            process.Start();
+
+            return ParseStream(process.StandardOutput);
+        }
+        catch (Exception)
+        {
+            try
+            {
+                if (!process.HasExited)
+                {
+                    process.Kill();
+                }
+            }
+            catch
+            {
+                // We do not care if this fails
+            }
+
+            throw;
+        }
+    }
+
+    internal static KeyframeData ParseStream(StreamReader reader)
+    {
+        var keyframes = new List<long>();
+        double streamDuration = 0;
+        double formatDuration = 0;
+
+        using (reader)
+        {
+            while (!reader.EndOfStream)
+            {
+                var line = reader.ReadLine().AsSpan();
+                if (line.IsEmpty)
+                {
+                    continue;
+                }
+
+                var firstComma = line.IndexOf(',');
+                var lineType = line[..firstComma];
+                var rest = line[(firstComma + 1)..];
+                if (lineType.Equals("packet", StringComparison.OrdinalIgnoreCase))
+                {
+                    // Split time and flags from the packet line. Example line: packet,7169.079000,K_
+                    var secondComma = rest.IndexOf(',');
+                    var ptsTime = rest[..secondComma];
+                    var flags = rest[(secondComma + 1)..];
+                    if (flags.StartsWith("K_"))
+                    {
+                        if (double.TryParse(ptsTime, NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var keyframe))
+                        {
+                            // Have to manually convert to ticks to avoid rounding errors as TimeSpan is only precise down to 1 ms when converting double.
+                            keyframes.Add(Convert.ToInt64(keyframe * TimeSpan.TicksPerSecond));
+                        }
+                    }
+                }
+                else if (lineType.Equals("stream", StringComparison.OrdinalIgnoreCase))
+                {
+                    if (double.TryParse(rest, NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var streamDurationResult))
+                    {
+                        streamDuration = streamDurationResult;
+                    }
+                }
+                else if (lineType.Equals("format", StringComparison.OrdinalIgnoreCase))
+                {
+                    if (double.TryParse(rest, NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var formatDurationResult))
+                    {
+                        formatDuration = formatDurationResult;
+                    }
+                }
+            }
+
+            // Prefer the stream duration as it should be more accurate
+            var duration = streamDuration > 0 ? streamDuration : formatDuration;
+
+            return new KeyframeData(TimeSpan.FromSeconds(duration).Ticks, keyframes);
+        }
+    }
+}