1 files changed, 95 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..351d880fe
--- /dev/null
+++ b/src/Jellyfin.MediaEncoding.Keyframes/FfProbe/FfProbeKeyframeExtractor.cs
@@ -0,0 +1,95 @@
+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 = "-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
+            };
+
+            process.Start();
+
+            return ParseStream(process.StandardOutput);
+        }
+
+        internal static KeyframeData ParseStream(StreamReader reader)
+        {
+            var keyframes = new List<long>();
+            double streamDuration = 0;
+            double formatDuration = 0;
+
+            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))
+                {
+                    if (rest.EndsWith(",K_"))
+                    {
+                        // Trim the flags from the packet line. Example line: packet,7169.079000,K_
+                        var keyframe = double.Parse(rest[..^3], NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture);
+                        // 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);
+        }
+    }
+}