1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
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
{
/// <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,
"-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}\"",
filePath),
CreateNoWindow = true,
UseShellExecute = false,
RedirectStandardOutput = true,
WindowStyle = ProcessWindowStyle.Hidden,
ErrorDialog = false,
},
EnableRaisingEvents = true
};
try
{
process.Start();
try
{
process.PriorityClass = ProcessPriorityClass.BelowNormal;
}
catch
{
// We do not care if process priority setting fails
// Ideally log a warning but this does not have a logger available
}
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);
}
}
}
|
