参考网址：https://blog.csdn.net/u013810234/article/details/57471780
以下为本次测试用到的音、视频格式：
audio ：”.wav;.mp3;.wma;.ra;.mid;.ogg;.ape;.au;.aac;”;
vedio ：”.mp4;.mpg;.mpeg;.avi;.rm;.rmvb;.wmv;.3gp;.flv;.mkv;.swf;.asf;”;
Note：
1. 测试音、视频均为对应格式的有效文件（下载自地址：包含了各种可供测试音视频格式，且不断更新中。。）； 2. 若某音/视频时长为0，表示对应库、组件无法解码文件，即不支持该格式； 3. 类之间的关系：定义了Duration父类，三个测试方案均继承自Duration，并重写父类GetDuration方法。获取时长父类
public abstract class Duration
{ /// <summary> /// Abstract method of getting duration(ms) of audio or vedio /// </summary> /// <param name="filePath">audio/vedio's path</param> /// <returns>Duration in original format, duration in milliseconds</returns> public abstract Tuple<string, long> GetDuration(string filePath);/// <summary>
/// Convert format of "00:10:16" and "00:00:19.82" into milliseconds /// </summary> /// <param name="formatTime"></param> /// <returns>Time in milliseconds</returns> public long GetTimeInMillisecond(string formatTime) { double totalMilliSecends = 0;if (!string.IsNullOrEmpty(formatTime))
{ string[] timeParts = formatTime.Split(':'); totalMilliSecends = Convert.ToInt16(timeParts[0]) * 60 * 60 * 1000 + Convert.ToInt16(timeParts[1]) * 60 * 1000 + Math.Round(double.Parse(timeParts[2]) * 1000); }return (long)totalMilliSecends;
} }使用NAudio.dll下载、引用NAudio.dll；
由于NAudio本身主要用于处理音频，用其获取视频时长并不合理（仅作统一测试），所以多数格式不支持，不足为奇；public class ByNAudio : Duration { /// <summary> /// Get duration(ms) of audio or vedio by NAudio.dll /// </summary> /// <param name="filePath">audio/vedio's path</param> /// <returns>Duration in original format, duration in milliseconds</returns> /// <remarks>return value from NAudio.dll is in format of: "00:00:19.820"</remarks> public override Tuple<string, long> GetDuration(string filePath) { TimeSpan ts; try { using (AudioFileReader audioFileReader = new AudioFileReader(filePath)) { ts = audioFileReader.TotalTime; } } catch (Exception) { /* As NAudio is mainly used for processing audio, so some formats may not surport, * just use 00:00:00 instead for these cases. */ ts = new TimeSpan(); //throw ex; }return Tuple.Create(ts.ToString(), GetTimeInMillisecond(ts.ToString()));
} }NAudio结果：
使用Shell32.dll
引用Shell32.dll，在COM里；
Windows自带的组件，仅支持常见的音视频格式；public class ByShell32 : Duration { /// <summary> /// Get duration(ms) of audio or vedio by Shell32.dll /// </summary> /// <param name="filePath">audio/vedio's path</param> /// <returns>Duration in original format, duration in milliseconds</returns> /// <remarks>return value from Shell32.dll is in format of: "00:10:16"</remarks> public override Tuple<string, long> GetDuration(string filePath) { try { string dir = Path.GetDirectoryName(filePath);// From Add Reference --> COM
Shell32.Shell shell = new Shell32.Shell(); Shell32.Folder folder = shell.NameSpace(dir); Shell32.FolderItem folderitem = folder.ParseName(Path.GetFileName(filePath));string duration = null;
// Deal with different versions of OS
if (Environment.OSVersion.Version.Major >= 6) { duration = folder.GetDetailsOf(folderitem, 27); } else { duration = folder.GetDetailsOf(folderitem, 21); }duration = string.IsNullOrEmpty(duration) ? "00:00:00" : duration;
return Tuple.Create(duration, GetTimeInMillisecond(duration)); } catch (Exception ex) { throw ex; } } }Shell32结果：
使用FFmpeg.exe
下载FFmpeg.exe；
异步调用“ffmpeg -i 文件路径”命令，获取返回文本，并解析出Duration部分；FFmpeg是对音视频进行各种处理的一套完整解决方案，包含了非常先进的音频/视频编解码库，因此可处理多种格式（本次测试的音、视频格式均可以进行有效解码）。public class ByFFmpeg : Duration { private StringBuilder result = new StringBuilder(); // Store output text of ffmpeg/// <summary>
/// Get duration(ms) of audio or vedio by FFmpeg.exe /// </summary> /// <param name="filePath">audio/vedio's path</param> /// <returns>Duration in original format, duration in milliseconds</returns> /// <remarks>return value from FFmpeg.exe is in format of: "00:00:19.82"</remarks> public override Tuple<string, long> GetDuration(string filePath) { GetMediaInfo(filePath); string duration = MatchDuration(result.ToString());return Tuple.Create(duration, GetTimeInMillisecond(duration));
}// Call exe async
private void GetMediaInfo(string filePath) { result.Clear(); // Clear result to avoid previous value's interferenceProcess p = new Process();
p.StartInfo.FileName = "ffmpeg.exe"; p.StartInfo.RedirectStandardError = true; p.StartInfo.UseShellExecute = false; p.StartInfo.Arguments = string.Concat("-i ", filePath); p.ErrorDataReceived += new DataReceivedEventHandler(OutputCallback);p.Start();
p.BeginErrorReadLine();p.WaitForExit();
p.Close(); p.Dispose(); }// Callback funciton of output stream
private void OutputCallback(object sender, DataReceivedEventArgs e) { if (!string.IsNullOrEmpty(e.Data)) { result.Append(e.Data); } }// Match the 'Duration' section in "ffmpeg -i filepath" output text
private string MatchDuration(string text) { string pattern = @"Duration:\s(\d{2}:\d{2}:\d{2}.\d+)"; Match m = Regex.Match(text, pattern);return m.Groups.Count == 2 ? m.Groups[1].ToString() : string.Empty;
} }ffmpeg -i filePath ……[mp3 @ 0233ca60] Estimating duration from bitrate, this may be inaccurate Input #0, mp3, from ‘2012.mp3’: Duration: 00:22:47.07, start: 0.000000, bitrate: 127 kb/s Stream #0:0: Audio: mp3, 44100 Hz, stereo, s16p, 128 kb/s At least one output file must be specifiedNote:以上为ffmpeg -i 命令的输出值，需要匹配到Duration的时长部分。FFmpeg结果：
Source Code（含测试音、视频文件）: