DirectShow GeDurturation donne une valeur de durée incorrecte

Question

J'essaie d'obtenir la durée du fichier multimédia avec DirectShow.J'utilise le code suivant (C #):

var seekingParser = filter as IMediaSeeking;
if (seekingParser != null)
{
   long duration;
   if (seekingParser.SetTimeFormat(TimeFormat.MediaTime) == 0
       && seekingParser.GetDuration(out duration) == 0)
       track.Duration = duration / 10000000f;
}

Pour obtenir la durée du fichier multimédia en secondes.Cependant, lorsque j'essaie d'ouvrir 3-4 minutes MP3, Track.Duration devient 11-12 minutes.J'ai essayé sur plusieurs fichiers et effet est toujours le même.Qu'est-ce qui peut être la raison?

Answer 1

You normally use IMediaPosition interface (instead of IMediaSeeking) from the application side. Duration is reported always in seconds. However this is unlikely to make a difference, and what might make it is reading duration from ID3 tags instead, using Windows Media API, ID3 Tag Support.

Are there more reliable ways to get exact duration of media file with DirectShow API?

Windows Media Player plays MP3 files through Media Foundation, a non-DirectShow API, so you don't have an option here to expect or do exactly the same from DirectShow.

Answer 2

From the documentation:

Depending on the source format, the duration might not be exact. For example, if the source contains a variable bit-rate (VBR) stream, the method might return an estimated duration.

Are you using a VBR stream, by any chance?

Answer 3

You can try the same on a clean windows installation. It might be possible you have a codec(pack) installed which is buggy.