MovieTexture .ogg file size limit?

I have to play the MovieTextures from external files in the standalone player.

The file sizes will vary.

At 35 MB works fine.

At 250 MB also works fine.

At 1900 MB gives "WWW: out of memory" error, but the film shows up after a while.

At 4 GB gives "WWW: out of memory" error and does not show up at all.

I use the script below.

What could be a fix for that?

Is there any file size limit for the video files in Unity?

 IEnumerator switchSprite(){
     string vpath = Application.dataPath;
     #if UNITY_EDITOR
     vpath = vpath.Replace("/Assets","");
 #endif
     vpath += "/filmy/conv20.ogg";
 WWW videorequest = new WWW ("file://" + vpath);
 yield return videorequest;
 movieTexture = (MovieTexture)videorequest.movie;
     moviePlane.Texture = movieTexture;    
 
     galery.IsVisible = true;
     content.IsVisible = false;
 }
 
 void Update () {
     if (!movieTexture)    return;
     if (movieTexture.isPlaying)    return;
     if (movieTexture.isReadyToPlay)    movieTexture.Play ();
 }