VideoPlayer from URL has extremely low frame rate in iOS

We need to render a video from URL onto a textured plane using a VideoPlayer object. Here's our code:

public class CustomVideoPlayer : MonoBehaviour { public MeshRenderer video_renderer;

 private VideoPlayer player_;

 private String video_url = "http://distribution.bbb3d.renderfarming.net/video/mp4/bbb_sunflower_1080p_30fps_normal.mp4";

 public void Start()
 {
     player_ = new GameObject().AddComponent<VideoPlayer>();
     player_.playOnAwake = false;
     player_.url = video_url;
     player_.renderMode = VideoRenderMode.MaterialOverride;
     player_.targetMaterialRenderer = video_renderer;
     player_.targetMaterialProperty = "_MainTex";
     player_.skipOnDrop = true;
     player_.isLooping = true;
     player_.audioOutputMode = VideoAudioOutputMode.None;
     player_.sendFrameReadyEvents = true;
     player_.Play();
 }

}

If we use a local video file it plays perfectly, but using the URL drops the frame rate to about 3 fps. However, that URL plays fine in my browser. Any suggestions on how to get the URL to play smoothly in Unity?