/// <summary>
/// Parses the <see cref="MediaDescription.ControlLine"/> and if present
/// </summary>
/// <param name="mediaDescription"></param>
/// <param name="source"></param>
/// <returns></returns>
public static Uri GetAbsoluteControlUri(this MediaDescription mediaDescription, Uri source, SessionDescription sessionDescription = null)
{
if (object.ReferenceEquals(source, null))
{
throw new ArgumentNullException("source");
}
if (IDisposedExtensions.IsNullOrDisposed(mediaDescription))
{
return(source);
}
if (source.IsAbsoluteUri.Equals(false))
{
throw new InvalidOperationException("source.IsAbsoluteUri must be true.");
}
SessionDescriptionLine controlLine = mediaDescription.ControlLine;
//If there is a control line in the SDP it contains the URI used to setup and control the media
if (object.ReferenceEquals(controlLine, null).Equals(false))
{
//Todo, make typed line for controlLine
string controlPart = controlLine.Parts.Last(); //controlLine.Parts.Where(p => p.StartsWith(AttributeFields.Control)).FirstOrDefault();
//If there is a controlPart in the controlLine
if (string.IsNullOrWhiteSpace(controlPart).Equals(false))
{
//Prepare the part
controlPart = controlPart.Split(Media.Sdp.SessionDescription.ColonSplit, 2, StringSplitOptions.RemoveEmptyEntries).Last();
//Create a uri
Uri controlUri = new Uri(controlPart, UriKind.RelativeOrAbsolute);
//Determine if its a Absolute Uri
if (controlUri.IsAbsoluteUri)
{
return(controlUri);
}
//Return a new uri using the original string and the controlUri relative path.
//Hopefully the direction of the braces matched..
//string.Join(source.OriginalString, controlUri.OriginalString);
return(new Uri(source.OriginalString.EndsWith(SessionDescription.ForwardSlashString) ? source.OriginalString + controlUri.OriginalString : string.Join(SessionDescription.ForwardSlashString, source.OriginalString, controlUri.OriginalString)));
//Todo, ensure that any parameters have also been restored...
#region Explination
//I wonder if Mr./(Dr) Fielding is happy...
//Let source =
//rtsp://alt1.v7.cache3.c.youtube.com/CigLENy73wIaHwmddh2T-s8niRMYDSANFEgGUgx1c2VyX3VwbG9hZHMM/0/0/0/1/video.3gp/trackID=0
//Call
//return new Uri(source, controlUri);
//Result =
//rtsp://alt1.v7.cache3.c.youtube.com/CigLENy73wIaHwmddh2T-s8niRMYDSANFEgGUgx1c2VyX3VwbG9hZHMM/0/0/0/1/trackID=0
//Useless when the source doesn't end with '/', e.g. same problem with Uri constructor.
//System.UriBuilder builder = new UriBuilder(source);
//builder.Path += controlUri.ToString();
//"rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mov/trackID=1"
#endregion
}
}
//Try to take the session level control uri
Uri sessionControlUri;
//If there was a session description given and it supports aggregate media control then return that uri
if (IDisposedExtensions.IsNullOrDisposed(sessionDescription).Equals(false) && sessionDescription.SupportsAggregateMediaControl(out sessionControlUri, source))
{
return(sessionControlUri);
}
//There is no control line, just return the source.
return(source);
}