Code: Build an Adaptive Bitrate SMIL File Using XmlDocument

Code Snippet

1. /// <summary>
2. /// Builds a smil file based on .mp4 files found in a given directory
3. /// Assumes files are named XXX_bitrate.mp4 (movie_300.mp4)
4. /// </summary>
5. public static XmlDocument BuildSmilFile(DirectoryInfo sourceDirectory)
6. {
7.     List<FileInfo> files = new List<FileInfo>();
8.     files.AddRange(sourceDirectory.GetFiles("*.mp4"));
9.  
10.     //biggest file (highest bitrate) first.
11.     files.Sort(delegate(FileInfo p1, FileInfo p2)
12.     {
13.         return p2.Length.CompareTo(p1.Length);
14.     });
15.  
16.     XmlDocument result = new XmlDocument();
17.  
18.     //create element nodes
19.     XmlNode smilNode = result.CreateElement("smil");
20.     XmlNode headNode = result.CreateElement("head");
21.     XmlNode bodyNode = result.CreateElement("body");
22.     XmlNode switchNode = result.CreateElement("switch");
23.  
24.     //add video nodes for each file
25.     foreach (FileInfo mp4File in files)
26.     {
27.         XmlNode videoNode = result.CreateElement("video");
28.  
29.         //Create and add attributes
30.         XmlAttribute srcAttr = result.CreateAttribute("src");
31.         srcAttr.Value = mp4File.Name;
32.         XmlAttribute bitrateAttr = result.CreateAttribute("system-bitrate");
33.         bitrateAttr.Value = Path.GetFileNameWithoutExtension(mp4File.Name).Substring(mp4File.Name.LastIndexOf("_") + 1) + "000";
34.         videoNode.Attributes.Append(srcAttr);
35.         videoNode.Attributes.Append(bitrateAttr);
36.  
37.         //add video node to switch
38.         switchNode.AppendChild(videoNode);
39.     }
40.  
41.     //append nodes to parent elements
42.     bodyNode.AppendChild(switchNode);
43.     smilNode.AppendChild(headNode);
44.     smilNode.AppendChild(bodyNode);
45.     result.AppendChild(smilNode);
46.  
47.     return result;
48. }