How to add DRM(Playready protection) with TransformManager API by C# code?

 Hi All,

I known a way to  mux mp4 files to smooth stream files by using TransformManager API, (http://pastebin.com/UmW2ZmED), how can I add DRM to the output smooth stream by TransformManger API?

I want to write a program with C# by using TransformManger API,  input several mp4 files and output smooth streaming files, now I want to add DRM to the output, I check the TransformManger API document, it seems NOT provide such kind of API, it that true? how can I add DRM?

the code example is like below:

using System;
using System.IO;
using HighPerformanceTimer;
using Microsoft.Web.Media.TransformManager.MP4toSmooth;

namespace TransPepe
{
    class Program
    {
        static void Main(string[] args)
        {
            /* define source files */
            string[] source_files = new[]
                                        {
                                            @"o:\transform_test\bbb_sd_1900.mp4",
                                            @"o:\transform_test\bbb_sd_1465.mp4",
                                            @"o:\transform_test\bbb_sd_1130.mp4",
                                            @"o:\transform_test\bbb_sd_800.mp4",
                                            @"o:\transform_test\bbb_sd_600.mp4",
                                            @"o:\transform_test\bbb_sd_530.mp4",
                                            @"o:\transform_test\bbb_sd_400.mp4",
                                            @"o:\transform_test\bbb_stereo_128k.m4a"
                                        };

            /* define output manifests */
            string ism_file = @"o:\transform_test\bbb_sd.ism";
            string ismc_file = @"o:\transform_test\bbb_sd.ismc";

            /*
             * The following two code blocks mimic the use of the code found in the file
             * %ProgramFiles%\IIS\Transform Manager\Microsoft.Web.Media.TransformManager.MP4toSmooth.dll
             *
             * to convert MP4 files to Smooth Streaming (ISMV and ISMA files).
             *
             * The first one processes the files as they are processed by the task.
             * That is, opens all the MP4 files *at once* and starts writing ISMV files.
             *
             * It's basically reading each MP4 file and transmuxing it to ISMV. But all 7 files at once. Bad for performance.
             * This method, of course, produces valid ISMV files and manifests.
             * (though I disabled the generation of manifests for benchmarking purposes)
             *
             * The second block is a hack. It processes one MP4 file at a time.
             * By doing this, we can achieve ~30% performance improvement on a 7200RPM SATA drive.
             *
             * But since it's not the way the SmoothTransmuxer class was supposed to be used, it doesn't produce valid manifests.
             *
             * Also, generated ISMV files differ from the ones generated by the first block.
             * I'm not sure whether they are valid or not, but that's beyond the scope of this test, which just benchmarks the speed of conversion.
             *
             */

            /* concurrent processing */
            HiPerfTimer hpt = new HiPerfTimer();
            hpt.Start();
            using (SmoothTransmuxer trans_conc = new SmoothTransmuxer())
            {
                MP4SourceTrackCollection[] source_tracks_conc = new MP4SourceTrackCollection[source_files.Length];
                for (int i = 0; i < source_tracks_conc.Length; i++)
                {
                    source_tracks_conc[i] = new MP4SourceTrackCollection(source_files[i]);
                    foreach (MP4SourceTrack mp4 in source_tracks_conc[i])
                    {
                        string out_file = mp4.Format.IsAudio ? Path.ChangeExtension(source_files[i], ".isma") : Path.ChangeExtension(source_files[i], ".ismv");
                        trans_conc.AddQualityLevel(mp4, mp4.AverageBitrate, 0, File.Open(out_file, FileMode.Create));
                    }
                }

                /* start remuxing */
                do ; while (trans_conc.ExecuteNextTask());

                /* write server & client manifests
                 * disabled for benchmarking purposes, since the second method can't write manifests
                 */
                //using (FileStream server_manifest = File.Open(ism_file, FileMode.Create),
                //       client_manifest = File.Open(ismc_file, FileMode.Create))
                //{
                //    trans_conc.WriteManifests(server_manifest, client_manifest);
                //}

                trans_conc.Close();
            }

            hpt.Stop();
            Console.WriteLine("concurrent: {0:F4} seconds", hpt.Duration);

            hpt = new HiPerfTimer();
            hpt.Start();

            /* consecutive processing */
            SmoothTransmuxer trans_cons = new SmoothTransmuxer();

            MP4SourceTrackCollection[] source_tracks = new MP4SourceTrackCollection[source_files.Length];
            for (int i = 0; i < source_tracks.Length; i++)
            {
                source_tracks[i] = new MP4SourceTrackCollection(source_files[i]);
                foreach (MP4SourceTrack mp4 in source_tracks[i])
                {
                    string out_file = mp4.Format.IsAudio ? Path.ChangeExtension(source_files[i], ".isma") : Path.ChangeExtension(source_files[i], ".ismv");
                    trans_cons = new SmoothTransmuxer();
                    trans_cons.AddQualityLevel(mp4, mp4.AverageBitrate, 0, File.Open(out_file, FileMode.Create));
                }

                /* start remuxing */
                do ; while (trans_cons.ExecuteNextTask());
                trans_cons.Close();
                trans_cons.Dispose();
            }
            hpt.Stop();
            Console.WriteLine("consecutive: {0:F4} seconds", hpt.Duration);
        }
    }
}