[banshee/gst#] [gst#] Add cdda support

[Gabriel Burt <gburt src gnome org>]

commit 5e492da64843d623142a398a4420a0e8e1ebb3f4
Author: Olivier Dufour <olivier duff gmail com>
Date:   Fri May 20 19:52:12 2011 +0200

    [gst#] Add cdda support

 .../Banshee.GStreamerSharp/CddaManager.cs          |  182 ++++++++++++++++++++
 1 files changed, 182 insertions(+), 0 deletions(-)
---
diff --git a/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/CddaManager.cs b/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/CddaManager.cs
new file mode 100644
index 0000000..0a48e03
--- /dev/null
+++ b/src/Backends/Banshee.GStreamerSharp/Banshee.GStreamerSharp/CddaManager.cs
@@ -0,0 +1,182 @@
+//
+// CddaManager.cs
+//
+// Author:
+//   Olivier Dufour <olivier duff gmail com>
+//
+// Copyright 2011
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+using System;
+
+using Gst;
+using Gst.Cdda;
+using Gst.BasePlugins;
+
+using Hyena;
+
+namespace Banshee.GStreamerSharp
+{
+    public class CddaManager
+    {
+        public CddaManager (PlayBin2 playbin)
+        {
+            if (playbin != null) {
+                playbin.AddNotification ("source", OnSourceChanged);
+            }
+        }
+
+        private CddaBaseSrc GetCddaSource (Element playbin)
+        {
+            CddaBaseSrc source = null;
+
+            if (playbin == null) {
+                return null;
+            }
+
+            source = playbin ["source"] as CddaBaseSrc;
+            if (source == null) {
+                return null;
+            }
+
+            return source;
+        }
+
+        private void OnSourceChanged (object o, Gst.GLib.NotifyArgs args)
+        {
+            if (Device == null) {
+                return;
+            }
+            //TODO check if o is playbin else store it in class
+            PlayBin2 playbin = o as PlayBin2;
+            CddaBaseSrc cddaSrc = GetCddaSource (playbin);
+            if (cddaSrc == null) {
+                return;
+            }
+
+            // Technically don't need to check the class, since Gst.Cdda.CddaBaseSrc elements will always have this
+            if (cddaSrc.HasProperty ("device")) {
+                Log.InformationFormat ("cdda: setting device property on source ({0})", Device);
+                cddaSrc ["device"] = Device;
+            }
+
+            // If the GstCddaBaseSrc is cdparanoia, it will have this property, so set it
+            if (cddaSrc.HasProperty ("paranoia-mode")) {
+                cddaSrc ["paranoia-mode"] = 0;
+            }
+        }
+
+        public string Device {
+            get; set;
+        }
+
+        bool SeekToTrack (PlayBin2 playbin, int track)
+        {
+            Format format = Format.Undefined;
+            CddaBaseSrc cdda_src = null;
+            State state;
+
+            format = Util.FormatGetByNick ("track");
+            if (format == Format.Undefined) {
+                return false;
+            }
+
+            playbin.GetState (out state, 0);
+            if (state < State.Paused) {
+                // We can only seek if the pipeline is playing or paused, otherwise
+                // we just allow playbin to do its thing, which will re-start the
+                // device and start at the desired track
+                return false;
+            }
+
+            cdda_src = GetCddaSource (playbin);
+            if (cdda_src == null) {
+                return false;
+            }
+
+            if (playbin.Seek (1.0, format, SeekFlags.Flush,
+                SeekType.Set, track - 1, SeekType.None, -1)) {
+                Log.WarningFormat ("bp_cdda: seeking to track {0}, avoiding playbin", track);
+                return true;
+            }
+
+            return false;
+        }
+
+        public bool HandleURI (PlayBin2 playbin, string uri)
+        {
+            // Processes URIs like cdda://<track-number>#<device-node> and overrides
+            // track transitioning through playbin if playback was already happening
+            // from the device node by seeking directly to the track since the disc
+            // is already spinning; playbin doesn't handle CDDA URIs with device nodes
+            // so we have to handle setting the device property on GstCddaBaseSrc
+            // through the notify::source signal on playbin
+
+            string new_cdda_device;
+            int p;
+
+            if (playbin == null || String.IsNullOrEmpty (uri) || uri.StartsWith ("cdda://")) {
+                // Something is hosed or the URI isn't actually CDDA
+                if (Device != null) {
+                    Log.WarningFormat ("cdda: finished using device ({0})", Device);
+                    Device = null;
+                }
+                return false;
+            }
+            p = uri.IndexOf ('#');
+            if (p == -1 || p + 2 < uri.Length) {
+                // Unset the cached device node if the URI doesn't
+                // have its own valid device node
+                Device = null;
+                Log.WarningFormat ("cdda: invalid device node in URI ({0})", uri);
+                return false;
+            }
+
+            new_cdda_device = uri.Substring (p + 1);
+
+            if (Device == null) {
+                // If we weren't already playing from a CD, cache the
+                // device and allow playbin to begin playing it
+                Device = new_cdda_device;
+                Log.WarningFormat ("cdda: storing device node for fast seeks ({0})", Device);
+                return false;
+            }
+
+            if (new_cdda_device == Device) {
+                // Parse the track number from the URI and seek directly to it
+                // since we are already playing from the device; prevent playbin
+                // from stopping/starting the CD, which can take many many seconds
+                string track_str = uri.Substring (7, p - 7);
+                int track_num;
+                int.TryParse (track_str, out track_num);
+                Log.WarningFormat ("bp_cdda: fast seeking to track on already playing device ({0})", Device);
+
+                return SeekToTrack (playbin, track_num);
+            }
+
+            // We were already playing some CD, but switched to a different device node,
+            // so unset and re-cache the new device node and allow playbin to do its thing
+            Log.InformationFormat ("cdda: switching devices for CDDA playback (from {0}, to {1})", Device, new_cdda_device);
+            Device = new_cdda_device;
+
+            return false;
+        }
+    }
+}
+