Basic support for decryption of imported DCPs.

14 files changed, 225 insertions, 13 deletions

diff --git a/src/lib/dcp_content.cc b/src/lib/dcp_content.cc
index 0eef075d7..9d4ee6388 100644
--- a/src/lib/dcp_content.cc
+++ b/src/lib/dcp_content.cc
@@ -18,16 +18,22 @@
 */
 
 #include <dcp/dcp.h>
+#include <dcp/exceptions.h>
 #include "dcp_content.h"
 #include "dcp_examiner.h"
 #include "job.h"
 #include "film.h"
+#include "config.h"
 #include "compose.hpp"
 
 #include "i18n.h"
 
 using std::string;
+using std::cout;
 using boost::shared_ptr;
+using boost::optional;
+
+int const DCPContentProperty::CAN_BE_PLAYED = 600;
 
 DCPContent::DCPContent (shared_ptr<const Film> f, boost::filesystem::path p)
 	: Content (f)
@@ -35,7 +41,9 @@ DCPContent::DCPContent (shared_ptr<const Film> f, boost::filesystem::path p)
 	, SingleStreamAudioContent (f)
 	, SubtitleContent (f)
 	, _has_subtitles (false)
+	, _encrypted (false)
 	, _directory (p)
+	, _kdm_valid (false)
 {
 	read_directory (p);
 }
@@ -49,6 +57,8 @@ DCPContent::DCPContent (shared_ptr<const Film> f, cxml::ConstNodePtr node, int v
 	_name = node->string_child ("Name");
 	_has_subtitles = node->bool_child ("HasSubtitles");
 	_directory = node->string_child ("Directory");
+	_encrypted = node->bool_child ("Encrypted");
+	_kdm_valid = node->bool_child ("KDMValid");
 }
 
 void
@@ -66,6 +76,8 @@ DCPContent::read_directory (boost::filesystem::path p)
 void
 DCPContent::examine (shared_ptr<Job> job)
 {
+	bool const could_be_played = can_be_played ();
+		
 	job->set_progress_unknown ();
 	Content::examine (job);
 	
@@ -76,6 +88,12 @@ DCPContent::examine (shared_ptr<Job> job)
 	boost::mutex::scoped_lock lm (_mutex);
 	_name = examiner->name ();
 	_has_subtitles = examiner->has_subtitles ();
+	_encrypted = examiner->encrypted ();
+	_kdm_valid = examiner->kdm_valid ();
+
+	if (could_be_played != can_be_played ()) {
+		signal_changed (DCPContentProperty::CAN_BE_PLAYED);
+	}
 }
 
 string
@@ -106,7 +124,10 @@ DCPContent::as_xml (xmlpp::Node* node) const
 	boost::mutex::scoped_lock lm (_mutex);
 	node->add_child("Name")->add_child_text (_name);
 	node->add_child("HasSubtitles")->add_child_text (_has_subtitles ? "1" : "0");
+	node->add_child("Encrypted")->add_child_text (_encrypted ? "1" : "0");
 	node->add_child("Directory")->add_child_text (_directory.string ());
+	/* XXX: KDM */
+	node->add_child("KDMValid")->add_child_text (_kdm_valid ? "1" : "0");
 }
 
 DCPTime
@@ -123,9 +144,14 @@ DCPContent::identifier () const
 	return SubtitleContent::identifier ();
 }
 
+void
+DCPContent::add_kdm (dcp::EncryptedKDM k)
+{
+	_kdm = k;
+}
+
 bool
-DCPContent::has_subtitles () const
+DCPContent::can_be_played () const
 {
-	boost::mutex::scoped_lock lm (_mutex);
-	return _has_subtitles;
+	return !_encrypted || _kdm_valid;
 }
diff --git a/src/lib/dcp_content.h b/src/lib/dcp_content.h
index 60b7142de..da78e6d72 100644
--- a/src/lib/dcp_content.h
+++ b/src/lib/dcp_content.h
@@ -17,15 +17,26 @@
 
 */
 
+#ifndef DCPOMATIC_DCP_CONTENT_H
+#define DCPOMATIC_DCP_CONTENT_H
+
 /** @file  src/lib/dcp_content.h
  *  @brief DCPContent class.
  */
 
 #include <libcxml/cxml.h>
+#include <dcp/encrypted_kdm.h>
+#include <dcp/decrypted_kdm.h>
 #include "video_content.h"
 #include "single_stream_audio_content.h"
 #include "subtitle_content.h"
 
+class DCPContentProperty
+{
+public:
+	static int const CAN_BE_PLAYED;
+};
+
 /** @class DCPContent
  *  @brief An existing DCP used as input.
  */
@@ -48,17 +59,40 @@ public:
 	std::string identifier () const;
 
 	/* SubtitleContent */
-	bool has_subtitles () const;
+	bool has_subtitles () const {
+		boost::mutex::scoped_lock lm (_mutex);
+		return _has_subtitles;
+	}
 	
 	boost::filesystem::path directory () const {
 		boost::mutex::scoped_lock lm (_mutex);
 		return _directory;
 	}
 
+	bool encrypted () const {
+		boost::mutex::scoped_lock lm (_mutex);
+		return _encrypted;
+	}
+
+	void add_kdm (dcp::EncryptedKDM);
+
+	boost::optional<dcp::EncryptedKDM> kdm () const {
+		return _kdm;
+	}
+
+	bool can_be_played () const;
+	
 private:
 	void read_directory (boost::filesystem::path);
 	
 	std::string _name;
 	bool _has_subtitles;
+	/** true if our DCP is encrypted */
+	bool _encrypted;
 	boost::filesystem::path _directory;
+	boost::optional<dcp::EncryptedKDM> _kdm;
+	/** true if _kdm successfully decrypts the first frame of our DCP */
+	bool _kdm_valid;
 };
+
+#endif
diff --git a/src/lib/dcp_decoder.cc b/src/lib/dcp_decoder.cc
index d0642d8b6..bf016ef87 100644
--- a/src/lib/dcp_decoder.cc
+++ b/src/lib/dcp_decoder.cc
@@ -31,6 +31,7 @@
 #include "dcp_content.h"
 #include "j2k_image_proxy.h"
 #include "image.h"
+#include "config.h"
 
 using std::list;
 using std::cout;
@@ -46,6 +47,9 @@ DCPDecoder::DCPDecoder (shared_ptr<const DCPContent> c, shared_ptr<Log> log)
 {
 	dcp::DCP dcp (c->directory ());
 	dcp.read ();
+	if (c->kdm ()) {
+		dcp.add (dcp::DecryptedKDM (c->kdm().get (), Config::instance()->decryption_private_key ()));
+	}
 	assert (dcp.cpls().size() == 1);
 	_reels = dcp.cpls().front()->reels ();
 	_reel = _reels.begin ();
@@ -54,7 +58,7 @@ DCPDecoder::DCPDecoder (shared_ptr<const DCPContent> c, shared_ptr<Log> log)
 bool
 DCPDecoder::pass ()
 {
-	if (_reel == _reels.end ()) {
+	if (_reel == _reels.end () || !_dcp_content->can_be_played ()) {
 		return true;
 	}
 
diff --git a/src/lib/dcp_examiner.cc b/src/lib/dcp_examiner.cc
index 625276e18..1e4cc899d 100644
--- a/src/lib/dcp_examiner.cc
+++ b/src/lib/dcp_examiner.cc
@@ -22,21 +22,38 @@
 #include <dcp/reel.h>
 #include <dcp/reel_picture_asset.h>
 #include <dcp/reel_sound_asset.h>
+#include <dcp/mono_picture_mxf.h>
+#include <dcp/mono_picture_frame.h>
+#include <dcp/stereo_picture_mxf.h>
+#include <dcp/stereo_picture_frame.h>
 #include <dcp/sound_mxf.h>
 #include "dcp_examiner.h"
 #include "dcp_content.h"
 #include "exceptions.h"
+#include "image.h"
+#include "config.h"
 
 #include "i18n.h"
 
 using std::list;
+using std::cout;
 using boost::shared_ptr;
+using boost::dynamic_pointer_cast;
 
 DCPExaminer::DCPExaminer (shared_ptr<const DCPContent> content)
+	: _video_length (0)
+	, _audio_length (0)
+	, _has_subtitles (false)
+	, _encrypted (false)
+	, _kdm_valid (false)
 {
 	dcp::DCP dcp (content->directory ());
 	dcp.read ();
 
+	if (content->kdm ()) {
+		dcp.add (dcp::DecryptedKDM (content->kdm().get(), Config::instance()->decryption_private_key ()));
+	}
+
 	if (dcp.cpls().size() == 0) {
 		throw DCPError ("No CPLs found in DCP");
 	} else if (dcp.cpls().size() > 1) {
@@ -89,4 +106,31 @@ DCPExaminer::DCPExaminer (shared_ptr<const DCPContent> content)
 			_has_subtitles = true;
 		}
 	}
+
+	_encrypted = dcp.encrypted ();
+	_kdm_valid = true;
+	
+	/* Check that we can read the first picture frame */
+	try {
+		if (!dcp.cpls().empty () && !dcp.cpls().front()->reels().empty ()) {
+			shared_ptr<dcp::PictureMXF> mxf = dcp.cpls().front()->reels().front()->main_picture()->mxf ();
+			shared_ptr<dcp::MonoPictureMXF> mono = dynamic_pointer_cast<dcp::MonoPictureMXF> (mxf);
+			shared_ptr<dcp::StereoPictureMXF> stereo = dynamic_pointer_cast<dcp::StereoPictureMXF> (mxf);
+			
+			shared_ptr<Image> image (new Image (PIX_FMT_RGB24, _video_size.get(), false));
+			
+			if (mono) {
+				mono->get_frame(0)->rgb_frame (image->data()[0]);
+			} else {
+				stereo->get_frame(0)->rgb_frame (dcp::EYE_LEFT, image->data()[0]);
+			}
+			
+		}
+	} catch (dcp::DCPReadError& e) {
+		_kdm_valid = false;
+		if (_encrypted && content->kdm ()) {
+			/* XXX: maybe don't use an exception for this */
+			throw StringError (_("The KDM does not decrypt the DCP.  Perhaps it is targeted at the wrong CPL"));
+		}
+	}
 }
diff --git a/src/lib/dcp_examiner.h b/src/lib/dcp_examiner.h
index 5b510743b..03d43d0f6 100644
--- a/src/lib/dcp_examiner.h
+++ b/src/lib/dcp_examiner.h
@@ -47,6 +47,10 @@ public:
 		return _has_subtitles;
 	}
 
+	bool encrypted () const {
+		return _encrypted;
+	}
+
 	int audio_channels () const {
 		return _audio_channels.get_value_or (0);
 	}
@@ -59,6 +63,10 @@ public:
 		return _audio_frame_rate.get_value_or (48000);
 	}
 
+	bool kdm_valid () const {
+		return _kdm_valid;
+	}
+
 private:
 	boost::optional<float> _video_frame_rate;
 	boost::optional<dcp::Size> _video_size;
@@ -68,4 +76,6 @@ private:
 	ContentTime _audio_length;
 	std::string _name;
 	bool _has_subtitles;
+	bool _encrypted;
+	bool _kdm_valid;
 };
diff --git a/src/lib/film.cc b/src/lib/film.cc
index c3194eca8..99a668e37 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -940,6 +940,13 @@ Film::content () const
 }
 
 void
+Film::examine_content (shared_ptr<Content> c)
+{
+	shared_ptr<Job> j (new ExamineContentJob (shared_from_this(), c));
+	JobManager::instance()->add (j);
+}
+
+void
 Film::examine_and_add_content (shared_ptr<Content> c)
 {
 	if (dynamic_pointer_cast<FFmpegContent> (c)) {
@@ -1083,7 +1090,7 @@ Film::make_kdm (
 	}
 	
 	return dcp::DecryptedKDM (
-		cpl, from, until, "DCP-o-matic", cpl->content_title_text(), dcp::LocalTime().as_string()
+		cpl, key(), from, until, "DCP-o-matic", cpl->content_title_text(), dcp::LocalTime().as_string()
 		).encrypt (signer, target, formulation);
 }
 
diff --git a/src/lib/film.h b/src/lib/film.h
index 6c3f78895..dea669d98 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -250,6 +250,7 @@ public:
 	void set_directory (boost::filesystem::path);
 	void set_name (std::string);
 	void set_use_isdcf_name (bool);
+	void examine_content (boost::shared_ptr<Content>);
 	void examine_and_add_content (boost::shared_ptr<Content>);
 	void add_content (boost::shared_ptr<Content>);
 	void remove_content (boost::shared_ptr<Content>);
diff --git a/src/lib/player.cc b/src/lib/player.cc
index c8ac591a7..06f9e1365 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -31,6 +31,7 @@
 #include "subtitle_content.h"
 #include "subrip_decoder.h"
 #include "subrip_content.h"
+#include "dcp_content.h"
 #include "playlist.h"
 #include "job.h"
 #include "image.h"
@@ -189,7 +190,8 @@ Player::content_changed (weak_ptr<Content> w, int property, bool frequent)
 		property == ContentProperty::TRIM_START ||
 		property == ContentProperty::TRIM_END ||
 		property == ContentProperty::PATH ||
-		property == VideoContentProperty::VIDEO_FRAME_TYPE
+		property == VideoContentProperty::VIDEO_FRAME_TYPE ||
+		property == DCPContentProperty::CAN_BE_PLAYED
 		) {
 		
 		_have_valid_pieces = false;
diff --git a/src/lib/video_content.cc b/src/lib/video_content.cc
index a8590ce55..0d9a8fc45 100644
--- a/src/lib/video_content.cc
+++ b/src/lib/video_content.cc
@@ -192,7 +192,7 @@ VideoContent::take_from_video_examiner (shared_ptr<VideoExaminer> d)
 	dcp::Size const vs = d->video_size ();
 	float const vfr = d->video_frame_rate ();
 	ContentTime vl = d->video_length ();
-	
+
 	{
 		boost::mutex::scoped_lock lm (_mutex);
 		_video_size = vs;
diff --git a/src/wx/config_dialog.cc b/src/wx/config_dialog.cc
index ee660832f..3775ae1bb 100644
--- a/src/wx/config_dialog.cc
+++ b/src/wx/config_dialog.cc
@@ -39,6 +39,8 @@
 #include "lib/colour_conversion.h"
 #include "lib/log.h"
 #include "lib/util.h"
+#include "lib/cross.h"
+#include "lib/exceptions.h"
 #include "config_dialog.h"
 #include "wx_util.h"
 #include "editable_list.h"
@@ -656,6 +658,10 @@ public:
 			s->Add (_load_decryption_private_key, 0, wxLEFT, DCPOMATIC_SIZER_X_GAP);
 			table->Add (s, 0);
 		}
+
+		_export_decryption_certificate = new wxButton (_panel, wxID_ANY, _("Export DCP decryption certificate..."));
+		table->Add (_export_decryption_certificate);
+		table->AddSpacer (0);
 		
 		_add_certificate->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&KeysPage::add_certificate, this));
 		_remove_certificate->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&KeysPage::remove_certificate, this));
@@ -664,6 +670,7 @@ public:
 		_load_signer_private_key->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&KeysPage::load_signer_private_key, this));
 		_load_decryption_certificate->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&KeysPage::load_decryption_certificate, this));
 		_load_decryption_private_key->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&KeysPage::load_decryption_private_key, this));
+		_export_decryption_certificate->Bind (wxEVT_COMMAND_BUTTON_CLICKED, boost::bind (&KeysPage::export_decryption_certificate, this));
 
 		_signer.reset (new dcp::Signer (*Config::instance()->signer().get ()));
 
@@ -814,6 +821,26 @@ private:
 		_decryption_private_key->SetLabel (std_to_wx (dcp::private_key_fingerprint (Config::instance()->decryption_private_key())));
 	}
 
+	void export_decryption_certificate ()
+	{
+		wxFileDialog* d = new wxFileDialog (
+			_panel, _("Select Certificate File"), wxEmptyString, wxEmptyString, wxT ("PEM files (*.pem)|*.pem"),
+			wxFD_SAVE | wxFD_OVERWRITE_PROMPT
+			);
+		
+		if (d->ShowModal () == wxID_OK) {
+			FILE* f = fopen_boost (wx_to_std (d->GetPath ()), "w");
+			if (!f) {
+				throw OpenFileError (wx_to_std (d->GetPath ()));
+			}
+
+			string const s = Config::instance()->decryption_certificate().certificate (true);
+			fwrite (s.c_str(), 1, s.length(), f);
+			fclose (f);
+		}
+		d->Destroy ();
+	}
+
 	wxPanel* _panel;
 	wxListCtrl* _certificates;
 	wxButton* _add_certificate;
@@ -824,6 +851,7 @@ private:
 	wxButton* _load_decryption_certificate;
 	wxStaticText* _decryption_private_key;
 	wxButton* _load_decryption_private_key;
+	wxButton* _export_decryption_certificate;
 	shared_ptr<dcp::Signer> _signer;
 };
 
diff --git a/src/wx/content_menu.cc b/src/wx/content_menu.cc
index b91c82ab1..b396ceb41 100644
--- a/src/wx/content_menu.cc
+++ b/src/wx/content_menu.cc
@@ -26,6 +26,7 @@
 #include "lib/examine_content_job.h"
 #include "lib/job_manager.h"
 #include "lib/exceptions.h"
+#include "lib/dcp_content.h"
 #include "content_menu.h"
 #include "repeat_dialog.h"
 #include "wx_util.h"
@@ -40,6 +41,7 @@ enum {
 	ID_repeat = 1,
 	ID_join,
 	ID_find_missing,
+	ID_kdm,
 	ID_remove
 };
 
@@ -50,12 +52,14 @@ ContentMenu::ContentMenu (wxWindow* p)
 	_repeat = _menu->Append (ID_repeat, _("Repeat..."));
 	_join = _menu->Append (ID_join, _("Join"));
 	_find_missing = _menu->Append (ID_find_missing, _("Find missing..."));
+	_kdm = _menu->Append (ID_kdm, _("Add KDM..."));
 	_menu->AppendSeparator ();
 	_remove = _menu->Append (ID_remove, _("Remove"));
 
 	_parent->Bind (wxEVT_COMMAND_MENU_SELECTED, boost::bind (&ContentMenu::repeat, this), ID_repeat);
 	_parent->Bind (wxEVT_COMMAND_MENU_SELECTED, boost::bind (&ContentMenu::join, this), ID_join);
 	_parent->Bind (wxEVT_COMMAND_MENU_SELECTED, boost::bind (&ContentMenu::find_missing, this), ID_find_missing);
+	_parent->Bind (wxEVT_COMMAND_MENU_SELECTED, boost::bind (&ContentMenu::kdm, this), ID_kdm);
 	_parent->Bind (wxEVT_COMMAND_MENU_SELECTED, boost::bind (&ContentMenu::remove, this), ID_remove);
 }
 
@@ -81,6 +85,14 @@ ContentMenu::popup (weak_ptr<Film> f, ContentList c, wxPoint p)
 	_join->Enable (n > 1);
 	
 	_find_missing->Enable (_content.size() == 1 && !_content.front()->paths_valid ());
+
+	if (_content.size() == 1) {
+		shared_ptr<DCPContent> dcp = dynamic_pointer_cast<DCPContent> (_content.front ());
+		_kdm->Enable (dcp && dcp->encrypted ());
+	} else {
+		_kdm->Enable (false);
+	}
+	
 	_remove->Enable (!_content.empty ());
 	_parent->PopupMenu (_menu, p);
 }
@@ -226,3 +238,22 @@ ContentMenu::maybe_found_missing (weak_ptr<Job> j, weak_ptr<Content> oc, weak_pt
 
 	old_content->set_path (new_content->path (0));
 }
+
+void
+ContentMenu::kdm ()
+{
+	assert (!_content.empty ());
+	shared_ptr<DCPContent> dcp = dynamic_pointer_cast<DCPContent> (_content.front ());
+	assert (dcp);
+	
+	wxFileDialog* d = new wxFileDialog (_parent, _("Select KDM"));
+		
+	if (d->ShowModal() == wxID_OK) {
+		dcp->add_kdm (dcp::EncryptedKDM (wx_to_std (d->GetPath ())));
+		shared_ptr<Film> film = _film.lock ();
+		assert (film);
+		film->examine_content (dcp);
+	}
+	
+	d->Destroy ();
+}
diff --git a/src/wx/content_menu.h b/src/wx/content_menu.h
index f2ad3aa75..fccd5f38a 100644
--- a/src/wx/content_menu.h
+++ b/src/wx/content_menu.h
@@ -39,6 +39,7 @@ private:
 	void repeat ();
 	void join ();
 	void find_missing ();
+	void kdm ();
 	void remove ();
 	void maybe_found_missing (boost::weak_ptr<Job>, boost::weak_ptr<Content>, boost::weak_ptr<Content>);
 	
@@ -50,6 +51,7 @@ private:
 	wxMenuItem* _repeat;
 	wxMenuItem* _join;
 	wxMenuItem* _find_missing;
+	wxMenuItem* _kdm;
 	wxMenuItem* _remove;
 };
 
diff --git a/src/wx/content_panel.cc b/src/wx/content_panel.cc
index 13ae2d88a..5ef2d8356 100644
--- a/src/wx/content_panel.cc
+++ b/src/wx/content_panel.cc
@@ -399,7 +399,7 @@ ContentPanel::set_selection (weak_ptr<Content> wc)
 void
 ContentPanel::film_content_changed (int property)
 {
-	if (property == ContentProperty::PATH || property == ContentProperty::POSITION) {
+	if (property == ContentProperty::PATH || property == ContentProperty::POSITION || property == DCPContentProperty::CAN_BE_PLAYED) {
 		setup ();
 	}
 		
@@ -425,19 +425,26 @@ ContentPanel::setup ()
 	for (ContentList::iterator i = content.begin(); i != content.end(); ++i) {
 		int const t = _content->GetItemCount ();
 		bool const valid = (*i)->paths_valid ();
+		shared_ptr<DCPContent> dcp = dynamic_pointer_cast<DCPContent> (*i);
+		bool const needs_kdm = !dcp->can_be_played ();
 
 		string s = (*i)->summary ();
+		
 		if (!valid) {
 			s = _("MISSING: ") + s;
 		}
 
+		if (needs_kdm) {
+			s = _("NEEDS KDM: ") + s;
+		}
+
 		_content->InsertItem (t, std_to_wx (s));
 
 		if ((*i)->summary() == selected_summary) {
 			_content->SetItemState (t, wxLIST_STATE_SELECTED, wxLIST_STATE_SELECTED);
 		}
 
-		if (!valid) {
+		if (!valid || needs_kdm) {
 			_content->SetItemTextColour (t, *wxRED);
 		}
 	}
diff --git a/src/wx/film_viewer.cc b/src/wx/film_viewer.cc
index 74e3b81ed..80b12bf76 100644
--- a/src/wx/film_viewer.cc
+++ b/src/wx/film_viewer.cc
@@ -24,6 +24,7 @@
 #include <iostream>
 #include <iomanip>
 #include <wx/tglbtn.h>
+#include <dcp/exceptions.h>
 #include "lib/film.h"
 #include "lib/ratio.h"
 #include "lib/util.h"
@@ -153,9 +154,24 @@ FilmViewer::get (DCPTime p, bool accurate)
 
 	list<shared_ptr<PlayerVideo> > pvf = _player->get_video (p, accurate);
 	if (!pvf.empty ()) {
-		_frame = pvf.front()->image (true);
-		_frame = _frame->scale (_frame->size(), Scaler::from_id ("fastbilinear"), PIX_FMT_RGB24, false);
-		_position = pvf.front()->time ();
+		try {
+			_frame = pvf.front()->image (true);
+			_frame = _frame->scale (_frame->size(), Scaler::from_id ("fastbilinear"), PIX_FMT_RGB24, false);
+			_position = pvf.front()->time ();
+		} catch (dcp::DCPReadError& e) {
+			/* This can happen on the following sequence of events:
+			 * - load encrypted DCP
+			 * - add KDM
+			 * - DCP is examined again, which sets its "playable" flag to 1
+			 * - as a side effect of the exam, the viewer is updated using the old pieces
+			 * - the DCPDecoder in the old piece gives us an encrypted frame
+			 * - then, the pieces are re-made (but too late).
+			 *
+			 * I hope there's a better way to handle this ...
+			 */
+			_frame.reset ();
+			_position = p;
+		}
 	} else {
 		_frame.reset ();
 		_position = p;