basic GUI support to auto-align video by LTC.

gtk2_ardour/ardour_ui.cc

@@ -77,6 +77,7 @@
 #include "ardour/diskstream.h"
 #include "ardour/filename_extensions.h"
 #include "ardour/filesystem_paths.h"
+#include "ardour/ltc_file_reader.h"
 #include "ardour/port.h"
 #include "ardour/plugin_manager.h"
 #include "ardour/process_thread.h"
@@ -3958,6 +3959,9 @@ ARDOUR_UI::add_video (Gtk::Window* float_window)
 		return;
 	}
 
+	std::string audio_from_video;
+	bool detect_ltc = false;
+
 	switch (add_video_dialog->import_option()) {
 		case VTL_IMPORT_TRANSCODE:
 			{
@@ -3969,9 +3973,15 @@ ARDOUR_UI::add_video (Gtk::Window* float_window)
 					delete transcode_video_dialog;
 					return;
 				}
-				if (!transcode_video_dialog->get_audiofile().empty()) {
+
+				audio_from_video = transcode_video_dialog->get_audiofile();
+
+				if (!audio_from_video.empty() && transcode_video_dialog->detect_ltc()) {
+					detect_ltc = true;
+				}
+				else if (!audio_from_video.empty()) {
 					editor->embed_audio_from_video(
-							transcode_video_dialog->get_audiofile(),
+							audio_from_video,
 							video_timeline->get_offset(),
 							(transcode_video_dialog->import_option() != VTL_IMPORT_NO_VIDEO)
 							);
@@ -4004,6 +4014,7 @@ ARDOUR_UI::add_video (Gtk::Window* float_window)
 	}
 
 	video_timeline->set_update_session_fps(auto_set_session_fps);
+
 	if (video_timeline->video_file_info(path, local_file)) {
 		XMLNode* node = new XMLNode(X_("Videotimeline"));
 		node->add_property (X_("Filename"), path);
@@ -4017,6 +4028,40 @@ ARDOUR_UI::add_video (Gtk::Window* float_window)
 		_session->add_extra_xml (*node);
 		_session->set_dirty ();
 
+		if (!audio_from_video.empty() && detect_ltc) {
+			std::vector<LTCFileReader::LTCMap> ltc_seq;
+
+			try {
+				/* TODO ask user about TV standard (LTC alignment if any) */
+				LTCFileReader ltcr (audio_from_video, video_timeline->get_video_file_fps());
+				/* TODO ASK user which channel:  0 .. ltcr->channels() - 1 */
+
+				ltc_seq = ltcr.read_ltc (/*channel*/ 0, /*max LTC frames to decode*/ 15);
+
+				/* TODO seek near end of file, and read LTC until end.
+				 * if it fails to find any LTC frames, scan complete file
+				 *
+				 * calculate drift of LTC compared to video-duration,
+				 * ask user for reference (timecode from start/mid/end)
+				 */
+			} catch (...) {
+				// LTCFileReader will have written error messages
+			}
+
+			::g_unlink(audio_from_video.c_str());
+
+			if (ltc_seq.size() == 0) {
+				PBD::error << _("No LTC detected, video will not be aligned.") << endmsg;
+			} else {
+				/* the very first TC in the file is somteimes not aligned properly */
+				int i = ltc_seq.size() -1;
+				ARDOUR::frameoffset_t video_start_offset =
+					_session->nominal_frame_rate() * (ltc_seq[i].timecode_sec - ltc_seq[i].framepos_sec);
+				PBD::info << string_compose (_("Align video-start to %1 [samples]"), video_start_offset) << endmsg;
+				video_timeline->set_offset(video_start_offset);
+			}
+		}
+
 		_session->maybe_update_session_range(
 			std::max(video_timeline->get_offset(), (ARDOUR::frameoffset_t) 0),
 			std::max(video_timeline->get_offset() + video_timeline->get_duration(), (ARDOUR::frameoffset_t) 0));

gtk2_ardour/transcode_video_dialog.cc

@@ -63,6 +63,7 @@ TranscodeVideoDialog::TranscodeVideoDialog (Session* s, std::string infile)
 	, aspect_checkbox (_("Height = "))
 	, height_adjustment (128, 0, 1920, 1, 16, 0)
 	, height_spinner (height_adjustment)
+	, ltc_detect (_("Extract LTC from audio and align video"))
 	, bitrate_checkbox (_("Manual Override"))
 	, bitrate_adjustment (2000, 500, 10000, 10, 100, 0)
 	, bitrate_spinner (bitrate_adjustment)
@@ -219,7 +220,7 @@ TranscodeVideoDialog::TranscodeVideoDialog (Session* s, std::string infile)
 
 	options_box->pack_start (video_combo, false, false, 4);
 
-	Table* t = manage (new Table (4, 3));
+	Table* t = manage (new Table (4, 4));
 	t->set_spacings (4);
 	options_box->pack_start (*t, true, true, 4);
 
@@ -254,6 +255,7 @@ TranscodeVideoDialog::TranscodeVideoDialog (Session* s, std::string infile)
 	t->attach (*l, 0, 1, 2, 3);
 	audio_combo.set_name ("PaddedButton");
 	t->attach (audio_combo, 1, 4, 2, 3);
+	t->attach (ltc_detect, 1, 4, 3, 4);
 	if (as.size() == 0) {
 		audio_combo.append_text(_("No Audio Track Present"));
 		audio_combo.set_sensitive(false);
@@ -264,6 +266,7 @@ TranscodeVideoDialog::TranscodeVideoDialog (Session* s, std::string infile)
 		}
 	}
 	audio_combo.set_active(0);
+	ltc_detect.set_sensitive (false);
 
 #if 1 /* tentative debug mode */
 	options_box->pack_start (debug_checkbox, false, true, 4);
@@ -461,6 +464,9 @@ TranscodeVideoDialog::video_combo_changed ()
 	}
 	if (i == 2 && audio_combo.get_active_row_number() == 0) {
 		audio_combo.set_active(1);
+	} else {
+		//update LTC option sensitivity
+		audio_combo_changed ();
 	}
 }
 
@@ -471,6 +477,17 @@ TranscodeVideoDialog::audio_combo_changed ()
 			&& audio_combo.get_active_row_number() == 0)
 	{
 		audio_combo.set_active(1);
+		ltc_detect.set_sensitive (false);
+		ltc_detect.set_active (false);
+	}
+
+	if (video_combo.get_active_row_number() != 2
+			&& audio_combo.get_active_row_number() > 0)
+	{
+		ltc_detect.set_sensitive (true);
+	} else {
+		ltc_detect.set_sensitive (false);
+		ltc_detect.set_active (false);
 	}
 }
 

gtk2_ardour/transcode_video_dialog.h

@@ -48,6 +48,7 @@ class TranscodeVideoDialog : public ArdourDialog , public PBD::ScopedConnectionL
 	std::string get_filename () { return path_entry.get_text(); }
 	std::string get_audiofile () { return audiofile; }
 	VtlTranscodeOption import_option ();
+	bool detect_ltc () { return ltc_detect.get_active (); }
 
   private:
 	void on_show ();
@@ -94,6 +95,7 @@ class TranscodeVideoDialog : public ArdourDialog , public PBD::ScopedConnectionL
 	Gtk::Adjustment   height_adjustment;
 	Gtk::SpinButton   height_spinner;
 	Gtk::ComboBoxText audio_combo;
+	Gtk::CheckButton  ltc_detect;
 	Gtk::CheckButton  bitrate_checkbox;
 	Gtk::Adjustment   bitrate_adjustment;
 	Gtk::SpinButton   bitrate_spinner;