libardour added.

git-svn-id: svn://localhost/trunk/ardour2@17 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 853 insertions, 0 deletions

diff --git a/libs/ardour/session_time.cc b/libs/ardour/session_time.cc
new file mode 100644
index 0000000000..27cc40ec47
--- /dev/null
+++ b/libs/ardour/session_time.cc
@@ -0,0 +1,853 @@
+
+/*
+  Copyright (C) 1999-2002 Paul Davis 
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software
+  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+  $Id$
+*/
+
+#include <iostream>
+#include <cmath>
+#include <unistd.h>
+
+#include <ardour/timestamps.h>
+
+#include <pbd/error.h>
+
+#include <ardour/ardour.h>
+#include <ardour/configuration.h>
+#include <ardour/audioengine.h>
+#include <ardour/session.h>
+#include <ardour/tempo.h>
+
+#include "i18n.h"
+
+using namespace ARDOUR;
+//using namespace sigc;
+
+/* BBT TIME*/
+
+void
+Session::bbt_time (jack_nframes_t when, BBT_Time& bbt)
+{
+	_tempo_map->bbt_time (when, bbt);
+}
+
+/* SMPTE TIME */
+
+int
+Session::set_smpte_type (float fps, bool drop_frames)
+{
+	smpte_frames_per_second = fps;
+	smpte_drop_frames = drop_frames;
+	_frames_per_smpte_frame = (double) _current_frame_rate / (double) smpte_frames_per_second;
+	_frames_per_hour = _current_frame_rate * 3600;
+	_smpte_frames_per_hour = (unsigned long) (smpte_frames_per_second * 3600.0);
+
+
+	last_smpte_valid = false;
+	// smpte type bits are the middle two in the upper nibble
+	switch ((int) ceil (fps)) {
+	case 24:
+		mtc_smpte_bits = 0;
+		break;
+
+	case 25:
+		mtc_smpte_bits = 0x20;
+		break;
+
+	case 30:
+	default:
+		if (drop_frames) {
+			mtc_smpte_bits = 0x40;
+		} else {
+			mtc_smpte_bits =  0x60;
+		}
+		break;
+	};
+
+	SMPTETypeChanged (); /* EMIT SIGNAL */
+
+	set_dirty();
+
+	return 0;
+}
+
+void
+Session::set_smpte_offset (jack_nframes_t off)
+{
+	_smpte_offset = off;
+	last_smpte_valid = false;
+	SMPTEOffsetChanged (); /* EMIT SIGNAL */
+}
+
+void
+Session::set_smpte_offset_negative (bool neg)
+{
+	_smpte_offset_negative = neg;
+	last_smpte_valid = false;
+	SMPTEOffsetChanged (); /* EMIT SIGNAL */
+}
+
+#define SMPTE_IS_AROUND_ZERO( sm ) (!(sm).frames && !(sm).seconds && !(sm).minutes && !(sm).hours)
+#define SMPTE_IS_ZERO( sm ) (!(sm).frames && !(sm).seconds && !(sm).minutes && !(sm).hours && !(sm.subframes))
+
+// Increment by exactly one frame (keep subframes value)
+// Return true if seconds wrap
+smpte_wrap_t
+Session::smpte_increment( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+
+	if (smpte.negative) {
+		if (SMPTE_IS_AROUND_ZERO(smpte) && smpte.subframes) {
+			// We have a zero transition involving only subframes
+			smpte.subframes = 80 - smpte.subframes;
+			smpte.negative = false;
+			return smpte_wrap_seconds;
+		}
+    
+		smpte.negative = false;
+		wrap = smpte_decrement( smpte );
+		if (!SMPTE_IS_ZERO( smpte )) {
+			smpte.negative = true;
+		}
+		return wrap;
+	}
+  
+	switch (mtc_smpte_bits >> 5) {
+	case MIDI::MTC_24_FPS:
+		if (smpte.frames == 23) {
+			smpte.frames = 0;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	case MIDI::MTC_25_FPS:
+		if (smpte.frames == 24) {
+			smpte.frames = 0;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	case MIDI::MTC_30_FPS_DROP:
+		if (smpte.frames == 29) {
+			if ( ((smpte.minutes + 1) % 10) && (smpte.seconds == 59) ) {
+				smpte.frames = 2;
+			}
+			else {
+				smpte.frames = 0;
+			}
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	case MIDI::MTC_30_FPS:
+		if (smpte.frames == 29) {
+			smpte.frames = 0;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	}
+  
+	if (wrap == smpte_wrap_seconds) {
+		if (smpte.seconds == 59) {
+			smpte.seconds = 0;
+			wrap = smpte_wrap_minutes;
+			if (smpte.minutes == 59) {
+				smpte.minutes = 0;
+				wrap = smpte_wrap_hours;
+				smpte.hours++;
+			} else {
+				smpte.minutes++;
+			}
+		} else {
+			smpte.seconds++;
+		}
+	} else {
+		smpte.frames++;
+	}
+  
+	return wrap;
+}
+
+// Decrement by exactly one frame (keep subframes value)
+smpte_wrap_t
+Session::smpte_decrement( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+  
+  
+	if (smpte.negative || SMPTE_IS_ZERO(smpte)) {
+		smpte.negative = false;
+		wrap = smpte_increment( smpte );
+		smpte.negative = true;
+		return wrap;
+	} else if (SMPTE_IS_AROUND_ZERO(smpte) && smpte.subframes) {
+		// We have a zero transition involving only subframes
+		smpte.subframes = 80 - smpte.subframes;
+		smpte.negative = true;
+		return smpte_wrap_seconds;
+	}
+  
+	switch (mtc_smpte_bits >> 5) {
+	case MIDI::MTC_24_FPS:
+		if (smpte.frames == 0) {
+			smpte.frames = 23;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	case MIDI::MTC_25_FPS:
+		if (smpte.frames == 0) {
+			smpte.frames = 24;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	case MIDI::MTC_30_FPS_DROP:
+		if ((smpte.minutes % 10) && (smpte.seconds == 0)) {
+			if (smpte.frames <= 2) {
+				smpte.frames = 29;
+				wrap = smpte_wrap_seconds;
+			}
+		} else if (smpte.frames == 0) {
+			smpte.frames = 29;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	case MIDI::MTC_30_FPS:
+		if (smpte.frames == 0) {
+			smpte.frames = 29;
+			wrap = smpte_wrap_seconds;
+		}
+		break;
+	}
+  
+	if (wrap == smpte_wrap_seconds) {
+		if (smpte.seconds == 0) {
+			smpte.seconds = 59;
+			wrap = smpte_wrap_minutes;
+			if (smpte.minutes == 0) {
+				smpte.minutes = 59;
+				wrap = smpte_wrap_hours;
+				smpte.hours--;
+			}
+			else {
+				smpte.minutes--;
+			}
+		} else {
+			smpte.seconds--;
+		}
+	} else {
+		smpte.frames--;
+	}
+  
+	if (SMPTE_IS_ZERO( smpte )) {
+		smpte.negative = false;
+	}
+  
+	return wrap;
+}
+
+// Go to lowest absolute subframe value in this frame (set to 0 :-)
+void
+Session::smpte_frames_floor( SMPTE_Time& smpte ) const
+{
+	smpte.subframes = 0;
+	if (SMPTE_IS_ZERO(smpte)) {
+		smpte.negative = false;
+	}
+}
+
+// Increment by one subframe
+smpte_wrap_t
+Session::smpte_increment_subframes( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+  
+	if (smpte.negative) {
+		smpte.negative = false;
+		wrap = smpte_decrement_subframes( smpte );
+		if (!SMPTE_IS_ZERO(smpte)) {
+			smpte.negative = true;
+		}
+		return wrap;
+	}
+  
+	smpte.subframes++;
+	if (smpte.subframes >= 80) {
+		smpte.subframes = 0;
+		smpte_increment( smpte );
+		return smpte_wrap_frames;
+	}
+	return smpte_wrap_none;
+}
+
+
+// Decrement by one subframe
+smpte_wrap_t
+Session::smpte_decrement_subframes( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+  
+	if (smpte.negative) {
+		smpte.negative = false;
+		wrap = smpte_increment_subframes( smpte );
+		smpte.negative = true;
+		return wrap;
+	}
+  
+	if (smpte.subframes <= 0) {
+		smpte.subframes = 0;
+		if (SMPTE_IS_ZERO(smpte)) {
+			smpte.negative = true;
+			smpte.subframes = 1;
+			return smpte_wrap_frames;
+		} else {
+			smpte_decrement( smpte );
+			smpte.subframes = 79;
+			return smpte_wrap_frames;
+		}
+	} else {
+		smpte.subframes--;
+		if (SMPTE_IS_ZERO(smpte)) {
+			smpte.negative = false;
+		}
+		return smpte_wrap_none;
+	}
+}
+
+
+// Go to next whole second (frames == 0 or frames == 2)
+smpte_wrap_t
+Session::smpte_increment_seconds( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+  
+	// Clear subframes
+	smpte_frames_floor( smpte );
+  
+	if (smpte.negative) {
+		// Wrap second if on second boundary
+		wrap = smpte_increment(smpte);
+		// Go to lowest absolute frame value
+		smpte_seconds_floor( smpte );
+		if (SMPTE_IS_ZERO(smpte)) {
+			smpte.negative = false;
+		}
+	} else {
+		// Go to highest possible frame in this second
+		switch (mtc_smpte_bits >> 5) {
+		case MIDI::MTC_24_FPS:
+			smpte.frames = 23;
+			break;
+		case MIDI::MTC_25_FPS:
+			smpte.frames = 24;
+			break;
+		case MIDI::MTC_30_FPS_DROP:
+		case MIDI::MTC_30_FPS:
+			smpte.frames = 29;
+			break;
+		}
+    
+		// Increment by one frame
+		wrap = smpte_increment( smpte );
+	}
+  
+	return wrap;
+}
+
+// Go to lowest (absolute) frame value in this second
+// Doesn't care about positive/negative
+void
+Session::smpte_seconds_floor( SMPTE_Time& smpte ) const
+{
+	// Clear subframes
+	smpte_frames_floor( smpte );
+  
+	// Go to lowest possible frame in this second
+	switch (mtc_smpte_bits >> 5) {
+	case MIDI::MTC_24_FPS:
+	case MIDI::MTC_25_FPS:
+	case MIDI::MTC_30_FPS:
+		smpte.frames = 0;
+		break;
+	case MIDI::MTC_30_FPS_DROP:
+		if ((smpte.minutes % 10) && (smpte.seconds == 0)) {
+			smpte.frames = 2;
+		} else {
+			smpte.frames = 0;
+		}
+		break;
+	}
+  
+	if (SMPTE_IS_ZERO(smpte)) {
+		smpte.negative = false;
+	}
+}
+
+
+// Go to next whole minute (seconds == 0, frames == 0 or frames == 2)
+smpte_wrap_t
+Session::smpte_increment_minutes( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+  
+	// Clear subframes
+	smpte_frames_floor( smpte );
+  
+	if (smpte.negative) {
+		// Wrap if on minute boundary
+		wrap = smpte_increment_seconds( smpte );
+		// Go to lowest possible value in this minute
+		smpte_minutes_floor( smpte );
+	} else {
+		// Go to highest possible second
+		smpte.seconds = 59;
+		// Wrap minute by incrementing second
+		wrap = smpte_increment_seconds( smpte );
+	}
+  
+	return wrap;
+}
+
+// Go to lowest absolute value in this minute
+void
+Session::smpte_minutes_floor( SMPTE_Time& smpte ) const
+{
+	// Go to lowest possible second
+	smpte.seconds = 0;
+	// Go to lowest possible frame
+	smpte_seconds_floor( smpte );
+
+	if (SMPTE_IS_ZERO(smpte)) {
+		smpte.negative = false;
+	}
+}
+
+// Go to next whole hour (minute = 0, second = 0, frame = 0)
+smpte_wrap_t
+Session::smpte_increment_hours( SMPTE_Time& smpte ) const
+{
+	smpte_wrap_t wrap = smpte_wrap_none;
+  
+	// Clear subframes
+	smpte_frames_floor(smpte);
+  
+	if (smpte.negative) {
+		// Wrap if on hour boundary
+		wrap = smpte_increment_minutes( smpte );
+		// Go to lowest possible value in this hour
+		smpte_hours_floor( smpte );
+	} else {
+		smpte.minutes = 59;
+		wrap = smpte_increment_minutes( smpte );
+	}
+  
+	return wrap;
+}
+
+// Go to lowest absolute value in this hour
+void
+Session::smpte_hours_floor( SMPTE_Time& smpte ) const
+{
+	smpte.minutes = 0;
+	smpte.seconds = 0;
+	smpte.frames = 0;
+	smpte.subframes = 0;
+  
+	if (SMPTE_IS_ZERO(smpte)) {
+		smpte.negative = false;
+	}
+}
+
+
+void
+Session::smpte_to_sample( SMPTE_Time& smpte, jack_nframes_t& sample, bool use_offset, bool use_subframes ) const
+{
+	if (smpte_drop_frames) {
+		// The drop frame format was created to better approximate the 30000/1001 = 29.97002997002997....
+		// framerate of NTSC color TV. The used frame rate of drop frame is 29.97, which drifts by about
+		// 0.108 frame per hour, or about 1.3 frames per 12 hours. This is not perfect, but a lot better
+		// than using 30 non drop, which will drift with about 1.8 frame per minute.
+		// Using 29.97, drop frame real time can be accurate only every 10th minute (10 minutes of 29.97 fps
+		// is exactly 17982 frames). One minute is 1798.2 frames, but we count 30 frames per second
+		// (30 * 60 = 1800). This means that at the first minute boundary (at the end of 0:0:59:29) we
+		// are 1.8 frames too late relative to real time. By dropping 2 frames (jumping to 0:1:0:2) we are
+		// approx. 0.2 frames too early. This adds up with 0.2 too early for each minute until we are 1.8
+		// frames too early at 0:9:0:2 (9 * 0.2 = 1.8). The 10th minute brings us 1.8 frames later again
+		// (at end of 0:9:59:29), which sums up to 0 (we are back to zero at 0:10:0:0 :-).
+		// 
+		// In table form:
+		// 
+		// SMPTE value    frames offset   subframes offset   seconds (rounded)  44100 sample (rounded)
+		//  0:00:00:00        0.0             0                     0.000                0 (accurate)
+		//  0:00:59:29        1.8           144                    60.027          2647177
+		//  0:01:00:02       -0.2           -16                    60.060          2648648
+		//  0:01:59:29        1.6           128                   120.020          5292883
+		//  0:02:00:02       -0.4           -32                   120.053          5294354
+		//  0:02:59:29        1.4           112                   180.013          7938588
+		//  0:03:00:02       -0.6           -48                   180.047          7940060
+		//  0:03:59:29        1.2            96                   240.007         10584294
+		//  0:04:00:02       -0.8           -64                   240.040         10585766
+		//  0:04:59:29        1.0            80                   300.000         13230000
+		//  0:05:00:02       -1.0           -80                   300.033         13231471
+		//  0:05:59:29        0.8            64                   359.993         15875706
+		//  0:06:00:02       -1.2           -96                   360.027         15877177
+		//  0:06:59:29        0.6            48                   419.987         18521411
+		//  0:07:00:02       -1.4          -112                   420.020         18522883
+		//  0:07:59:29        0.4            32                   478.980         21167117
+		//  0:08:00:02       -1.6          -128                   480.013         21168589
+		//  0:08:59:29        0.2            16                   539.973         23812823
+		//  0:09:00:02       -1.8          -144                   540.007         23814294
+		//  0:09:59:29        0.0+            0+                  599.967         26458529
+		//  0:10:00:00        0.0             0                   600.000         26460000 (accurate)
+		//
+		//  Per Sigmond <per@sigmond.no>
+    
+		// Samples inside time dividable by 10 minutes (real time accurate)
+		jack_nframes_t base_samples = ((smpte.hours * 60 * 60) + ((smpte.minutes / 10) * 10 * 60)) * frame_rate();
+		// Samples inside time exceeding the nearest 10 minutes (always offset, see above)
+		long exceeding_df_minutes = smpte.minutes % 10;
+		long exceeding_df_seconds = (exceeding_df_minutes * 60) + smpte.seconds;
+		long exceeding_df_frames = (30 * exceeding_df_seconds) + smpte.frames - (2 * exceeding_df_minutes);
+		jack_nframes_t exceeding_samples = (jack_nframes_t) rint(exceeding_df_frames * _frames_per_smpte_frame);
+		sample = base_samples + exceeding_samples;
+	} else {
+		// Non drop is easy:
+		sample = (((smpte.hours * 60 * 60) + (smpte.minutes * 60) + smpte.seconds) * frame_rate()) + (jack_nframes_t)rint(smpte.frames * _frames_per_smpte_frame);
+	}
+  
+	if (use_subframes) {
+		sample += (long) (((double)smpte.subframes * _frames_per_smpte_frame) / 80.0);
+	}
+  
+	if (use_offset) {
+		if (smpte_offset_negative()) {
+			if (sample >= smpte_offset()) {
+				sample -= smpte_offset();
+			} else {
+				/* Prevent song-time from becoming negative */
+				sample = 0;
+			}
+		} else {
+			if (smpte.negative) {
+				if (sample <= smpte_offset()) {
+					sample = smpte_offset() - sample;
+				} else {
+					sample = 0;
+				}
+			} else {
+				sample += smpte_offset();
+			}
+		}
+	}
+}
+
+
+void
+Session::sample_to_smpte( jack_nframes_t sample, SMPTE_Time& smpte, bool use_offset, bool use_subframes ) const
+{
+	jack_nframes_t offset_sample;
+  
+	if (!use_offset) {
+		offset_sample = sample;
+		smpte.negative = false;
+	} else {
+		if (_smpte_offset_negative) {
+			offset_sample =  sample + _smpte_offset;
+			smpte.negative = false;
+		} else {
+			if (sample < _smpte_offset) {
+				offset_sample = (_smpte_offset - sample);
+				smpte.negative = true;
+			} else {
+				offset_sample =  sample - _smpte_offset;
+				smpte.negative = false;
+			}
+		}
+	}
+  
+	double smpte_frames_left_exact;
+	double smpte_frames_fraction;
+	unsigned long smpte_frames_left;
+  
+	// Extract whole hours. Do this to prevent rounding errors with
+	// high sample numbers in the calculations that follow.
+	smpte.hours = offset_sample / _frames_per_hour;
+	offset_sample = offset_sample % _frames_per_hour;
+  
+	// Calculate exact number of (exceeding) smpte frames and fractional frames
+	smpte_frames_left_exact = (double) offset_sample / _frames_per_smpte_frame;
+	smpte_frames_fraction = smpte_frames_left_exact - floor( smpte_frames_left_exact );
+	smpte.subframes = (long) rint(smpte_frames_fraction * 80.0);
+  
+	// XXX Not sure if this is necessary anymore...
+	if (smpte.subframes == 80) {
+		// This can happen with 24 fps (and 29.97 fps ?)
+		smpte_frames_left_exact = ceil( smpte_frames_left_exact );
+		smpte.subframes = 0;
+	}
+
+	// Extract hour-exceeding frames for minute, second and frame calculations
+	smpte_frames_left = ((long) floor( smpte_frames_left_exact ));
+
+	if (smpte_drop_frames) {
+		// See long explanation in smpte_to_sample()...
+
+		// Number of 10 minute chunks
+		smpte.minutes = (smpte_frames_left / 17982) * 10; // exactly 17982 frames in 10 minutes
+		// frames exceeding the nearest 10 minute barrier
+		long exceeding_df_frames = smpte_frames_left % 17982;
+
+		// Find minutes exceeding the nearest 10 minute barrier
+		if (exceeding_df_frames >= 1800) { // nothing to do if we are inside the first minute (0-1799)
+			exceeding_df_frames -= 1800; // take away first minute (different number of frames than the others)
+			long extra_minutes_minus_1 = exceeding_df_frames / 1798; // how many minutes after the first one
+			exceeding_df_frames -= extra_minutes_minus_1 * 1798; // take away the (extra) minutes just found
+			smpte.minutes += extra_minutes_minus_1 + 1; // update with exceeding minutes
+		}
+    
+		// Adjust frame numbering for dropped frames (frame 0 and 1 skipped at start of every minute except every 10th)
+		if (smpte.minutes % 10) {
+			// Every minute except every 10th
+			if (exceeding_df_frames < 28) {
+				// First second, frames 0 and 1 are skipped
+				smpte.seconds = 0;
+				smpte.frames = exceeding_df_frames + 2;
+			} else {
+				// All other seconds, all 30 frames are counted
+				exceeding_df_frames -= 28;
+				smpte.seconds = (exceeding_df_frames / 30) + 1;
+				smpte.frames = exceeding_df_frames % 30;
+			}
+		} else {
+			// Every 10th minute, all 30 frames counted in all seconds
+			smpte.seconds = exceeding_df_frames / 30;
+			smpte.frames = exceeding_df_frames % 30;
+		}
+	} else {
+		// Non drop is easy
+		smpte.minutes = smpte_frames_left / ((long) smpte_frames_per_second * 60);
+		smpte_frames_left = smpte_frames_left % ((long) smpte_frames_per_second * 60);
+		smpte.seconds = smpte_frames_left / (long) smpte_frames_per_second;
+		smpte.frames = smpte_frames_left % (long) smpte_frames_per_second;
+	}
+
+	if (!use_subframes) {
+		smpte.subframes = 0;
+	}
+}
+
+void
+Session::smpte_time (jack_nframes_t when, SMPTE_Time& smpte)
+{
+	if (last_smpte_valid && when == last_smpte_when) {
+		smpte = last_smpte;
+		return;
+	}
+
+	sample_to_smpte( when, smpte, true /* use_offset */, false /* use_subframes */ );
+
+	last_smpte_when = when;
+	last_smpte = smpte;
+	last_smpte_valid = true;
+}
+
+void
+Session::smpte_time_subframes (jack_nframes_t when, SMPTE_Time& smpte)
+{
+	if (last_smpte_valid && when == last_smpte_when) {
+		smpte = last_smpte;
+		return;
+	}
+  
+	sample_to_smpte( when, smpte, true /* use_offset */, true /* use_subframes */ );
+
+	last_smpte_when = when;
+	last_smpte = smpte;
+	last_smpte_valid = true;
+}
+
+void
+Session::smpte_duration (jack_nframes_t when, SMPTE_Time& smpte) const
+{
+	sample_to_smpte( when, smpte, false /* use_offset */, true /* use_subframes */ );
+}
+
+void
+Session::smpte_duration_string (char* buf, jack_nframes_t when) const
+{
+	SMPTE_Time smpte;
+
+	smpte_duration (when, smpte);
+	snprintf (buf, sizeof (buf), "%02ld:%02ld:%02ld:%02ld", smpte.hours, smpte.minutes, smpte.seconds, smpte.frames);
+}
+
+void
+Session::smpte_time (SMPTE_Time &t)
+
+{
+	smpte_time (_transport_frame, t);
+}
+
+int
+Session::jack_sync_callback (jack_transport_state_t state,
+			     jack_position_t* pos)
+{
+	bool slave = synced_to_jack();
+
+	switch (state) {
+	case JackTransportStopped:
+		if (slave && _transport_frame != pos->frame && post_transport_work == 0) {
+		 	request_locate (pos->frame, false);
+			// cerr << "SYNC: stopped, locate to " << pos->frame << " from " << _transport_frame << endl;
+			return false;
+		} else {
+			return true;
+		}
+		
+	case JackTransportStarting:
+		// cerr << "SYNC: starting @ " << pos->frame << " a@ " << _transport_frame << " our work = " <<  post_transport_work << " pos matches ? " << (_transport_frame == pos->frame) << endl;
+		if (slave) {
+			return _transport_frame == pos->frame && post_transport_work == 0;
+		} else {
+			return true;
+		}
+		break;
+
+	case JackTransportRolling:
+		// cerr << "SYNC: rolling slave = " << slave << endl;
+		if (slave) {
+			start_transport ();
+		}
+		break;
+
+	default:
+		error << compose (_("Unknown JACK transport state %1 in sync callback"), state)
+		      << endmsg;
+	} 
+
+	return true;
+}
+
+void
+Session::jack_timebase_callback (jack_transport_state_t state,
+				 jack_nframes_t nframes,
+				 jack_position_t* pos,
+				 int new_position)
+{
+	BBT_Time bbt;
+
+	/* frame info */
+
+	pos->frame = _transport_frame;
+	pos->valid = JackPositionTimecode;
+
+	/* BBT info */
+	
+	if (_tempo_map) {
+
+		TempoMap::Metric metric (_tempo_map->metric_at (_transport_frame));
+		_tempo_map->bbt_time_with_metric (_transport_frame, bbt, metric);
+		
+		pos->bar = bbt.bars;
+		pos->beat = bbt.beats;
+		pos->tick = bbt.ticks;
+
+		// XXX still need to set bar_start_tick
+
+		pos->beats_per_bar = metric.meter().beats_per_bar();
+		pos->beat_type = metric.meter().note_divisor();
+		pos->ticks_per_beat = Meter::ticks_per_beat;
+		pos->beats_per_minute = metric.tempo().beats_per_minute();
+
+		pos->valid = jack_position_bits_t (pos->valid | JackPositionBBT);
+	}
+
+#if 0
+	/* SMPTE info */
+
+	t.smpte_offset = _smpte_offset;
+	t.smpte_frame_rate = smpte_frames_per_second;
+
+	if (_transport_speed) {
+
+		if (auto_loop) {
+
+			Location* location = _locations.auto_loop_location();
+
+			if (location) {
+
+				t.transport_state = JackTransportLooping;
+				t.loop_start = location->start();
+				t.loop_end = location->end();
+				t.valid = jack_transport_bits_t (t.valid | JackTransportLoop);
+
+			} else {
+
+				t.loop_start = 0;
+				t.loop_end = 0;
+				t.transport_state = JackTransportRolling;
+
+			}
+
+		} else {
+
+			t.loop_start = 0;
+			t.loop_end = 0;
+			t.transport_state = JackTransportRolling;
+
+		}
+
+	} 
+
+#endif		
+}
+
+jack_nframes_t
+Session::convert_to_frames_at (jack_nframes_t position, AnyTime& any)
+{
+	double secs;
+	
+	switch (any.type) {
+	case AnyTime::BBT:
+		return _tempo_map->frame_time ( any.bbt);
+		break;
+
+	case AnyTime::SMPTE:
+		/* XXX need to handle negative values */
+		secs = any.smpte.hours * 60 * 60;
+		secs += any.smpte.minutes * 60;
+		secs += any.smpte.seconds;
+		secs += any.smpte.frames / smpte_frames_per_second;
+		if (_smpte_offset_negative) 
+		{
+			return (jack_nframes_t) floor (secs * frame_rate()) - _smpte_offset;
+		}
+		else
+		{
+			return (jack_nframes_t) floor (secs * frame_rate()) + _smpte_offset;
+		}
+		break;
+
+	case AnyTime::Seconds:
+		return (jack_nframes_t) floor (any.seconds * frame_rate());
+		break;
+
+	case AnyTime::Frames:
+		return any.frames;
+		break;
+	}
+
+	return any.frames;
+}