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session_time.cc

/*
  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.

*/

#include <iostream>
#include <cmath>
#include <unistd.h>

#include <ardour/timestamps.h>

#include <pbd/error.h>
#include <pbd/enumwriter.h>
#include <pbd/stacktrace.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 PBD;

/* BBT TIME*/

void
Session::bbt_time (nframes_t when, BBT_Time& bbt)
{
      _tempo_map->bbt_time (when, bbt);
}

/* SMPTE TIME */
float
Session::smpte_frames_per_second() const
{
      switch (Config->get_smpte_format()) {
            case smpte_23976: 
                  return 23.976;

                  break;
            case smpte_24: 
                  return 24;

                  break;
            case smpte_24976: 
                  return 24.976;

                  break;
            case smpte_25: 
                  return 25;

                  break;
            case smpte_2997: 
                  return 29.97;

                  break;
            case smpte_2997drop: 
                  return 29.97;

                  break;
            case smpte_30: 
                  return 30;

                  break;
            case smpte_30drop: 
                  return 30;

                  break;
            case smpte_5994: 
                  return 59.94;

                  break;
            case smpte_60: 
                  return 60;

                  break;
              default:
              cerr << "Editor received unexpected smpte type" << endl;
      }
      return 30.0;
}
bool
Session::smpte_drop_frames() const
{
      switch (Config->get_smpte_format()) {
            case smpte_23976: 
                  return false;

                  break;
            case smpte_24: 
                  return false;

                  break;
            case smpte_24976: 
                  return false;

                  break;
            case smpte_25: 
                  return false;

                  break;
            case smpte_2997: 
                  return false;

                  break;
            case smpte_2997drop: 
                  return true;

                  break;
            case smpte_30: 
                  return false;

                  break;
            case smpte_30drop: 
                  return true;

                  break;
            case smpte_5994: 
                  return false;

                  break;
            case smpte_60: 
                  return false;

                  break;
              default:
                  cerr << "Editor received unexpected smpte type" << endl;
      }
      return false;
}
void
Session::sync_time_vars ()
{
      _current_frame_rate = (nframes_t) round (_base_frame_rate * (1.0 + (Config->get_video_pullup()/100.0)));
      _frames_per_smpte_frame = (double) _current_frame_rate / (double) smpte_frames_per_second();
      if (smpte_drop_frames()) {
        _frames_per_hour = (long)(107892 * _frames_per_smpte_frame);
      } else {
        _frames_per_hour = (long)(3600 * rint(smpte_frames_per_second()) * _frames_per_smpte_frame);
      }
      _smpte_frames_per_hour = (nframes_t)rint(smpte_frames_per_second() * 3600.0);

      last_smpte_valid = false;
      // smpte type bits are the middle two in the upper nibble
      switch ((int) ceil (smpte_frames_per_second())) {
      case 24:
            mtc_smpte_bits = 0;
            break;

      case 25:
            mtc_smpte_bits = 0x20;
            break;

      case 30:
      default:
            if (smpte_drop_frames()) {
                  mtc_smpte_bits = 0x40;
            } else {
                  mtc_smpte_bits =  0x60;
            }
            break;
      };
}

int
Session::set_smpte_format (SmpteFormat format)
{
      /* this will trigger any other changes needed */
      Config->set_smpte_format (format);
      return 0;
}

void
Session::set_smpte_offset (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 */
}

void
Session::smpte_to_sample( SMPTE::Time& smpte, nframes_t& sample, bool use_offset, bool use_subframes ) const
{

      if (smpte.drop) {
            // 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)
            nframes_t base_samples = (nframes_t) (((smpte.hours * 107892) + ((smpte.minutes / 10) * 17982)) * _frames_per_smpte_frame);

            // 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);
            nframes_t exceeding_samples = (nframes_t) rint(exceeding_df_frames * _frames_per_smpte_frame);
            sample = base_samples + exceeding_samples;
      } else {
            /* 
               Non drop is easy.. just note the use of 
               rint(smpte.rate) * _frames_per_smpte_frame
               (frames per SMPTE second), which is larger than  
               frame_rate() in the non-integer SMPTE rate case.
            */

            sample = (nframes_t)rint((((smpte.hours * 60 * 60) + (smpte.minutes * 60) + smpte.seconds) * (rint(smpte.rate) * _frames_per_smpte_frame)) + (smpte.frames * _frames_per_smpte_frame));
      }
  
      if (use_subframes) {
            sample += (long) (((double)smpte.subframes * _frames_per_smpte_frame) / Config->get_subframes_per_frame());
      }
  
      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( nframes_t sample, SMPTE::Time& smpte, bool use_offset, bool use_subframes ) const
{
      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 * Config->get_subframes_per_frame());
  
      // XXX Not sure if this is necessary anymore...
      if (smpte.subframes == Config->get_subframes_per_frame()) {
            // 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) rint (smpte_frames_per_second ()) * 60);
            smpte_frames_left = smpte_frames_left % ((long) rint (smpte_frames_per_second ()) * 60);
            smpte.seconds = smpte_frames_left / (long) rint(smpte_frames_per_second ());
            smpte.frames = smpte_frames_left % (long) rint(smpte_frames_per_second ());
      }

      if (!use_subframes) {
            smpte.subframes = 0;
      }
      /* set frame rate and drop frame */
      smpte.rate = smpte_frames_per_second ();
      smpte.drop = smpte_drop_frames();
}

void
Session::smpte_time (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 (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 (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, nframes_t when) const
{
      SMPTE::Time smpte;

      smpte_duration (when, smpte);
      snprintf (buf, sizeof (buf), "%02" PRIu32 ":%02" PRIu32 ":%02" PRIu32 ":%02" PRIu32, 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 << string_compose (_("Unknown JACK transport state %1 in sync callback"), state)
                  << endmsg;
      } 

      return true;
}

void
Session::jack_timebase_callback (jack_transport_state_t state,
                         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);
      }

#ifdef HAVE_JACK_VIDEO_SUPPORT
      //poke audio video ratio so Ardour can track Video Sync
      pos->audio_frames_per_video_frame = frame_rate() / smpte_frames_per_second();
      pos->valid = jack_position_bits_t (pos->valid | JackAudioVideoRatio);
#endif

#if 0
      /* SMPTE info */

      t.smpte_offset = _smpte_offset;
      t.smpte_frame_rate = smpte_frames_per_second();

      if (_transport_speed) {

            if (play_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            
}

nframes_t
Session::convert_to_frames_at (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 (nframes_t) floor (secs * frame_rate()) - _smpte_offset;
            }
            else
            {
                  return (nframes_t) floor (secs * frame_rate()) + _smpte_offset;
            }
            break;

      case AnyTime::Seconds:
            return (nframes_t) floor (any.seconds * frame_rate());
            break;

      case AnyTime::Frames:
            return any.frames;
            break;
      }

      return any.frames;
}

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