ardour/livetrax
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fix MTC alignment

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This commit is contained in:
Robin Gareus 2016-05-25 17:13:09 +02:00
parent f34722bf49
commit 5550eebe2f
1 changed files with 28 additions and 19 deletions
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47
libs/ardour/session_midi.cc
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@ -387,16 +387,29 @@ Session::send_full_time_code (framepos_t const t, MIDI::pframes_t nframes)
framepos_t mtc_tc;
timecode_to_sample(timecode, mtc_tc, true, false);
outbound_mtc_timecode_frame = mtc_tc;
transmitting_timecode_time = timecode;
LatencyRange mtc_out_latency; // TODO cache this, update on engine().GraphReordered()
_midi_ports->mtc_output_port ()->get_connected_latency_range (ltc_out_latency, true);
frameoffset_t mtc_offset = worst_playback_latency() - mtc_out_latency.max;
// only if rolling.. ?
outbound_mtc_timecode_frame += mtc_offset;
// outbound_mtc_timecode_frame needs to be >= _transport_frame
// or a new full timecode will be queued next cycle.
while (outbound_mtc_timecode_frame < t) {
Timecode::increment (transmitting_timecode_time, config.get_subframes_per_frame());
outbound_mtc_timecode_frame += _frames_per_timecode_frame;
}
double const quarter_frame_duration = ((framecnt_t) _frames_per_timecode_frame) / 4.0;
if (ceil((t - mtc_tc) / quarter_frame_duration) > 0) {
Timecode::increment (transmitting_timecode_time, config.get_subframes_per_frame());
outbound_mtc_timecode_frame += _frames_per_timecode_frame;
}
DEBUG_TRACE (DEBUG::MTC, string_compose ("Full MTC TC %1\n", outbound_mtc_timecode_frame));
DEBUG_TRACE (DEBUG::MTC, string_compose ("Full MTC TC %1 (off %2)\n", outbound_mtc_timecode_frame, mtc_offset));
// I don't understand this bit yet.. [DR]
// I do [rg]:
@ -407,21 +420,6 @@ Session::send_full_time_code (framepos_t const t, MIDI::pframes_t nframes)
outbound_mtc_timecode_frame += _frames_per_timecode_frame;
}
#if 0 // compensate for audio latency -- disabled [rg]
/* this needs more thought and work.
* the proper solution will be to just offset MTC by the MIDI port's latency.
*
* using worst_playback_latency() is wrong when the generated MTC is used to sync
* clients which send audio to Ardour for recording.
* worst_capture_latency() vs. worst_playback_latency()
*
* NB. similarly to session_ltc, the offset should be subtracted from the timecode to send,
* instead of being added to timestamp when to send the timecode.
* Otherwise the timestamp may not fall into the jack-cycle of the current _transport frame.
* and no MTC QF will be sent.
*/
outbound_mtc_timecode_frame += worst_playback_latency();
#endif
next_quarter_frame_to_send = 0;
// Sync slave to the same Timecode time as we are on
@ -456,6 +454,8 @@ Session::send_full_time_code (framepos_t const t, MIDI::pframes_t nframes)
int
Session::send_midi_time_code_for_cycle (framepos_t start_frame, framepos_t end_frame, ARDOUR::pframes_t nframes)
{
// start_frame == start_frame for normal cycles
// start_frame > _transport_frame for split cycles
if (_engine.freewheeling() || !_send_qf_mtc || transmitting_timecode_time.negative || (next_quarter_frame_to_send < 0)) {
// cerr << "(MTC) Not sending MTC\n";
return 0;
@ -464,6 +464,11 @@ Session::send_midi_time_code_for_cycle (framepos_t start_frame, framepos_t end_f
return 0;
}
if (_transport_speed < 0) {
// we don't support rolling backwards
return 0;
}
/* MTC is max. 30 fps - assert() below will fail
* TODO actually limit it to 24,25,29df,30fps
* talk to oofus, first.
@ -483,7 +488,12 @@ Session::send_midi_time_code_for_cycle (framepos_t start_frame, framepos_t end_f
next_quarter_frame_to_send, quarter_frame_duration));
if (rint(outbound_mtc_timecode_frame + (next_quarter_frame_to_send * quarter_frame_duration)) < _transport_frame) {
// send full timecode and set outbound_mtc_timecode_frame, next_quarter_frame_to_send
send_full_time_code (_transport_frame, nframes);
}
if (rint(outbound_mtc_timecode_frame + (next_quarter_frame_to_send * quarter_frame_duration)) < start_frame) {
// no QF for this cycle
return 0;
}
@ -555,8 +565,7 @@ Session::send_midi_time_code_for_cycle (framepos_t start_frame, framepos_t end_f
// Increment timecode time twice
Timecode::increment (transmitting_timecode_time, config.get_subframes_per_frame());
Timecode::increment (transmitting_timecode_time, config.get_subframes_per_frame());
// Re-calculate timing of first quarter frame
//timecode_to_sample( transmitting_timecode_time, outbound_mtc_timecode_frame, true /* use_offset */, false );
// Increment timing of first quarter frame
outbound_mtc_timecode_frame += 2.0 * _frames_per_timecode_frame;
}
}