ardour/ardour
ardour
/
ardour
13
1
Fork 0
Code Pull Requests Releases Activity

Add an API to query if the audible frame is latent pending a locate 

eg. at the end of a loop, the session may already be playing the
beginning of the loop. The TransportLooped signal was emitted.
Yet due to playback latency, the audible frame is still at the end of
the loop.

To interpolate the playhead position the UI needs to be able to know:
Relying on the TransportLooped signal is not sufficient because it
does not take playback latency into account.
This commit is contained in:
Robin Gareus 2017-03-31 12:59:44 +02:00
parent 9436d0cb86
commit f2c0b0ee3f
3 changed files with 17 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
libs/ardour/ardour/session.h
View File

@ -681,7 +681,7 @@ class LIBARDOUR_API Session : public PBD::StatefulDestructible, public PBD::Scop
framepos_t transport_frame () const {return _transport_frame; }
framepos_t record_location () const {return _last_record_location; }
framepos_t audible_frame () const;
framepos_t audible_frame (bool* latent_locate = NULL) const;
framepos_t requested_return_frame() const { return _requested_return_frame; }
void set_requested_return_frame(framepos_t return_to);

17
libs/ardour/session.cc
View File

@ -2067,12 +2067,15 @@ Session::maybe_enable_record (bool rt_context)
}
framepos_t
Session::audible_frame () const
Session::audible_frame (bool* latent_locate) const
{
framepos_t ret;
frameoffset_t offset = worst_playback_latency (); // - _engine.samples_since_cycle_start ();
offset *= transport_speed ();
if (latent_locate) {
*latent_locate = false;
}
if (synced_to_engine()) {
/* Note: this is basically just sync-to-JACK */
@ -2097,14 +2100,24 @@ Session::audible_frame () const
if (!play_loop || !have_looped) {
if (ret < _last_roll_or_reversal_location) {
if (latent_locate) {
*latent_locate = true;
}
return _last_roll_or_reversal_location;
}
} else {
// latent loops
/* the play-position wrapped at the loop-point
* ardour is already playing the beginning of the loop,
* but due to playback latency, the "audible frame"
* is still at the end of the loop.
*/
Location *location = _locations->auto_loop_location();
frameoffset_t lo = location->start() - ret;
if (lo > 0) {
ret = location->end () - lo;
if (latent_locate) {
*latent_locate = true;
}
}
}

2
libs/ardour/session_state.cc
View File

@ -233,7 +233,7 @@ Session::post_engine_init ()
msc->set_input_port (boost::dynamic_pointer_cast<MidiPort>(scene_input_port()));
msc->set_output_port (boost::dynamic_pointer_cast<MidiPort>(scene_output_port()));
boost::function<framecnt_t(void)> timer_func (boost::bind (&Session::audible_frame, this));
boost::function<framecnt_t(void)> timer_func (boost::bind (&Session::audible_frame, this, (bool*)(0)));
boost::dynamic_pointer_cast<AsyncMIDIPort>(scene_input_port())->set_timer (timer_func);
setup_midi_machine_control ();