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MTC: map between timecodes

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allow external timecode device to supply timecode with
framerates other than ardour session's framerate.

also fix latency overcompensation. The slave is supposed to
provide transport time - and not audible frame time.

git-svn-id: svn://localhost/ardour2/branches/3.0@13250 d708f5d6-7413-0410-9779-e7cbd77b26cf
This commit is contained in:
Robin Gareus 2012-10-12 01:08:32 +00:00
parent a9abe3b1e1
commit 617d291d1b
3 changed files with 45 additions and 51 deletions
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2
libs/ardour/ardour/slave.h
View File

@ -260,6 +260,8 @@ class MTC_Slave : public Slave {
int busy_guard1;
int busy_guard2;
double speedup_due_to_tc_mismatch;
double quarter_frame_duration;
Timecode::TimecodeFormat mtc_timecode;
Timecode::TimecodeFormat a3e_timecode;
bool printed_timecode_warning;

82
libs/ardour/mtc_slave.cc
View File

@ -61,6 +61,7 @@ MTC_Slave::MTC_Slave (Session& s, MIDI::Port& p)
busy_guard1 = busy_guard2 = 0;
last_mtc_fps_byte = session.get_mtc_timecode_bits ();
quarter_frame_duration = (double(session.frames_per_timecode_frame()) / 4.0);
mtc_timecode = timecode_60; // track changes of MTC timecode
a3e_timecode = timecode_60; // track canges of Ardour's timecode
@ -111,13 +112,13 @@ MTC_Slave::give_slave_full_control_over_transport_speed() const
ARDOUR::framecnt_t
MTC_Slave::resolution () const
{
return (framecnt_t) session.frames_per_timecode_frame();
return (framecnt_t) quarter_frame_duration * 4.0;
}
ARDOUR::framecnt_t
MTC_Slave::seekahead_distance () const
{
return session.frames_per_timecode_frame() * 2 * transport_direction;
return quarter_frame_duration * 8 * transport_direction;
}
bool
@ -218,14 +219,14 @@ MTC_Slave::read_current (SafeTime *st) const
}
void
MTC_Slave::init_mtc_dll(framepos_t mtc_frame, double qtr)
MTC_Slave::init_mtc_dll(framepos_t tme, double qtr)
{
omega = 2.0 * M_PI * (session.frames_per_timecode_frame() / 4.0) / double(session.frame_rate());
omega = 2.0 * M_PI * qtr / double(session.frame_rate());
b = 1.4142135623730950488 * omega;
c = omega * omega;
e2 = qtr;
t0 = double(mtc_frame);
t0 = double(tme);
t1 = t0 + e2;
DEBUG_TRACE (DEBUG::MTC, string_compose ("[re-]init MTC DLL %1 %2 %3\n", t0, t1, e2));
}
@ -236,8 +237,8 @@ void
MTC_Slave::update_mtc_qtr (Parser& /*p*/, int which_qtr, framepos_t now)
{
busy_guard1++;
const framepos_t qtr = (session.frames_per_timecode_frame() / 4);
const double qtr_d = (session.frames_per_timecode_frame() / 4.0);
const double qtr_d = quarter_frame_duration;
const framepos_t qtr = rint(qtr_d);
mtc_frame += qtr * transport_direction;
@ -251,8 +252,8 @@ MTC_Slave::update_mtc_qtr (Parser& /*p*/, int which_qtr, framepos_t now)
t1 += b * e + e2;
e2 += c * e;
mtc_speed = (t1 - t0) / qtr_d;
DEBUG_TRACE (DEBUG::MTC, string_compose ("qtr frame DLL t0:%1 t1:%2 err:%3 spd:%4\n", t0, t1, e, mtc_speed));
mtc_speed = (t1 - t0) / qtr_d;
DEBUG_TRACE (DEBUG::MTC, string_compose ("qtr frame DLL t0:%1 t1:%2 err:%3 spd:%4 ddt:%5\n", t0, t1, e, mtc_speed, e2 - qtr_d));
}
current.guard1++;
@ -360,20 +361,28 @@ MTC_Slave::update_mtc_time (const byte *msg, bool was_full, framepos_t now)
}
mtc_timecode = tc_format;
a3e_timecode = cur_timecode;
speedup_due_to_tc_mismatch = timecode.rate / Timecode::timecode_to_frames_per_second(a3e_timecode);
}
DEBUG_TRACE (DEBUG::MTC, string_compose ("MTC at %1 TC %2 = mtc_frame %3 (from full message ? %4)\n",
now, timecode, mtc_frame, was_full));
/* do a careful conversion of the timecode value to a position
so that we take drop/nondrop and all that nonsense into
consideration.
*/
quarter_frame_duration = (double(session.frame_rate()) / (double) timecode.rate / 4.0);
session.timecode_to_sample (timecode, mtc_frame, true, false); // audio-frame according to Ardour's FPS
DEBUG_TRACE (DEBUG::MTC, string_compose ("MTC at %1 TC %2 = mtc_frame %3 (from full message ? %4) tc-ratio %5\n",
now, timecode, mtc_frame, was_full, speedup_due_to_tc_mismatch));
if (was_full || outside_window (mtc_frame)) {
DEBUG_TRACE (DEBUG::MTC, string_compose ("update_mtc_time: full TC or outside window. - TID:%1\n", ::pthread_self()));
session.timecode_to_sample (timecode, mtc_frame, true, false); // sets mtc_frame
session.request_locate (mtc_frame, false);
session.request_transport_speed (0);
update_mtc_status (MIDI::MTC_Stopped);
reset (false);
reset_window (mtc_frame);
} else {
/* we've had the first set of 8 qtr frame messages, determine position
@ -381,24 +390,16 @@ MTC_Slave::update_mtc_time (const byte *msg, bool was_full, framepos_t now)
and speed information.
*/
/* do a careful conversion of the timecode value to a position
so that we take drop/nondrop and all that nonsense into
consideration.
*/
session.timecode_to_sample (timecode, mtc_frame, true, false); // sets mtc_frame
/* We received the last quarter frame 7 quarter frames (1.75 mtc
frames) after the instance when the contents of the mtc quarter
frames were decided. Add time to compensate for the elapsed 1.75
frames. Also compensate for audio latency.
frames.
*/
double qtr = quarter_frame_duration;
long int mtc_off = (long) rint(7.0 * qtr);
DEBUG_TRACE (DEBUG::MTC, string_compose ("new mtc_frame = %1 | %2 FPTC | LAT: %3\n",
mtc_frame, session.frames_per_timecode_frame(), session.worst_playback_latency()));
long int mtc_off = (long) (1.75 * session.frames_per_timecode_frame()) + session.worst_playback_latency();
double qtr = (session.frames_per_timecode_frame() / 4.0);
DEBUG_TRACE (DEBUG::MTC, string_compose ("new mtc_frame: %1 | MTC-FpT: %2 A3-FpT:%3\n",
mtc_frame, (4.0*qtr), session.frames_per_timecode_frame()));
switch (port->parser()->mtc_running()) {
case MTC_Backward:
@ -412,7 +413,7 @@ MTC_Slave::update_mtc_time (const byte *msg, bool was_full, framepos_t now)
break;
}
DEBUG_TRACE (DEBUG::MTC, string_compose ("new mtc_frame (w/latency comp) = %1\n", mtc_frame));
DEBUG_TRACE (DEBUG::MTC, string_compose ("new mtc_frame (w/offset) = %1\n", mtc_frame));
if (now) {
if (first_mtc_timestamp == 0 || current.timestamp == 0) {
@ -479,35 +480,22 @@ MTC_Slave::reset_window (framepos_t root)
of acceptable MTC frames wide open. otherwise, shrink it down to just 2 video frames
ahead of the window root (taking direction into account).
*/
framecnt_t const d = (quarter_frame_duration * 4 * frame_tolerance);
switch (port->parser()->mtc_running()) {
case MTC_Forward:
window_begin = root;
transport_direction = 1;
if (session.slave_state() == Session::Running) {
window_end = root + (session.frames_per_timecode_frame() * frame_tolerance);
} else {
window_end = root + labs(seekahead_distance ());
}
window_end = root + d;
break;
case MTC_Backward:
transport_direction = -1;
if (session.slave_state() == Session::Running) {
framecnt_t const d = session.frames_per_timecode_frame() * frame_tolerance;
if (root > d) {
window_begin = root - d;
window_end = root;
} else {
window_begin = 0;
}
if (root > d) {
window_begin = root - d;
window_end = root;
} else {
framecnt_t const d = labs(seekahead_distance ());
if (root > d) {
window_begin = root - d;
} else {
window_begin = 0;
}
window_begin = 0;
}
window_end = root;
break;
@ -609,7 +597,7 @@ MTC_Slave::speed_and_position (double& speed, framepos_t& pos)
te1 += be * e + ee2;
ee2 += ce * e;
speed_flt = (te1 - te0) / double(session.engine().frames_per_cycle());
DEBUG_TRACE (DEBUG::MTC, string_compose ("engine DLL t0:%1 t1:%2 err:%3 spd:%4\n", te0, te1, e, speed_flt));
DEBUG_TRACE (DEBUG::MTC, string_compose ("engine DLL t0:%1 t1:%2 err:%3 spd:%4 ddt:%5\n", te0, te1, e, speed_flt, ee2 - session.engine().frames_per_cycle() ));
}
}

12
libs/ardour/session_time.cc
View File

@ -100,6 +100,10 @@ Session::sync_time_vars ()
void
Session::timecode_to_sample( Timecode::Time& timecode, framepos_t& sample, bool use_offset, bool use_subframes ) const
{
double my_frames_per_timecode_frame = _frames_per_timecode_frame;
if (timecode.rate > 0) {
my_frames_per_timecode_frame = (double) _current_frame_rate / (double) timecode.rate;
}
if (timecode.drop) {
// The drop frame format was created to better approximate the 30000/1001 = 29.97002997002997....
@ -142,13 +146,13 @@ Session::timecode_to_sample( Timecode::Time& timecode, framepos_t& sample, bool
// Per Sigmond <per@sigmond.no>
// Samples inside time dividable by 10 minutes (real time accurate)
framecnt_t base_samples = (framecnt_t) (((timecode.hours * 107892) + ((timecode.minutes / 10) * 17982)) * _frames_per_timecode_frame);
framecnt_t base_samples = (framecnt_t) (((timecode.hours * 107892) + ((timecode.minutes / 10) * 17982)) * my_frames_per_timecode_frame);
// Samples inside time exceeding the nearest 10 minutes (always offset, see above)
int32_t exceeding_df_minutes = timecode.minutes % 10;
int32_t exceeding_df_seconds = (exceeding_df_minutes * 60) + timecode.seconds;
int32_t exceeding_df_frames = (30 * exceeding_df_seconds) + timecode.frames - (2 * exceeding_df_minutes);
framecnt_t exceeding_samples = (framecnt_t) rint(exceeding_df_frames * _frames_per_timecode_frame);
framecnt_t exceeding_samples = (framecnt_t) rint(exceeding_df_frames * my_frames_per_timecode_frame);
sample = base_samples + exceeding_samples;
} else {
/*
@ -158,11 +162,11 @@ Session::timecode_to_sample( Timecode::Time& timecode, framepos_t& sample, bool
frame_rate() in the non-integer Timecode rate case.
*/
sample = (framecnt_t)rint((((timecode.hours * 60 * 60) + (timecode.minutes * 60) + timecode.seconds) * (rint(timecode.rate) * _frames_per_timecode_frame)) + (timecode.frames * _frames_per_timecode_frame));
sample = (framecnt_t)rint((((timecode.hours * 60 * 60) + (timecode.minutes * 60) + timecode.seconds) * (rint(timecode.rate) * my_frames_per_timecode_frame)) + (timecode.frames * my_frames_per_timecode_frame));
}
if (use_subframes) {
sample += (int32_t) (((double)timecode.subframes * _frames_per_timecode_frame) / config.get_subframes_per_frame());
sample += (int32_t) (((double)timecode.subframes * my_frames_per_timecode_frame) / config.get_subframes_per_frame());
}
if (use_offset) {