: session (s)
{
can_notify_on_unknown_rate = true;
-
+ did_reset_tc_format = false;
+
last_mtc_fps_byte = session.get_mtc_timecode_bits ();
rebind (p);
MTC_Slave::~MTC_Slave()
{
+ if (did_reset_tc_format) {
+ session.config.set_timecode_format (saved_tc_format);
+ }
}
void
}
void
-MTC_Slave::update_mtc_qtr (Parser& /*p*/)
+MTC_Slave::update_mtc_qtr (Parser& /*p*/, int which_qtr, nframes_t now)
{
- nframes64_t now = session.engine().frame_time();
- nframes_t qtr;
+ DEBUG_TRACE (DEBUG::MTC, string_compose ("qtr frame %1 at %2, valid-for-time? %3\n", which_qtr, now, qtr_frame_messages_valid_for_time));
- qtr = (long) (session.frames_per_timecode_frame() / 4);
- mtc_frame += qtr;
+ if (qtr_frame_messages_valid_for_time) {
- current.guard1++;
- current.position = mtc_frame;
- current.timestamp = now;
- current.guard2++;
+ if (which_qtr != 7) {
+
+ /* leave position and speed updates for the last
+ qtr frame message of the 8 to be taken
+ care of in update_mtc_time(), invoked
+ by the Parser right after this.
+ */
- last_inbound_frame = now;
+ nframes_t qtr;
+
+ qtr = (long) (session.frames_per_timecode_frame() / 4);
+ mtc_frame += qtr;
+
+ double speed = compute_apparent_speed (now);
+
+ current.guard1++;
+ current.position = mtc_frame;
+ current.timestamp = now;
+ current.speed = speed;
+ current.guard2++;
+ }
+
+ last_inbound_frame = now;
+ }
}
void
-MTC_Slave::update_mtc_time (const byte *msg, bool was_full)
+MTC_Slave::update_mtc_time (const byte *msg, bool was_full, nframes_t now)
{
- nframes64_t now = session.engine().frame_time();
- Timecode::Time timecode;
+ /* "now" can be zero if this is called from a context where we do not have or do not want
+ to use a timestamp indicating when this MTC time was received.
+ */
+ Timecode::Time timecode;
+ TimecodeFormat tc_format;
+ bool reset_tc = true;
+
+ DEBUG_TRACE (DEBUG::MTC, string_compose ("full mtc time known at %1, full ? %2\n", now, was_full));
+
timecode.hours = msg[3];
timecode.minutes = msg[2];
timecode.seconds = msg[1];
case MTC_24_FPS:
timecode.rate = 24;
timecode.drop = false;
+ tc_format = timecode_24;
can_notify_on_unknown_rate = true;
break;
case MTC_25_FPS:
timecode.rate = 25;
timecode.drop = false;
+ tc_format = timecode_25;
can_notify_on_unknown_rate = true;
break;
case MTC_30_FPS_DROP:
timecode.rate = 30;
timecode.drop = true;
+ tc_format = timecode_30drop;
can_notify_on_unknown_rate = true;
break;
case MTC_30_FPS:
timecode.rate = 30;
timecode.drop = false;
can_notify_on_unknown_rate = true;
+ tc_format = timecode_30;
break;
default:
/* throttle error messages about unknown MTC rates */
}
timecode.rate = session.timecode_frames_per_second();
timecode.drop = session.timecode_drop_frames();
+ reset_tc = false;
}
- session.timecode_to_sample (timecode, mtc_frame, true, false);
+ if (reset_tc) {
+ if (!did_reset_tc_format) {
+ saved_tc_format = session.config.get_timecode_format();
+ did_reset_tc_format = true;
+ }
+ session.config.set_timecode_format (tc_format);
+ }
- DEBUG_TRACE (DEBUG::MTC, string_compose ("MTC time now %1 = frame %2 (from full message ? %3)\n", timecode, mtc_frame, was_full));
+ DEBUG_TRACE (DEBUG::MTC, string_compose ("MTC time timestamp = %1 TC %2 = frame %3 (from full message ? %4)\n",
+ now, timecode, mtc_frame, was_full));
if (was_full) {
- current.guard1++;
- current.position = mtc_frame;
- current.timestamp = 0;
- current.speed = 0;
- current.guard2++;
-
+ session.timecode_to_sample (timecode, mtc_frame, true, false);
session.request_locate (mtc_frame, false);
session.request_transport_speed (0);
update_mtc_status (MIDI::Parser::MTC_Stopped);
} else {
- double speed;
-
+
+ /* we've had the first set of 8 qtr frame messages, determine position
+ and allow continuing qtr frame messages to provide position
+ and speed information.
+ */
+
+ qtr_frame_messages_valid_for_time = true;
+ session.timecode_to_sample (timecode, mtc_frame, true, false);
+
/* 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. Also compensate for audio latency.
*/
-
+
mtc_frame += (long) (1.75 * session.frames_per_timecode_frame()) + session.worst_output_latency();
- if (current.timestamp != 0) {
-
- speed = (double) ((mtc_frame - current.position) / (double) (now - current.timestamp));
- DEBUG_TRACE (DEBUG::MTC, string_compose ("instantaneous speed = %1 from %2 - %3 / %4 - %5\n",
- speed, mtc_frame, current.position, now, current.timestamp));
+ if (now) {
+ double speed = compute_apparent_speed (now);
+
+ current.guard1++;
+ current.position = mtc_frame;
+ current.timestamp = now;
+ current.speed = speed;
+ current.guard2++;
+ }
+ }
- accumulator[accumulator_index++] = speed;
+ if (now) {
+ last_inbound_frame = now;
+ }
+}
- if (accumulator_index >= accumulator_size) {
- have_first_accumulated_speed = true;
- accumulator_index = 0;
+double
+MTC_Slave::compute_apparent_speed (nframes64_t now)
+{
+ if (current.timestamp != 0) {
+
+ double speed = (double) ((mtc_frame - current.position) / (double) (now - current.timestamp));
+ DEBUG_TRACE (DEBUG::MTC, string_compose ("instantaneous speed = %1 from %2 / %3\n",
+ speed, mtc_frame - current.position, now - current.timestamp));
+
+ /* crude low pass filter/smoother for speed */
+
+ accumulator[accumulator_index++] = speed;
+
+ if (accumulator_index >= accumulator_size) {
+ have_first_accumulated_speed = true;
+ accumulator_index = 0;
+ }
+
+ if (have_first_accumulated_speed) {
+ double total = 0;
+
+ for (int32_t i = 0; i < accumulator_size; ++i) {
+ total += accumulator[i];
}
- if (have_first_accumulated_speed) {
- double total = 0;
-
- for (int32_t i = 0; i < accumulator_size; ++i) {
- total += accumulator[i];
- }
-
- speed = total / accumulator_size;
- DEBUG_TRACE (DEBUG::MTC, string_compose ("speed smoothed to %1\n", speed));
- }
-
- } else {
-
- speed = 0;
- }
+ speed = total / accumulator_size;
+ DEBUG_TRACE (DEBUG::MTC, string_compose ("speed smoothed to %1\n", speed));
+ }
- current.guard1++;
- current.position = mtc_frame;
- current.timestamp = now;
- current.speed = speed;
- current.guard2++;
+ return speed;
+
+ } else {
+
+ return 0;
}
-
- last_inbound_frame = now;
}
void
mtc[1] = mmc_tc[2];
mtc[0] = mmc_tc[3];
- update_mtc_time (mtc, true);
+ update_mtc_time (mtc, true, 0);
}
void
MTC_Slave::read_current (SafeTime *st) const
{
int tries = 0;
+
do {
if (tries == 10) {
error << _("MTC Slave: atomic read of current time failed, sleeping!") << endmsg;
usleep (20);
tries = 0;
}
-
*st = current;
tries++;
/* scale elapsed time by the current MTC speed */
if (last.timestamp && (now > last.timestamp)) {
- elapsed = (nframes_t) floor (speed * (now - last.timestamp));
+ elapsed = (nframes_t) floor (last.speed * (now - last.timestamp));
+ DEBUG_TRACE (DEBUG::MTC, string_compose ("last timecode received @ %1, now = %2, elapsed frames = %3 w/speed= %4\n",
+ last.timestamp, now, elapsed, speed));
} else {
elapsed = 0; /* XXX is this right? */
}
current.guard2++;
accumulator_index = 0;
have_first_accumulated_speed = false;
+ qtr_frame_messages_valid_for_time = false;
}
projects / ardour.git / blobdiff