#include "ardour/session.h"
#include "ardour/slave.h"
-#include "i18n.h"
+#include "pbd/i18n.h"
using namespace std;
using namespace ARDOUR;
* This filter is adaptive so that fast vari-speed signals
* will not be affected by it.
*/
-#define LTC_RISE_TIME(speed) MIN (100, MAX(40, (4000000 / ((speed==0)?1:speed) / engine().frame_rate())))
+#define LTC_RISE_TIME(speed) MIN (100, MAX(40, (4000000 / ((speed==0)?1:speed) / engine().sample_rate())))
#define TV_STANDARD(tcf) \
(timecode_to_frames_per_second(tcf)==25.0 ? LTC_TV_625_50 : \
* since the fps can change and A3's min fps: 24000/1001 */
ltc_enc_buf = (ltcsnd_sample_t*) calloc((nominal_frame_rate() / 23), sizeof(ltcsnd_sample_t));
ltc_speed = 0;
+ ltc_prev_cycle = -1;
ltc_tx_reset();
ltc_tx_resync_latency();
Xrun.connect_same_thread (*this, boost::bind (&Session::ltc_tx_reset, this));
offset_tc.drop = timecode_drop_frames();
timecode_to_sample(offset_tc, ltc_timecode_offset, false, false);
ltc_timecode_negative_offset = !offset_tc.negative;
+ ltc_prev_cycle = -1;
}
void
if (cur_timecode != ltc_enc_tcformat) {
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX1: TC format mismatch - reinit sr: %1 fps: %2\n", nominal_frame_rate(), timecode_to_frames_per_second(cur_timecode)));
if (ltc_encoder_reinit(ltc_encoder, nominal_frame_rate(),
- timecode_to_frames_per_second(cur_timecode),
+ timecode_to_frames_per_second(cur_timecode),
TV_STANDARD(cur_timecode), 0
)) {
PBD::error << _("LTC encoder: invalid framerate - LTC encoding is disabled for the remainder of this session.") << endmsg;
/* port latency compensation:
* The _generated timecode_ is offset by the port-latency,
* therefore the offset depends on the direction of transport.
+ *
+ * latency is compensated by adding it to the timecode to
+ * be generated. e.g. if the signal will reach the output in
+ * N samples time from now, generate the timecode for (now + N).
+ *
+ * sample-sync is achieved by further calculating the difference
+ * between the timecode and the session-transport and offsetting the
+ * buffer.
+ *
+ * The timecode is generated directly in the Session process callback
+ * using _transport_frame. It requires that the session has set the
+ * port's playback latency to worst_playback_latency() prior to
+ * calling ltc_tx_send_time_code_for_cycle().
*/
- framepos_t cycle_start_frame = (current_speed < 0) ? (start_frame - ltc_out_latency.max) : (start_frame + ltc_out_latency.max);
+ framepos_t cycle_start_frame;
+
+ if (current_speed < 0) {
+ cycle_start_frame = (start_frame - ltc_out_latency.max + worst_playback_latency());
+ } else if (current_speed > 0) {
+ cycle_start_frame = (start_frame + ltc_out_latency.max - worst_playback_latency());
+ } else {
+ /* There is no need to compensate for latency when not rolling
+ * rather send the accurate NOW timecode
+ * (LTC encoder compenates latency by sending earlier timecode)
+ */
+ cycle_start_frame = start_frame;
+ }
/* LTC TV standard offset */
- cycle_start_frame -= ltc_frame_alignment(frames_per_timecode_frame(), TV_STANDARD(cur_timecode));
+ if (current_speed != 0) {
+ /* ditto - send "NOW" if not rolling */
+ cycle_start_frame -= ltc_frame_alignment(samples_per_timecode_frame(), TV_STANDARD(cur_timecode));
+ }
/* cycle-start may become negative due to latency compensation */
if (cycle_start_frame < 0) { cycle_start_frame = 0; }
ltc_tx_reset();
}
- if (ltc_speed != new_ltc_speed) {
+ if (ltc_speed != new_ltc_speed
+ /* but only once if, current_speed changes to 0. In that case
+ * new_ltc_speed is > 0 because (end_frame - start_frame) == jack-period for no-roll
+ * but ltc_speed will still be 0
+ */
+ && (current_speed != 0 || ltc_speed != current_speed)
+ ) {
/* check ./libs/ardour/interpolation.cc CubicInterpolation::interpolate
* if target_speed != current_speed we should interpolate, too.
*
* end_frame is calculated from 'frames_moved' which includes the interpolation.
* so we're good.
*/
- DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: speed change old: %1 cur: %2 tgt: %3 ctd: %4\n", ltc_speed, current_speed, target_speed, fabs(current_speed) - target_speed));
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: speed change old: %1 cur: %2 tgt: %3 ctd: %4\n", ltc_speed, current_speed, target_speed, fabs(current_speed) - target_speed, new_ltc_speed));
speed_changed = true;
ltc_encoder_set_filter(ltc_encoder, LTC_RISE_TIME(new_ltc_speed));
}
ltc_speed = new_ltc_speed;
return;
}
+ if (start_frame != ltc_prev_cycle) {
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: no-roll seek from %1 to %2 (%3)\n", ltc_prev_cycle, start_frame, cycle_start_frame));
+ ltc_tx_reset();
+ }
}
if (fabs(new_ltc_speed) > 10.0) {
}
}
+ ltc_prev_cycle = start_frame;
ltc_speed = new_ltc_speed;
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: transport speed %1.\n", ltc_speed));
/* difference between current frame and TC frame in samples */
frameoffset_t soff = cycle_start_frame - tc_sample_start;
+ if (current_speed == 0) {
+ soff = 0;
+ }
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX3: A3cycle: %1 = A3tc: %2 +off: %3\n",
cycle_start_frame, tc_sample_start, soff));
// (4) check if alignment matches
- const double fptcf = frames_per_timecode_frame();
+ const double fptcf = samples_per_timecode_frame();
/* maximum difference of bit alignment in audio-samples.
*
rint(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame
));
+ const framecnt_t wrap24h = 86400. * frame_rate();
if (ltc_enc_pos < 0
- || (ltc_speed != 0 && fabs(ceil(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame) > maxdiff)
+ || (ltc_speed != 0 && fabs(fmod(ceil(ltc_enc_pos + ltc_enc_cnt - poff), wrap24h) - (cycle_start_frame % wrap24h)) > maxdiff)
) {
// (5) re-align
/* set frame to encode */
SMPTETimecode tc;
- tc.hours = tc_start.hours;
+ tc.hours = tc_start.hours % 24;
tc.mins = tc_start.minutes;
tc.secs = tc_start.seconds;
tc.frame = tc_start.frames;
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: now: %1 trs: %2 toff %3\n", cycle_start_frame, tc_sample_start, soff));
- uint32_t cyc_off;
+ int32_t cyc_off;
if (soff < 0 || soff >= fptcf) {
/* session framerate change between (2) and now */
ltc_tx_reset();
restarting = true;
}
- if (cyc_off > 0 && cyc_off <= nframes) {
+ if (cyc_off >= 0 && cyc_off <= (int32_t) nframes) {
/* offset in this cycle */
txf= rint(cyc_off / fabs(ltc_speed));
memset(out, 0, cyc_off * sizeof(Sample));
return;
}
- ltc_enc_pos = tc_sample_start;
+ ltc_enc_pos = tc_sample_start % wrap24h;
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX5 restart @ %1 + %2 - %3 | byte %4\n",
ltc_enc_pos, ltc_enc_cnt, cyc_off, ltc_enc_byte));
* To do better than this, resampling (or a rewrite of the
* encoder) is required.
*/
- ltc_speed -= ((ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame) / engine().frame_rate();
+ ltc_speed -= fmod(((ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame), wrap24h) / engine().sample_rate();
}