fix no-roll LTC encoder, honor locates when transport is stopped

diff --git a/libs/ardour/ardour/session.h b/libs/ardour/ardour/session.h
index 8012970133bca81a85b83cc610fe1b6a116ff05c..efe51e7b499b172e526289a5daf33689e09c7f60 100644 (file)
--- a/libs/ardour/ardour/session.h
+++ b/libs/ardour/ardour/session.h
@@ -1211,6 +1211,7 @@ class Session : public PBD::StatefulDestructible, public PBD::ScopedConnectionLi
        double            ltc_enc_cnt;
        framepos_t        ltc_enc_off;
        bool              restarting;
+       framepos_t        ltc_prev_cycle;
 
        framepos_t        ltc_timecode_offset;
        bool              ltc_timecode_negative_offset;

diff --git a/libs/ardour/session_ltc.cc b/libs/ardour/session_ltc.cc
index f293970dd4087ba8e888ed80b5c722cc545966c8..d873bc07f96effd01e5ff5852523d1685c3f1061 100644 (file)
--- a/libs/ardour/session_ltc.cc
+++ b/libs/ardour/session_ltc.cc
@@ -82,6 +82,7 @@ Session::ltc_tx_initialize()
         * 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));
@@ -132,6 +133,7 @@ Session::ltc_tx_parse_offset() {
        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
@@ -214,7 +216,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
        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;
@@ -244,10 +246,25 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
         * The _generated timecode_ is offset by the port-latency,
         * therefore the offset depends on the direction of transport.
         */
-       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);
+       } else if (current_speed > 0) {
+               cycle_start_frame = (start_frame + ltc_out_latency.max);
+       } 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(frames_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; }
@@ -262,7 +279,13 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
                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.
                 *
@@ -272,7 +295,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
                 * 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));
        }
@@ -292,6 +315,10 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
                        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) {
@@ -375,6 +402,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
                }
        }
 
+       ltc_prev_cycle = start_frame;
        ltc_speed = new_ltc_speed;
        DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: transport speed %1.\n", ltc_speed));
 
@@ -400,6 +428,9 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
 
        /* 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));
 
@@ -501,7 +532,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end
                        restarting = true;
                }
 
-               if (cyc_off > 0 && cyc_off <= nframes) {
+               if (cyc_off >= 0 && cyc_off <= nframes) {
                        /* offset in this cycle */
                        txf= rint(cyc_off / fabs(ltc_speed));
                        memset(out, 0, cyc_off * sizeof(Sample));