X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fardour%2Fsession_ltc.cc;h=2671bfccf40b6b9589460ef74a9433f2ef5a3eca;hb=a6e0b60ae1df3676ba45eeb302108eecfe7a7797;hp=36af8d8b3c9244a30db0d1ad0e85e42c831ad16f;hpb=05b1f0c196b57af6060b0175ce76f15ae11ba479;p=ardour.git diff --git a/libs/ardour/session_ltc.cc b/libs/ardour/session_ltc.cc index 36af8d8b3c..2671bfccf4 100644 --- a/libs/ardour/session_ltc.cc +++ b/libs/ardour/session_ltc.cc @@ -17,17 +17,20 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include "ardour/debug.h" + #include "timecode/time.h" -#include "ardour/session.h" + #include "ardour/audioengine.h" #include "ardour/audio_port.h" +#include "ardour/debug.h" +#include "ardour/io.h" +#include "ardour/session.h" +#include "ardour/slave.h" #include "i18n.h" using namespace std; using namespace ARDOUR; -using namespace MIDI; using namespace PBD; using namespace Timecode; @@ -35,17 +38,42 @@ using namespace Timecode; //#define LTC_GEN_FRAMEDBUG //#define LTC_GEN_TXDBUG +#ifndef MAX +#define MAX(a,b) ( (a) > (b) ? (a) : (b) ) +#endif +#ifndef MIN +#define MIN(a,b) ( (a) < (b) ? (a) : (b) ) +#endif + +/* LTC signal should have a rise time of 25 us +/- 5 us. + * yet with most sound-cards a square-wave of 1-2 sample + * introduces ringing and small oscillations. + * https://en.wikipedia.org/wiki/Gibbs_phenomenon + * A low-pass filter in libltc can reduce this at + * the cost of being slightly out of spec WRT to rise-time. + * + * 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 TV_STANDARD(tcf) \ + (timecode_to_frames_per_second(tcf)==25.0 ? LTC_TV_625_50 : \ + timecode_has_drop_frames(tcf)? LTC_TV_525_60 : LTC_TV_FILM_24) + void Session::ltc_tx_initialize() { ltc_enc_tcformat = config.get_timecode_format(); + ltc_tx_parse_offset(); DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX init sr: %1 fps: %2\n", nominal_frame_rate(), timecode_to_frames_per_second(ltc_enc_tcformat))); ltc_encoder = ltc_encoder_create(nominal_frame_rate(), timecode_to_frames_per_second(ltc_enc_tcformat), - 0); + TV_STANDARD(ltc_enc_tcformat), 0); ltc_encoder_set_bufsize(ltc_encoder, nominal_frame_rate(), 23.0); + ltc_encoder_set_filter(ltc_encoder, LTC_RISE_TIME(1.0)); /* buffersize for 1 LTC frame: (1 + sample-rate / fps) bytes * usually returned by ltc_encoder_get_buffersize(encoder) @@ -53,18 +81,36 @@ 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)); + engine().GraphReordered.connect_same_thread (*this, boost::bind (&Session::ltc_tx_resync_latency, this)); + restarting = false; } void Session::ltc_tx_cleanup() { DEBUG_TRACE (DEBUG::LTC, "LTC TX cleanup\n"); - if (ltc_enc_buf) free(ltc_enc_buf); + free(ltc_enc_buf); + ltc_enc_buf = NULL; ltc_encoder_free(ltc_encoder); ltc_encoder = NULL; } +void +Session::ltc_tx_resync_latency() +{ + DEBUG_TRACE (DEBUG::LTC, "LTC TX resync latency\n"); + if (!deletion_in_progress()) { + boost::shared_ptr ltcport = ltc_output_port(); + if (ltcport) { + ltcport->get_connected_latency_range(ltc_out_latency, true); + } + } +} + void Session::ltc_tx_reset() { @@ -74,6 +120,19 @@ Session::ltc_tx_reset() ltc_buf_off = 0; ltc_enc_byte = 0; ltc_enc_cnt = 0; + + ltc_encoder_reset(ltc_encoder); +} + +void +Session::ltc_tx_parse_offset() { + Timecode::Time offset_tc; + Timecode::parse_timecode_format(config.get_timecode_generator_offset(), offset_tc); + offset_tc.rate = timecode_frames_per_second(); + 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 @@ -91,51 +150,56 @@ Session::ltc_tx_recalculate_position() a3tc.drop = timecode_has_drop_frames(ltc_enc_tcformat); Timecode::timecode_to_sample (a3tc, ltc_enc_pos, true, false, - double(frame_rate()), + (double)frame_rate(), config.get_subframes_per_frame(), - config.get_timecode_offset_negative(), config.get_timecode_offset() + ltc_timecode_negative_offset, ltc_timecode_offset ); + restarting = false; } -int +void Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end_frame, - double target_speed, double current_speed, - pframes_t nframes) + double target_speed, double current_speed, + pframes_t nframes) { - assert(nframes > 0); + assert (nframes > 0); - jack_default_audio_sample_t *out; + Sample *out; pframes_t txf = 0; - boost::shared_ptr ltcport = engine().ltc_output_port(); + boost::shared_ptr ltcport = ltc_output_port(); - if (!ltc_encoder || !ltc_enc_buf || !ltcport || ! ltcport->jack_port()) return 0; + Buffer& buf (ltcport->get_buffer (nframes)); - out = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes); - if (!out) return 0; + if (!ltc_encoder || !ltc_enc_buf) { + return; + } - if (engine().freewheeling()|| !Config->get_send_ltc() - /* TODO - * we can relax this a bit, JACK or sample-synced slaves should be fine. - * test before allowing it, do the same for MTC generator in - * libs/ardour/session_midi.cc - * */ - // || config.get_external_sync() // XXX XXX - ) { - memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); - return nframes; + SyncSource sync_src = Config->get_sync_source(); + if (engine().freewheeling() || !Config->get_send_ltc() + /* TODO + * decide which time-sources we can generated LTC from. + * Internal, JACK or sample-synced slaves should be fine. + * talk to oofus. + * + || (config.get_external_sync() && sync_src == LTC) + || (config.get_external_sync() && sync_src == MTC) + */ + ||(config.get_external_sync() && sync_src == MIDIClock) + ) { + return; } + out = dynamic_cast(&buf)->data (); + /* range from libltc (38..218) || - 128.0 -> (-90..90) */ const float ltcvol = Config->get_ltc_output_volume()/(90.0); // pow(10, db/20.0)/(90.0); - jack_latency_range_t ltc_latency; - ltcport->get_connected_latency_range(ltc_latency, true); - DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX %1 to %2 / %3 | lat: %4\n", start_frame, end_frame, nframes, ltc_latency.max)); + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX %1 to %2 / %3 | lat: %4\n", start_frame, end_frame, nframes, ltc_out_latency.max)); /* all systems go. Now here's the plan: * * 1) check if fps has changed - * 2) check direction of encoding, calc speed, resample existing buffer + * 2) check direction of encoding, calc speed, re-sample existing buffer * 3) calculate frame and byte to send aligned to jack-period size * 4) check if it's the frame/byte that is already in the queue * 5) if (4) mismatch, re-calculate offset of LTC frame relative to period size @@ -150,51 +214,89 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end TimecodeFormat cur_timecode = config.get_timecode_format(); 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), 0)) { + if (ltc_encoder_reinit(ltc_encoder, nominal_frame_rate(), + 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; ltc_tx_cleanup(); - return 0; + return; } + ltc_encoder_set_filter(ltc_encoder, LTC_RISE_TIME(ltc_speed)); ltc_enc_tcformat = cur_timecode; + ltc_tx_parse_offset(); ltc_tx_reset(); } /* LTC is max. 30 fps */ if (timecode_to_frames_per_second(cur_timecode) > 30) { - memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); - return nframes; + return; } // (2) speed & direction + + /* speed 0 aka transport stopped is interpreted as rolling forward. + * keep repeating current frame + */ #define SIGNUM(a) ( (a) < 0 ? -1 : 1) bool speed_changed = false; - // XXX - //framepos_t cycle_start_frame = (current_speed < 0) ? (start_frame - ltc_latency.max) : (start_frame + ltc_latency.max); - framepos_t cycle_start_frame = start_frame; + /* port latency compensation: + * The _generated timecode_ is offset by the port-latency, + * therefore the offset depends on the direction of transport. + */ + 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 */ + 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 comensation */ + /* cycle-start may become negative due to latency compensation */ if (cycle_start_frame < 0) { cycle_start_frame = 0; } - double new_ltc_speed = double(labs(end_frame - start_frame) * SIGNUM(current_speed)) / double(nframes); + double new_ltc_speed = (double)(labs(end_frame - start_frame) * SIGNUM(current_speed)) / (double)nframes; + if (nominal_frame_rate() != frame_rate()) { + new_ltc_speed *= (double)nominal_frame_rate() / (double)frame_rate(); + } if (SIGNUM(new_ltc_speed) != SIGNUM (ltc_speed)) { DEBUG_TRACE (DEBUG::LTC, "LTC TX2: transport changed direction\n"); 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. * - * However, currenly in A3 target_speed == current_speed for each process cycle + * However, currency in A3 target_speed == current_speed for each process cycle * (except for the sign and if target_speed > 8.0). - * Besides, above speed calulation uses the difference (end_frame - start_frame). + * Besides, above speed calculation uses the difference (end_frame - start_frame). * 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)); } if (end_frame == start_frame || fabs(current_speed) < 0.1 ) { @@ -210,16 +312,18 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end new_ltc_speed = 0; if (!Config->get_ltc_send_continuously()) { ltc_speed = new_ltc_speed; - memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); - return nframes; + 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) { DEBUG_TRACE (DEBUG::LTC, "LTC TX2: speed is out of bounds.\n"); ltc_tx_reset(); - memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); - return nframes; + return; } if (ltc_speed == 0 && new_ltc_speed != 0) { @@ -227,8 +331,9 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end ltc_tx_reset(); } - /* the timecode duration corresponding to the samples still in the buffer - * here we use prev. speed to match the begining of this cycle for aligment. + /* the timecode duration corresponding to the samples that are still + * in the buffer. Here, the speed of previous cycle is used to calculate + * the alignment at the beginning of this cycle later. */ double poff = (ltc_buf_len - ltc_buf_off) * ltc_speed; @@ -236,8 +341,8 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end /* we need to re-sample the existing buffer. * "make space for the en-coder to catch up to the new speed" * - * since the LTC signal is a rect waveform we can simply squeeze it - * by removing samples or duplicating /here and there/. + * since the LTC signal is a rectangular waveform we can simply squeeze it + * by removing samples or duplicating samples /here and there/. * * There may be a more elegant way to do this, in fact one could * simply re-render the buffer using ltc_encoder_encode_byte() @@ -245,8 +350,8 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end * which is left for later.. */ - double oldbuflen = double(ltc_buf_len - ltc_buf_off); - double newbuflen = double(ltc_buf_len - ltc_buf_off) * fabs(ltc_speed / new_ltc_speed); + double oldbuflen = (double)(ltc_buf_len - ltc_buf_off); + double newbuflen = (double)(ltc_buf_len - ltc_buf_off) * fabs(ltc_speed / new_ltc_speed); DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: bufOld %1 bufNew %2 | diff %3\n", (ltc_buf_len - ltc_buf_off), newbuflen, newbuflen - oldbuflen @@ -296,43 +401,64 @@ 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)); - - // (3) bit/sample aligment + // (3) bit/sample alignment Timecode::Time tc_start; framepos_t tc_sample_start; /* calc timecode frame from current position - round down to nearest timecode */ - sample_to_timecode(cycle_start_frame, tc_start, true, false); + Timecode::sample_to_timecode(cycle_start_frame, tc_start, true, false, + timecode_frames_per_second(), + timecode_drop_frames(), + (double)frame_rate(), + config.get_subframes_per_frame(), + ltc_timecode_negative_offset, ltc_timecode_offset + ); /* convert timecode back to sample-position */ Timecode::timecode_to_sample (tc_start, tc_sample_start, true, false, - double(frame_rate()), + (double)frame_rate(), config.get_subframes_per_frame(), - config.get_timecode_offset_negative(), config.get_timecode_offset() + ltc_timecode_negative_offset, ltc_timecode_offset ); /* 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 aligment matches - const double fptcf = frames_per_timecode_frame(); // convenient, used a lot below. - double maxdiff; + // (4) check if alignment matches + const double fptcf = frames_per_timecode_frame(); - /* due to rounding error and variations in LTC-bit duration depending - * on the speed, we can be off by +- speed samples. - * during speed-changes we can acually ready += 2*speed audio-samples - * in the cycle after the speed change. The average delta however is 0. + /* maximum difference of bit alignment in audio-samples. + * + * if transport and LTC generator differs more than this, the LTC + * generator will be re-initialized + * + * due to rounding error and variations in LTC-bit duration depending + * on the speed, it can be off by +- ltc_speed audio-samples. + * When the playback speed changes, it can actually reach +- 2 * ltc_speed + * in the cycle _after_ the speed changed. The average delta however is 0. */ - if (config.get_external_sync()) { - maxdiff = fptcf; // TODO get slave max delta + double maxdiff; + + if (config.get_external_sync() && slave()) { + maxdiff = slave()->resolution(); } else { maxdiff = ceil(fabs(ltc_speed))*2.0; + if (nominal_frame_rate() != frame_rate()) { + maxdiff *= 3.0; + } + if (ltc_enc_tcformat == Timecode::timecode_23976 || ltc_enc_tcformat == Timecode::timecode_24976) { + maxdiff *= 15.0; + } } DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: enc: %1 + %2 - %3 || buf-bytes: %4 enc-byte: %5\n", @@ -343,8 +469,10 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end rint(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame )); - if (fabs(ceil(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame) > maxdiff) - { + if (ltc_enc_pos < 0 + || (ltc_speed != 0 && fabs(ceil(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame) > maxdiff) + ) { + // (5) re-align ltc_tx_reset(); @@ -357,8 +485,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end ltc_encoder_set_timecode(ltc_encoder, &tc); /* workaround for libltc recognizing 29.97 and 30000/1001 as drop-frame TC. - * in A3 only 30000/1001 is drop-frame and there are also other questionable - * DF timecodes such as 24k/1001 and 25k/1001. + * In A3 30000/1001 or 30 fps can be drop-frame. */ LTCFrame ltcframe; ltc_encoder_get_frame(ltc_encoder, <cframe); @@ -368,13 +495,17 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end 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; - assert(soff >= 0 && soff < fptcf); + int32_t cyc_off; + if (soff < 0 || soff >= fptcf) { + /* session framerate change between (2) and now */ + ltc_tx_reset(); + return; + } if (ltc_speed < 0 ) { /* calculate the byte that starts at or after the current position */ ltc_enc_byte = floor((10.0 * soff) / (fptcf)); - ltc_enc_cnt = double(ltc_enc_byte * fptcf / 10.0); + ltc_enc_cnt = ltc_enc_byte * fptcf / 10.0; /* calculate difference between the current position and the byte to send */ cyc_off = soff- ceil(ltc_enc_cnt); @@ -382,7 +513,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end } else { /* calculate the byte that starts at or after the current position */ ltc_enc_byte = ceil((10.0 * soff) / fptcf); - ltc_enc_cnt = double(ltc_enc_byte * fptcf / 10.0); + ltc_enc_cnt = ltc_enc_byte * fptcf / 10.0; /* calculate difference between the current position and the byte to send */ cyc_off = ceil(ltc_enc_cnt) - soff; @@ -396,16 +527,18 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX5 restart encoder: soff %1 byte %2 cycoff %3\n", soff, ltc_enc_byte, cyc_off)); - if (ltc_speed == 0) { - /* don't bother to align non-moving loops */ - } else if (cyc_off > 0 && cyc_off <= nframes) { + if ( (ltc_speed < 0 && ltc_enc_byte !=9 ) || (ltc_speed >= 0 && ltc_enc_byte !=0 ) ) { + restarting = true; + } + + 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(jack_default_audio_sample_t)); - } else if (cyc_off > 0) { + memset(out, 0, cyc_off * sizeof(Sample)); + } else { /* resync next cycle */ - memset(out, 0, cyc_off * sizeof(jack_default_audio_sample_t)); - return nframes; + memset(out, 0, nframes * sizeof(Sample)); + return; } ltc_enc_pos = tc_sample_start; @@ -413,6 +546,26 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end 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)); } + else if (ltc_speed != 0 && (fptcf / ltc_speed / 80) > 3 ) { + /* reduce (low freq) jitter. + * The granularity of the LTC encoder speed is 1 byte = + * (frames-per-timecode-frame / 10) audio-samples. + * Thus, tiny speed changes [as produced by some slaves] + * may not have any effect in the cycle when they occur, + * but they will add up over time. + * + * This is a linear approx to compensate for this jitter + * and prempt re-sync when the drift builds up. + * + * However, for very fast speeds - when 1 LTC bit is + * <= 3 audio-sample - adjusting speed may lead to + * invalid frames. + * + * 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(); + } // (6) encode and output @@ -423,7 +576,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end // (6a) send remaining buffer while ((ltc_buf_off < ltc_buf_len) && (txf < nframes)) { const float v1 = ltc_enc_buf[ltc_buf_off++] - 128.0; - const jack_default_audio_sample_t val = (jack_default_audio_sample_t) (v1*ltcvol); + const Sample val = (Sample) (v1*ltcvol); out[txf++] = val; } #ifdef LTC_GEN_TXDBUG @@ -433,7 +586,7 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end if (txf >= nframes) { DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX7 enc: %1 [ %2 / %3 ] byte: %4 spd %5 fpp %6 || nf: %7\n", ltc_enc_pos, ltc_buf_off, ltc_buf_len, ltc_enc_byte, ltc_speed, nframes, txf)); - return nframes; + break; } ltc_buf_len = 0; @@ -450,14 +603,24 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end } } - if (ltc_encoder_encode_byte(ltc_encoder, ltc_enc_byte, (ltc_speed==0)?1.0:(1.0/ltc_speed))) { - DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.3 encoder error byte %1\n", ltc_enc_byte)); - ltc_encoder_buffer_flush(ltc_encoder); - ltc_tx_reset(); - memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); - return -1; + int enc_frames; + + if (restarting) { + /* write zero bytes -- don't touch encoder until we're at a frame-boundary + * otherwise the biphase polarity may be inverted. + */ + enc_frames = fptcf / 10.0; + memset(<c_enc_buf[ltc_buf_len], 127, enc_frames * sizeof(ltcsnd_sample_t)); + } else { + if (ltc_encoder_encode_byte(ltc_encoder, ltc_enc_byte, (ltc_speed==0)?1.0:(1.0/ltc_speed))) { + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.3 encoder error byte %1\n", ltc_enc_byte)); + ltc_encoder_buffer_flush(ltc_encoder); + ltc_tx_reset(); + return; + } + enc_frames = ltc_encoder_get_buffer(ltc_encoder, &(ltc_enc_buf[ltc_buf_len])); } - int enc_frames = ltc_encoder_get_buffer(ltc_encoder, &(ltc_enc_buf[ltc_buf_len])); + #ifdef LTC_GEN_FRAMEDBUG DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.3 encoded %1 bytes for LTC-byte %2 at spd %3\n", enc_frames, ltc_enc_byte, ltc_speed)); #endif @@ -465,24 +628,30 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end DEBUG_TRACE (DEBUG::LTC, "LTC TX6.3 encoder empty buffer.\n"); ltc_encoder_buffer_flush(ltc_encoder); ltc_tx_reset(); - memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); - return -1; + return; } ltc_buf_len += enc_frames; if (ltc_speed < 0) - ltc_enc_cnt -= fptcf/10.0; //enc_frames * ltc_speed; + ltc_enc_cnt -= fptcf/10.0; else - ltc_enc_cnt += fptcf/10.0; //enc_frames * ltc_speed; + ltc_enc_cnt += fptcf/10.0; if (ltc_speed >= 0) { ltc_enc_byte = (ltc_enc_byte + 1)%10; if (ltc_enc_byte == 0 && ltc_speed != 0) { ltc_encoder_inc_timecode(ltc_encoder); +#if 0 /* force fixed parity -- scope debug */ + LTCFrame f; + ltc_encoder_get_frame(ltc_encoder, &f); + f.biphase_mark_phase_correction=0; + ltc_encoder_set_frame(ltc_encoder, &f); +#endif ltc_tx_recalculate_position(); ltc_enc_cnt = 0; } else if (ltc_enc_byte == 0) { ltc_enc_cnt = 0; + restarting=false; } } #ifdef LTC_GEN_FRAMEDBUG @@ -490,5 +659,6 @@ Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end #endif } - return nframes; + dynamic_cast(&buf)->set_written (true); + return; }