diff options
author | Robin Gareus <robin@gareus.org> | 2012-10-21 14:07:10 +0000 |
---|---|---|
committer | Robin Gareus <robin@gareus.org> | 2012-10-21 14:07:10 +0000 |
commit | ec94210a4d5009bd635b24e7f5af8946f6b7669d (patch) | |
tree | 0dc48dfca1a301a7c0a7b6f484ab397ac34c1cff /libs/ardour/session_ltc.cc | |
parent | 4c13d205d4adc5dde130e199ea1f228ce670b588 (diff) |
add LTC generator
git-svn-id: svn://localhost/ardour2/branches/3.0@13315 d708f5d6-7413-0410-9779-e7cbd77b26cf
Diffstat (limited to 'libs/ardour/session_ltc.cc')
-rw-r--r-- | libs/ardour/session_ltc.cc | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/libs/ardour/session_ltc.cc b/libs/ardour/session_ltc.cc new file mode 100644 index 0000000000..2982255024 --- /dev/null +++ b/libs/ardour/session_ltc.cc @@ -0,0 +1,393 @@ +/* + Copyright (C) 2012 Paul Davis + Written by Robin Gareus <robin@gareus.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + 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 "i18n.h" + +using namespace std; +using namespace ARDOUR; +using namespace MIDI; +using namespace PBD; +using namespace Timecode; + +//#define LTC_GEN_FRAMEDBUG + +void +Session::ltc_tx_initialize() +{ + ltc_enc_tcformat = config.get_timecode_format(); + + 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); + + ltc_encoder_set_bufsize(ltc_encoder, nominal_frame_rate(), 23.0); + + /* buffersize for 1 LTC frame: (1 + sample-rate / fps) bytes + * usually returned by ltc_encoder_get_buffersize(encoder) + * + * 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_tx_reset(); +} + +void +Session::ltc_tx_cleanup() +{ + DEBUG_TRACE (DEBUG::LTC, "LTC TX cleanup\n"); + if (ltc_enc_buf) free(ltc_enc_buf); + ltc_encoder_free(ltc_encoder); + ltc_encoder = NULL; +} + +void +Session::ltc_tx_reset() +{ + DEBUG_TRACE (DEBUG::LTC, "LTC TX reset\n"); + ltc_enc_pos = -1; // force re-start + ltc_buf_len = 0; + ltc_buf_off = 0; + ltc_enc_byte = 0; +} + +int +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) +{ + assert(nframes > 0); + + const float smult = 2.0/(3.0*255.0); + SMPTETimecode tc; + jack_default_audio_sample_t *out; + pframes_t txf = 0; + boost::shared_ptr<Port> ltcport = engine().ltc_output_port(); + + if (!ltc_encoder || !ltc_enc_buf || !ltcport || ! ltcport->jack_port()) return 0; + + out = (jack_default_audio_sample_t*) jack_port_get_buffer (ltcport->jack_port(), nframes); + if (!out) return 0; + + if (engine().freewheeling() || !Config->get_send_ltc()) { + memset(out, 0, nframes * sizeof(jack_default_audio_sample_t)); + return nframes; + } + + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX %1 to %2 / %3\n", start_frame, end_frame, nframes)); + + /* all systems go. Now here's the plan: + * + * 1) check if fps has changed + * 2) check direction of encoding, calc speed + * 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 + * 6) actual LTC audio output + * 6a) send remaining part of already queued frame; break on nframes + * 6b) encode new LTC-frame byte + * 6c) goto 6a + * 7) done + */ + + // (1) + 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)) { + PBD::error << _("LTC encoder: invalid framerate - LTC encoding is disabled for the remainder of this session.") << endmsg; + ltc_tx_cleanup(); + return 0; + } + ltc_enc_tcformat = cur_timecode; + 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; + } + + // (2) +#define SIGNUM(a) ( (a) < 0 ? -1 : 1) + + framepos_t cycle_start_frame = (current_speed < 0) ? end_frame :start_frame; + double new_ltc_speed = double(labs(end_frame - start_frame) * SIGNUM(current_speed)) / double(nframes); + + if (SIGNUM(new_ltc_speed) != SIGNUM (ltc_speed)) { + // transport changed direction + DEBUG_TRACE (DEBUG::LTC, "LTC TX2: transport direction changed\n"); + ltc_tx_reset(); + } + + if (ltc_speed != current_speed || target_speed != fabs(current_speed)) { + /* TODO 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 + * (except for the sign). Besides, above speed calulation uses the + * difference (end_frame - start_frame). + * end_frame is calculated from 'frames_moved' which includes the interpolation. + * so we're good, except for the fact that each LTC byte is sent at fixed 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)); + } + + if (end_frame == start_frame || fabs(current_speed) < 0.1 ) { + DEBUG_TRACE (DEBUG::LTC, "LTC TX2: transport is not rolling or absolute-speed < 0.1\n"); + /* keep repeating current frame + * + * an LTC generator must be able to continue generating LTC when Ardours transport is in stop + * some machines do odd things if LTC goes away: + * e.g. a tape based machine (video or audio), some think they have gone into park if LTC goes away, + * so unspool the tape from the playhead. That might be inconvenient. + * If LTC keeps arriving they remain in a stop position with the tape on the playhead. + */ + new_ltc_speed = 0; + } + + ltc_speed = new_ltc_speed; + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: transport speed %1.\n", ltc_speed)); + + if (fabs(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; + } + + // (3) + Timecode::Time tc_start; + framepos_t tc_sample_start; + + /* calc timecode frame from current position - round down to nearest timecode */ + int boff; + if (ltc_speed == 0) { + boff = 0; + } else if (ltc_speed < 0) { + boff = (ltc_enc_byte - 9) * frames_per_timecode_frame() / 10; + } else { + boff = ltc_enc_byte * frames_per_timecode_frame() / 10; + } + + sample_to_timecode(cycle_start_frame + - boff + - ltc_speed * (ltc_buf_len - ltc_buf_off), + tc_start, true, false); + + /* convert timecode back to sample-position */ + Timecode::timecode_to_sample (tc_start, tc_sample_start, true, false, + double(frame_rate()), + config.get_subframes_per_frame(), + config.get_timecode_offset_negative(), config.get_timecode_offset() + ); + + /* difference between current frame and TC frame in samples */ + frameoffset_t soff = cycle_start_frame - tc_sample_start; + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX3: now: %1 tra: %2 eoff %3\n", cycle_start_frame, tc_sample_start, soff)); + + // (4) + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: enc: %1 boff: %2 || enc-byte:%3\n", ltc_enc_pos, boff, ltc_enc_byte)); + if (ltc_enc_pos != tc_sample_start) { + + /* re-calc timecode w/o buffer offset */ + sample_to_timecode(cycle_start_frame, tc_start, true, false); + Timecode::timecode_to_sample (tc_start, tc_sample_start, true, false, + double(frame_rate()), + config.get_subframes_per_frame(), + config.get_timecode_offset_negative(), config.get_timecode_offset() + ); + soff = cycle_start_frame - tc_sample_start; + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: now: %1 trs: %2 toff %3\n", cycle_start_frame, tc_sample_start, soff)); + + tc.hours = tc_start.hours; + tc.mins = tc_start.minutes; + tc.secs = tc_start.seconds; + tc.frame = tc_start.frames; + ltc_encoder_set_timecode(ltc_encoder, &tc); + +#if 1 + /* 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. + */ + LTCFrame ltcframe; + ltc_encoder_get_frame(ltc_encoder, <cframe); + ltcframe.dfbit = timecode_has_drop_frames(cur_timecode)?1:0; + ltc_encoder_set_frame(ltc_encoder, <cframe); +#endif + + // (5) + int fdiff = 0; + if (soff < 0) { + fdiff = ceil(-soff / frames_per_timecode_frame()); + soff += fdiff * frames_per_timecode_frame(); + for (int i=0; i < fdiff; ++i) { + ltc_encoder_inc_timecode(ltc_encoder); + } + } + else if (soff >= frames_per_timecode_frame()) { + fdiff = floor(soff / frames_per_timecode_frame()); + soff -= fdiff * frames_per_timecode_frame(); + for (int i=0; i < fdiff; ++i) { + ltc_encoder_dec_timecode(ltc_encoder); + } + } + + assert(soff >= 0 && soff < frames_per_timecode_frame()); + + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX5 restart encoder fdiff %1 sdiff %2\n", fdiff, soff)); + ltc_tx_reset(); + + if (ltc_speed == 0) { + // offset is irrelevant when not rolling + soff = 0; + } + if (soff > 0 && soff <= nframes) { + txf=soff; + memset(out, 0, soff * sizeof(jack_default_audio_sample_t)); + } else if (soff > 0) { + /* resync next cycle */ + memset(out, 0, soff * sizeof(jack_default_audio_sample_t)); + return nframes; + } + + ltc_enc_byte = soff * 10 / frames_per_timecode_frame(); + + if (ltc_speed < 0 ) { + ltc_enc_byte = 9 - ltc_enc_byte; + } + + ltc_enc_pos = tc_sample_start; + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX5 restart @ %1 byte %2\n", ltc_enc_pos, ltc_enc_byte)); + } + + // (6) + while (1) { +#ifdef LTC_GEN_FRAMEDBUG + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.1 @%1 [ %2 / %3 ]\n", txf, ltc_buf_off, ltc_buf_len)); +#endif + // (6a) + 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*smult); + out[txf++] = val; + } +#ifdef LTC_GEN_FRAMEDBUG + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.2 @%1 [ %2 / %3 ]\n", txf, ltc_buf_off, ltc_buf_len)); +#endif + + if (txf >= nframes) { + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX7 txf = %1 nframes = %2\n", txf, nframes)); + return nframes; + } + + ltc_buf_len = 0; + ltc_buf_off = 0; + + // (6b) + + if (SIGNUM(ltc_speed) == -1) { + ltc_enc_byte = (ltc_enc_byte + 9)%10; + if (ltc_enc_byte == 9) { + ltc_encoder_dec_timecode(ltc_encoder); +#if 0 // this does not work for fractional or drop-frame TC + ltc_enc_pos -= frames_per_timecode_frame(); +#else // TODO make this a function + SMPTETimecode enctc; + Timecode::Time a3tc; + ltc_encoder_get_timecode(ltc_encoder, &enctc); + + a3tc.hours = enctc.hours ; + a3tc.minutes = enctc.mins ; + a3tc.seconds = enctc.secs ; + a3tc.frames = enctc.frame ; + a3tc.rate = timecode_to_frames_per_second(cur_timecode); + a3tc.drop = timecode_has_drop_frames(cur_timecode); + + Timecode::timecode_to_sample (a3tc, ltc_enc_pos, true, false, + double(frame_rate()), + config.get_subframes_per_frame(), + config.get_timecode_offset_negative(), config.get_timecode_offset() + ); +#endif + } + } + + 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 = 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 LTC-byte %2 at spd %3\n", enc_frames, ltc_enc_byte, ltc_speed)); +#endif + if (enc_frames <=0) { + 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; + } + + ltc_buf_len += enc_frames; + + if (SIGNUM(ltc_speed) == 1) { + ltc_enc_byte = (ltc_enc_byte + 1)%10; + if (ltc_enc_byte == 0 && ltc_speed != 0) { + ltc_encoder_inc_timecode(ltc_encoder); +#if 0 // this does not work for fractional or drop-frame TC + ltc_enc_pos += frames_per_timecode_frame(); +#else // TODO make this a function + SMPTETimecode enctc; + Timecode::Time a3tc; + ltc_encoder_get_timecode(ltc_encoder, &enctc); + + a3tc.hours = enctc.hours ; + a3tc.minutes = enctc.mins ; + a3tc.seconds = enctc.secs ; + a3tc.frames = enctc.frame ; + a3tc.rate = timecode_to_frames_per_second(cur_timecode); + a3tc.drop = timecode_has_drop_frames(cur_timecode); + + Timecode::timecode_to_sample (a3tc, ltc_enc_pos, true, false, + double(frame_rate()), + config.get_subframes_per_frame(), + config.get_timecode_offset_negative(), config.get_timecode_offset() + ); +#endif + } + } +#ifdef LTC_GEN_FRAMEDBUG + DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.4 fno: %1 [ %2 / %3 ] spd %4\n", ltc_enc_pos, ltc_buf_off, ltc_buf_len, ltc_speed)); +#endif + } + + return nframes; +} |