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(),
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX init sr: %1 fps: %2\n", nominal_sample_rate(), timecode_to_frames_per_second(ltc_enc_tcformat)));
+ ltc_encoder = ltc_encoder_create(nominal_sample_rate(),
timecode_to_frames_per_second(ltc_enc_tcformat),
TV_STANDARD(ltc_enc_tcformat), 0);
- ltc_encoder_set_bufsize(ltc_encoder, nominal_frame_rate(), 23.0);
+ ltc_encoder_set_bufsize(ltc_encoder, nominal_sample_rate(), 23.0);
ltc_encoder_set_filter(ltc_encoder, LTC_RISE_TIME(1.0));
- /* buffersize for 1 LTC frame: (1 + sample-rate / fps) bytes
+ /* buffersize for 1 LTC sample: (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_enc_buf = (ltcsnd_sample_t*) calloc((nominal_sample_rate() / 23), sizeof(ltcsnd_sample_t));
ltc_speed = 0;
ltc_prev_cycle = -1;
ltc_tx_reset();
a3tc.drop = timecode_has_drop_frames(ltc_enc_tcformat);
Timecode::timecode_to_sample (a3tc, ltc_enc_pos, true, false,
- (double)frame_rate(),
+ (double)sample_rate(),
config.get_subframes_per_frame(),
ltc_timecode_negative_offset, ltc_timecode_offset
);
}
void
-Session::ltc_tx_send_time_code_for_cycle (framepos_t start_frame, framepos_t end_frame,
+Session::ltc_tx_send_time_code_for_cycle (samplepos_t start_sample, samplepos_t end_sample,
double target_speed, double current_speed,
pframes_t nframes)
{
/* 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);
- DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX %1 to %2 / %3 | lat: %4\n", start_frame, end_frame, nframes, ltc_out_latency.max));
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX %1 to %2 / %3 | lat: %4\n", start_sample, end_sample, 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, 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
+ * 3) calculate sample and byte to send aligned to jack-period size
+ * 4) check if it's the sample/byte that is already in the queue
+ * 5) if (4) mismatch, re-calculate offset of LTC sample 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
+ * 6a) send remaining part of already queued sample; break on nframes
+ * 6b) encode new LTC-sample byte
* 6c) goto 6a
* 7) done
*/
// (1) check fps
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(),
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX1: TC format mismatch - reinit sr: %1 fps: %2\n", nominal_sample_rate(), timecode_to_frames_per_second(cur_timecode)));
+ if (ltc_encoder_reinit(ltc_encoder, nominal_sample_rate(),
timecode_to_frames_per_second(cur_timecode),
TV_STANDARD(cur_timecode), 0
)) {
// (2) speed & direction
/* speed 0 aka transport stopped is interpreted as rolling forward.
- * keep repeating current frame
+ * keep repeating current sample
*/
#define SIGNUM(a) ( (a) < 0 ? -1 : 1)
bool speed_changed = false;
* buffer.
*
* The timecode is generated directly in the Session process callback
- * using _transport_frame. It requires that the session has set the
+ * using _transport_sample. 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;
+ samplepos_t cycle_start_sample;
if (current_speed < 0) {
- cycle_start_frame = (start_frame - ltc_out_latency.max + worst_playback_latency());
+ cycle_start_sample = (start_sample - ltc_out_latency.max + worst_playback_latency());
} else if (current_speed > 0) {
- cycle_start_frame = (start_frame + ltc_out_latency.max - worst_playback_latency());
+ cycle_start_sample = (start_sample + 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;
+ cycle_start_sample = start_sample;
}
/* LTC TV standard offset */
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_sample -= 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; }
+ if (cycle_start_sample < 0) { cycle_start_sample = 0; }
- 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();
+ double new_ltc_speed = (double)(labs(end_sample - start_sample) * SIGNUM(current_speed)) / (double)nframes;
+ if (nominal_sample_rate() != sample_rate()) {
+ new_ltc_speed *= (double)nominal_sample_rate() / (double)sample_rate();
}
if (SIGNUM(new_ltc_speed) != SIGNUM (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
+ * new_ltc_speed is > 0 because (end_sample - start_sample) == jack-period for no-roll
* but ltc_speed will still be 0
*/
&& (current_speed != 0 || ltc_speed != current_speed)
*
* 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 calculation uses the difference (end_frame - start_frame).
- * end_frame is calculated from 'frames_moved' which includes the interpolation.
+ * Besides, above speed calculation uses the difference (end_sample - start_sample).
+ * end_sample is calculated from 'samples_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, new_ltc_speed));
ltc_encoder_set_filter(ltc_encoder, LTC_RISE_TIME(new_ltc_speed));
}
- if (end_frame == start_frame || fabs(current_speed) < 0.1 ) {
+ if (end_sample == start_sample || 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
+ /* keep repeating current sample
*
* 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:
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));
+ if (start_sample != ltc_prev_cycle) {
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: no-roll seek from %1 to %2 (%3)\n", ltc_prev_cycle, start_sample, cycle_start_sample));
ltc_tx_reset();
}
}
}
}
- ltc_prev_cycle = start_frame;
+ ltc_prev_cycle = start_sample;
ltc_speed = new_ltc_speed;
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX2: transport speed %1.\n", ltc_speed));
// (3) bit/sample alignment
Timecode::Time tc_start;
- framepos_t tc_sample_start;
+ samplepos_t tc_sample_start;
/* calc timecode frame from current position - round down to nearest timecode */
- Timecode::sample_to_timecode(cycle_start_frame, tc_start, true, false,
+ Timecode::sample_to_timecode(cycle_start_sample, tc_start, true, false,
timecode_frames_per_second(),
timecode_drop_frames(),
- (double)frame_rate(),
+ (double)sample_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)sample_rate(),
config.get_subframes_per_frame(),
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;
+ /* difference between current sample and TC sample in samples */
+ sampleoffset_t soff = cycle_start_sample - 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));
+ cycle_start_sample, tc_sample_start, soff));
// (4) check if alignment matches
maxdiff = slave()->resolution();
} else {
maxdiff = ceil(fabs(ltc_speed))*2.0;
- if (nominal_frame_rate() != frame_rate()) {
+ if (nominal_sample_rate() != sample_rate()) {
maxdiff *= 3.0;
}
if (ltc_enc_tcformat == Timecode::timecode_23976 || ltc_enc_tcformat == Timecode::timecode_24976) {
DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: enc-pos: %1 | d: %2\n",
ltc_enc_pos + ltc_enc_cnt - poff,
- rint(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame
+ rint(ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_sample
));
- const framecnt_t wrap24h = 86400. * frame_rate();
+ const samplecnt_t wrap24h = 86400. * sample_rate();
if (ltc_enc_pos < 0
- || (ltc_speed != 0 && fabs(fmod(ceil(ltc_enc_pos + ltc_enc_cnt - poff), wrap24h) - (cycle_start_frame % wrap24h)) > maxdiff)
+ || (ltc_speed != 0 && fabs(fmod(ceil(ltc_enc_pos + ltc_enc_cnt - poff), wrap24h) - (cycle_start_sample % wrap24h)) > maxdiff)
) {
// (5) re-align
ltc_tx_reset();
- /* set frame to encode */
+ /* set sample to encode */
SMPTETimecode tc;
tc.hours = tc_start.hours % 24;
tc.mins = tc_start.minutes;
tc.frame = tc_start.frames;
ltc_encoder_set_timecode(ltc_encoder, &tc);
- /* workaround for libltc recognizing 29.97 and 30000/1001 as drop-frame TC.
- * In A3 30000/1001 or 30 fps can be drop-frame.
+ /* workaround for libltc recognizing 29.97 and 30000/1001 as drop-sample TC.
+ * In A3 30000/1001 or 30 fps can be drop-sample.
*/
LTCFrame ltcframe;
ltc_encoder_get_frame(ltc_encoder, <cframe);
ltc_encoder_set_frame(ltc_encoder, <cframe);
- DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: now: %1 trs: %2 toff %3\n", cycle_start_frame, tc_sample_start, soff));
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX4: now: %1 trs: %2 toff %3\n", cycle_start_sample, tc_sample_start, soff));
int32_t cyc_off;
if (soff < 0 || soff >= fptcf) {
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.
+ * (samples-per-timecode-sample / 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.
*
* However, for very fast speeds - when 1 LTC bit is
* <= 3 audio-sample - adjusting speed may lead to
- * invalid frames.
+ * invalid samples.
*
* To do better than this, resampling (or a rewrite of the
* encoder) is required.
*/
- ltc_speed -= fmod(((ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_frame), wrap24h) / engine().sample_rate();
+ ltc_speed -= fmod(((ltc_enc_pos + ltc_enc_cnt - poff) - cycle_start_sample), wrap24h) / engine().sample_rate();
}
}
}
- int enc_frames;
+ int enc_samples;
if (restarting) {
- /* write zero bytes -- don't touch encoder until we're at a frame-boundary
+ /* write zero bytes -- don't touch encoder until we're at a sample-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));
+ enc_samples = fptcf / 10.0;
+ memset(<c_enc_buf[ltc_buf_len], 127, enc_samples * 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_tx_reset();
return;
}
- enc_frames = ltc_encoder_get_buffer(ltc_encoder, &(ltc_enc_buf[ltc_buf_len]));
+ enc_samples = 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));
+ DEBUG_TRACE (DEBUG::LTC, string_compose("LTC TX6.3 encoded %1 bytes for LTC-byte %2 at spd %3\n", enc_samples, ltc_enc_byte, ltc_speed));
#endif
- if (enc_frames <=0) {
+ if (enc_samples <=0) {
DEBUG_TRACE (DEBUG::LTC, "LTC TX6.3 encoder empty buffer.\n");
ltc_encoder_buffer_flush(ltc_encoder);
ltc_tx_reset();
return;
}
- ltc_buf_len += enc_frames;
+ ltc_buf_len += enc_samples;
if (ltc_speed < 0)
ltc_enc_cnt -= fptcf/10.0;
else
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