- nframes_t offset_sample;
-
- if (!use_offset) {
- offset_sample = sample;
- smpte.negative = false;
- } else {
- if (_smpte_offset_negative) {
- offset_sample = sample + _smpte_offset;
- smpte.negative = false;
- } else {
- if (sample < _smpte_offset) {
- offset_sample = (_smpte_offset - sample);
- smpte.negative = true;
- } else {
- offset_sample = sample - _smpte_offset;
- smpte.negative = false;
- }
- }
- }
-
- double smpte_frames_left_exact;
- double smpte_frames_fraction;
- unsigned long smpte_frames_left;
-
- // Extract whole hours. Do this to prevent rounding errors with
- // high sample numbers in the calculations that follow.
- smpte.hours = offset_sample / _frames_per_hour;
- offset_sample = offset_sample % _frames_per_hour;
-
- // Calculate exact number of (exceeding) smpte frames and fractional frames
- smpte_frames_left_exact = (double) offset_sample / _frames_per_smpte_frame;
- smpte_frames_fraction = smpte_frames_left_exact - floor( smpte_frames_left_exact );
- smpte.subframes = (long) rint(smpte_frames_fraction * config.get_subframes_per_frame());
-
- // XXX Not sure if this is necessary anymore...
- if (smpte.subframes == config.get_subframes_per_frame()) {
- // This can happen with 24 fps (and 29.97 fps ?)
- smpte_frames_left_exact = ceil( smpte_frames_left_exact );
- smpte.subframes = 0;
- }
-
- // Extract hour-exceeding frames for minute, second and frame calculations
- smpte_frames_left = ((long) floor( smpte_frames_left_exact ));
-
- if (smpte_drop_frames()) {
- // See long explanation in smpte_to_sample()...
-
- // Number of 10 minute chunks
- smpte.minutes = (smpte_frames_left / 17982) * 10; // exactly 17982 frames in 10 minutes
- // frames exceeding the nearest 10 minute barrier
- long exceeding_df_frames = smpte_frames_left % 17982;
-
- // Find minutes exceeding the nearest 10 minute barrier
- if (exceeding_df_frames >= 1800) { // nothing to do if we are inside the first minute (0-1799)
- exceeding_df_frames -= 1800; // take away first minute (different number of frames than the others)
- long extra_minutes_minus_1 = exceeding_df_frames / 1798; // how many minutes after the first one
- exceeding_df_frames -= extra_minutes_minus_1 * 1798; // take away the (extra) minutes just found
- smpte.minutes += extra_minutes_minus_1 + 1; // update with exceeding minutes
- }
-
- // Adjust frame numbering for dropped frames (frame 0 and 1 skipped at start of every minute except every 10th)
- if (smpte.minutes % 10) {
- // Every minute except every 10th
- if (exceeding_df_frames < 28) {
- // First second, frames 0 and 1 are skipped
- smpte.seconds = 0;
- smpte.frames = exceeding_df_frames + 2;
- } else {
- // All other seconds, all 30 frames are counted
- exceeding_df_frames -= 28;
- smpte.seconds = (exceeding_df_frames / 30) + 1;
- smpte.frames = exceeding_df_frames % 30;
- }
- } else {
- // Every 10th minute, all 30 frames counted in all seconds
- smpte.seconds = exceeding_df_frames / 30;
- smpte.frames = exceeding_df_frames % 30;
- }
- } else {
- // Non drop is easy
- smpte.minutes = smpte_frames_left / ((long) rint (smpte_frames_per_second ()) * 60);
- smpte_frames_left = smpte_frames_left % ((long) rint (smpte_frames_per_second ()) * 60);
- smpte.seconds = smpte_frames_left / (long) rint(smpte_frames_per_second ());
- smpte.frames = smpte_frames_left % (long) rint(smpte_frames_per_second ());
- }
-
- if (!use_subframes) {
- smpte.subframes = 0;
- }
- /* set frame rate and drop frame */
- smpte.rate = smpte_frames_per_second ();
- smpte.drop = smpte_drop_frames();
-}
-
-void
-Session::smpte_time (nframes_t when, SMPTE::Time& smpte)
-{
- if (last_smpte_valid && when == last_smpte_when) {
- smpte = last_smpte;