- bool const c = _film && !_film->content().empty ();
-
- _slider->Enable (c);
- _back_button->Enable (c);
- _forward_button->Enable (c);
- _play_button->Enable (c);
- _outline_content->Enable (c);
- _frame_number->Enable (c);
- _timecode->Enable (c);
+ if (_audio.isStreamRunning ()) {
+ return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime());
+ }
+
+ return _video_position;
+}
+
+DCPTime
+FilmViewer::time () const
+{
+ if (_audio.isStreamRunning ()) {
+ return DCPTime::from_seconds (const_cast<RtAudio*>(&_audio)->getStreamTime ()) -
+ DCPTime::from_frames (average_latency(), _film->audio_frame_rate());
+ }
+
+ return _video_position;
+}
+
+int
+FilmViewer::audio_callback (void* out_p, unsigned int frames)
+{
+ while (true) {
+ optional<DCPTime> t = _butler->get_audio (reinterpret_cast<float*> (out_p), frames);
+ if (!t || DCPTime(uncorrected_time() - *t) < one_video_frame()) {
+ /* There was an underrun or this audio is on time; carry on */
+ break;
+ }
+ /* The audio we just got was (very) late; drop it and get some more. */
+ }
+
+ boost::mutex::scoped_lock lm (_latency_history_mutex, boost::try_to_lock);
+ if (lm) {
+ _latency_history.push_back (_audio.getStreamLatency ());
+ if (_latency_history.size() > static_cast<size_t> (_latency_history_count)) {
+ _latency_history.pop_front ();
+ }
+ }
+
+ return 0;
+}
+
+Frame
+FilmViewer::average_latency () const
+{
+ boost::mutex::scoped_lock lm (_latency_history_mutex);
+ if (_latency_history.empty()) {
+ return 0;
+ }
+
+ Frame total = 0;
+ BOOST_FOREACH (Frame i, _latency_history) {
+ total += i;
+ }
+
+ return total / _latency_history.size();