Make terminate_threads() less likely to leave _threads containing invalid pointers.
[dcpomatic.git] / src / lib / audio_merger.cc
index d50420c31d5343dcabe0b25eb13b8b704599d37f..a16c378c67309dac758c90abd27fc275ef7db769 100644 (file)
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2013-2014 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2013-2017 Carl Hetherington <cth@carlh.net>
 
     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
 
 */
 
-#include "audio_buffers.h"
+/** @file  src/audio_merger.cc
+ *  @brief AudioMerger class.
+ */
+
 #include "audio_merger.h"
+#include "dcpomatic_time.h"
+#include <iostream>
 
+using std::pair;
 using std::min;
 using std::max;
+using std::list;
+using std::cout;
+using std::make_pair;
 using boost::shared_ptr;
+using boost::optional;
 
-AudioMerger::AudioMerger (int channels, int frame_rate)
-       : _buffers (new AudioBuffers (channels, 0))
-       , _frame_rate (frame_rate)
-       , _last_pull (0)
+AudioMerger::AudioMerger (int frame_rate)
+       : _frame_rate (frame_rate)
 {
 
 }
 
+Frame
+AudioMerger::frames (DCPTime t) const
+{
+       return t.frames_floor (_frame_rate);
+}
 
-TimedAudioBuffers<DCPTime>
+/** Pull audio up to a given time; after this call, no more data can be pushed
+ *  before the specified time.
+ *  @param time Time to pull up to.
+ *  @return Blocks of merged audio up to `time'.
+ */
+list<pair<shared_ptr<AudioBuffers>, DCPTime> >
 AudioMerger::pull (DCPTime time)
 {
-       assert (time >= _last_pull);
-       
-       TimedAudioBuffers<DCPTime> out;
-       
-       int64_t const to_return = DCPTime (time - _last_pull).frames (_frame_rate);
-       out.audio.reset (new AudioBuffers (_buffers->channels(), to_return));
-       /* And this is how many we will get from our buffer */
-       int64_t const to_return_from_buffers = min (to_return, int64_t (_buffers->frames ()));
-       
-       /* Copy the data that we have to the back end of the return buffer */
-       out.audio->copy_from (_buffers.get(), to_return_from_buffers, 0, to_return - to_return_from_buffers);
-       /* Silence any gap at the start */
-       out.audio->make_silent (0, to_return - to_return_from_buffers);
-       
-       out.time = _last_pull;
-       _last_pull = time;
-       
-       /* And remove the data we're returning from our buffers */
-       if (_buffers->frames() > to_return_from_buffers) {
-               _buffers->move (to_return_from_buffers, 0, _buffers->frames() - to_return_from_buffers);
+       list<pair<shared_ptr<AudioBuffers>, DCPTime> > out;
+
+       list<Buffer> new_buffers;
+
+       _buffers.sort (AudioMerger::BufferComparator());
+       BOOST_FOREACH (Buffer i, _buffers) {
+               if (i.period().to <= time) {
+                       /* Completely within the pull period */
+                       DCPOMATIC_ASSERT (i.audio->frames() > 0);
+                       out.push_back (make_pair (i.audio, i.time));
+               } else if (i.time < time) {
+                       /* Overlaps the end of the pull period */
+                       shared_ptr<AudioBuffers> audio (new AudioBuffers (i.audio->channels(), frames(DCPTime(time - i.time))));
+                       /* Though time > i.time, audio->frames() could be 0 if the difference in time is less than one frame */
+                       if (audio->frames() > 0) {
+                               audio->copy_from (i.audio.get(), audio->frames(), 0, 0);
+                               out.push_back (make_pair (audio, i.time));
+                               i.audio->trim_start (audio->frames ());
+                               i.time += DCPTime::from_frames(audio->frames(), _frame_rate);
+                               DCPOMATIC_ASSERT (i.audio->frames() > 0);
+                               new_buffers.push_back (i);
+                       }
+               } else {
+                       /* Not involved */
+                       DCPOMATIC_ASSERT (i.audio->frames() > 0);
+                       new_buffers.push_back (i);
+               }
        }
-       _buffers->set_frames (_buffers->frames() - to_return_from_buffers);
-       
+
+       _buffers = new_buffers;
+
+       for (list<pair<shared_ptr<AudioBuffers>, DCPTime> >::const_iterator i = out.begin(); i != out.end(); ++i) {
+               DCPOMATIC_ASSERT (i->first->frames() > 0);
+       }
+
        return out;
 }
 
+/** Push some data into the merger at a given time */
 void
-AudioMerger::push (shared_ptr<const AudioBuffers> audio, DCPTime time)
+AudioMerger::push (boost::shared_ptr<const AudioBuffers> audio, DCPTime time)
 {
-       assert (time >= _last_pull);
-       
-       int64_t frame = time.frames (_frame_rate);
-       int64_t after = max (int64_t (_buffers->frames()), frame + audio->frames() - _last_pull.frames (_frame_rate));
-       _buffers->ensure_size (after);
-       _buffers->accumulate_frames (audio.get(), 0, frame - _last_pull.frames (_frame_rate), audio->frames ());
-       _buffers->set_frames (after);
-}
+       DCPOMATIC_ASSERT (audio->frames() > 0);
 
-TimedAudioBuffers<DCPTime>
-AudioMerger::flush ()
-{
-       if (_buffers->frames() == 0) {
-               return TimedAudioBuffers<DCPTime> ();
+       DCPTimePeriod period (time, time + DCPTime::from_frames (audio->frames(), _frame_rate));
+
+       /* Mix any overlapping parts of this new block with existing ones */
+       BOOST_FOREACH (Buffer i, _buffers) {
+               optional<DCPTimePeriod> overlap = i.period().overlap (period);
+               if (overlap) {
+                       int32_t const offset = frames(DCPTime(overlap->from - i.time));
+                       int32_t const frames_to_mix = frames(overlap->duration());
+                       if (i.time < time) {
+                               i.audio->accumulate_frames(audio.get(), frames_to_mix, 0, offset);
+                       } else {
+                               i.audio->accumulate_frames(audio.get(), frames_to_mix, offset, 0);
+                       }
+               }
+       }
+
+       list<DCPTimePeriod> periods;
+       BOOST_FOREACH (Buffer i, _buffers) {
+               periods.push_back (i.period ());
+       }
+
+       /* Add the non-overlapping parts */
+       BOOST_FOREACH (DCPTimePeriod i, subtract (period, periods)) {
+               list<Buffer>::iterator before = _buffers.end();
+               list<Buffer>::iterator after = _buffers.end();
+               for (list<Buffer>::iterator j = _buffers.begin(); j != _buffers.end(); ++j) {
+                       if (j->period().to == i.from) {
+                               before = j;
+                       }
+                       if (j->period().from == i.to) {
+                               after = j;
+                       }
+               }
+
+               /* Get the part of audio that we want to use */
+               shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), frames(i.to) - frames(i.from)));
+               part->copy_from (audio.get(), part->frames(), frames(DCPTime(i.from - time)), 0);
+
+               if (before == _buffers.end() && after == _buffers.end()) {
+                       /* New buffer */
+                       DCPOMATIC_ASSERT (part->frames() > 0);
+                       _buffers.push_back (Buffer (part, time, _frame_rate));
+               } else if (before != _buffers.end() && after == _buffers.end()) {
+                       /* We have an existing buffer before this one; append new data to it */
+                       before->audio->append (part);
+               } else if (before ==_buffers.end() && after != _buffers.end()) {
+                       /* We have an existing buffer after this one; append it to the new data and replace */
+                       part->append (after->audio);
+                       after->audio = part;
+                       after->time = time;
+               } else {
+                       /* We have existing buffers both before and after; coalesce them all */
+                       before->audio->append (part);
+                       before->audio->append (after->audio);
+                       _buffers.erase (after);
+               }
        }
-       
-       return TimedAudioBuffers<DCPTime> (_buffers, _last_pull);
 }
 
 void
-AudioMerger::clear (DCPTime t)
+AudioMerger::clear ()
 {
-       _last_pull = t;
-       _buffers.reset (new AudioBuffers (_buffers->channels(), 0));
+       _buffers.clear ();
 }