Do split buffers over reel boundaries correctly.

[dcpomatic.git] / src / lib / writer.cc

diff --git a/src/lib/writer.cc b/src/lib/writer.cc
index b5123ad74cf2e81511dbc1ad988a593c2fe52cb9..10e4514fbcc134ef333d333d5086511b6b5660a3 100644 (file)
--- a/src/lib/writer.cc
+++ b/src/lib/writer.cc
@@ -231,36 +231,61 @@ Writer::fake_write (Frame frame, Eyes eyes)
 }
 
 /** Write some audio frames to the DCP.
- *  @param audio Audio data or 0 if there is no audio to be written here (i.e. it is referenced).
+ *  @param audio Audio data.
+ *  @param time Time of this data within the DCP.
  *  This method is not thread safe.
  */
 void
-Writer::write (shared_ptr<const AudioBuffers> audio)
+Writer::write (shared_ptr<const AudioBuffers> audio, DCPTime const time)
 {
+       DCPOMATIC_ASSERT (audio);
+
+       int const afr = _film->audio_frame_rate();
+
+       DCPTime const end = time + DCPTime::from_frames(audio->frames(), afr);
+
        /* The audio we get might span a reel boundary, and if so we have to write it in bits */
 
-       int32_t offset = 0;
-       while (offset < audio->frames ()) {
+       DCPTime t = time;
+       while (t < end) {
 
                if (_audio_reel == _reels.end ()) {
                        /* This audio is off the end of the last reel; ignore it */
                        return;
                }
 
-               int32_t const remaining = audio->frames() - offset;
-               int32_t const reel_space = _audio_reel->period().duration().frames_floor(_film->audio_frame_rate()) - _audio_reel->total_written_audio_frames();
-
-               if (remaining <= reel_space) {
+               if (end <= _audio_reel->period().to) {
                        /* Easy case: we can write all the audio to this reel */
                        _audio_reel->write (audio);
-                       offset += remaining;
+                       t = end;
                } else {
-                       /* Write the part we can */
-                       shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), reel_space));
-                       part->copy_from (audio.get(), reel_space, offset, 0);
-                       _audio_reel->write (part);
+                       /* Split the audio into two and write the first part */
+                       DCPTime part_lengths[2] = {
+                               _audio_reel->period().to - t,
+                               end - _audio_reel->period().to
+                       };
+
+                       Frame part_frames[2] = {
+                               part_lengths[0].frames_ceil(afr),
+                               part_lengths[1].frames_ceil(afr)
+                       };
+
+                       if (part_frames[0]) {
+                               shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), part_frames[0]));
+                               part->copy_from (audio.get(), part_frames[0], 0, 0);
+                               _audio_reel->write (part);
+                       }
+
+                       if (part_frames[1]) {
+                               shared_ptr<AudioBuffers> part (new AudioBuffers (audio->channels(), part_frames[1]));
+                               part->copy_from (audio.get(), part_frames[1], part_frames[0], 0);
+                               audio = part;
+                       } else {
+                               audio.reset ();
+                       }
+
                        ++_audio_reel;
-                       offset += reel_space;
+                       t += part_lengths[0];
                }
        }
 }
@@ -676,16 +701,7 @@ operator== (QueueItem const & a, QueueItem const & b)
 void
 Writer::set_encoder_threads (int threads)
 {
-       /* I think the scaling factor here should be the ratio of the longest frame
-          encode time to the shortest; if the thread count is T, longest time is L
-          and the shortest time S we could encode L/S frames per thread whilst waiting
-          for the L frame to encode so we might have to store LT/S frames.
-
-          However we don't want to use too much memory, so keep it a bit lower than we'd
-          perhaps like.  A J2K frame is typically about 1Mb so 3 here will mean we could
-          use about 240Mb with 72 encoding threads.
-       */
-       _maximum_frames_in_memory = lrint (threads * 3);
+       _maximum_frames_in_memory = lrint (threads * Config::instance()->frames_in_memory_multiplier());
 }
 
 void