Fix merge; other tweaks.

diff --cc src/lib/decoder.cc
index 4287a0d5f8d4d63ae9e69013eec286e54dbfb756,110d2aa887d2f1365b2236e59814bd6cd02c9d60..1f93c6c609ed9d9cdecdbbb6e8ec4e8a47e4580f
--- 1/src/lib/decoder.cc
--- 2/src/lib/decoder.cc
+++ b/src/lib/decoder.cc
@@@ -40,6 -40,6 +40,7 @@@
  using std::string;
  using std::stringstream;
  using std::min;
++using std::pair;
  using std::list;
  using boost::shared_ptr;
  
@@@ -54,12 -55,11 +55,12 @@@ Decoder::Decoder (boost::shared_ptr<Fil
        , _opt (o)
        , _job (j)
        , _minimal (minimal)
 -      , _ignore_length (ignore_length)
 -      , _video_frame_index (0)
 +      , _video_frames_in (0)
 +      , _video_frames_out (0)
 +      , _audio_frames_in (0)
 +      , _audio_frames_out (0)
        , _delay_line (0)
-       , _delay_in_bytes (0)
+       , _delay_in_frames (0)
 -      , _audio_frames_processed (0)
  {
        
  }
@@@ -75,75 -73,45 +76,58 @@@ Decoder::~Decoder (
  void
  Decoder::process_begin ()
  {
-       _delay_in_bytes = _film->audio_delay() * audio_sample_rate() * audio_channels() * bytes_per_audio_sample() / 1000;
-       _delay_line = new DelayLine (_delay_in_bytes);
+       _delay_in_frames = _film->audio_delay() * audio_sample_rate() / 1000;
 -      delete _delay_line;
+       _delay_line = new DelayLine (audio_channels(), _delay_in_frames);
 -
 -      _audio_frames_processed = 0;
  }
  
  /** Finish off a decode processing run */
  void
  Decoder::process_end ()
  {
-       if (_delay_in_bytes < 0) {
-               /* Empty the delay line */
-               uint8_t remainder[-_delay_in_bytes];
-               _delay_line->get_remaining (remainder);
-               emit_audio (remainder, -_delay_in_bytes);
+       if (_delay_in_frames < 0 && _opt->decode_audio && audio_channels()) {
+               shared_ptr<AudioBuffers> b (new AudioBuffers (audio_channels(), -_delay_in_frames));
+               b->make_silent ();
+               emit_audio (b);
        }
  
-       if (_opt->decode_audio) {
 -      /* If we cut the decode off, the audio may be short; push some silence
 -         in to get it to the right length.
 -      */
++      if (_opt->decode_audio && audio_channels()) {
  
 -      int64_t const video_length_in_audio_frames = ((int64_t) video_frame_index() * audio_sample_rate() / frames_per_second());
 -      int64_t const audio_short_by_frames = video_length_in_audio_frames - _audio_frames_processed;
 +              /* Ensure that our video and audio emissions are the same length */
  
-               int64_t video_frames_out_in_audio_frames = ((int64_t) _video_frames_out * audio_sample_rate() / frames_per_second());
-               int64_t audio_short_by_frames = video_frames_out_in_audio_frames - _audio_frames_out;
 -      _film->log()->log (
 -              String::compose ("Source length is %1 (%2 audio frames); %3 frames of audio processed.",
 -                               video_frame_index(),
 -                               video_length_in_audio_frames,
 -                               _audio_frames_processed)
 -              );
 -      
 -      if (audio_short_by_frames > 0 && _opt->decode_audio && audio_channels()) {
++              int64_t audio_short_by_frames = video_frames_to_audio_frames (_video_frames_out) - _audio_frames_out;
  
 -              _film->log()->log (String::compose ("Source length is %1; %2 frames of audio processed.", video_frame_index(), _audio_frames_processed));
 -              _film->log()->log (String::compose ("Adding %1 frames of silence to the end.", audio_short_by_frames));
 +              _film->log()->log (
 +                      String::compose ("Decoder has emitted %1 video frames (which equals %2 audio frames) and %3 audio frames",
 +                                       _video_frames_out,
-                                        video_frames_out_in_audio_frames,
++                                       video_frames_to_audio_frames (_video_frames_out),
 +                                       _audio_frames_out)
 +                      );
  
 -              shared_ptr<AudioBuffers> b (new AudioBuffers (audio_channels(), audio_short_by_frames));
 -              b->make_silent ();
 -              emit_audio (b);
 +              if (audio_short_by_frames < 0) {
 +
 +                      _film->log()->log (String::compose ("Emitted %1 too many audio frames", -audio_short_by_frames));
 +                      
 +                      /* We have emitted more audio than video.  Emit enough black video frames so that we reverse this */
 +                      int const black_video_frames = ceil (-audio_short_by_frames * frames_per_second() / audio_sample_rate());
 +
 +                      _film->log()->log (String::compose ("Emitting %1 frames of black video", black_video_frames));
 +
 +                      shared_ptr<Image> black (new CompactImage (pixel_format(), native_size()));
 +                      black->make_black ();
 +                      for (int i = 0; i < black_video_frames; ++i) {
 +                              emit_video (black, shared_ptr<Subtitle> ());
 +                      }
 +
-                       /* Now recompute our check values */
-                       video_frames_out_in_audio_frames = ((int64_t) _video_frames_out * audio_sample_rate() / frames_per_second());
-                       audio_short_by_frames = video_frames_out_in_audio_frames - _audio_frames_out;
++                      /* Now recompute our check value */
++                      audio_short_by_frames = video_frames_to_audio_frames (_video_frames_out) - _audio_frames_out;
 +              }
 +      
 +              if (audio_short_by_frames > 0) {
- 
 +                      _film->log()->log (String::compose ("Emitted %1 too few audio frames", audio_short_by_frames));
- 
-                       /* XXX: this is slightly questionable; does memset () give silence with all
-                          sample formats?
-                       */
-                       
-                       int64_t bytes = audio_short_by_frames * _film->audio_channels() * bytes_per_audio_sample();
-                       
-                       int64_t const silence_size = 16 * 1024 * _film->audio_channels() * bytes_per_audio_sample();
-                       uint8_t silence[silence_size];
-                       memset (silence, 0, silence_size);
-                       
-                       while (bytes) {
-                               int64_t const t = min (bytes, silence_size);
-                               emit_audio (silence, t);
-                               bytes -= t;
-                       }
++                      shared_ptr<AudioBuffers> b (new AudioBuffers (audio_channels(), audio_short_by_frames));
++                      b->make_silent ();
++                      emit_audio (b);
 +              }
        }
  }
  
@@@ -260,10 -228,15 +230,42 @@@ Decoder::process_audio (uint8_t* data, 
                }
        }
  
-       /* Update the number of audio frames we've pushed to the encoder */
-       _audio_frames_out += audio->frames ();
+       _delay_line->feed (audio);
 -      emit_audio (audio);
++
++      /* Decode range in audio frames */
++      pair<int64_t, int64_t> required_range (
++              video_frames_to_audio_frames (_film->dcp_trim_start()),
++              video_frames_to_audio_frames (_film->dcp_trim_start() + _film->dcp_length().get())
++              );
++
++      /* Range of this block of data */
++      pair<int64_t, int64_t> this_range (
++              _audio_frames_in,
++              _audio_frames_in + audio->frames()
++              );
++
++      /* Trim start */
++      if (required_range.first >= this_range.first && required_range.first < this_range.second) {
++              int64_t const shift = this_range.first - required_range.first;
++              audio->move (shift, 0, audio->frames() - shift);
++              audio->set_frames (audio->frames() - shift);
++      }
++
++      /* Trim end */
++      if (required_range.second >= this_range.first && required_range.second < this_range.second) {
++              audio->set_frames (this_range.first - required_range.second);
++      }
 +
++      if (audio->frames()) {
++              emit_audio (audio);
++      }
+ }
+ 
+ void
+ Decoder::emit_audio (shared_ptr<AudioBuffers> audio)
+ {
        Audio (audio);
 -      _audio_frames_processed += audio->frames ();
++      _audio_frames_out += audio->frames ();
  }
  
  /** Called by subclasses to tell the world that some video data is ready.
@@@ -282,13 -253,8 +284,13 @@@ Decoder::process_video (AVFrame* frame
  
        /* Use Film::length here as our one may be wrong */
  
 -      if (_opt->decode_video_skip != 0 && (_video_frame_index % _opt->decode_video_skip) != 0) {
 -              ++_video_frame_index;
 +      if (_opt->decode_video_skip != 0 && (_video_frames_in % _opt->decode_video_skip) != 0) {
 +              ++_video_frames_in;
 +              return;
 +      }
 +
-       if (!within_range (_video_frames_in)) {
++      if (_video_frames_in < _film->dcp_trim_start() || _video_frames_in > (_film->dcp_trim_start() + _film->length().get())) {
 +              ++_video_frames_in;
                return;
        }
  
@@@ -357,10 -322,3 +359,9 @@@ Decoder::bytes_per_audio_sample () cons
  {
        return av_get_bytes_per_sample (audio_sample_format ());
  }
- /** @param s A video frame index within the source */
- bool
- Decoder::within_range (SourceFrames s) const
 +
-       return (s >= _film->dcp_trim_start() && s < (_film->length().get() + _film->dcp_trim_start()));
++int64_t
++Decoder::video_frames_to_audio_frames (SourceFrame v) const
 +{
++      return ((int64_t) v * audio_sample_rate() / frames_per_second());
 +}

diff --cc src/lib/decoder.h
index c60ae4e599f0031f8cf4f2954baf64f1dc1696f1,9c7b2de3896b9e21a2476789c1ec584d60730977..2154da8bf6183102c9963ead832b0a9077b1a406
--- 1/src/lib/decoder.h
--- 2/src/lib/decoder.h
+++ b/src/lib/decoder.h
@@@ -126,20 -128,25 +126,22 @@@ protected
         */
        bool _minimal;
  
 -      /** ignore_length Ignore the content's claimed length when computing progress */
 -      bool _ignore_length;
 -
  private:
-       void emit_audio (uint8_t* data, int size);
 +      void emit_video (boost::shared_ptr<Image>, boost::shared_ptr<Subtitle>);
 -      
 -      /** last video frame to be processed */
 -      int _video_frame_index;
+       void emit_audio (boost::shared_ptr<AudioBuffers>);
  
++      int64_t video_frames_to_audio_frames (SourceFrame v) const;
++      
 +      SourceFrame _video_frames_in;
 +      SourceFrame _video_frames_out;
 +      int64_t _audio_frames_in;
 +      int64_t _audio_frames_out;
 +      
        std::list<boost::shared_ptr<FilterGraph> > _filter_graphs;
  
        DelayLine* _delay_line;
-       int _delay_in_bytes;
+       int _delay_in_frames;
  
 -      /* Number of audio frames that we have pushed to the encoder
 -         (at the DCP sample rate).
 -      */
 -      int64_t _audio_frames_processed;
 -
        boost::shared_ptr<TimedSubtitle> _timed_subtitle;
  
        boost::shared_ptr<Image> _last_image;

diff --cc src/lib/util.h
Simple merge

diff --cc test/test.cc
Simple merge