Small optimisations to audio analysis.

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

diff --git a/src/lib/analyse_audio_job.cc b/src/lib/analyse_audio_job.cc
index 0660d8f2027b79c4a19ff160ccdf1ae4b3dbd5a7..164c57b14ab9eef984e71f59886d560e12f962ff 100644 (file)
--- a/src/lib/analyse_audio_job.cc
+++ b/src/lib/analyse_audio_job.cc
@@ -43,12 +43,18 @@ AnalyseAudioJob::AnalyseAudioJob (shared_ptr<const Film> film, shared_ptr<const
        , _playlist (playlist)
        , _done (0)
        , _samples_per_point (1)
+       , _current (0)
        , _overall_peak (0)
        , _overall_peak_frame (0)
 {
 
 }
 
+AnalyseAudioJob::~AnalyseAudioJob ()
+{
+       delete[] _current;
+}
+
 string
 AnalyseAudioJob::name () const
 {
@@ -70,7 +76,8 @@ AnalyseAudioJob::run ()
        int64_t const len = _playlist->length().frames_round (_film->audio_frame_rate());
        _samples_per_point = max (int64_t (1), len / _num_points);
 
-       _current.resize (_film->audio_channels ());
+       delete[] _current;
+       _current = new AudioPoint[_film->audio_channels ()];
        _analysis.reset (new AudioAnalysis (_film->audio_channels ()));
 
        bool has_any_audio = false;
@@ -109,19 +116,19 @@ AnalyseAudioJob::run ()
 void
 AnalyseAudioJob::analyse (shared_ptr<const AudioBuffers> b)
 {
-       for (int i = 0; i < b->frames(); ++i) {
-               for (int j = 0; j < b->channels(); ++j) {
+       int const frames = b->frames ();
+       int const channels = b->channels ();
+
+       for (int i = 0; i < frames; ++i) {
+               for (int j = 0; j < channels; ++j) {
                        float s = b->data(j)[i];
-                       if (fabsf (s) < 10e-7) {
+                       float as = fabsf (s);
+                       if (as < 10e-7) {
                                /* SafeStringStream can't serialise and recover inf or -inf, so prevent such
                                   values by replacing with this (140dB down) */
-                               s = 10e-7;
+                               s = as = 10e-7;
                        }
                        _current[j][AudioPoint::RMS] += pow (s, 2);
-                       _current[j][AudioPoint::PEAK] = max (_current[j][AudioPoint::PEAK], fabsf (s));
-
-                       float const as = fabs (s);
-
                        _current[j][AudioPoint::PEAK] = max (_current[j][AudioPoint::PEAK], as);
 
                        if (as > _overall_peak) {
@@ -132,7 +139,6 @@ AnalyseAudioJob::analyse (shared_ptr<const AudioBuffers> b)
                        if ((_done % _samples_per_point) == 0) {
                                _current[j][AudioPoint::RMS] = sqrt (_current[j][AudioPoint::RMS] / _samples_per_point);
                                _analysis->add_point (j, _current[j]);
-
                                _current[j] = AudioPoint ();
                        }
                }