Refactoring

src/engine/gstfastspectrum.h

@@ -0,0 +1,91 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ * Copyright (C) <2009> Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ * Copyright (C) <2018-2024> Jonas Kvinge <jonas@jkvinge.net>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+// Adapted from gstspectrum for Clementine with the following changes:
+//   - Uses fftw instead of kiss fft (2x faster).
+//   - Hardcoded to 1 channel (use an audioconvert element to do the work
+//     instead, simplifies this code a lot).
+//   - Send output via a callback instead of GST messages (less overhead).
+//   - Removed all properties except interval and band.
+
+#ifndef GST_STRAWBERRY_FASTSPECTRUM_H
+#define GST_STRAWBERRY_FASTSPECTRUM_H
+
+#include <functional>
+
+#include <gst/gst.h>
+#include <gst/audio/gstaudiofilter.h>
+#include <fftw3.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_STRAWBERRY_FASTSPECTRUM            (gst_strawberry_fastspectrum_get_type())
+#define GST_STRAWBERRY_FASTSPECTRUM(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj), GST_TYPE_FASTSPECTRUM, GstStrawberryFastSpectrum))
+#define GST_IS_STRAWBERRY_FASTSPECTRUM(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj), GST_TYPE_FASTSPECTRUM))
+#define GST_STRAWBERRY_FASTSPECTRUM_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass), GST_TYPE_FASTSPECTRUM, GstStrawberryFastSpectrumClass))
+#define GST_IS_STRAWBERRY_FASTSPECTRUM_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass), GST_TYPE_FASTSPECTRUM))
+
+typedef void (*GstStrawberryFastSpectrumInputData)(const guint8 *in, double *out, guint64 len, double max_value, guint op, guint nfft);
+
+using GstStrawberryFastSpectrumOutputCallback = std::function<void(double *magnitudes, int size)>;
+
+struct GstStrawberryFastSpectrum {
+  GstAudioFilter parent;
+
+  // Properties
+  guint64 interval;            // How many nanoseconds between emits
+  guint64 frames_per_interval; // How many frames per interval
+  guint64 frames_todo;
+  guint bands;                 // Number of spectrum bands
+  gboolean multi_channel;      // Send separate channel results
+
+  guint64 num_frames;          // Frame count (1 sample per channel) since last emit
+  guint64 num_fft;             // Number of FFTs since last emit
+  GstClockTime message_ts;     // Starttime for next message
+
+  // <private>
+  bool channel_data_initialized;
+  double *input_ring_buffer;
+  double *fft_input;
+  fftw_complex *fft_output;
+  double *spect_magnitude;
+  fftw_plan plan;
+
+  guint input_pos;
+  guint64 error_per_interval;
+  guint64 accumulated_error;
+
+  GMutex lock;
+
+  GstStrawberryFastSpectrumInputData input_data;
+  GstStrawberryFastSpectrumOutputCallback output_callback;
+};
+
+struct GstStrawberryFastSpectrumClass {
+  GstAudioFilterClass parent_class;
+  GMutex fftw_lock;
+};
+
+GType gst_strawberry_fastspectrum_get_type(void);
+
+G_END_DECLS
+
+#endif  // GST_STRAWBERRY_FASTSPECTRUM_H