text: /* GStreamer
   * Copyright (C) 2008 Sebastian Dröge <slomo@circular-chaos.org>
   *
   * 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.
   */
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  /* FIXME: workaround for SoundTouch.h of version 1.3.1 defining those
   * variables while it shouldn't. */
  #undef VERSION
  #undef PACKAGE_VERSION
  #undef PACKAGE_TARNAME
  #undef PACKAGE_STRING
  #undef PACKAGE_NAME
  #undef PACKAGE_BUGREPORT
  #undef PACKAGE
  
  #include <soundtouch/BPMDetect.h>
  
  #include <gst/audio/audio.h>
  #include <gst/audio/gstaudiofilter.h>
  #include <math.h>
  #include <string.h>
  #include "gstbpmdetect.hh"
  
  GST_DEBUG_CATEGORY_STATIC (gst_bpm_detect_debug);
  #define GST_CAT_DEFAULT gst_bpm_detect_debug
  
  #define GST_BPM_DETECT_GET_PRIVATE(o) (o->priv)
  
  struct _GstBPMDetectPrivate
  {
    gfloat bpm;
  #ifdef HAVE_SOUNDTOUCH_1_4
      soundtouch::BPMDetect * detect;
  #else
    BPMDetect *detect;
  #endif
  };
  
  /* For soundtouch 1.4 */
  #if defined(INTEGER_SAMPLES)
  #define SOUNDTOUCH_INTEGER_SAMPLES 1
  #elif defined(FLOAT_SAMPLES)
  #define SOUNDTOUCH_FLOAT_SAMPLES 1
  #endif
   
  #if defined(SOUNDTOUCH_FLOAT_SAMPLES)
    #define ALLOWED_CAPS \
      "audio/x-raw, " \
        "format = (string) " GST_AUDIO_NE (F32) ", " \
        "rate = (int) [ 8000, MAX ], " \
        "channels = (int) [ 1, 2 ]"
  #elif defined(SOUNDTOUCH_INTEGER_SAMPLES)
    #define ALLOWED_CAPS \
      "audio/x-raw, " \
        "format = (string) " GST_AUDIO_NE (S16) ", " \
        "rate = (int) [ 8000, MAX ], " \
        "channels = (int) [ 1, 2 ]"
  #else
  #error "Only integer or float samples are supported"
  #endif
  
  #define gst_bpm_detect_parent_class parent_class
  G_DEFINE_TYPE_WITH_PRIVATE (GstBPMDetect, gst_bpm_detect, GST_TYPE_AUDIO_FILTER);
  
  static void gst_bpm_detect_finalize (GObject * object);
  static gboolean gst_bpm_detect_stop (GstBaseTransform * trans);
  static gboolean gst_bpm_detect_event (GstBaseTransform * trans,
      GstEvent * event);
  static GstFlowReturn gst_bpm_detect_transform_ip (GstBaseTransform * trans,
      GstBuffer * in);
  static gboolean gst_bpm_detect_setup (GstAudioFilter * filter,
      const GstAudioInfo * info);
  
  static void
  gst_bpm_detect_class_init (GstBPMDetectClass * klass)
  {
    GstCaps *caps;
    GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
    GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
    GstBaseTransformClass *trans_class = GST_BASE_TRANSFORM_CLASS (klass);
    GstAudioFilterClass *filter_class = GST_AUDIO_FILTER_CLASS (klass);
  
    GST_DEBUG_CATEGORY_INIT (gst_bpm_detect_debug, "bpm_detect", 0,
        "audio bpm detection element");
  
    gobject_class->finalize = gst_bpm_detect_finalize;
  
    gst_element_class_set_static_metadata (element_class, "BPM Detector",
        "Filter/Analyzer/Audio", "Detect the BPM of an audio stream",
        "Sebastian Dröge <slomo@circular-chaos.org>");
  
    caps = gst_caps_from_string (ALLOWED_CAPS);
    gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),
        caps);
    gst_caps_unref (caps);
  
    trans_class->stop = GST_DEBUG_FUNCPTR (gst_bpm_detect_stop);
    trans_class->sink_event = GST_DEBUG_FUNCPTR (gst_bpm_detect_event);
    trans_class->transform_ip = GST_DEBUG_FUNCPTR (gst_bpm_detect_transform_ip);
    trans_class->passthrough_on_same_caps = TRUE;
  
    filter_class->setup = GST_DEBUG_FUNCPTR (gst_bpm_detect_setup);
  }
  
  static void
  gst_bpm_detect_init (GstBPMDetect * bpm_detect)
  {
    bpm_detect->priv =
        (GstBPMDetectPrivate *) gst_bpm_detect_get_instance_private (bpm_detect);
    bpm_detect->priv->detect = NULL;
    bpm_detect->bpm = 0.0;
  }
  
  static void
  gst_bpm_detect_finalize (GObject * object)
  {
    GstBPMDetect *bpm_detect = GST_BPM_DETECT (object);
  
    if (bpm_detect->priv->detect) {
      delete bpm_detect->priv->detect;
  
      bpm_detect->priv->detect = NULL;
    }
  
    G_OBJECT_CLASS (parent_class)->finalize (object);
  }
  
  static gboolean
  gst_bpm_detect_stop (GstBaseTransform * trans)
  {
    GstBPMDetect *bpm_detect = GST_BPM_DETECT (trans);
  
    if (bpm_detect->priv->detect) {
      delete bpm_detect->priv->detect;
  
      bpm_detect->priv->detect = NULL;
    }
    bpm_detect->bpm = 0.0;
  
    return TRUE;
  }
  
  static gboolean
  gst_bpm_detect_event (GstBaseTransform * trans, GstEvent * event)
  {
    GstBPMDetect *bpm_detect = GST_BPM_DETECT (trans);
  
    switch (GST_EVENT_TYPE (event)) {
      case GST_EVENT_FLUSH_STOP:
      case GST_EVENT_EOS:
      case GST_EVENT_SEGMENT:
        if (bpm_detect->priv->detect) {
          delete bpm_detect->priv->detect;
  
          bpm_detect->priv->detect = NULL;
        }
        bpm_detect->bpm = 0.0;
        break;
      default:
        break;
    }
  
    return GST_BASE_TRANSFORM_CLASS (parent_class)->sink_event (trans, event);
  }
  
  static gboolean
  gst_bpm_detect_setup (GstAudioFilter * filter, const GstAudioInfo * info)
  {
    GstBPMDetect *bpm_detect = GST_BPM_DETECT (filter);
  
    if (bpm_detect->priv->detect) {
      delete bpm_detect->priv->detect;
  
      bpm_detect->priv->detect = NULL;
    }
  
    return TRUE;
  }
  
  static GstFlowReturn
  gst_bpm_detect_transform_ip (GstBaseTransform * trans, GstBuffer * in)
  {
    GstBPMDetect *bpm_detect = GST_BPM_DETECT (trans);
    GstAudioFilter *filter = GST_AUDIO_FILTER (trans);
    gint nsamples;
    gfloat bpm;
    GstMapInfo info;
  
    if (G_UNLIKELY (!bpm_detect->priv->detect)) {
      if (GST_AUDIO_INFO_FORMAT (&filter->info) == GST_AUDIO_FORMAT_UNKNOWN) {
        GST_ERROR_OBJECT (bpm_detect, "No channels or rate set yet");
        return GST_FLOW_ERROR;
      }
  #ifdef HAVE_SOUNDTOUCH_1_4
      bpm_detect->priv->detect =
          new soundtouch::BPMDetect (GST_AUDIO_INFO_CHANNELS (&filter->info),
          GST_AUDIO_INFO_RATE (&filter->info));
  #else
      bpm_detect->priv->detect =
          new BPMDetect (GST_AUDIO_INFO_CHANNELS (&filter->info),
          GST_AUDIO_INFO_RATE (&filter->info));
  #endif
    }
  
    gst_buffer_map (in, &info, GST_MAP_READ);
  
    nsamples = info.size / (GST_AUDIO_INFO_BPF (&filter->info) * GST_AUDIO_INFO_CHANNELS (&filter->info));
  
    /* For stereo BPMDetect->inputSamples() does downmixing into the input
     * data but our buffer data shouldn't be modified.
     */
    if (GST_AUDIO_INFO_CHANNELS (&filter->info) == 1) {
      soundtouch::SAMPLETYPE *inbuf = (soundtouch::SAMPLETYPE *) info.data;
  
      while (nsamples > 0) {
        bpm_detect->priv->detect->inputSamples (inbuf, MIN (nsamples, 2048));
        nsamples -= 2048;
        inbuf += 2048;
      }
    } else {
      soundtouch::SAMPLETYPE *inbuf, *intmp, data[2 * 2048];
  
      inbuf = (soundtouch::SAMPLETYPE *) info.data;
      intmp = data;
  
      while (nsamples > 0) {
        memcpy (intmp, inbuf, sizeof (soundtouch::SAMPLETYPE) * 2 * MIN (nsamples, 2048));
        bpm_detect->priv->detect->inputSamples (intmp, MIN (nsamples, 2048));
        nsamples -= 2048;
        inbuf += 2048 * 2;
      }
    }
    gst_buffer_unmap (in, &info);
  
    bpm = bpm_detect->priv->detect->getBpm ();
    if (bpm >= 1.0 && fabs (bpm_detect->bpm - bpm) >= 1.0) {
      GstTagList *tags = gst_tag_list_new_empty ();
  
      gst_tag_list_add (tags, GST_TAG_MERGE_REPLACE_ALL, GST_TAG_BEATS_PER_MINUTE,
          bpm, (void *) NULL);
      gst_pad_push_event (trans->srcpad, gst_event_new_tag (tags));
  
      GST_INFO_OBJECT (bpm_detect, "Detected BPM: %lf", bpm);
      bpm_detect->bpm = bpm;
    }
  
    return GST_FLOW_OK;
  }
  