/* 

 * GStreamer

 * Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>

 * Copyright (C) 2006 Stefan Kost <ensonic@users.sf.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., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/**

 * SECTION:element-audioinvert

 *

 * Swaps upper and lower half of audio samples. Mixing an inverted sample on top of

 * the original with a slight delay can produce effects that sound like resonance.

 * Creating a stereo sample from a mono source, with one channel inverted produces wide-stereo sounds.

 *

 * <refsect2>

 * <title>Example launch line</title>

 * |[

 * gst-launch audiotestsrc wave=saw ! audioinvert invert=0.4 ! alsasink

 * gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audioinvert invert=0.4 ! alsasink

 * gst-launch audiotestsrc wave=saw ! audioconvert ! audioinvert invert=0.4 ! audioconvert ! alsasink

 * ]|

 * </refsect2>

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <gst/gst.h>

#include <gst/base/gstbasetransform.h>

#include <gst/audio/audio.h>

#include <gst/audio/gstaudiofilter.h>

#include <gst/controller/gstcontroller.h>

#include "audioinvert.h"

#define GST_CAT_DEFAULT gst_audio_invert_debug

GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

static const GstElementDetails element_details =

GST_ELEMENT_DETAILS ("Audio inversion",

    "Filter/Effect/Audio",

    "Swaps upper and lower half of audio samples",

    "Sebastian Dröge <slomo@circular-chaos.org>");

/* Filter signals and args */

enum

{

  /* FILL ME */

  LAST_SIGNAL

};

enum

{

  PROP_0,

  PROP_DEGREE

};

#define ALLOWED_CAPS \

    "audio/x-raw-int,"                                                \

    " depth=(int)16,"                                                 \

    " width=(int)16,"                                                 \

    " endianness=(int)BYTE_ORDER,"                                    \

    " signed=(bool)TRUE,"                                             \

    " rate=(int)[1,MAX],"                                             \

    " channels=(int)[1,MAX]; "                                        \

    "audio/x-raw-float,"                                              \

    " width=(int)32,"                                                 \

    " endianness=(int)BYTE_ORDER,"                                    \

    " rate=(int)[1,MAX],"                                             \

    " channels=(int)[1,MAX]"

#define DEBUG_INIT(bla) \

  GST_DEBUG_CATEGORY_INIT (gst_audio_invert_debug, "audioinvert", 0, "audioinvert element");

GST_BOILERPLATE_FULL (GstAudioInvert, gst_audio_invert, GstAudioFilter,

    GST_TYPE_AUDIO_FILTER, DEBUG_INIT);

static void gst_audio_invert_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec);

static void gst_audio_invert_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec);

static gboolean gst_audio_invert_setup (GstAudioFilter * filter,

    GstRingBufferSpec * format);

static GstFlowReturn gst_audio_invert_transform_ip (GstBaseTransform * base,

    GstBuffer * buf);

static void gst_audio_invert_transform_int (GstAudioInvert * filter,

    gint16 * data, guint num_samples);

static void gst_audio_invert_transform_float (GstAudioInvert * filter,

    gfloat * data, guint num_samples);

/* GObject vmethod implementations */

static void

gst_audio_invert_base_init (gpointer klass)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  GstCaps *caps;

  gst_element_class_set_details (element_class, &element_details);

  caps = gst_caps_from_string (ALLOWED_CAPS);

  gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),

      caps);

  gst_caps_unref (caps);

}

static void

gst_audio_invert_class_init (GstAudioInvertClass * klass)

{

  GObjectClass *gobject_class;

  gobject_class = (GObjectClass *) klass;

  gobject_class->set_property = gst_audio_invert_set_property;

  gobject_class->get_property = gst_audio_invert_get_property;

  g_object_class_install_property (gobject_class, PROP_DEGREE,

      g_param_spec_float ("degree", "Degree",

          "Degree of inversion", 0.0, 1.0,

          0.0, G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));

  GST_AUDIO_FILTER_CLASS (klass)->setup =

      GST_DEBUG_FUNCPTR (gst_audio_invert_setup);

  GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =

      GST_DEBUG_FUNCPTR (gst_audio_invert_transform_ip);

}

static void

gst_audio_invert_init (GstAudioInvert * filter, GstAudioInvertClass * klass)

{

  filter->degree = 0.0;

  gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);

  gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (filter), TRUE);

}

static void

gst_audio_invert_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec)

{

  GstAudioInvert *filter = GST_AUDIO_INVERT (object);

  switch (prop_id) {

    case PROP_DEGREE:

      filter->degree = g_value_get_float (value);

      gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (filter),

          filter->degree == 0.0);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

static void

gst_audio_invert_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec)

{

  GstAudioInvert *filter = GST_AUDIO_INVERT (object);

  switch (prop_id) {

    case PROP_DEGREE:

      g_value_set_float (value, filter->degree);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

/* GstAudioFilter vmethod implementations */

static gboolean

gst_audio_invert_setup (GstAudioFilter * base, GstRingBufferSpec * format)

{

  GstAudioInvert *filter = GST_AUDIO_INVERT (base);

  gboolean ret = TRUE;

  if (format->type == GST_BUFTYPE_FLOAT && format->width == 32)

    filter->process = (GstAudioInvertProcessFunc)

        gst_audio_invert_transform_float;

  else if (format->type == GST_BUFTYPE_LINEAR && format->width == 16)

    filter->process = (GstAudioInvertProcessFunc)

        gst_audio_invert_transform_int;

  else

    ret = FALSE;

  return ret;

}

static void

gst_audio_invert_transform_int (GstAudioInvert * filter,

    gint16 * data, guint num_samples)

{

  gint i;

  gfloat dry = 1.0 - filter->degree;

  glong val;

  for (i = 0; i < num_samples; i++) {

    val = (*data) * dry + (-1 - (*data)) * filter->degree;

    *data++ = (gint16) CLAMP (val, G_MININT16, G_MAXINT16);

  }

}

static void

gst_audio_invert_transform_float (GstAudioInvert * filter,

    gfloat * data, guint num_samples)

{

  gint i;

  gfloat dry = 1.0 - filter->degree;

  glong val;

  for (i = 0; i < num_samples; i++) {

    val = (*data) * dry - (*data) * filter->degree;

    *data++ = val;

  }

}

/* GstBaseTransform vmethod implementations */

static GstFlowReturn

gst_audio_invert_transform_ip (GstBaseTransform * base, GstBuffer * buf)

{

  GstAudioInvert *filter = GST_AUDIO_INVERT (base);

  guint num_samples =

      GST_BUFFER_SIZE (buf) / (GST_AUDIO_FILTER (filter)->format.width / 8);

  if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buf)))

    gst_object_sync_values (G_OBJECT (filter), GST_BUFFER_TIMESTAMP (buf));

  if (gst_base_transform_is_passthrough (base) ||

      G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))

    return GST_FLOW_OK;

  filter->process (filter, GST_BUFFER_DATA (buf), num_samples);

  return GST_FLOW_OK;

}