gst/audiofx/: Add new audiofx element "audioinvert". This element swaps the upper and lower half of samples and can b...

Original commit message from CVS:
reviewed by: Stefan Kost  <ensonic@users.sf.net>
* gst/audiofx/Makefile.am:
* gst/audiofx/audiofx.c: (plugin_init):
* gst/audiofx/audioinvert.c: (gst_audio_invert_base_init),
(gst_audio_invert_class_init), (gst_audio_invert_init),
(gst_audio_invert_set_property), (gst_audio_invert_get_property),
(gst_audio_invert_set_caps), (gst_audio_invert_transform_int),
(gst_audio_invert_transform_float),
(gst_audio_invert_transform_ip):
* gst/audiofx/audioinvert.h:
Add new audiofx element "audioinvert". This element swaps the upper
and lower half of samples and can be used for example for a
wide-stereo effect. Fixes #396057
* docs/plugins/Makefile.am:
* docs/plugins/gst-plugins-good-plugins-docs.sgml:
* docs/plugins/gst-plugins-good-plugins-sections.txt:
* docs/plugins/gst-plugins-good-plugins.args:
* docs/plugins/inspect/plugin-audiofx.xml:
Add docs for the audioinvert element and add them to the build system.
* tests/check/Makefile.am:
* tests/check/elements/audioinvert.c: (setup_invert),
(cleanup_invert), (GST_START_TEST), (invert_suite), (main):
Add unit test suite for the audioinvert element.

12 files changed, 690 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 6101ec08..851001a6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,30 @@
+2007-01-23  Sebastian Dröge  <slomo@circular-chaos.org>
+
+	reviewed by: Stefan Kost  <ensonic@users.sf.net>
+
+	* gst/audiofx/Makefile.am:
+	* gst/audiofx/audiofx.c: (plugin_init):
+	* gst/audiofx/audioinvert.c: (gst_audio_invert_base_init),
+	(gst_audio_invert_class_init), (gst_audio_invert_init),
+	(gst_audio_invert_set_property), (gst_audio_invert_get_property),
+	(gst_audio_invert_set_caps), (gst_audio_invert_transform_int),
+	(gst_audio_invert_transform_float),
+	(gst_audio_invert_transform_ip):
+	* gst/audiofx/audioinvert.h:
+	Add new audiofx element "audioinvert". This element swaps the upper
+	and lower half of samples and can be used for example for a
+	wide-stereo effect. Fixes #396057
+	* docs/plugins/Makefile.am:
+	* docs/plugins/gst-plugins-good-plugins-docs.sgml:
+	* docs/plugins/gst-plugins-good-plugins-sections.txt:
+	* docs/plugins/gst-plugins-good-plugins.args:
+	* docs/plugins/inspect/plugin-audiofx.xml:
+	Add docs for the audioinvert element and add them to the build system.
+	* tests/check/Makefile.am:
+	* tests/check/elements/audioinvert.c: (setup_invert),
+	(cleanup_invert), (GST_START_TEST), (invert_suite), (main):
+	Add unit test suite for the audioinvert element.
+
 2007-01-23  Wim Taymans  <wim@fluendo.com>
 
 	* gst/rtp/gstrtpmp4gdepay.c: (gst_rtp_mp4g_depay_parse_int),
diff --git a/docs/plugins/Makefile.am b/docs/plugins/Makefile.am
index 31f3721c..e7746e30 100644
--- a/docs/plugins/Makefile.am
+++ b/docs/plugins/Makefile.am
@@ -76,6 +76,7 @@ IGNORE_CFILES =
 EXTRA_HFILES = \
 	$(top_srcdir)/gst/apetag/gstapedemux.h \
 	$(top_srcdir)/gst/audiofx/audiopanorama.h \
+	$(top_srcdir)/gst/audiofx/audioinvert.h \
 	$(top_srcdir)/gst/autodetect/gstautoaudiosink.h \
 	$(top_srcdir)/gst/autodetect/gstautovideosink.h \
 	$(top_srcdir)/gst/avi/gstavidemux.h \
diff --git a/docs/plugins/gst-plugins-good-plugins-docs.sgml b/docs/plugins/gst-plugins-good-plugins-docs.sgml
index f8f9d0ee..5f7af731 100644
--- a/docs/plugins/gst-plugins-good-plugins-docs.sgml
+++ b/docs/plugins/gst-plugins-good-plugins-docs.sgml
@@ -15,6 +15,7 @@
     <xi:include href="xml/element-apedemux.xml" />
     <xi:include href="xml/element-apev2mux.xml" />
     <xi:include href="xml/element-audiopanorama.xml" />
+    <xi:include href="xml/element-audioinvert.xml" />
     <xi:include href="xml/element-autoaudiosink.xml" />
     <xi:include href="xml/element-autovideosink.xml" />
     <xi:include href="xml/element-avidemux.xml" />
diff --git a/docs/plugins/gst-plugins-good-plugins-sections.txt b/docs/plugins/gst-plugins-good-plugins-sections.txt
index e29b25df..9da8dacf 100644
--- a/docs/plugins/gst-plugins-good-plugins-sections.txt
+++ b/docs/plugins/gst-plugins-good-plugins-sections.txt
@@ -38,6 +38,16 @@ GST_AUDIO_PANORAMA_CLASS
 </SECTION>
 
 <SECTION>
+<FILE>element-audioinvert</FILE>
+GstAudioInvert
+<TITLE>audioinvert</TITLE>
+<SUBSECTION Standard>
+GstAudioInvertClass
+GST_AUDIO_INVERT
+GST_AUDIO_INVERT_CLASS
+</SECTION>
+
+<SECTION>
 <FILE>element-autoaudiosink</FILE>
 GstAutoAudioSink
 <TITLE>autoaudiosink</TITLE>
diff --git a/docs/plugins/gst-plugins-good-plugins.args b/docs/plugins/gst-plugins-good-plugins.args
index 02494ebc..19bc7f5d 100644
--- a/docs/plugins/gst-plugins-good-plugins.args
+++ b/docs/plugins/gst-plugins-good-plugins.args
@@ -16638,3 +16638,13 @@
 <DEFAULT>Psychoacoustic Panning (default)</DEFAULT>
 </ARG>
 
+<ARG>
+<NAME>GstAudioInvert::degree</NAME>
+<TYPE>gfloat</TYPE>
+<RANGE>[0,1]</RANGE>
+<FLAGS>rw</FLAGS>
+<NICK>Degree</NICK>
+<BLURB>Degree of inversion.</BLURB>
+<DEFAULT>0</DEFAULT>
+</ARG>
+
diff --git a/docs/plugins/inspect/plugin-audiofx.xml b/docs/plugins/inspect/plugin-audiofx.xml
index 2ad709e9..54b4926c 100644
--- a/docs/plugins/inspect/plugin-audiofx.xml
+++ b/docs/plugins/inspect/plugin-audiofx.xml
@@ -10,6 +10,13 @@
   <origin>http://gstreamer.net/</origin>
   <elements>
     <element>
+      <name>audioinvert</name>
+      <longname>AudioInvert</longname>
+      <class>Filter/Effect/Audio</class>
+      <description>Swaps upper and lower half of audio samples</description>
+      <author>Sebastian Dröge &lt;slomo@circular-chaos.org&gt;</author>
+    </element>
+    <element>
       <name>audiopanorama</name>
       <longname>AudioPanorama</longname>
       <class>Filter/Effect/Audio</class>
diff --git a/gst/audiofx/Makefile.am b/gst/audiofx/Makefile.am
index 82fc9aa3..0b8be7a9 100644
--- a/gst/audiofx/Makefile.am
+++ b/gst/audiofx/Makefile.am
@@ -4,7 +4,8 @@ plugin_LTLIBRARIES = libgstaudiofx.la
 
 # sources used to compile this plug-in
 libgstaudiofx_la_SOURCES = audiofx.c\
-	audiopanorama.c
+	audiopanorama.c \
+	audioinvert.c
 
 # flags used to compile this plugin
 libgstaudiofx_la_CFLAGS = $(GST_CFLAGS) \
@@ -16,4 +17,5 @@ libgstaudiofx_la_LIBADD = $(GST_LIBS) \
 libgstaudiofx_la_LDFLAGS = $(GST_PLUGIN_LDFLAGS)
 
 # headers we need but don't want installed
-noinst_HEADERS = audiopanorama.h
+noinst_HEADERS = audiopanorama.h \
+	audioinvert.h
diff --git a/gst/audiofx/audiofx.c b/gst/audiofx/audiofx.c
index 907c0545..541aa143 100644
--- a/gst/audiofx/audiofx.c
+++ b/gst/audiofx/audiofx.c
@@ -26,6 +26,7 @@
 #include <gst/controller/gstcontroller.h>
 
 #include "audiopanorama.h"
+#include "audioinvert.h"
 
 /* entry point to initialize the plug-in
  * initialize the plug-in itself
@@ -38,8 +39,10 @@ plugin_init (GstPlugin * plugin)
   /* initialize gst controller library */
   gst_controller_init (NULL, NULL);
 
-  return gst_element_register (plugin, "audiopanorama", GST_RANK_NONE,
-      GST_TYPE_AUDIO_PANORAMA);
+  return (gst_element_register (plugin, "audiopanorama", GST_RANK_NONE,
+          GST_TYPE_AUDIO_PANORAMA) &&
+      gst_element_register (plugin, "audioinvert", GST_RANK_NONE,
+          GST_TYPE_AUDIO_INVERT));
 }
 
 GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
diff --git a/gst/audiofx/audioinvert.c b/gst/audiofx/audioinvert.c
new file mode 100644
index 00000000..3c808552
--- /dev/null
+++ b/gst/audiofx/audioinvert.c
@@ -0,0 +1,278 @@
+/* 
+ * 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
+ * @short_description: Swaps upper and lower half of audio samples
+ *
+ * <refsect2>
+ * 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.
+ * <title>Example launch line</title>
+ * <para>
+ * <programlisting>
+ * 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
+ * </programlisting>
+ * </para>
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <gst/base/gstbasetransform.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 ("AudioInvert",
+    "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
+};
+
+static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw-float, "
+        "rate = (int) [ 1, MAX ], "
+        "channels = (int) [ 1, MAX ], "
+        "endianness = (int) BYTE_ORDER, " "width = (int) 32; "
+        "audio/x-raw-int, "
+        "rate = (int) [ 1, MAX ], "
+        "channels = (int) [ 1, MAX ], "
+        "endianness = (int) BYTE_ORDER, "
+        "width = (int) 16, " "depth = (int) 16, " "signed = (boolean) true")
+    );
+
+static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw-float, "
+        "rate = (int) [ 1, MAX ], "
+        "channels = (int) [ 1, MAX], "
+        "endianness = (int) BYTE_ORDER, " "width = (int) 32; "
+        "audio/x-raw-int, "
+        "rate = (int) [ 1, MAX ], "
+        "channels = (int) [ 1, MAX ], "
+        "endianness = (int) BYTE_ORDER, "
+        "width = (int) 16, " "depth = (int) 16, " "signed = (boolean) true")
+    );
+
+#define DEBUG_INIT(bla) \
+  GST_DEBUG_CATEGORY_INIT (gst_audio_invert_debug, "audioinvert", 0, "audioinvert element");
+
+GST_BOILERPLATE_FULL (GstAudioInvert, gst_audio_invert, GstBaseTransform,
+    GST_TYPE_BASE_TRANSFORM, 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_set_caps (GstBaseTransform * base,
+    GstCaps * incaps, GstCaps * outcaps);
+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);
+
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&src_template));
+  gst_element_class_add_pad_template (element_class,
+      gst_static_pad_template_get (&sink_template));
+  gst_element_class_set_details (element_class, &element_details);
+}
+
+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_BASE_TRANSFORM_CLASS (klass)->set_caps =
+      GST_DEBUG_FUNCPTR (gst_audio_invert_set_caps);
+  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;
+  filter->width = 0;
+  gst_base_transform_set_in_place (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;
+  }
+}
+
+/* GstBaseTransform vmethod implementations */
+
+static gboolean
+gst_audio_invert_set_caps (GstBaseTransform * base, GstCaps * incaps,
+    GstCaps * outcaps)
+{
+  GstAudioInvert *filter = GST_AUDIO_INVERT (base);
+  const GstStructure *structure;
+  gboolean ret;
+  gint width;
+  const gchar *fmt;
+
+  /*GST_INFO ("incaps are %" GST_PTR_FORMAT, incaps); */
+
+  structure = gst_caps_get_structure (incaps, 0);
+
+  ret = gst_structure_get_int (structure, "width", &width);
+  if (!ret)
+    goto no_width;
+  filter->width = width / 8;
+
+
+  fmt = gst_structure_get_name (structure);
+  if (!strcmp (fmt, "audio/x-raw-int"))
+    filter->process = (GstAudioInvertProcessFunc)
+        gst_audio_invert_transform_int;
+  else
+    filter->process = (GstAudioInvertProcessFunc)
+        gst_audio_invert_transform_float;
+
+  return TRUE;
+
+no_width:
+  GST_DEBUG ("no width in caps");
+  return FALSE;
+}
+
+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;
+  }
+}
+
+
+/* this function does the actual processing
+ */
+static GstFlowReturn
+gst_audio_invert_transform_ip (GstBaseTransform * base, GstBuffer * buf)
+{
+  GstAudioInvert *filter = GST_AUDIO_INVERT (base);
+  guint num_samples = GST_BUFFER_SIZE (buf) / filter->width;
+
+  if (!gst_buffer_is_writable (buf))
+    return GST_FLOW_OK;
+
+  filter->process (filter, GST_BUFFER_DATA (buf), num_samples);
+
+  return GST_FLOW_OK;
+}
diff --git a/gst/audiofx/audioinvert.h b/gst/audiofx/audioinvert.h
new file mode 100644
index 00000000..15ac7b3e
--- /dev/null
+++ b/gst/audiofx/audioinvert.h
@@ -0,0 +1,60 @@
+/* 
+ * 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.
+ */
+
+#ifndef __GST_AUDIO_INVERT_H__
+#define __GST_AUDIO_INVERT_H__
+
+#include <gst/gst.h>
+#include <gst/base/gstbasetransform.h>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_AUDIO_INVERT            (gst_audio_invert_get_type())
+#define GST_AUDIO_INVERT(obj)            (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_AUDIO_INVERT,GstAudioInvert))
+#define GST_IS_AUDIO_INVERT(obj)         (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_AUDIO_INVERT))
+#define GST_AUDIO_INVERT_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST((klass) ,GST_TYPE_AUDIO_INVERT,GstAudioInvertClass))
+#define GST_IS_AUDIO_INVERT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass) ,GST_TYPE_AUDIO_INVERT))
+#define GST_AUDIO_INVERT_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS((obj) ,GST_TYPE_AUDIO_INVERT,GstAudioInvertClass))
+
+typedef struct _GstAudioInvert      GstAudioInvert;
+typedef struct _GstAudioInvertClass GstAudioInvertClass;
+
+typedef void (*GstAudioInvertProcessFunc)(GstAudioInvert*, guint8*, guint);
+
+struct _GstAudioInvert {
+  GstBaseTransform element;
+
+  gfloat degree;
+  
+  /* < private > */
+  GstAudioInvertProcessFunc process;
+  gint width;
+};
+
+struct _GstAudioInvertClass {
+  GstBaseTransformClass parent;
+};
+
+GType gst_audio_invert_get_type (void);
+
+G_END_DECLS
+
+#endif /* __GST_AUDIO_INVERT_H__ */
diff --git a/tests/check/Makefile.am b/tests/check/Makefile.am
index 55198e38..9b6fac23 100644
--- a/tests/check/Makefile.am
+++ b/tests/check/Makefile.am
@@ -34,6 +34,7 @@ endif
 check_PROGRAMS = \
 	$(check_annodex) \
 	elements/audiopanorama \
+	elements/audioinvert \
 	elements/avimux \
 	elements/level \
 	elements/matroskamux \
diff --git a/tests/check/elements/audioinvert.c b/tests/check/elements/audioinvert.c
new file mode 100644
index 00000000..ae40ea93
--- /dev/null
+++ b/tests/check/elements/audioinvert.c
@@ -0,0 +1,286 @@
+/* GStreamer
+ *
+ * unit test for audioinvert
+ *
+ * Copyright (C) 2007 Sebastian Dröge <slomo@circular-chaos.org>
+ *
+ * Greatly based on the audiopanorama unit test
+ * 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.
+ */
+
+#include <unistd.h>
+
+#include <gst/base/gstbasetransform.h>
+#include <gst/check/gstcheck.h>
+
+gboolean have_eos = FALSE;
+
+/* For ease of programming we use globals to keep refs for our floating
+ * src and sink pads we create; otherwise we always have to do get_pad,
+ * get_peer, and then remove references in every test function */
+GstPad *mysrcpad, *mysinkpad;
+
+
+#define INVERT_CAPS_STRING    \
+    "audio/x-raw-int, "                 \
+    "channels = (int) 1, "              \
+    "rate = (int) 44100, "              \
+    "endianness = (int) BYTE_ORDER, "   \
+    "width = (int) 16, "                \
+    "depth = (int) 16, "                \
+    "signed = (bool) TRUE"
+
+static GstStaticPadTemplate sinktemplate = GST_STATIC_PAD_TEMPLATE ("sink",
+    GST_PAD_SINK,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw-int, "
+        "channels = (int) 1, "
+        "rate = (int) [ 1,  MAX ], "
+        "endianness = (int) BYTE_ORDER, "
+        "width = (int) 16, " "depth = (int) 16, " "signed = (bool) TRUE")
+    );
+static GstStaticPadTemplate srctemplate = GST_STATIC_PAD_TEMPLATE ("src",
+    GST_PAD_SRC,
+    GST_PAD_ALWAYS,
+    GST_STATIC_CAPS ("audio/x-raw-int, "
+        "channels = (int) 1, "
+        "rate = (int) [ 1,  MAX ], "
+        "endianness = (int) BYTE_ORDER, "
+        "width = (int) 16, " "depth = (int) 16, " "signed = (bool) TRUE")
+    );
+
+GstElement *
+setup_invert ()
+{
+  GstElement *invert;
+
+  GST_DEBUG ("setup_invert");
+  invert = gst_check_setup_element ("audioinvert");
+  mysrcpad = gst_check_setup_src_pad (invert, &srctemplate, NULL);
+  mysinkpad = gst_check_setup_sink_pad (invert, &sinktemplate, NULL);
+  gst_pad_set_active (mysrcpad, TRUE);
+  gst_pad_set_active (mysinkpad, TRUE);
+
+  return invert;
+}
+
+void
+cleanup_invert (GstElement * invert)
+{
+  GST_DEBUG ("cleanup_invert");
+
+  g_list_foreach (buffers, (GFunc) gst_mini_object_unref, NULL);
+  g_list_free (buffers);
+  buffers = NULL;
+
+  gst_pad_set_active (mysrcpad, FALSE);
+  gst_pad_set_active (mysinkpad, FALSE);
+  gst_check_teardown_src_pad (invert);
+  gst_check_teardown_sink_pad (invert);
+  gst_check_teardown_element (invert);
+}
+
+GST_START_TEST (test_passthrough)
+{
+  GstElement *invert;
+  GstBuffer *inbuffer, *outbuffer;
+  GstCaps *caps;
+  gint16 in[4] = { 16384, -256, 128, -512 };
+  gint16 *res;
+
+  invert = setup_invert ();
+  fail_unless (gst_element_set_state (invert,
+          GST_STATE_PLAYING) == GST_STATE_CHANGE_SUCCESS,
+      "could not set to playing");
+
+  inbuffer = gst_buffer_new_and_alloc (8);
+  memcpy (GST_BUFFER_DATA (inbuffer), in, 8);
+  fail_unless (memcmp (GST_BUFFER_DATA (inbuffer), in, 8) == 0);
+  caps = gst_caps_from_string (INVERT_CAPS_STRING);
+  gst_buffer_set_caps (inbuffer, caps);
+  gst_caps_unref (caps);
+  ASSERT_BUFFER_REFCOUNT (inbuffer, "inbuffer", 1);
+
+  /* pushing gives away my reference ... */
+  fail_unless (gst_pad_push (mysrcpad, inbuffer) == GST_FLOW_OK);
+  /* ... but it ends up being collected on the global buffer list */
+  fail_unless_equals_int (g_list_length (buffers), 1);
+  fail_if ((outbuffer = (GstBuffer *) buffers->data) == NULL);
+
+  res = (gint16 *) GST_BUFFER_DATA (outbuffer);
+  GST_INFO ("expected %+5ld %+5ld %+5ld %+5ld real %+5ld %+5ld %+5ld %+5ld",
+      in[0], in[1], in[2], in[3], res[0], res[1], res[2], res[3]);
+  fail_unless (memcmp (GST_BUFFER_DATA (outbuffer), in, 8) == 0);
+
+  /* cleanup */
+  cleanup_invert (invert);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_zero)
+{
+  GstElement *invert;
+  GstBuffer *inbuffer, *outbuffer;
+  GstCaps *caps;
+  gint16 in[4] = { 16384, -256, 128, -512 };
+  gint16 out[4] = { 0, 0, 0, 0 };
+  gint16 *res;
+
+  invert = setup_invert ();
+  g_object_set (G_OBJECT (invert), "degree", 0.5, NULL);
+  fail_unless (gst_element_set_state (invert,
+          GST_STATE_PLAYING) == GST_STATE_CHANGE_SUCCESS,
+      "could not set to playing");
+
+  inbuffer = gst_buffer_new_and_alloc (8);
+  memcpy (GST_BUFFER_DATA (inbuffer), in, 8);
+  fail_unless (memcmp (GST_BUFFER_DATA (inbuffer), in, 8) == 0);
+  caps = gst_caps_from_string (INVERT_CAPS_STRING);
+  gst_buffer_set_caps (inbuffer, caps);
+  gst_caps_unref (caps);
+  ASSERT_BUFFER_REFCOUNT (inbuffer, "inbuffer", 1);
+
+  /* pushing gives away my reference ... */
+  fail_unless (gst_pad_push (mysrcpad, inbuffer) == GST_FLOW_OK);
+  /* ... and puts a new buffer on the global list */
+  fail_unless_equals_int (g_list_length (buffers), 1);
+  fail_if ((outbuffer = (GstBuffer *) buffers->data) == NULL);
+
+  res = (gint16 *) GST_BUFFER_DATA (outbuffer);
+  GST_INFO ("expected %+5ld %+5ld %+5ld %+5ld real %+5ld %+5ld %+5ld %+5ld",
+      out[0], out[1], out[2], out[3], res[0], res[1], res[2], res[3]);
+  fail_unless (memcmp (GST_BUFFER_DATA (outbuffer), out, 8) == 0);
+
+  /* cleanup */
+  cleanup_invert (invert);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_full_inverse)
+{
+  GstElement *invert;
+  GstBuffer *inbuffer, *outbuffer;
+  GstCaps *caps;
+  gint16 in[4] = { 16384, -256, 128, -512 };
+  gint16 out[4] = { -16385, 255, -129, 511 };
+  gint16 *res;
+
+  invert = setup_invert ();
+  g_object_set (G_OBJECT (invert), "degree", 1.0, NULL);
+  fail_unless (gst_element_set_state (invert,
+          GST_STATE_PLAYING) == GST_STATE_CHANGE_SUCCESS,
+      "could not set to playing");
+
+  inbuffer = gst_buffer_new_and_alloc (8);
+  memcpy (GST_BUFFER_DATA (inbuffer), in, 8);
+  fail_unless (memcmp (GST_BUFFER_DATA (inbuffer), in, 8) == 0);
+  caps = gst_caps_from_string (INVERT_CAPS_STRING);
+  gst_buffer_set_caps (inbuffer, caps);
+  gst_caps_unref (caps);
+  ASSERT_BUFFER_REFCOUNT (inbuffer, "inbuffer", 1);
+
+  /* pushing gives away my reference ... */
+  fail_unless (gst_pad_push (mysrcpad, inbuffer) == GST_FLOW_OK);
+  /* ... and puts a new buffer on the global list */
+  fail_unless_equals_int (g_list_length (buffers), 1);
+  fail_if ((outbuffer = (GstBuffer *) buffers->data) == NULL);
+
+  res = (gint16 *) GST_BUFFER_DATA (outbuffer);
+  GST_INFO ("expected %+5ld %+5ld %+5ld %+5ld real %+5ld %+5ld %+5ld %+5ld",
+      out[0], out[1], out[2], out[3], res[0], res[1], res[2], res[3]);
+  fail_unless (memcmp (GST_BUFFER_DATA (outbuffer), out, 8) == 0);
+
+  /* cleanup */
+  cleanup_invert (invert);
+}
+
+GST_END_TEST;
+
+GST_START_TEST (test_25_inverse)
+{
+  GstElement *invert;
+  GstBuffer *inbuffer, *outbuffer;
+  GstCaps *caps;
+  gint16 in[4] = { 16384, -256, 128, -512 };
+  gint16 out[4] = { 8191, -128, 63, -256 };
+  gint16 *res;
+
+  invert = setup_invert ();
+  g_object_set (G_OBJECT (invert), "degree", 0.25, NULL);
+  fail_unless (gst_element_set_state (invert,
+          GST_STATE_PLAYING) == GST_STATE_CHANGE_SUCCESS,
+      "could not set to playing");
+
+  inbuffer = gst_buffer_new_and_alloc (8);
+  memcpy (GST_BUFFER_DATA (inbuffer), in, 8);
+  fail_unless (memcmp (GST_BUFFER_DATA (inbuffer), in, 8) == 0);
+  caps = gst_caps_from_string (INVERT_CAPS_STRING);
+  gst_buffer_set_caps (inbuffer, caps);
+  gst_caps_unref (caps);
+  ASSERT_BUFFER_REFCOUNT (inbuffer, "inbuffer", 1);
+
+  /* pushing gives away my reference ... */
+  fail_unless (gst_pad_push (mysrcpad, inbuffer) == GST_FLOW_OK);
+  /* ... and puts a new buffer on the global list */
+  fail_unless_equals_int (g_list_length (buffers), 1);
+  fail_if ((outbuffer = (GstBuffer *) buffers->data) == NULL);
+
+  res = (gint16 *) GST_BUFFER_DATA (outbuffer);
+  GST_INFO ("expected %+5ld %+5ld %+5ld %+5ld real %+5ld %+5ld %+5ld %+5ld",
+      out[0], out[1], out[2], out[3], res[0], res[1], res[2], res[3]);
+  fail_unless (memcmp (GST_BUFFER_DATA (outbuffer), out, 8) == 0);
+
+  /* cleanup */
+  cleanup_invert (invert);
+}
+
+GST_END_TEST;
+
+Suite *
+invert_suite (void)
+{
+  Suite *s = suite_create ("invert");
+  TCase *tc_chain = tcase_create ("general");
+
+  suite_add_tcase (s, tc_chain);
+  tcase_add_test (tc_chain, test_passthrough);
+  tcase_add_test (tc_chain, test_zero);
+  tcase_add_test (tc_chain, test_full_inverse);
+  tcase_add_test (tc_chain, test_25_inverse);
+
+  return s;
+}
+
+int
+main (int argc, char **argv)
+{
+  int nf;
+
+  Suite *s = invert_suite ();
+  SRunner *sr = srunner_create (s);
+
+  gst_check_init (&argc, &argv);
+
+  srunner_run_all (sr, CK_NORMAL);
+  nf = srunner_ntests_failed (sr);
+  srunner_free (sr);
+
+  return nf;
+}