1 /* 

     2  * GStreamer

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

     4  * Copyright (C) 2006 Stefan Kost <ensonic@users.sf.net>

     5  *

     6  * This library is free software; you can redistribute it and/or

     7  * modify it under the terms of the GNU Library General Public

     8  * License as published by the Free Software Foundation; either

     9  * version 2 of the License, or (at your option) any later version.

    10  *

    11  * This library is distributed in the hope that it will be useful,

    12  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    14  * Library General Public License for more details.

    15  *

    16  * You should have received a copy of the GNU Library General Public

    17  * License along with this library; if not, write to the

    18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

    19  * Boston, MA 02111-1307, USA.

    20  */

    21 

    22 /**

    23  * SECTION:element-audioinvert

    24  *

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

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

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

    28  *

    29  * <refsect2>

    30  * <title>Example launch line</title>

    31  * |[

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

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

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

    35  * ]|

    36  * </refsect2>

    37  */

    38 

    39 #ifdef HAVE_CONFIG_H

    40 #include "config.h"

    41 #endif

    42 

    43 #include <gst/gst.h>

    44 #include <gst/base/gstbasetransform.h>

    45 #include <gst/audio/audio.h>

    46 #include <gst/audio/gstaudiofilter.h>

    47 #include <gst/controller/gstcontroller.h>

    48 

    49 #include "audioinvert.h"

    50 

    51 #define GST_CAT_DEFAULT gst_audio_invert_debug

    52 GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT);

    53 

    54 static const GstElementDetails element_details =

    55 GST_ELEMENT_DETAILS ("Audio inversion",

    56     "Filter/Effect/Audio",

    57     "Swaps upper and lower half of audio samples",

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

    59 

    60 /* Filter signals and args */

    61 enum

    62 {

    63   /* FILL ME */

    64   LAST_SIGNAL

    65 };

    66 

    67 enum

    68 {

    69   PROP_0,

    70   PROP_DEGREE

    71 };

    72 

    73 #define ALLOWED_CAPS \

    74     "audio/x-raw-int,"                                                \

    75     " depth=(int)16,"                                                 \

    76     " width=(int)16,"                                                 \

    77     " endianness=(int)BYTE_ORDER,"                                    \

    78     " signed=(bool)TRUE,"                                             \

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

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

    81     "audio/x-raw-float,"                                              \

    82     " width=(int)32,"                                                 \

    83     " endianness=(int)BYTE_ORDER,"                                    \

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

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

    86 

    87 #define DEBUG_INIT(bla) \

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

    89 

    90 GST_BOILERPLATE_FULL (GstAudioInvert, gst_audio_invert, GstAudioFilter,

    91     GST_TYPE_AUDIO_FILTER, DEBUG_INIT);

    92 

    93 static void gst_audio_invert_set_property (GObject * object, guint prop_id,

    94     const GValue * value, GParamSpec * pspec);

    95 static void gst_audio_invert_get_property (GObject * object, guint prop_id,

    96     GValue * value, GParamSpec * pspec);

    97 

    98 static gboolean gst_audio_invert_setup (GstAudioFilter * filter,

    99     GstRingBufferSpec * format);

   100 static GstFlowReturn gst_audio_invert_transform_ip (GstBaseTransform * base,

   101     GstBuffer * buf);

   102 

   103 static void gst_audio_invert_transform_int (GstAudioInvert * filter,

   104     gint16 * data, guint num_samples);

   105 static void gst_audio_invert_transform_float (GstAudioInvert * filter,

   106     gfloat * data, guint num_samples);

   107 

   108 /* GObject vmethod implementations */

   109 

   110 static void

   111 gst_audio_invert_base_init (gpointer klass)

   112 {

   113   GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

   114   GstCaps *caps;

   115 

   116   gst_element_class_set_details (element_class, &element_details);

   117 

   118   caps = gst_caps_from_string (ALLOWED_CAPS);

   119   gst_audio_filter_class_add_pad_templates (GST_AUDIO_FILTER_CLASS (klass),

   120       caps);

   121   gst_caps_unref (caps);

   122 }

   123 

   124 static void

   125 gst_audio_invert_class_init (GstAudioInvertClass * klass)

   126 {

   127   GObjectClass *gobject_class;

   128 

   129   gobject_class = (GObjectClass *) klass;

   130   gobject_class->set_property = gst_audio_invert_set_property;

   131   gobject_class->get_property = gst_audio_invert_get_property;

   132 

   133   g_object_class_install_property (gobject_class, PROP_DEGREE,

   134       g_param_spec_float ("degree", "Degree",

   135           "Degree of inversion", 0.0, 1.0,

   136           0.0, G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));

   137 

   138   GST_AUDIO_FILTER_CLASS (klass)->setup =

   139       GST_DEBUG_FUNCPTR (gst_audio_invert_setup);

   140   GST_BASE_TRANSFORM_CLASS (klass)->transform_ip =

   141       GST_DEBUG_FUNCPTR (gst_audio_invert_transform_ip);

   142 }

   143 

   144 static void

   145 gst_audio_invert_init (GstAudioInvert * filter, GstAudioInvertClass * klass)

   146 {

   147   filter->degree = 0.0;

   148   gst_base_transform_set_in_place (GST_BASE_TRANSFORM (filter), TRUE);

   149   gst_base_transform_set_gap_aware (GST_BASE_TRANSFORM (filter), TRUE);

   150 }

   151 

   152 static void

   153 gst_audio_invert_set_property (GObject * object, guint prop_id,

   154     const GValue * value, GParamSpec * pspec)

   155 {

   156   GstAudioInvert *filter = GST_AUDIO_INVERT (object);

   157 

   158   switch (prop_id) {

   159     case PROP_DEGREE:

   160       filter->degree = g_value_get_float (value);

   161       gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (filter),

   162           filter->degree == 0.0);

   163       break;

   164     default:

   165       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

   166       break;

   167   }

   168 }

   169 

   170 static void

   171 gst_audio_invert_get_property (GObject * object, guint prop_id,

   172     GValue * value, GParamSpec * pspec)

   173 {

   174   GstAudioInvert *filter = GST_AUDIO_INVERT (object);

   175 

   176   switch (prop_id) {

   177     case PROP_DEGREE:

   178       g_value_set_float (value, filter->degree);

   179       break;

   180     default:

   181       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

   182       break;

   183   }

   184 }

   185 

   186 /* GstAudioFilter vmethod implementations */

   187 

   188 static gboolean

   189 gst_audio_invert_setup (GstAudioFilter * base, GstRingBufferSpec * format)

   190 {

   191   GstAudioInvert *filter = GST_AUDIO_INVERT (base);

   192   gboolean ret = TRUE;

   193 

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

   195     filter->process = (GstAudioInvertProcessFunc)

   196         gst_audio_invert_transform_float;

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

   198     filter->process = (GstAudioInvertProcessFunc)

   199         gst_audio_invert_transform_int;

   200   else

   201     ret = FALSE;

   202 

   203   return ret;

   204 }

   205 

   206 static void

   207 gst_audio_invert_transform_int (GstAudioInvert * filter,

   208     gint16 * data, guint num_samples)

   209 {

   210   gint i;

   211   gfloat dry = 1.0 - filter->degree;

   212   glong val;

   213 

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

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

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

   217   }

   218 }

   219 

   220 static void

   221 gst_audio_invert_transform_float (GstAudioInvert * filter,

   222     gfloat * data, guint num_samples)

   223 {

   224   gint i;

   225   gfloat dry = 1.0 - filter->degree;

   226   glong val;

   227 

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

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

   230     *data++ = val;

   231   }

   232 }

   233 

   234 /* GstBaseTransform vmethod implementations */

   235 static GstFlowReturn

   236 gst_audio_invert_transform_ip (GstBaseTransform * base, GstBuffer * buf)

   237 {

   238   GstAudioInvert *filter = GST_AUDIO_INVERT (base);

   239   guint num_samples =

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

   241 

   242   if (GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buf)))

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

   244 

   245   if (gst_base_transform_is_passthrough (base) ||

   246       G_UNLIKELY (GST_BUFFER_FLAG_IS_SET (buf, GST_BUFFER_FLAG_GAP)))

   247     return GST_FLOW_OK;

   248 

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

   250 

   251   return GST_FLOW_OK;

   252 }