2 * Copyright (C) 2004 Benjamin Otte <otte@gnome.org>
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Library General Public License for more details.
14 * You should have received a copy of the GNU Library General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
20 * SECTION:element-breakmydata
22 * This element modifies the contents of the buffer it is passed randomly
23 * according to the parameters set.
24 * It otherwise acts as an identity.
32 #include <gst/base/gstbasetransform.h>
34 GST_DEBUG_CATEGORY_STATIC (gst_break_my_data_debug);
35 #define GST_CAT_DEFAULT gst_break_my_data_debug
37 #define GST_TYPE_BREAK_MY_DATA \
38 (gst_break_my_data_get_type())
39 #define GST_BREAK_MY_DATA(obj) \
40 (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BREAK_MY_DATA,GstBreakMyData))
41 #define GST_BREAK_MY_DATA_CLASS(klass) \
42 (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BREAK_MY_DATA,GstBreakMyDataClass))
43 #define GST_IS_BREAK_MY_DATA(obj) \
44 (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BREAK_MY_DATA))
45 #define GST_IS_BREAK_MY_DATA_CLASS(klass) \
46 (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BREAK_MY_DATA))
57 typedef struct _GstBreakMyData GstBreakMyData;
58 typedef struct _GstBreakMyDataClass GstBreakMyDataClass;
60 struct _GstBreakMyData
62 GstBaseTransform basetransform;
73 struct _GstBreakMyDataClass
75 GstBaseTransformClass parent_class;
78 static void gst_break_my_data_set_property (GObject * object,
79 guint prop_id, const GValue * value, GParamSpec * pspec);
80 static void gst_break_my_data_get_property (GObject * object,
81 guint prop_id, GValue * value, GParamSpec * pspec);
83 static GstFlowReturn gst_break_my_data_transform_ip (GstBaseTransform * trans,
85 static gboolean gst_break_my_data_stop (GstBaseTransform * trans);
86 static gboolean gst_break_my_data_start (GstBaseTransform * trans);
88 static const GstElementDetails details = GST_ELEMENT_DETAILS ("Break my data",
90 "randomly change data in the stream",
91 "Benjamin Otte <otte@gnome>");
93 GstStaticPadTemplate bmd_src_template = GST_STATIC_PAD_TEMPLATE ("src",
98 GstStaticPadTemplate bmd_sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
101 GST_STATIC_CAPS_ANY);
103 GST_BOILERPLATE (GstBreakMyData, gst_break_my_data, GstBaseTransform,
104 GST_TYPE_BASE_TRANSFORM);
107 gst_break_my_data_base_init (gpointer g_class)
109 GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
111 gst_element_class_add_pad_template (gstelement_class,
112 gst_static_pad_template_get (&bmd_sink_template));
113 gst_element_class_add_pad_template (gstelement_class,
114 gst_static_pad_template_get (&bmd_src_template));
116 gst_element_class_set_details (gstelement_class, &details);
120 gst_break_my_data_class_init (GstBreakMyDataClass * klass)
122 GstBaseTransformClass *gstbasetrans_class;
123 GObjectClass *gobject_class;
125 gobject_class = G_OBJECT_CLASS (klass);
126 gstbasetrans_class = GST_BASE_TRANSFORM_CLASS (klass);
128 gobject_class->set_property =
129 GST_DEBUG_FUNCPTR (gst_break_my_data_set_property);
130 gobject_class->get_property =
131 GST_DEBUG_FUNCPTR (gst_break_my_data_get_property);
133 g_object_class_install_property (gobject_class, ARG_SEED,
134 g_param_spec_uint ("seed", "seed",
135 "seed for randomness (initialized when going from READY to PAUSED)",
136 0, G_MAXUINT32, 0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
137 g_object_class_install_property (gobject_class, ARG_SET_TO,
138 g_param_spec_int ("set-to", "set-to",
139 "set changed bytes to this value (-1 means random value",
140 -1, G_MAXUINT8, -1, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
141 g_object_class_install_property (gobject_class, ARG_SKIP,
142 g_param_spec_uint ("skip", "skip",
143 "amount of bytes skipped at the beginning of stream",
144 0, G_MAXUINT, 0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
145 g_object_class_install_property (gobject_class, ARG_PROBABILITY,
146 g_param_spec_double ("probability", "probability",
147 "probability for each byte in the buffer to be changed", 0.0, 1.0,
148 0.0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
150 gstbasetrans_class->transform_ip =
151 GST_DEBUG_FUNCPTR (gst_break_my_data_transform_ip);
152 gstbasetrans_class->start = GST_DEBUG_FUNCPTR (gst_break_my_data_start);
153 gstbasetrans_class->stop = GST_DEBUG_FUNCPTR (gst_break_my_data_stop);
157 gst_break_my_data_init (GstBreakMyData * bmd, GstBreakMyDataClass * g_class)
159 gst_base_transform_set_in_place (GST_BASE_TRANSFORM (bmd), TRUE);
160 gst_base_transform_set_passthrough (GST_BASE_TRANSFORM (bmd), TRUE);
164 gst_break_my_data_set_property (GObject * object, guint prop_id,
165 const GValue * value, GParamSpec * pspec)
167 GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);
169 GST_OBJECT_LOCK (bmd);
173 bmd->seed = g_value_get_uint (value);
176 bmd->set = g_value_get_int (value);
179 bmd->skip = g_value_get_uint (value);
181 case ARG_PROBABILITY:
182 bmd->probability = g_value_get_double (value);
185 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
189 GST_OBJECT_UNLOCK (bmd);
193 gst_break_my_data_get_property (GObject * object, guint prop_id, GValue * value,
196 GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);
198 GST_OBJECT_LOCK (bmd);
202 g_value_set_uint (value, bmd->seed);
205 g_value_set_int (value, bmd->set);
208 g_value_set_uint (value, bmd->skip);
210 case ARG_PROBABILITY:
211 g_value_set_double (value, bmd->probability);
214 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
218 GST_OBJECT_UNLOCK (bmd);
222 gst_break_my_data_transform_ip (GstBaseTransform * trans, GstBuffer * buf)
224 GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);
227 g_return_val_if_fail (gst_buffer_is_writable (buf), GST_FLOW_ERROR);
229 GST_OBJECT_LOCK (bmd);
231 if (bmd->skipped < bmd->skip) {
232 i = bmd->skip - bmd->skipped;
237 size = GST_BUFFER_SIZE (buf);
240 "got buffer %p (size %u, timestamp %" G_GUINT64_FORMAT ", offset %"
241 G_GUINT64_FORMAT "", buf, size, GST_BUFFER_TIMESTAMP (buf),
242 GST_BUFFER_OFFSET (buf));
244 for (; i < size; i++) {
245 if (g_rand_double_range (bmd->rand, 0, 1.0) <= bmd->probability) {
249 new = g_rand_int_range (bmd->rand, 0, 256);
253 GST_INFO_OBJECT (bmd, "changing byte %u from 0x%02X to 0x%02X", i,
254 (guint) GST_READ_UINT8 (GST_BUFFER_DATA (buf) + i),
255 (guint) ((guint8) new));
256 GST_BUFFER_DATA (buf)[i] = new;
260 bmd->skipped += MIN (G_MAXUINT - bmd->skipped, GST_BUFFER_SIZE (buf));
262 GST_OBJECT_UNLOCK (bmd);
268 gst_break_my_data_start (GstBaseTransform * trans)
270 GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);
272 GST_OBJECT_LOCK (bmd);
273 bmd->rand = g_rand_new_with_seed (bmd->seed);
275 GST_OBJECT_UNLOCK (bmd);
281 gst_break_my_data_stop (GstBaseTransform * trans)
283 GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);
285 GST_OBJECT_LOCK (bmd);
286 g_rand_free (bmd->rand);
288 GST_OBJECT_UNLOCK (bmd);
294 gst_break_my_data_plugin_init (GstPlugin * plugin)
296 if (!gst_element_register (plugin, "breakmydata", GST_RANK_NONE,
297 GST_TYPE_BREAK_MY_DATA))
300 GST_DEBUG_CATEGORY_INIT (gst_break_my_data_debug, "breakmydata", 0,
301 "debugging category for breakmydata element");