1 /* GStreamer
2  * Copyright (C) 2004 Benjamin Otte <otte@gnome.org>
3  *
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.
8  *
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.
13  *
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., 51 Franklin St, Fifth Floor,
17  * Boston, MA 02110-1301, USA.
18  */
19 /**
20  * SECTION:element-breakmydata
21  *
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.
25  */
26 
27 #ifdef HAVE_CONFIG_H
28 #  include "config.h"
29 #endif
30 
31 #include <gst/gst.h>
32 #include <gst/base/gstbasetransform.h>
33 
34 GST_DEBUG_CATEGORY_STATIC (gst_break_my_data_debug);
35 #define GST_CAT_DEFAULT gst_break_my_data_debug
36 
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))
47 
48 GType gst_break_my_data_get_type (void);
49 
50 enum
51 {
52   PROP_0,
53   PROP_SEED,
54   PROP_SET_TO,
55   PROP_SKIP,
56   PROP_PROBABILITY
57 };
58 
59 typedef struct _GstBreakMyData GstBreakMyData;
60 typedef struct _GstBreakMyDataClass GstBreakMyDataClass;
61 
62 struct _GstBreakMyData
63 {
64   GstBaseTransform basetransform;
65 
66   GRand *rand;
67   guint skipped;
68 
69   guint32 seed;
70   gint set;
71   guint skip;
72   gdouble probability;
73 };
74 
75 struct _GstBreakMyDataClass
76 {
77   GstBaseTransformClass parent_class;
78 };
79 
80 static void gst_break_my_data_set_property (GObject * object,
81     guint prop_id, const GValue * value, GParamSpec * pspec);
82 static void gst_break_my_data_get_property (GObject * object,
83     guint prop_id, GValue * value, GParamSpec * pspec);
84 
85 static GstFlowReturn gst_break_my_data_transform_ip (GstBaseTransform * trans,
86     GstBuffer * buf);
87 static gboolean gst_break_my_data_stop (GstBaseTransform * trans);
88 static gboolean gst_break_my_data_start (GstBaseTransform * trans);
89 
90 GstStaticPadTemplate bmd_src_template = GST_STATIC_PAD_TEMPLATE ("src",
91     GST_PAD_SRC,
92     GST_PAD_ALWAYS,
93     GST_STATIC_CAPS_ANY);
94 
95 GstStaticPadTemplate bmd_sink_template = GST_STATIC_PAD_TEMPLATE ("sink",
96     GST_PAD_SINK,
97     GST_PAD_ALWAYS,
98     GST_STATIC_CAPS_ANY);
99 
100 #define gst_break_my_data_parent_class parent_class
101 G_DEFINE_TYPE (GstBreakMyData, gst_break_my_data, GST_TYPE_BASE_TRANSFORM);
102 
103 
104 static void
gst_break_my_data_class_init(GstBreakMyDataClass * klass)105 gst_break_my_data_class_init (GstBreakMyDataClass * klass)
106 {
107   GstBaseTransformClass *gstbasetrans_class;
108   GstElementClass *gstelement_class;
109   GObjectClass *gobject_class;
110 
111   gobject_class = G_OBJECT_CLASS (klass);
112   gstelement_class = GST_ELEMENT_CLASS (klass);
113   gstbasetrans_class = GST_BASE_TRANSFORM_CLASS (klass);
114 
115   GST_DEBUG_CATEGORY_INIT (gst_break_my_data_debug, "breakmydata", 0,
116       "debugging category for breakmydata element");
117 
118   gobject_class->set_property = gst_break_my_data_set_property;
119   gobject_class->get_property = gst_break_my_data_get_property;
120 
121   g_object_class_install_property (gobject_class, PROP_SEED,
122       g_param_spec_uint ("seed", "seed",
123           "seed for randomness (initialized when going from READY to PAUSED)",
124           0, G_MAXUINT32, 0,
125           G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
126   g_object_class_install_property (gobject_class, PROP_SET_TO,
127       g_param_spec_int ("set-to", "set-to",
128           "set changed bytes to this value (-1 means random value",
129           -1, G_MAXUINT8, -1,
130           G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
131   g_object_class_install_property (gobject_class, PROP_SKIP,
132       g_param_spec_uint ("skip", "skip",
133           "amount of bytes skipped at the beginning of stream",
134           0, G_MAXUINT, 0,
135           G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
136   g_object_class_install_property (gobject_class, PROP_PROBABILITY,
137       g_param_spec_double ("probability", "probability",
138           "probability for each byte in the buffer to be changed", 0.0, 1.0,
139           0.0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));
140 
141   gst_element_class_add_static_pad_template (gstelement_class,
142       &bmd_sink_template);
143   gst_element_class_add_static_pad_template (gstelement_class,
144       &bmd_src_template);
145 
146   gst_element_class_set_static_metadata (gstelement_class, "Break my data",
147       "Testing",
148       "randomly change data in the stream", "Benjamin Otte <otte@gnome>");
149 
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);
154 }
155 
156 static void
gst_break_my_data_init(GstBreakMyData * bmd)157 gst_break_my_data_init (GstBreakMyData * bmd)
158 {
159   gst_base_transform_set_in_place (GST_BASE_TRANSFORM (bmd), TRUE);
160 }
161 
162 static void
gst_break_my_data_set_property(GObject * object,guint prop_id,const GValue * value,GParamSpec * pspec)163 gst_break_my_data_set_property (GObject * object, guint prop_id,
164     const GValue * value, GParamSpec * pspec)
165 {
166   GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);
167 
168   GST_OBJECT_LOCK (bmd);
169 
170   switch (prop_id) {
171     case PROP_SEED:
172       bmd->seed = g_value_get_uint (value);
173       break;
174     case PROP_SET_TO:
175       bmd->set = g_value_get_int (value);
176       break;
177     case PROP_SKIP:
178       bmd->skip = g_value_get_uint (value);
179       break;
180     case PROP_PROBABILITY:
181       bmd->probability = g_value_get_double (value);
182       break;
183     default:
184       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
185       break;
186   }
187 
188   GST_OBJECT_UNLOCK (bmd);
189 }
190 
191 static void
gst_break_my_data_get_property(GObject * object,guint prop_id,GValue * value,GParamSpec * pspec)192 gst_break_my_data_get_property (GObject * object, guint prop_id, GValue * value,
193     GParamSpec * pspec)
194 {
195   GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);
196 
197   GST_OBJECT_LOCK (bmd);
198 
199   switch (prop_id) {
200     case PROP_SEED:
201       g_value_set_uint (value, bmd->seed);
202       break;
203     case PROP_SET_TO:
204       g_value_set_int (value, bmd->set);
205       break;
206     case PROP_SKIP:
207       g_value_set_uint (value, bmd->skip);
208       break;
209     case PROP_PROBABILITY:
210       g_value_set_double (value, bmd->probability);
211       break;
212     default:
213       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
214       break;
215   }
216 
217   GST_OBJECT_UNLOCK (bmd);
218 }
219 
220 static GstFlowReturn
gst_break_my_data_transform_ip(GstBaseTransform * trans,GstBuffer * buf)221 gst_break_my_data_transform_ip (GstBaseTransform * trans, GstBuffer * buf)
222 {
223   GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);
224   GstMapInfo map;
225   gsize i;
226 
227   g_return_val_if_fail (gst_buffer_is_writable (buf), GST_FLOW_ERROR);
228 
229   GST_OBJECT_LOCK (bmd);
230 
231   if (bmd->skipped < bmd->skip) {
232     i = bmd->skip - bmd->skipped;
233   } else {
234     i = 0;
235   }
236 
237   gst_buffer_map (buf, &map, GST_MAP_READWRITE);
238 
239   GST_LOG_OBJECT (bmd,
240       "got buffer %p (size %" G_GSIZE_FORMAT ", timestamp %" G_GUINT64_FORMAT
241       ", offset %" G_GUINT64_FORMAT "", buf, map.size,
242       GST_BUFFER_TIMESTAMP (buf), GST_BUFFER_OFFSET (buf));
243 
244   for (; i < map.size; i++) {
245     if (g_rand_double_range (bmd->rand, 0, 1.0) <= bmd->probability) {
246       guint8 new;
247 
248       if (bmd->set < 0) {
249         new = g_rand_int_range (bmd->rand, 0, 256);
250       } else {
251         new = bmd->set;
252       }
253       GST_INFO_OBJECT (bmd,
254           "changing byte %" G_GSIZE_FORMAT " from 0x%02X to 0x%02X", i,
255           (guint) GST_READ_UINT8 (map.data + i), (guint) ((guint8) new));
256       map.data[i] = new;
257     }
258   }
259   /* don't overflow */
260   bmd->skipped += MIN (G_MAXUINT - bmd->skipped, map.size);
261 
262   gst_buffer_unmap (buf, &map);
263 
264   GST_OBJECT_UNLOCK (bmd);
265 
266   return GST_FLOW_OK;
267 }
268 
269 static gboolean
gst_break_my_data_start(GstBaseTransform * trans)270 gst_break_my_data_start (GstBaseTransform * trans)
271 {
272   GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);
273 
274   GST_OBJECT_LOCK (bmd);
275   bmd->rand = g_rand_new_with_seed (bmd->seed);
276   bmd->skipped = 0;
277   GST_OBJECT_UNLOCK (bmd);
278 
279   return TRUE;
280 }
281 
282 static gboolean
gst_break_my_data_stop(GstBaseTransform * trans)283 gst_break_my_data_stop (GstBaseTransform * trans)
284 {
285   GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);
286 
287   GST_OBJECT_LOCK (bmd);
288   g_rand_free (bmd->rand);
289   bmd->rand = NULL;
290   GST_OBJECT_UNLOCK (bmd);
291 
292   return TRUE;
293 }
294