gst/debug/: add element that quasi-randomly changes bytes in the stream.

Original commit message from CVS:
* gst/debug/Makefile.am:
* gst/debug/breakmydata.c:
add element that quasi-randomly changes bytes in the stream.
Intended use is robustness checking of demuxers and decoders in
media tests.

1 files changed, 272 insertions, 0 deletions

diff --git a/gst/debug/breakmydata.c b/gst/debug/breakmydata.c
new file mode 100644
index 00000000..eebce32e
--- /dev/null
+++ b/gst/debug/breakmydata.c
@@ -0,0 +1,272 @@
+/* GStreamer
+ * Copyright (C) 2004 Benjamin Otte <otte@gnome.org>
+ *
+ * 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include <gst/gst.h>
+
+GST_DEBUG_CATEGORY_STATIC (gst_break_my_data_debug);
+#define GST_CAT_DEFAULT gst_break_my_data_debug
+
+/* This plugin modifies the contents of the buffer it is passed randomly 
+ * according to the parameters set.
+ * It otherwise acts as an identity.
+ */
+
+#define GST_TYPE_BREAK_MY_DATA \
+  (gst_break_my_data_get_type())
+#define GST_BREAK_MY_DATA(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_BREAK_MY_DATA,GstBreakMyData))
+#define GST_BREAK_MY_DATA_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_BREAK_MY_DATA,GstBreakMyDataClass))
+#define GST_IS_BREAK_MY_DATA(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_BREAK_MY_DATA))
+#define GST_IS_BREAK_MY_DATA_CLASS(obj) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BREAK_MY_DATA))
+
+enum
+{
+  ARG_0,
+  ARG_SEED,
+  ARG_SET_TO,
+  ARG_SKIP,
+  ARG_PROBABILITY
+};
+
+typedef struct _GstBreakMyData GstBreakMyData;
+typedef struct _GstBreakMyDataClass GstBreakMyDataClass;
+
+struct _GstBreakMyData
+{
+  GstElement element;
+
+  GstPad *sinkpad;
+  GstPad *srcpad;
+
+  GRand *rand;
+  guint skipped;
+
+  guint32 seed;
+  gint set;
+  guint skip;
+  gdouble probability;
+};
+
+struct _GstBreakMyDataClass
+{
+  GstElementClass parent_class;
+};
+
+GST_BOILERPLATE (GstBreakMyData, gst_break_my_data, GstElement,
+    GST_TYPE_ELEMENT)
+
+     static void gst_break_my_data_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec);
+     static void gst_break_my_data_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec);
+
+     static void gst_break_my_data_chain (GstPad * pad, GstData * _data);
+     static GstElementStateReturn gst_break_my_data_change_state (GstElement *
+    element);
+
+     static void gst_break_my_data_base_init (gpointer g_class)
+{
+  static GstElementDetails details = GST_ELEMENT_DETAILS ("breakmydata",
+      "Testing",
+      "randomly change data in the stream",
+      "Benjamin Otte <otte@gnome>");
+  GstElementClass *gstelement_class = GST_ELEMENT_CLASS (g_class);
+
+  gst_element_class_set_details (gstelement_class, &details);
+}
+
+static void
+gst_break_my_data_class_init (GstBreakMyDataClass * klass)
+{
+  GObjectClass *object = G_OBJECT_CLASS (klass);
+  GstElementClass *element = GST_ELEMENT_CLASS (klass);
+
+  object->set_property = GST_DEBUG_FUNCPTR (gst_break_my_data_set_property);
+  object->get_property = GST_DEBUG_FUNCPTR (gst_break_my_data_get_property);
+
+  g_object_class_install_property (object, ARG_SEED,
+      g_param_spec_uint ("seed", "seed",
+          "seed for randomness (initialized when goint from READY to PAUSED)",
+          0, 0xFFFFFFFF, 0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
+  g_object_class_install_property (object, ARG_SET_TO,
+      g_param_spec_int ("set-to", "set-to",
+          "set changed bytes to this value (-1 means random value",
+          -1, 255, -1, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
+  g_object_class_install_property (object, ARG_SKIP,
+      g_param_spec_uint ("skip", "skip",
+          "amount of bytes skipped at the beginning of stream",
+          0, G_MAXUINT, 0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
+  g_object_class_install_property (object, ARG_PROBABILITY,
+      g_param_spec_double ("probability", "probability",
+          "probability that a buffer is changed", 0.0, 1.0, 0.0,
+          G_PARAM_READWRITE | G_PARAM_CONSTRUCT));
+
+  element->change_state = gst_break_my_data_change_state;
+}
+
+static void
+gst_break_my_data_init (GstBreakMyData * break_my_data)
+{
+  break_my_data->sinkpad = gst_pad_new ("sink", GST_PAD_SINK);
+  gst_element_add_pad (GST_ELEMENT (break_my_data), break_my_data->sinkpad);
+  gst_pad_set_chain_function (break_my_data->sinkpad,
+      GST_DEBUG_FUNCPTR (gst_break_my_data_chain));
+  gst_pad_set_link_function (break_my_data->sinkpad, gst_pad_proxy_pad_link);
+  gst_pad_set_getcaps_function (break_my_data->sinkpad, gst_pad_proxy_getcaps);
+
+  break_my_data->srcpad = gst_pad_new ("src", GST_PAD_SRC);
+  gst_element_add_pad (GST_ELEMENT (break_my_data), break_my_data->srcpad);
+  gst_pad_set_link_function (break_my_data->srcpad, gst_pad_proxy_pad_link);
+  gst_pad_set_getcaps_function (break_my_data->srcpad, gst_pad_proxy_getcaps);
+}
+
+static void
+gst_break_my_data_chain (GstPad * pad, GstData * data)
+{
+  GstBuffer *copy = NULL, *buf = GST_BUFFER (data);
+  GstBreakMyData *bmd = GST_BREAK_MY_DATA (gst_pad_get_parent (pad));
+  guint i, size;
+
+  if (bmd->skipped < bmd->skip) {
+    i = bmd->skip - bmd->skipped;
+  } else {
+    i = 0;
+  }
+  size = GST_BUFFER_SIZE (buf);
+  GST_LOG_OBJECT (bmd,
+      "got buffer %p (size %u, timestamp %" G_GUINT64_FORMAT ", offset %"
+      G_GUINT64_FORMAT "", buf, size, GST_BUFFER_TIMESTAMP (buf),
+      GST_BUFFER_OFFSET (buf));
+  for (; i < size; i++) {
+    if (g_rand_double_range (bmd->rand, 0, 1) < bmd->probability) {
+      guint8 new;
+
+      if (!copy)
+        copy = gst_buffer_copy_on_write (buf);
+      if (bmd->set < 0) {
+        new = g_rand_int_range (bmd->rand, 0, 256);
+      } else {
+        new = bmd->set;
+      }
+      GST_INFO_OBJECT (bmd, "changing byte %u from 0x%2X to 0x%2X", i,
+          (gint) GST_BUFFER_DATA (copy)[i], (gint) new);
+      GST_BUFFER_DATA (copy)[i] = new;
+    }
+  }
+  /* don't overflow */
+  bmd->skipped += MIN (G_MAXUINT - bmd->skipped, GST_BUFFER_SIZE (buf));
+  gst_pad_push (bmd->srcpad, GST_DATA (copy ? copy : buf));
+}
+
+static void
+gst_break_my_data_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);
+
+  switch (prop_id) {
+    case ARG_SEED:
+      bmd->seed = g_value_get_uint (value);
+      break;
+    case ARG_SET_TO:
+      bmd->set = g_value_get_int (value);
+      break;
+    case ARG_SKIP:
+      bmd->skip = g_value_get_uint (value);
+      break;
+    case ARG_PROBABILITY:
+      bmd->probability = g_value_get_double (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_break_my_data_get_property (GObject * object, guint prop_id, GValue * value,
+    GParamSpec * pspec)
+{
+  GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);
+
+  switch (prop_id) {
+    case ARG_SEED:
+      g_value_set_uint (value, bmd->seed);
+      break;
+    case ARG_SET_TO:
+      g_value_set_int (value, bmd->set);
+      break;
+    case ARG_SKIP:
+      g_value_set_uint (value, bmd->skip);
+      break;
+    case ARG_PROBABILITY:
+      g_value_set_double (value, bmd->probability);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static GstElementStateReturn
+gst_break_my_data_change_state (GstElement * element)
+{
+  GstBreakMyData *bmd = GST_BREAK_MY_DATA (element);
+
+  switch (GST_STATE_TRANSITION (element)) {
+    case GST_STATE_READY_TO_PAUSED:
+      bmd->rand = g_rand_new_with_seed (bmd->seed);
+      bmd->skipped = 0;
+      break;
+    case GST_STATE_PAUSED_TO_READY:
+      g_rand_free (bmd->rand);
+      break;
+    default:
+      break;
+  }
+
+  return GST_CALL_PARENT_WITH_DEFAULT (GST_ELEMENT_CLASS, change_state,
+      (element), GST_STATE_SUCCESS);
+}
+
+static gboolean
+plugin_init (GstPlugin * plugin)
+{
+  if (!gst_element_register (plugin, "breakmydata", GST_RANK_NONE,
+          GST_TYPE_BREAK_MY_DATA))
+    return FALSE;
+
+  GST_DEBUG_CATEGORY_INIT (gst_break_my_data_debug, "breakmydata", 0,
+      "debugging category for breakmydata element");
+
+  return TRUE;
+}
+
+GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
+    GST_VERSION_MINOR,
+    "debug",
+    "elements for testing and debugging",
+    plugin_init, VERSION, "LGPL", GST_PACKAGE, GST_ORIGIN)