/* 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., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

/**

 * SECTION:element-breakmydata

 *

 * This element modifies the contents of the buffer it is passed randomly

 * according to the parameters set.

 * It otherwise acts as an identity.

 */

#ifdef HAVE_CONFIG_H

#  include "config.h"

#endif

#include <gst/gst.h>

#include <gst/base/gstbasetransform.h>

GST_DEBUG_CATEGORY_STATIC (gst_break_my_data_debug);

#define GST_CAT_DEFAULT gst_break_my_data_debug

#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(klass) \

  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_BREAK_MY_DATA))

GType gst_break_my_data_get_type (void);

enum

{

  PROP_0,

  PROP_SEED,

  PROP_SET_TO,

  PROP_SKIP,

  PROP_PROBABILITY

};

typedef struct _GstBreakMyData GstBreakMyData;

typedef struct _GstBreakMyDataClass GstBreakMyDataClass;

struct _GstBreakMyData

{

  GstBaseTransform basetransform;

  GRand *rand;

  guint skipped;

  guint32 seed;

  gint set;

  guint skip;

  gdouble probability;

};

struct _GstBreakMyDataClass

{

  GstBaseTransformClass parent_class;

};

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 GstFlowReturn gst_break_my_data_transform_ip (GstBaseTransform * trans,

    GstBuffer * buf);

static gboolean gst_break_my_data_stop (GstBaseTransform * trans);

static gboolean gst_break_my_data_start (GstBaseTransform * trans);

GstStaticPadTemplate bmd_src_template = GST_STATIC_PAD_TEMPLATE ("src",

    GST_PAD_SRC,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS_ANY);

GstStaticPadTemplate bmd_sink_template = GST_STATIC_PAD_TEMPLATE ("sink",

    GST_PAD_SINK,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS_ANY);

#define gst_break_my_data_parent_class parent_class

G_DEFINE_TYPE (GstBreakMyData, gst_break_my_data, GST_TYPE_BASE_TRANSFORM);

static void

gst_break_my_data_class_init (GstBreakMyDataClass * klass)

{

  GstBaseTransformClass *gstbasetrans_class;

  GstElementClass *gstelement_class;

  GObjectClass *gobject_class;

  gobject_class = G_OBJECT_CLASS (klass);

  gstelement_class = GST_ELEMENT_CLASS (klass);

  gstbasetrans_class = GST_BASE_TRANSFORM_CLASS (klass);

  GST_DEBUG_CATEGORY_INIT (gst_break_my_data_debug, "breakmydata", 0,

      "debugging category for breakmydata element");

  gobject_class->set_property = gst_break_my_data_set_property;

  gobject_class->get_property = gst_break_my_data_get_property;

  g_object_class_install_property (gobject_class, PROP_SEED,

      g_param_spec_uint ("seed", "seed",

          "seed for randomness (initialized when going from READY to PAUSED)",

          0, G_MAXUINT32, 0,

          G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_SET_TO,

      g_param_spec_int ("set-to", "set-to",

          "set changed bytes to this value (-1 means random value",

          -1, G_MAXUINT8, -1,

          G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_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_PARAM_STATIC_STRINGS));

  g_object_class_install_property (gobject_class, PROP_PROBABILITY,

      g_param_spec_double ("probability", "probability",

          "probability for each byte in the buffer to be changed", 0.0, 1.0,

          0.0, G_PARAM_READWRITE | G_PARAM_CONSTRUCT | G_PARAM_STATIC_STRINGS));

  gst_element_class_add_static_pad_template (gstelement_class,

      &bmd_sink_template);

  gst_element_class_add_static_pad_template (gstelement_class,

      &bmd_src_template);

  gst_element_class_set_static_metadata (gstelement_class, "Break my data",

      "Testing",

      "randomly change data in the stream", "Benjamin Otte <otte@gnome>");

  gstbasetrans_class->transform_ip =

      GST_DEBUG_FUNCPTR (gst_break_my_data_transform_ip);

  gstbasetrans_class->start = GST_DEBUG_FUNCPTR (gst_break_my_data_start);

  gstbasetrans_class->stop = GST_DEBUG_FUNCPTR (gst_break_my_data_stop);

}

static void

gst_break_my_data_init (GstBreakMyData * bmd)

{

  gst_base_transform_set_in_place (GST_BASE_TRANSFORM (bmd), TRUE);

}

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);

  GST_OBJECT_LOCK (bmd);

  switch (prop_id) {

    case PROP_SEED:

      bmd->seed = g_value_get_uint (value);

      break;

    case PROP_SET_TO:

      bmd->set = g_value_get_int (value);

      break;

    case PROP_SKIP:

      bmd->skip = g_value_get_uint (value);

      break;

    case PROP_PROBABILITY:

      bmd->probability = g_value_get_double (value);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

  GST_OBJECT_UNLOCK (bmd);

}

static void

gst_break_my_data_get_property (GObject * object, guint prop_id, GValue * value,

    GParamSpec * pspec)

{

  GstBreakMyData *bmd = GST_BREAK_MY_DATA (object);

  GST_OBJECT_LOCK (bmd);

  switch (prop_id) {

    case PROP_SEED:

      g_value_set_uint (value, bmd->seed);

      break;

    case PROP_SET_TO:

      g_value_set_int (value, bmd->set);

      break;

    case PROP_SKIP:

      g_value_set_uint (value, bmd->skip);

      break;

    case PROP_PROBABILITY:

      g_value_set_double (value, bmd->probability);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

  GST_OBJECT_UNLOCK (bmd);

}

static GstFlowReturn

gst_break_my_data_transform_ip (GstBaseTransform * trans, GstBuffer * buf)

{

  GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);

  GstMapInfo map;

  gsize i;

  g_return_val_if_fail (gst_buffer_is_writable (buf), GST_FLOW_ERROR);

  GST_OBJECT_LOCK (bmd);

  if (bmd->skipped < bmd->skip) {

    i = bmd->skip - bmd->skipped;

  } else {

    i = 0;

  }

  gst_buffer_map (buf, &map, GST_MAP_READWRITE);

  GST_LOG_OBJECT (bmd,

      "got buffer %p (size %" G_GSIZE_FORMAT ", timestamp %" G_GUINT64_FORMAT

      ", offset %" G_GUINT64_FORMAT "", buf, map.size,

      GST_BUFFER_TIMESTAMP (buf), GST_BUFFER_OFFSET (buf));

  for (; i < map.size; i++) {

    if (g_rand_double_range (bmd->rand, 0, 1.0) <= bmd->probability) {

      guint8 new;

      if (bmd->set < 0) {

        new = g_rand_int_range (bmd->rand, 0, 256);

      } else {

        new = bmd->set;

      }

      GST_INFO_OBJECT (bmd,

          "changing byte %" G_GSIZE_FORMAT " from 0x%02X to 0x%02X", i,

          (guint) GST_READ_UINT8 (map.data + i), (guint) ((guint8) new));

      map.data[i] = new;

    }

  }

  /* don't overflow */

  bmd->skipped += MIN (G_MAXUINT - bmd->skipped, map.size);

  gst_buffer_unmap (buf, &map);

  GST_OBJECT_UNLOCK (bmd);

  return GST_FLOW_OK;

}

static gboolean

gst_break_my_data_start (GstBaseTransform * trans)

{

  GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);

  GST_OBJECT_LOCK (bmd);

  bmd->rand = g_rand_new_with_seed (bmd->seed);

  bmd->skipped = 0;

  GST_OBJECT_UNLOCK (bmd);

  return TRUE;

}

static gboolean

gst_break_my_data_stop (GstBaseTransform * trans)

{

  GstBreakMyData *bmd = GST_BREAK_MY_DATA (trans);

  GST_OBJECT_LOCK (bmd);

  g_rand_free (bmd->rand);

  bmd->rand = NULL;

  GST_OBJECT_UNLOCK (bmd);

  return TRUE;

}