gstreamer/gst/gstevent.c

/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wim.taymans@chello.be>
 *
 * gstevent.c: GstEvent subsystem
 *
 * 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.
 */

#include <string.h>             /* memcpy */

#include "gst_private.h"
#include "gstdata_private.h"

#include "gstclock.h"
#include "gstinfo.h"
#include "gstmemchunk.h"
#include "gstevent.h"
#include "gsttag.h"

#ifndef GST_DISABLE_TRACE
/* #define GST_WITH_ALLOC_TRACE */
#include "gsttrace.h"
static GstAllocTrace *_event_trace;
#endif

static GstMemChunk *chunk;

/* #define MEMPROF */

GType _gst_event_type;

void
_gst_event_initialize (void)
{
  /* register the type */
  _gst_event_type = g_boxed_type_register_static ("GstEvent",
      (GBoxedCopyFunc) gst_data_copy, (GBoxedFreeFunc) gst_data_unref);

#ifndef GST_DISABLE_TRACE
  _event_trace = gst_alloc_trace_register (GST_EVENT_TRACE_NAME);
#endif

  chunk = gst_mem_chunk_new ("GstEventChunk", sizeof (GstEvent),
      sizeof (GstEvent) * 50, 0);
}

static GstEvent *
_gst_event_copy (GstEvent * event)
{
  GstEvent *copy;

  copy = gst_mem_chunk_alloc (chunk);
#ifndef GST_DISABLE_TRACE
  gst_alloc_trace_new (_event_trace, copy);
#endif

  memcpy (copy, event, sizeof (GstEvent));
  if (GST_EVENT_SRC (copy)) {
    gst_object_ref (GST_EVENT_SRC (copy));
  }

  /* FIXME copy/ref additional fields */
  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_TAG:
      copy->event_data.structure.structure =
          gst_tag_list_copy ((GstTagList *) event->event_data.structure.
          structure);
      break;
    case GST_EVENT_NAVIGATION:
      copy->event_data.structure.structure =
          gst_structure_copy (event->event_data.structure.structure);
    default:
      break;
  }

  return copy;
}

static void
_gst_event_free (GstEvent * event)
{
  GST_CAT_INFO (GST_CAT_EVENT, "freeing event %p", event);

  if (GST_EVENT_SRC (event)) {
    gst_object_unref (GST_EVENT_SRC (event));
  }
  switch (GST_EVENT_TYPE (event)) {
    case GST_EVENT_TAG:
      if (GST_IS_TAG_LIST (event->event_data.structure.structure)) {
        gst_tag_list_free (event->event_data.structure.structure);
      } else {
        g_warning ("tag event %p didn't contain a valid tag list!", event);
        GST_ERROR ("tag event %p didn't contain a valid tag list!", event);
      }
      break;
    case GST_EVENT_NAVIGATION:
      gst_structure_free (event->event_data.structure.structure);
      break;
    default:
      break;
  }
  _GST_DATA_DISPOSE (GST_DATA (event));
#ifndef GST_DISABLE_TRACE
  gst_alloc_trace_free (_event_trace, event);
#endif
  gst_mem_chunk_free (chunk, event);
}

/**
 * gst_event_masks_contains:
 * @masks: The eventmask array to search
 * @mask: the event mask to find
 *
 * See if the given eventmask is inside the eventmask array.
 *
 * Returns: TRUE if the eventmask is found inside the array
 */
gboolean
gst_event_masks_contains (const GstEventMask * masks, GstEventMask * mask)
{
  g_return_val_if_fail (mask != NULL, FALSE);

  if (!masks)
    return FALSE;

  while (masks->type) {
    if (masks->type == mask->type &&
        (masks->flags & mask->flags) == mask->flags)
      return TRUE;

    masks++;
  }

  return FALSE;
}

GType
gst_event_get_type (void)
{
  return _gst_event_type;
}

/**
 * gst_event_new:
 * @type: The type of the new event
 *
 * Allocate a new event of the given type.
 *
 * Returns: A new event.
 */
GstEvent *
gst_event_new (GstEventType type)
{
  GstEvent *event;

  event = gst_mem_chunk_alloc0 (chunk);
#ifndef GST_DISABLE_TRACE
  gst_alloc_trace_new (_event_trace, event);
#endif

  GST_CAT_INFO (GST_CAT_EVENT, "creating new event type %d: %p", type, event);

  _GST_DATA_INIT (GST_DATA (event),
      _gst_event_type,
      0,
      (GstDataFreeFunction) _gst_event_free,
      (GstDataCopyFunction) _gst_event_copy);

  GST_EVENT_TYPE (event) = type;
  GST_EVENT_TIMESTAMP (event) = G_GINT64_CONSTANT (0);
  GST_EVENT_SRC (event) = NULL;
  GST_DATA_FLAG_SET (GST_DATA (event), GST_EVENT_COMMON_FLAG_NEED_RESPONSE);

  return event;
}

/**
 * gst_event_new_seek:
 * @type: The type of the seek event
 * @offset: The offset of the seek
 *
 * Allocate a new seek event with the given parameters.
 *
 * Returns: A new seek event.
 */
GstEvent *
gst_event_new_seek (GstSeekType type, gint64 offset)
{
  GstEvent *event;

  event = gst_event_new (GST_EVENT_SEEK);

  GST_EVENT_SEEK_TYPE (event) = type;
  GST_EVENT_SEEK_OFFSET (event) = offset;
  GST_EVENT_SEEK_ENDOFFSET (event) = -1;

  return event;
}

/**
 * gst_event_new_discontinuous_valist:
 * @new_media: A flag indicating a new media type starts
 * @format1: The format of the discont value
 * @var_args: more discont values and formats
 *
 * Allocate a new discontinuous event with the given format/value pairs. Note
 * that the values are of type gint64 - you may not use simple integers such
 * as "0" when calling this function, always cast them like "(gint64) 0".
 * Terminate the list with #GST_FORMAT_UNDEFINED.
 *
 * Returns: A new discontinuous event.
 */
GstEvent *
gst_event_new_discontinuous_valist (gboolean new_media, GstFormat format1,
    va_list var_args)
{
  GstEvent *event;
  gint count = 0;

  event = gst_event_new (GST_EVENT_DISCONTINUOUS);
  GST_EVENT_DISCONT_NEW_MEDIA (event) = new_media;

  while (format1 != GST_FORMAT_UNDEFINED && count < 8) {

    GST_EVENT_DISCONT_OFFSET (event, count).format =
        format1 & GST_SEEK_FORMAT_MASK;
    GST_EVENT_DISCONT_OFFSET (event, count).value = va_arg (var_args, gint64);

    format1 = va_arg (var_args, GstFormat);

    count++;
  }

  GST_EVENT_DISCONT_OFFSET_LEN (event) = count;

  return event;
}

/**
 * gst_event_new_discontinuous:
 * @new_media: A flag indicating a new media type starts
 * @format1: The format of the discont value
 * @...: more discont values and formats
 *
 * Allocate a new discontinuous event with the given format/value pairs. Note
 * that the values are of type gint64 - you may not use simple integers such
 * as "0" when calling this function, always cast them like "(gint64) 0".
 * Terminate the list with #GST_FORMAT_UNDEFINED.
 *
 * Returns: A new discontinuous event.
 */
GstEvent *
gst_event_new_discontinuous (gboolean new_media, GstFormat format1, ...)
{
  va_list var_args;
  GstEvent *event;

  va_start (var_args, format1);

  event = gst_event_new_discontinuous_valist (new_media, format1, var_args);

  va_end (var_args);

  return event;
}

/**
 * gst_event_discont_get_value:
 * @event: The event to query
 * @format: The format of the discontinuous value
 * @value: A pointer to the value
 *
 * Get the value for the given format in the discontinous event.
 *
 * Returns: TRUE if the discontinuous event carries the specified
 * format/value pair.
 */
gboolean
gst_event_discont_get_value (GstEvent * event, GstFormat format, gint64 * value)
{
  gint i, n;

  g_return_val_if_fail (event != NULL, FALSE);
  g_return_val_if_fail (value != NULL, FALSE);

  n = GST_EVENT_DISCONT_OFFSET_LEN (event);

  for (i = 0; i < n; i++) {
    if (GST_EVENT_DISCONT_OFFSET (event, i).format == format) {
      *value = GST_EVENT_DISCONT_OFFSET (event, i).value;
      return TRUE;
    }
  }

  return FALSE;
}


/**
 * gst_event_new_size:
 * @format: The format of the size value
 * @value: The value of the size event
 *
 * Create a new size event with the given values.
 *
 * Returns: The new size event.
 */
GstEvent *
gst_event_new_size (GstFormat format, gint64 value)
{
  GstEvent *event;

  event = gst_event_new (GST_EVENT_SIZE);

  GST_EVENT_SIZE_FORMAT (event) = format;
  GST_EVENT_SIZE_VALUE (event) = value;

  return event;
}


/**
 * gst_event_new_segment_seek:
 * @type: The type of the seek event
 * @start: The start offset of the seek
 * @stop: The stop offset of the seek
 *
 * Allocate a new segment seek event with the given parameters. 
 *
 * Returns: A new segment seek event.
 */
GstEvent *
gst_event_new_segment_seek (GstSeekType type, gint64 start, gint64 stop)
{
  GstEvent *event;

  g_return_val_if_fail (start < stop, NULL);

  event = gst_event_new (GST_EVENT_SEEK_SEGMENT);

  GST_EVENT_SEEK_TYPE (event) = type;
  GST_EVENT_SEEK_OFFSET (event) = start;
  GST_EVENT_SEEK_ENDOFFSET (event) = stop;

  return event;
}

/**
 * gst_event_new_filler_stamped:
 * @time: timestamp of the filler, in nanoseconds.
 * @duration: duration of the filler, in nanoseconds.
 *
 * Creates "filler" data, which is basically empty data that is used to
 * synchronize streams if one stream has no data for a while. This is
 * used to prevent deadlocks.
 *
 * Returns: the newly created event.
 */

GstEvent *
gst_event_new_filler_stamped (guint64 time, guint64 duration)
{
  GstEvent *event = gst_event_new_filler ();

  GST_EVENT_TIMESTAMP (event) = time;
  if (GST_CLOCK_TIME_IS_VALID (duration)) {
    GValue value = { 0 };

    event->event_data.structure.structure =
        gst_structure_new ("application/x-gst-filler", NULL);
    g_value_init (&value, G_TYPE_UINT64);
    g_value_set_uint64 (&value, duration);
    gst_structure_set_value (event->event_data.structure.structure,
        "duration", &value);
    g_value_unset (&value);
  }

  return event;
}

/**
 * gst_event_filler_get_duration:
 * @event: the event to get the duration from.
 *
 * Filler events are used to synchronize streams (and thereby prevent
 * application deadlocks) if one stream receives no data for a while.
 * This function gets the duration of a filler event, which is the
 * amount of time from the start of this event (see GST_EVENT_TIMESTAMP())
 * that no data is available.
 *
 * Returns: duration of the lack of data, or GST_CLOCK_TIME_NONE.
 */

guint64
gst_event_filler_get_duration (GstEvent * event)
{
  const GValue *value;

  g_return_val_if_fail (event != NULL, GST_CLOCK_TIME_NONE);
  g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FILLER,
      GST_CLOCK_TIME_NONE);

  /* check the event */
  if (!event->event_data.structure.structure)
    return GST_CLOCK_TIME_NONE;
  value = gst_structure_get_value (event->event_data.structure.structure,
      "duration");
  if (!value)
    return GST_CLOCK_TIME_NONE;
  g_return_val_if_fail (G_VALUE_TYPE (value) == G_TYPE_UINT64,
      GST_CLOCK_TIME_NONE);

  /* return */
  return g_value_get_uint64 (value);
}