gstreamer/gst/gsttimecache.c

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/* GStreamer
* Copyright (C) 2001 RidgeRun (http://www.ridgerun.com/)
* Written by Erik Walthinsen <omega@ridgerun.com>
*
* gsttimecache.c: Cache for location<>time mapping
*
* 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 "gst_private.h"
#include "gsttimecache.h"
static void gst_time_cache_class_init (GstTimeCacheClass *klass);
static void gst_time_cache_init (GstTimeCache *tc);
static GstObject *timecache_parent_class = NULL;
GType
gst_time_cache_get_type(void) {
static GType tc_type = 0;
if (!tc_type) {
static const GTypeInfo tc_info = {
sizeof(GstTimeCacheClass),
NULL,
NULL,
(GClassInitFunc)gst_time_cache_class_init,
NULL,
NULL,
sizeof(GstTimeCache),
1,
(GInstanceInitFunc)gst_time_cache_init,
NULL
};
tc_type = g_type_register_static(GST_TYPE_OBJECT, "GstTimeCache", &tc_info, 0);
}
return tc_type;
}
static void
gst_time_cache_class_init (GstTimeCacheClass *klass)
{
timecache_parent_class = g_type_class_ref(GST_TYPE_OBJECT);
}
static GstTimeCacheGroup *
gst_time_cache_group_new(guint groupnum)
{
GstTimeCacheGroup *tcgroup = g_new(GstTimeCacheGroup,1);
tcgroup->groupnum = groupnum;
tcgroup->entries = NULL;
tcgroup->certainty = GST_TIME_CACHE_UNKNOWN;
tcgroup->peergroup = -1;
tcgroup->mintimestamp = 0LL;
tcgroup->maxtimestamp = 0LL;
tcgroup->minlocation = 0LL;
tcgroup->maxlocation = 0LL;
GST_DEBUG(0, "created new timecache group %d",groupnum);
return tcgroup;
}
static void
gst_time_cache_init (GstTimeCache *tc)
{
tc->curgroup = gst_time_cache_group_new(0);
tc->maxgroup = 0;
tc->groups = g_list_prepend(NULL, tc->curgroup);
GST_DEBUG(0, "created new timecache");
}
/**
* gst_time_cache_new:
*
* Create a new tilecache object
*
* Returns: a new timecache object
*/
GstTimeCache *
gst_time_cache_new()
{
GstTimeCache *tc;
tc = g_object_new (gst_time_cache_get_type (), NULL);
return tc;
}
/**
* gst_time_cache_get_group:
* @tc: the timecache to get the current group from
*
* Get the id of the current group.
*
* Returns: the id of the current group.
*/
gint
gst_time_cache_get_group(GstTimeCache *tc)
{
return tc->curgroup->groupnum;
}
/**
* gst_time_cache_new_group:
* @tc: the timecache to create the new group in
*
* Create a new group for the given timecache. It will be
* set as the current group.
*
* Returns: the id of the newly created group.
*/
gint
gst_time_cache_new_group(GstTimeCache *tc)
{
tc->curgroup = gst_time_cache_group_new(++tc->maxgroup);
tc->groups = g_list_append(tc->groups,tc->curgroup);
GST_DEBUG(0, "created new group %d in timecache",tc->maxgroup);
return tc->maxgroup;
}
/**
* gst_time_cache_set_group:
* @tc: the timecache to set the new group in
* @groupnum: the groupnumber to set
*
* Set the current groupnumber to the given argument.
*
* Returns: TRUE if the operation succeeded, FALSE if the group
* did not exist.
*/
gboolean
gst_time_cache_set_group(GstTimeCache *tc, gint groupnum)
{
GList *list;
GstTimeCacheGroup *tcgroup;
/* first check for null change */
if (groupnum == tc->curgroup->groupnum)
return TRUE;
/* else search for the proper group */
list = tc->groups;
while (list) {
tcgroup = (GstTimeCacheGroup *)(list->data);
list = g_list_next(list);
if (tcgroup->groupnum == groupnum) {
tc->curgroup = tcgroup;
GST_DEBUG(0, "switched to timecache group %d", tcgroup->groupnum);
return TRUE;
}
}
/* couldn't find the group in question */
GST_DEBUG(0, "couldn't find timecache group %d",groupnum);
return FALSE;
}
/**
* gst_time_cache_set_certainty:
* @tc: the timecache to set the certainty on
* @certainty: the certainty to set
*
* Set the certainty of the given timecache.
*/
void
gst_time_cache_set_certainty(GstTimeCache *tc, GstTimeCacheCertainty certainty)
{
tc->curgroup->certainty = certainty;
}
/**
* gst_time_cache_get_certainty:
* @tc: the timecache to get the certainty of
*
* Get the certainty of the given timecache.
*
* Returns: the certainty of the timecache.
*/
GstTimeCacheCertainty
gst_time_cache_get_certainty(GstTimeCache *tc)
{
return tc->curgroup->certainty;
}
/**
* gst_time_cache_add_entry:
* @tc: the timecache to add the entry to
* @location: the location
* @timestamp: the timestamp
*
* Associate the given timestamp with the given location in the
* timecache.
*/
void
gst_time_cache_add_entry (GstTimeCache *tc, guint64 location, gint64 timestamp)
{
GstTimeCacheEntry *entry = g_new(GstTimeCacheEntry,1);
entry->location = location;
entry->timestamp = timestamp;
/* add the entry to the list */
tc->curgroup->entries = g_list_prepend(tc->curgroup->entries,entry);
/* update the bounds */
if (tc->curgroup->mintimestamp > timestamp) tc->curgroup->mintimestamp = timestamp;
if (tc->curgroup->maxtimestamp < timestamp) tc->curgroup->maxtimestamp = timestamp;
if (tc->curgroup->minlocation > location) tc->curgroup->minlocation = location;
if (tc->curgroup->maxlocation < location) tc->curgroup->maxlocation = location;
GST_DEBUG(0, "added entry to timecache group %d",tc->curgroup->groupnum);
}
static gint
_gst_time_cache_find_location (const GstTimeCacheEntry *entry, const guint64 *location)
{
if (*location < entry->location) return -1;
else if (*location > entry->location) return 1;
else return 0;
}
/**
* gst_time_cache_find_location:
* @tc: the timecache to find the timestamp in
* @location: the location
* @timestamp: the timestamp
*
* Look up the associated timestamp for the given location in the
* timecache.
*
* Returns: TRUE if the location was found in the timecache.
*/
gboolean
gst_time_cache_find_location (GstTimeCache *tc, guint64 location, gint64 *timestamp)
{
GList *list;
GstTimeCacheEntry *entry = NULL;
/* first check to see if it's in the current group */
if ((tc->curgroup->minlocation <= location) && (location <= tc->curgroup->maxlocation)) {
GST_DEBUG(0, "location %Ld is in group %d",location,tc->curgroup->groupnum);
list = g_list_find_custom(tc->curgroup->entries,&location,(GCompareFunc)_gst_time_cache_find_location);
if (list) entry = (GstTimeCacheEntry *)(list->data);
if (entry) *timestamp = entry->timestamp;
return TRUE;
}
/* TODO: search other groups */
/* failure */
return FALSE;
}
static gint
_gst_time_cache_find_timestamp (const GstTimeCacheEntry *entry, const gint64 *timestamp)
{
if (*timestamp < entry->timestamp) return -1;
else if (*timestamp > entry->timestamp) return 1;
else return 0;
}
/**
* gst_time_cache_find_timestamp:
* @tc: the timecache to find the location in
* @location: the location
* @timestamp: the timestamp
*
* Look up the associated location for the given timestamp in the
* timecache.
*
* Returns: TRUE if the timestamp was found in the timecache.
*/
gboolean
gst_time_cache_find_timestamp (GstTimeCache *tc, gint64 timestamp, guint64 *location)
{
GList *entries, *groups;
GstTimeCacheEntry *entry = NULL;
GstTimeCacheGroup *group;
/* first check to see if it's in the current group */
if ((tc->curgroup->mintimestamp <= timestamp) && (timestamp <= tc->curgroup->maxtimestamp)) {
GST_DEBUG(0, "timestamp %Ld may be in group %d",timestamp,tc->curgroup->groupnum);
entries = g_list_find_custom(tc->curgroup->entries,&timestamp,(GCompareFunc)_gst_time_cache_find_timestamp);
if (entries) entry = (GstTimeCacheEntry *)(entries->data);
if (entry) {
*location = entry->location;
return TRUE;
}
}
groups = tc->groups;
while (groups) {
group = (GstTimeCacheGroup *)(groups->data);
groups = g_list_next(groups);
if ((group->mintimestamp <= timestamp) && (timestamp <= group->maxtimestamp)) {
GST_DEBUG(0, "timestamp %Ld may be in group %d",timestamp,group->groupnum);
entries = g_list_find_custom(group->entries,&timestamp,(GCompareFunc)_gst_time_cache_find_timestamp);
if (entries) entry = (GstTimeCacheEntry *)(entries->data);
if (entry) {
*location = entry->location;
return TRUE;
}
}
}
/* failure */
return FALSE;
}