/*
* Copyright (c) 2007 Wayne Meissner
*
* This file is part of gstreamer-java.
*
* This code is free software: you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License version 3 only, as
* published by the Free Software Foundation.
*
* This code 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 Lesser General Public License
* version 3 for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* version 3 along with this work. If not, see <http://www.gnu.org/licenses/>.
*/
package org.gstreamer;
import static org.gstreamer.lowlevel.GlibAPI.GLIB_API;
import java.util.AbstractList;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import org.gstreamer.glib.GDate;
import org.gstreamer.lowlevel.GType;
import org.gstreamer.lowlevel.GstNative;
import org.gstreamer.lowlevel.GstTagAPI;
import org.gstreamer.lowlevel.GstTagListAPI;
import org.gstreamer.lowlevel.annotations.CallerOwnsReturn;
import com.sun.jna.Pointer;
import com.sun.jna.ptr.PointerByReference;
/**
* List of tags and values used to describe media metadata.
*/
@SuppressWarnings("serial")
public class TagList extends Structure {
private static interface API extends GstTagListAPI, GstTagAPI {
@CallerOwnsReturn Pointer ptr_gst_tag_list_new();
@CallerOwnsReturn Pointer ptr_gst_tag_list_copy(TagList list);
@CallerOwnsReturn Pointer ptr_gst_tag_list_merge(TagList list1, TagList list2, TagMergeMode mode);
void gst_tag_list_free(Pointer list);
}
private static final API gst = GstNative.load(API.class);
/**
* Creates a new instance of TagList
* @param init internal initialization data.
*/
public TagList(Initializer init) {
super(init);
}
/**
* Constructs a new empty tag list.
*/
public TagList() {
super(initializer(gst.ptr_gst_tag_list_new()));
}
/**
* Gets the number of values of type {@code tag} stored in the list.
*
* @param tag the name of the tag to get the size of.
* @return the number of values for {@code tag} in this list.
*/
public int getValueCount(String tag) {
return gst.gst_tag_list_get_tag_size(this, tag);
}
/**
* Gets all data values for a tag contained in this list.
*
* @param tag the name of the tag to retrieve.
* @return the data associated with {@code tag}.
*/
public List<Object> getValues(final String tag) {
final int size = getValueCount(tag);
return new AbstractList<Object>() {
@Override
public int size() {
return size;
}
@Override
public Object get(int index) {
return getValue(tag, index);
}
};
}
/**
* Gets all data values for a tag contained in this list.
*
* @param tag the name of the tag to retrieve.
* @return the data associated with {@code tag}.
*/
public List<Object> getValues(Tag tag) {
return getValues(tag.getId());
}
/**
* Gets data for a tag from this list.
*
* @param tag the tag to retrieve.
* @param index which element of the array of data for this tag to retrieve.
* @return the data for the tag.
*/
public Object getValue(String tag, int index) {
TagGetter get = MapHolder.getterMap.get(getTagType(tag));
return get != null ? get.get(this, tag, index) : "";
}
/**
* Gets data for a tag from this list.
*
* @param tag the tag to retrieve.
* @param index which element of the array of data for this tag to retrieve.
* @return the data for the tag.
*/
public Object getValue(Tag tag, int index) {
return getValue(tag.getId(), index);
}
/**
* Gets a string tag from this list.
*
* @param tag the tag to retrieve.
* @param index which element of the array of data for this tag to retrieve.
* @return the data for the tag.
*/
@Override
public String getString(String tag, int index) {
return getValue(tag, index).toString();
}
/**
* Gets a string tag from this list.
*
* @param tag the tag to retrieve.
* @param index which element of the array of data for this tag to retrieve.
* @return the data for the tag.
*/
public String getString(Tag tag, int index) {
return getString(tag.getId(), index);
}
/**
* Gets a numeric tag from this list.
*
* @param tag the tag to retrieve.
* @param index which element of the array of data for this tag to retrieve.
* @return the data for the tag.
*/
public Number getNumber(String tag, int index) {
Object data = getValue(tag, index);
if (!(data instanceof Number)) {
throw new IllegalArgumentException("Tag [" + tag + "] is not a number");
}
return (Number) data;
}
/**
* Gets a numeric tag from this list.
*
* @param tag the tag to retrieve.
* @param index which element of the array of data for this tag to retrieve.
* @return the data for the tag.
*/
public Number getNumber(Tag tag, int index) {
return getNumber(tag.getId(), index);
}
/**
* Gets a list of all the tags contained in this list.
*
* @return a list of tag names.
*/
public List<String> getTagNames() {
final List<String> list = new LinkedList<String>();
gst.gst_tag_list_foreach(this, new GstTagListAPI.TagForeachFunc() {
public void callback(Pointer ptr, String tag, Pointer user_data) {
list.add(tag);
}
}, null);
return list;
}
/**
* Merges this tag list and {@code list2} into a new list.
* If {@code list2} is null, a copy of this list is returned.
*
* @param list2 the other tag list to merge with this one.
* @param mode the {@link TagMergeMode}.
* @return a new tag list.
*/
public TagList merge(TagList list2, TagMergeMode mode) {
return gst.gst_tag_list_merge(this, list2, mode);
}
/**
* Gets the low level type for the tag.
*
* @param tag the tag
* @return the type of {@code tag}
*/
private static GType getTagType(String tag) {
GType type = MapHolder.tagTypeMap.get(tag);
if (type != null) {
return type;
}
MapHolder.tagTypeMap.put(tag, type = gst.gst_tag_get_type(tag));
return type;
}
@Override
protected void disposeNativeHandle(Pointer ptr) {
gst.gst_tag_list_free(ptr);
}
private static interface TagGetter {
Object get(TagList tl, String tag, int index);
}
//
// Put the maps in a holder class so they don't get initialized until used.
// This helps avoid calling gstreamer methods before Gst.init().
//
private static final class MapHolder {
private static final Map<GType, TagGetter> getterMap = new HashMap<GType, TagGetter>() {{
put(GType.INT, new TagGetter() {
public Object get(TagList tl, String tag, int index) {
int[] value = { 0 };
gst.gst_tag_list_get_int_index(tl, tag, index, value);
return value[0];
}
});
put(GType.UINT, new TagGetter() {
public Object get(TagList tl, String tag, int index) {
int[] value = { 0 };
gst.gst_tag_list_get_uint_index(tl, tag, index, value);
return value[0];
}
});
put(GType.INT64, new TagGetter() {
public Object get(TagList tl, String tag, int index) {
long[] value = { 0 };
gst.gst_tag_list_get_int64_index(tl, tag, index, value);
return value[0];
}
});
put(GType.DOUBLE, new TagGetter() {
public Object get(TagList tl, String tag, int index) {
double[] value = { 0d };
gst.gst_tag_list_get_double_index(tl, tag, index, value);
return value[0];
}
});
put(GType.STRING, new TagGetter() {
public Object get(TagList tl, String tag, int index) {
Pointer[] value = { null };
gst.gst_tag_list_get_string_index(tl, tag, index, value);
if (value[0] == null) {
return null;
}
@SuppressWarnings("deprecation")
String ret = value[0].getString(0, false);
GLIB_API.g_free(value[0]);
return ret;
}
});
put(GDate.GTYPE, new TagGetter() {
public Object get(TagList tl, String tag, int index) {
PointerByReference value = new PointerByReference();
gst.gst_tag_list_get_date_index(tl, tag, index, value);
if (value.getValue() == null) {
return null;
}
return new GDate(value.getValue(), false, true);
}
});
}};
static private final Map<String, GType> tagTypeMap = new ConcurrentHashMap<String, GType>();
}
}