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+/*
+ * GStreamer
+ * Copyright (C) 2006 James Livingston <doclivingston@gmail.com>
+ * Copyright (C) 2008 Vincent Penquerc'h <ogg.k.ogg.k@googlemail.com>
+ *
+ * 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.
+ */
+
+/**
+ * SECTION:element-katetag
+ * @see_also: #oggdemux, #oggmux, #kateparse, #GstTagSetter
+ * @short_description: retags kate streams
+ *
+ * <refsect2>
+ * <para>
+ * The katetag element can change the tag contained within a raw
+ * kate stream. Specifically, it modifies the comments header packet
+ * of the kate stream, as well as the language and category of the
+ * kate stream.
+ * </para>
+ * <para>
+ * The element will also process the stream as the #kateparse element does
+ * so it can be used when remuxing an Ogg Kate stream, without additional
+ * elements.
+ * </para>
+ * <para>
+ * Applications can set the tags to write using the #GstTagSetter interface.
+ * Tags contained within the kate stream will be picked up
+ * automatically (and merged according to the merge mode set via the tag
+ * setter interface).
+ * </para>
+ * <title>Example pipelines</title>
+ * <para>
+ * This element is only useful with gst-launch for modifying the language
+ * and/or category (which are properties of the stream located in the kate
+ * beginning of stream header), because it does not support setting the tags
+ * on a #GstTagSetter interface. Conceptually, the element will usually be
+ * used like:
+ * <programlisting>
+ * gst-launch -v filesrc location=foo.ogg ! oggdemux ! katetag ! oggmux ! filesink location=bar.ogg
+ * </programlisting>
+ * </para>
+ * <para>
+ * This pipeline will set the language and category of the stream to the
+ * given values:
+ * <programlisting>
+ * gst-launch -v filesrc location=foo.ogg ! oggdemux ! katetag language=pt_BR category=subtitles ! oggmux ! filesink location=bar.ogg
+ * </programlisting>
+ * </para>
+ * </refsect2>
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <string.h>
+#include <glib.h>
+#include <gst/tag/tag.h>
+#include <gst/gsttagsetter.h>
+
+#include <kate/kate.h>
+
+#include "gstkatetag.h"
+
+
+GST_DEBUG_CATEGORY_EXTERN (gst_katetag_debug);
+#define GST_CAT_DEFAULT gst_katetag_debug
+
+enum
+{
+ ARG_0,
+ ARG_LANGUAGE,
+ ARG_CATEGORY,
+ ARG_ORIGINAL_CANVAS_WIDTH,
+ ARG_ORIGINAL_CANVAS_HEIGHT,
+};
+
+static void gst_kate_tag_base_init (gpointer g_class);
+static void gst_kate_tag_class_init (GstKateTagClass * klass);
+static void gst_kate_tag_init (GstKateTag * kt, GstKateTagClass * g_class);
+static GstFlowReturn gst_kate_tag_parse_packet (GstKateParse * parse,
+ GstBuffer * buffer);
+static void gst_kate_tag_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec);
+static void gst_kate_tag_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec);
+static void gst_kate_tag_dispose (GObject * object);
+
+
+#define _do_init(type) \
+ G_STMT_START{ \
+ static const GInterfaceInfo tag_setter_info = { \
+ NULL, \
+ NULL, \
+ NULL \
+ }; \
+ g_type_add_interface_static (type, GST_TYPE_TAG_SETTER, \
+ &tag_setter_info); \
+ }G_STMT_END
+
+GST_BOILERPLATE_FULL (GstKateTag, gst_kate_tag, GstKateParse,
+ GST_TYPE_KATE_PARSE, _do_init);
+
+static GstElementDetails kate_tag_details =
+GST_ELEMENT_DETAILS ("Kate stream tagger",
+ "Formatter/Metadata",
+ "Retags kate streams",
+ "Vincent Penquerc'h <ogg.k.ogg.k@googlemail.com>");
+
+
+static void
+gst_kate_tag_base_init (gpointer g_class)
+{
+ GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);
+
+ gst_element_class_set_details (element_class, &kate_tag_details);
+}
+
+static void
+gst_kate_tag_class_init (GstKateTagClass * klass)
+{
+ GObjectClass *gobject_class;
+ GstKateParseClass *gstkateparse_class;
+
+ gobject_class = (GObjectClass *) klass;
+ gstkateparse_class = GST_KATE_PARSE_CLASS (klass);
+
+ gobject_class->set_property = GST_DEBUG_FUNCPTR (gst_kate_tag_set_property);
+ gobject_class->get_property = GST_DEBUG_FUNCPTR (gst_kate_tag_get_property);
+ gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_kate_tag_dispose);
+
+ g_object_class_install_property (gobject_class, ARG_LANGUAGE,
+ g_param_spec_string ("language", "Language",
+ "Set the language of the stream", "", G_PARAM_READWRITE));
+
+ g_object_class_install_property (gobject_class, ARG_CATEGORY,
+ g_param_spec_string ("category", "Category",
+ "Set the category of the stream", "", G_PARAM_READWRITE));
+
+ g_object_class_install_property (gobject_class, ARG_ORIGINAL_CANVAS_WIDTH,
+ g_param_spec_int ("original-canvas-width", "Original canvas width",
+ "Set the width of the canvas this stream was authored for (0 is unspecified)",
+ 0, G_MAXINT, 0, G_PARAM_READWRITE));
+
+ g_object_class_install_property (gobject_class, ARG_ORIGINAL_CANVAS_HEIGHT,
+ g_param_spec_int ("original-canvas-height", "Original canvas height",
+ "Set the height of the canvas this stream was authored for (0 is unspecified)",
+ 0, G_MAXINT, 0, G_PARAM_READWRITE));
+
+ gstkateparse_class->parse_packet =
+ GST_DEBUG_FUNCPTR (gst_kate_tag_parse_packet);
+}
+
+static void
+gst_kate_tag_init (GstKateTag * kt, GstKateTagClass * g_class)
+{
+ kt->language = NULL;
+ kt->category = NULL;
+ kt->original_canvas_width = -1;
+ kt->original_canvas_height = -1;
+}
+
+static void
+gst_kate_tag_dispose (GObject * object)
+{
+ GstKateTag *kt = GST_KATE_TAG (object);
+
+ GST_LOG_OBJECT (kt, "disposing");
+
+ if (kt->language) {
+ g_free (kt->language);
+ kt->language = NULL;
+ }
+ if (kt->category) {
+ g_free (kt->category);
+ kt->category = NULL;
+ }
+
+ GST_CALL_PARENT (G_OBJECT_CLASS, dispose, (object));
+}
+
+static void
+gst_kate_tag_set_property (GObject * object, guint prop_id,
+ const GValue * value, GParamSpec * pspec)
+{
+ GstKateTag *kt = GST_KATE_TAG (object);
+ const char *str;
+
+ switch (prop_id) {
+ case ARG_LANGUAGE:
+ if (kt->language) {
+ g_free (kt->language);
+ kt->language = NULL;
+ }
+ str = g_value_get_string (value);
+ if (str)
+ kt->language = g_strdup (str);
+ break;
+ case ARG_CATEGORY:
+ if (kt->category) {
+ g_free (kt->category);
+ kt->category = NULL;
+ }
+ str = g_value_get_string (value);
+ if (str)
+ kt->category = g_strdup (str);
+ break;
+ case ARG_ORIGINAL_CANVAS_WIDTH:
+ kt->original_canvas_width = g_value_get_int (value);
+ break;
+ case ARG_ORIGINAL_CANVAS_HEIGHT:
+ kt->original_canvas_height = g_value_get_int (value);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static void
+gst_kate_tag_get_property (GObject * object, guint prop_id,
+ GValue * value, GParamSpec * pspec)
+{
+ GstKateTag *kt = GST_KATE_TAG (object);
+
+ switch (prop_id) {
+ case ARG_LANGUAGE:
+ g_value_set_string (value, kt->language ? kt->language : "");
+ break;
+ case ARG_CATEGORY:
+ g_value_set_string (value, kt->category ? kt->category : "");
+ break;
+ case ARG_ORIGINAL_CANVAS_WIDTH:
+ g_value_set_int (value, kt->original_canvas_width);
+ break;
+ case ARG_ORIGINAL_CANVAS_HEIGHT:
+ g_value_set_int (value, kt->original_canvas_height);
+ break;
+ default:
+ G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+ break;
+ }
+}
+
+static guint16
+encode_canvas_size (size_t size)
+{
+ size_t base = size;
+ size_t shift = 0;
+ int value;
+
+ while (base & ~((1 << 12) - 1)) {
+ /* we have a high bit we can't fit, increase shift if we wouldn't lose low bits */
+ if ((size >> shift) & 1)
+ return 0;
+ ++shift;
+ base >>= 1;
+ }
+ if (G_UNLIKELY (shift >= 16))
+ return 0;
+
+ /* the size can be represented in our encoding */
+ value = (base << 4) | shift;
+
+ return (guint16) value;
+}
+
+static GstFlowReturn
+gst_kate_tag_parse_packet (GstKateParse * parse, GstBuffer * buffer)
+{
+ GstTagList *old_tags, *new_tags;
+ const GstTagList *user_tags;
+ GstKateTag *kt;
+ gchar *encoder = NULL;
+ GstBuffer *new_buf;
+
+ kt = GST_KATE_TAG (parse);
+
+ /* rewrite the language and category */
+ if (GST_BUFFER_SIZE (buffer) >= 64 && GST_BUFFER_DATA (buffer)[0] == 0x80) {
+ buffer = gst_buffer_copy (buffer);
+
+ /* language is at offset 32, 16 bytes, zero terminated */
+ if (kt->language) {
+ strncpy ((char *) GST_BUFFER_DATA (buffer) + 32, kt->language, 15);
+ GST_BUFFER_DATA (buffer)[47] = 0;
+ }
+ /* category is at offset 48, 16 bytes, zero terminated */
+ if (kt->category) {
+ strncpy ((char *) GST_BUFFER_DATA (buffer) + 48, kt->category, 15);
+ GST_BUFFER_DATA (buffer)[63] = 0;
+ }
+ if (kt->original_canvas_width >= 0) {
+ guint16 v = encode_canvas_size (kt->original_canvas_width);
+ GST_BUFFER_DATA (buffer)[16] = v & 0xff;
+ GST_BUFFER_DATA (buffer)[17] = (v >> 8) & 0xff;
+ }
+ if (kt->original_canvas_height >= 0) {
+ guint16 v = encode_canvas_size (kt->original_canvas_height);
+ GST_BUFFER_DATA (buffer)[18] = v & 0xff;
+ GST_BUFFER_DATA (buffer)[19] = (v >> 8) & 0xff;
+ }
+ }
+
+ /* rewrite the comments packet */
+ if (GST_BUFFER_SIZE (buffer) >= 9 && GST_BUFFER_DATA (buffer)[0] == 0x81) {
+ old_tags =
+ gst_tag_list_from_vorbiscomment_buffer (buffer,
+ (const guint8 *) "\201kate\0\0\0\0", 9, &encoder);
+ user_tags = gst_tag_setter_get_tag_list (GST_TAG_SETTER (kt));
+
+ /* build new tag list */
+ new_tags = gst_tag_list_merge (user_tags, old_tags,
+ gst_tag_setter_get_tag_merge_mode (GST_TAG_SETTER (kt)));
+ gst_tag_list_free (old_tags);
+
+ new_buf =
+ gst_tag_list_to_vorbiscomment_buffer (new_tags,
+ (const guint8 *) "\201kate\0\0\0\0", 9, encoder);
+ gst_buffer_copy_metadata (new_buf, buffer, GST_BUFFER_COPY_TIMESTAMPS);
+
+ gst_tag_list_free (new_tags);
+ g_free (encoder);
+ gst_buffer_unref (buffer);
+
+ /* the buffer will have the framing bit used by Vorbis, but we don't use it */
+ --GST_BUFFER_SIZE (new_buf);
+
+ buffer = new_buf;
+ }
+
+ return GST_KATE_PARSE_CLASS (parent_class)->parse_packet (parse, buffer);
+}
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