diff options
Diffstat (limited to 'ext/metadata/gstmetadatademux.c')
| -rw-r--r-- | ext/metadata/gstmetadatademux.c | 224 |
1 files changed, 164 insertions, 60 deletions
diff --git a/ext/metadata/gstmetadatademux.c b/ext/metadata/gstmetadatademux.c index 6393319e..a183739f 100644 --- a/ext/metadata/gstmetadatademux.c +++ b/ext/metadata/gstmetadatademux.c @@ -42,18 +42,57 @@ */ /** - * SECTION:metadatademux-metadata + * SECTION: element-metadatademux + * @short_description: element that parse or demux metadata from image files + * @see_also: #metadatamux * * <refsect2> + * <para> + * This element parses image files JPEG and PNG, to find metadata chunks (EXIF, + * IPTC, XMP) in it, and then send individual tags as a 'tag message' do the + * application and as 'tag event' to the next element in pipeline. It also + * strips out the metadata chunks from original stream (unless the 'parse-only' + * property is set to 'true'). In addition the whole metadata chunk (striped + * or not) it also sent as a message to the application bus, so the application + * can have more controls about the metadata. + * </para> * <title>Example launch line</title> * <para> * <programlisting> - * gst-launch -v -m filesrc location=./test.jpeg ! metadatademux ! fakesink silent=TRUE + * gst-launch -v -m filesrc location=./test.jpeg ! metadatademux ! fakesink + * silent=TRUE + * </programlisting> + * <programlisting> + * GST_DEBUG:*metadata:5 gst-launch filesrc location=./test.jpeg ! + * metadatademux ! fakesink + * </programlisting> + * </para> + * <title>Application sample code using 'libexif' to have more control</title> + * <para> + * <programlisting> + * val = gst_tag_list_get_value_index (taglist, GST_TAG_EXIF, 0); + * if (val) { + * exif_chunk = gst_value_get_buffer (val); + * if (exif_chunk) { + * ed = exif_data_new_from_data (GST_BUFFER_DATA (exif_chunk), + * GST_BUFFER_SIZE (exif_chunk)); + * } + * } * </programlisting> + * This same idea can be used to handle IPTC and XMP directly by using + * libdata and exempi (or any other libraries). Notice: the whole metadata + * chunk sent as a message to the application contains only metadata data, i.e. + * the wrapper specific to the file format (JPEG, PNG, ...) is already + * striped out. * </para> * </refsect2> */ + +/* + * includes + */ + #ifdef HAVE_CONFIG_H # include <config.h> #endif @@ -70,16 +109,13 @@ #include <string.h> -GST_DEBUG_CATEGORY_STATIC (gst_metadata_demux_debug); -#define GST_CAT_DEFAULT gst_metadata_demux_debug -#define GOTO_DONE_IF_NULL(ptr) do { if ( NULL == (ptr) ) goto done; } while(FALSE) -#define GOTO_DONE_IF_NULL_AND_FAIL(ptr, ret) do { if ( NULL == (ptr) ) { (ret) = FALSE; goto done; } } while(FALSE) +/* + * enum and types + */ -/* Filter signals and args */ enum { - /* FILL ME */ LAST_SIGNAL }; @@ -89,6 +125,19 @@ enum ARG_PARSE_ONLY }; +/* + * defines and static global vars + */ + + +GST_DEBUG_CATEGORY_STATIC (gst_metadata_demux_debug); +#define GST_CAT_DEFAULT gst_metadata_demux_debug + +#define GOTO_DONE_IF_NULL(ptr) \ + do { if ( NULL == (ptr) ) goto done; } while(FALSE) +#define GOTO_DONE_IF_NULL_AND_FAIL(ptr, ret) \ + do { if ( NULL == (ptr) ) { (ret) = FALSE; goto done; } } while(FALSE) + static GstStaticPadTemplate sink_factory = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, @@ -105,35 +154,113 @@ static GstStaticPadTemplate src_factory = GST_STATIC_PAD_TEMPLATE ("src", "image/png, " "tags-extracted = (bool) true") ); -GST_BOILERPLATE (GstMetadataDemux, gst_metadata_demux, GstBaseMetadata, - GST_TYPE_BASE_METADATA); - static GstMetadataDemuxClass *metadata_parent_class = NULL; +/* + * static helper functions declaration + */ + +static gboolean +gst_metadata_demux_configure_srccaps (GstMetadataDemux * filter); + +/* + * GObject callback functions declaration + */ + +static void gst_metadata_demux_base_init (gpointer gclass); + +static void gst_metadata_demux_class_init (GstMetadataDemuxClass * klass); + +static void +gst_metadata_demux_init (GstMetadataDemux * filter, + GstMetadataDemuxClass * gclass); + static void gst_metadata_demux_dispose (GObject * object); static void gst_metadata_demux_finalize (GObject * object); static void gst_metadata_demux_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); + static void gst_metadata_demux_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); -static GstCaps *gst_metadata_demux_get_caps (GstPad * pad); +/* + * GstBaseMetadata virtual functions declaration + */ + +static void gst_metadata_demux_send_tags (GstBaseMetadata * base); + static gboolean gst_metadata_demux_set_caps (GstPad * pad, GstCaps * caps); + +static GstCaps *gst_metadata_demux_get_caps (GstPad * pad); + static gboolean gst_metadata_demux_sink_event (GstPad * pad, GstEvent * event); -static void gst_metadata_demux_send_tags (GstBaseMetadata * base); + +/* + * GST BOILERPLATE + */ + +GST_BOILERPLATE (GstMetadataDemux, gst_metadata_demux, GstBaseMetadata, + GST_TYPE_BASE_METADATA); + +/* + * static helper functions implementation + */ + +static gboolean +gst_metadata_demux_configure_srccaps (GstMetadataDemux * filter) +{ + GstCaps *caps = NULL; + gboolean ret = FALSE; + gchar *mime = NULL; + + switch (GST_BASE_METADATA_IMG_TYPE (filter)) { + case IMG_JPEG: + mime = "image/jpeg"; + break; + case IMG_PNG: + mime = "image/png"; + break; + default: + ret = FALSE; + goto done; + break; + } + + caps = + gst_caps_new_simple (mime, "tags-extracted", G_TYPE_BOOLEAN, TRUE, NULL); + + ret = gst_pad_set_caps (GST_BASE_METADATA_SRC_PAD (filter), caps); + +done: + + if (caps) { + gst_caps_unref (caps); + caps = NULL; + } + + return ret; + +} + +/* + * GObject callback functions implementation + */ static void gst_metadata_demux_base_init (gpointer gclass) { +/* *INDENT-OFF* */ static GstElementDetails element_details = { - "Metadata demuxr", - "Demuxr/Extracter/Metadata", - "Send metadata tags (EXIF, IPTC and XMP) and remove metadata chunks from stream", + "Metadata demuxer", + "Demuxer/Extracter/Metadata", + "Send metadata tags (EXIF, IPTC and XMP) and " + "remove metadata chunks from stream", "Edgard Lima <edgard.lima@indt.org.br>" }; +/* *INDENT-ON* */ GstElementClass *element_class = GST_ELEMENT_CLASS (gclass); gst_element_class_add_pad_template (element_class, @@ -143,7 +270,6 @@ gst_metadata_demux_base_init (gpointer gclass) gst_element_class_set_details (element_class, &element_details); } -/* initialize the plugin's class */ static void gst_metadata_demux_class_init (GstMetadataDemuxClass * klass) { @@ -180,11 +306,6 @@ gst_metadata_demux_class_init (GstMetadataDemuxClass * klass) } -/* initialize the new element - * instantiate pads and add them to element - * set functions - * initialize structure - */ static void gst_metadata_demux_init (GstMetadataDemux * filter, GstMetadataDemuxClass * gclass) @@ -250,6 +371,23 @@ gst_metadata_demux_finalize (GObject * object) G_OBJECT_CLASS (metadata_parent_class)->finalize (object); } + +/* + * GstBaseMetadata virtual functions implementation + */ + +/* + * gst_metadata_demux_send_tags: + * @base: the base metadata instance + * + * Send individual tags as message to the bus and as event to the next + * element, and send the whole metadata chunk (with file specific wrapper + * striped) to the next element as a event. + * + * Returns: nothing + * + */ + static void gst_metadata_demux_send_tags (GstBaseMetadata * base) { @@ -260,6 +398,8 @@ gst_metadata_demux_send_tags (GstBaseMetadata * base) GstEvent *event; GstPad *srcpad = GST_BASE_METADATA_SRC_PAD (filter); + /* get whole chunk */ + if (gst_base_metadata_get_option_flag (base) & META_OPT_EXIF) metadataparse_exif_tag_list_add (taglist, GST_TAG_MERGE_KEEP, GST_BASE_METADATA_EXIF_ADAPTER (base), METADATA_TAG_MAP_WHOLECHUNK); @@ -284,6 +424,8 @@ gst_metadata_demux_send_tags (GstBaseMetadata * base) if (!taglist) taglist = gst_tag_list_new (); + /*get individual tags */ + if (gst_base_metadata_get_option_flag (base) & META_OPT_EXIF) metadataparse_exif_tag_list_add (taglist, GST_TAG_MERGE_KEEP, GST_BASE_METADATA_EXIF_ADAPTER (base), METADATA_TAG_MAP_INDIVIDUALS); @@ -307,44 +449,6 @@ gst_metadata_demux_send_tags (GstBaseMetadata * base) } static gboolean -gst_metadata_demux_configure_srccaps (GstMetadataDemux * filter) -{ - GstCaps *caps = NULL; - gboolean ret = FALSE; - gchar *mime = NULL; - - switch (GST_BASE_METADATA_IMG_TYPE (filter)) { - case IMG_JPEG: - mime = "image/jpeg"; - break; - case IMG_PNG: - mime = "image/png"; - break; - default: - ret = FALSE; - goto done; - break; - } - - caps = - gst_caps_new_simple (mime, "tags-extracted", G_TYPE_BOOLEAN, TRUE, NULL); - - ret = gst_pad_set_caps (GST_BASE_METADATA_SRC_PAD (filter), caps); - -done: - - if (caps) { - gst_caps_unref (caps); - caps = NULL; - } - - return ret; - -} - - -/* this function handles the link with other elements */ -static gboolean gst_metadata_demux_set_caps (GstPad * pad, GstCaps * caps) { GstMetadataDemux *filter = NULL; |