/* GStreamer * Copyright (C) 2009 Stefan Kost * * 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., 51 Franklin St, Fifth Floor, * Boston, MA 02110-1301, USA. */ /** * SECTION:element-zbar * @title: zbar * * Detect bar codes in the video streams and send them as element messages to * the #GstBus if .#GstZBar:message property is %TRUE. * If the .#GstZBar:attach-frame property is %TRUE, the posted barcode message * includes a sample of the frame where the barcode was detected (Since 1.6). * * The element generate messages named`barcode`. The structure containes these fields: * * * #GstClockTime `timestamp`: the timestamp of the buffer that triggered the message. * * gchar * `type`: the symbol type. * * gchar * `symbol`: the deteted bar code data. * * gint `quality`: an unscaled, relative quantity: larger values are better than smaller * values. * * GstSample `frame`: the frame in which the barcode message was detected, if * the .#GstZBar:attach-frame property was set to %TRUE (Since 1.6) * * ## Example launch lines * |[ * gst-launch-1.0 -m v4l2src ! videoconvert ! zbar ! videoconvert ! xvimagesink * ]| This pipeline will detect barcodes and send them as messages. * |[ * gst-launch-1.0 -m v4l2src ! tee name=t ! queue ! videoconvert ! zbar ! fakesink t. ! queue ! xvimagesink * ]| Same as above, but running the filter on a branch to keep the display in color * */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include "gstzbar.h" #include #include #include GST_DEBUG_CATEGORY_STATIC (zbar_debug); #define GST_CAT_DEFAULT zbar_debug /* GstZBar signals and args */ enum { /* FILL ME */ LAST_SIGNAL }; enum { PROP_0, PROP_MESSAGE, PROP_ATTACH_FRAME, PROP_CACHE }; #define DEFAULT_CACHE FALSE #define DEFAULT_MESSAGE TRUE #define DEFAULT_ATTACH_FRAME FALSE #define ZBAR_YUV_CAPS \ "{ Y800, I420, YV12, NV12, NV21, Y41B, Y42B, YUV9, YVU9 }" static GstStaticPadTemplate gst_zbar_src_template = GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS, GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE (ZBAR_YUV_CAPS)) ); static GstStaticPadTemplate gst_zbar_sink_template = GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS, GST_STATIC_CAPS (GST_VIDEO_CAPS_MAKE (ZBAR_YUV_CAPS)) ); static void gst_zbar_finalize (GObject * object); static void gst_zbar_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec); static void gst_zbar_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec); static gboolean gst_zbar_start (GstBaseTransform * base); static gboolean gst_zbar_stop (GstBaseTransform * base); static GstFlowReturn gst_zbar_transform_frame_ip (GstVideoFilter * vfilter, GstVideoFrame * frame); #define gst_zbar_parent_class parent_class G_DEFINE_TYPE (GstZBar, gst_zbar, GST_TYPE_VIDEO_FILTER); static void gst_zbar_class_init (GstZBarClass * g_class) { GObjectClass *gobject_class; GstElementClass *gstelement_class; GstBaseTransformClass *trans_class; GstVideoFilterClass *vfilter_class; gobject_class = G_OBJECT_CLASS (g_class); gstelement_class = GST_ELEMENT_CLASS (g_class); trans_class = GST_BASE_TRANSFORM_CLASS (g_class); vfilter_class = GST_VIDEO_FILTER_CLASS (g_class); gobject_class->set_property = gst_zbar_set_property; gobject_class->get_property = gst_zbar_get_property; gobject_class->finalize = gst_zbar_finalize; g_object_class_install_property (gobject_class, PROP_MESSAGE, g_param_spec_boolean ("message", "message", "Post a barcode message for each detected code", DEFAULT_MESSAGE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); /** * GstZBar::attach-frame: * * Attach the frame in which the barcode was detected to the posted * barcode message. * * Since: 1.6 */ g_object_class_install_property (gobject_class, PROP_ATTACH_FRAME, g_param_spec_boolean ("attach-frame", "Attach frame", "Attach a frame dump to each barcode message", DEFAULT_ATTACH_FRAME, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)); g_object_class_install_property (gobject_class, PROP_CACHE, g_param_spec_boolean ("cache", "cache", "Enable or disable the inter-image result cache", DEFAULT_CACHE, G_PARAM_READWRITE | GST_PARAM_MUTABLE_READY | G_PARAM_STATIC_STRINGS)); gst_element_class_set_static_metadata (gstelement_class, "Barcode detector", "Filter/Analyzer/Video", "Detect bar codes in the video streams", "Stefan Kost "); gst_element_class_add_static_pad_template (gstelement_class, &gst_zbar_sink_template); gst_element_class_add_static_pad_template (gstelement_class, &gst_zbar_src_template); trans_class->start = GST_DEBUG_FUNCPTR (gst_zbar_start); trans_class->stop = GST_DEBUG_FUNCPTR (gst_zbar_stop); trans_class->transform_ip_on_passthrough = FALSE; vfilter_class->transform_frame_ip = GST_DEBUG_FUNCPTR (gst_zbar_transform_frame_ip); } static void gst_zbar_init (GstZBar * zbar) { zbar->cache = DEFAULT_CACHE; zbar->message = DEFAULT_MESSAGE; zbar->attach_frame = DEFAULT_ATTACH_FRAME; zbar->scanner = zbar_image_scanner_create (); } static void gst_zbar_finalize (GObject * object) { GstZBar *zbar = GST_ZBAR (object); zbar_image_scanner_destroy (zbar->scanner); G_OBJECT_CLASS (parent_class)->finalize (object); } static void gst_zbar_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) { GstZBar *zbar; g_return_if_fail (GST_IS_ZBAR (object)); zbar = GST_ZBAR (object); switch (prop_id) { case PROP_CACHE: zbar->cache = g_value_get_boolean (value); break; case PROP_MESSAGE: zbar->message = g_value_get_boolean (value); break; case PROP_ATTACH_FRAME: zbar->attach_frame = g_value_get_boolean (value); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static void gst_zbar_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) { GstZBar *zbar; g_return_if_fail (GST_IS_ZBAR (object)); zbar = GST_ZBAR (object); switch (prop_id) { case PROP_CACHE: g_value_set_boolean (value, zbar->cache); break; case PROP_MESSAGE: g_value_set_boolean (value, zbar->message); break; case PROP_ATTACH_FRAME: g_value_set_boolean (value, zbar->attach_frame); break; default: G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); break; } } static GstFlowReturn gst_zbar_transform_frame_ip (GstVideoFilter * vfilter, GstVideoFrame * frame) { GstZBar *zbar = GST_ZBAR (vfilter); gpointer data; gint stride, height; zbar_image_t *image; const zbar_symbol_t *symbol; int n; image = zbar_image_create (); /* all formats we support start with an 8-bit Y plane. zbar doesn't need * to know about the chroma plane(s) */ data = GST_VIDEO_FRAME_COMP_DATA (frame, 0); stride = GST_VIDEO_FRAME_COMP_STRIDE (frame, 0); height = GST_VIDEO_FRAME_HEIGHT (frame); zbar_image_set_format (image, GST_MAKE_FOURCC ('Y', '8', '0', '0')); zbar_image_set_size (image, stride, height); zbar_image_set_data (image, (gpointer) data, stride * height, NULL); /* scan the image for barcodes */ n = zbar_scan_image (zbar->scanner, image); if (G_UNLIKELY (n == -1)) { GST_WARNING_OBJECT (zbar, "Error trying to scan frame. Skipping"); goto out; } if (n == 0) goto out; /* extract results */ symbol = zbar_image_first_symbol (image); for (; symbol; symbol = zbar_symbol_next (symbol)) { zbar_symbol_type_t typ = zbar_symbol_get_type (symbol); const char *data = zbar_symbol_get_data (symbol); gint quality = zbar_symbol_get_quality (symbol); GST_DEBUG_OBJECT (zbar, "decoded %s symbol \"%s\" at quality %d", zbar_get_symbol_name (typ), data, quality); if (zbar->cache && zbar_symbol_get_count (symbol) != 0) continue; if (zbar->message) { GstMessage *m; GstStructure *s; GstSample *sample; GstCaps *sample_caps; s = gst_structure_new ("barcode", "timestamp", G_TYPE_UINT64, GST_BUFFER_TIMESTAMP (frame->buffer), "type", G_TYPE_STRING, zbar_get_symbol_name (typ), "symbol", G_TYPE_STRING, data, "quality", G_TYPE_INT, quality, NULL); if (zbar->attach_frame) { /* create a sample from image */ sample_caps = gst_video_info_to_caps (&frame->info); sample = gst_sample_new (frame->buffer, sample_caps, NULL, NULL); gst_caps_unref (sample_caps); gst_structure_set (s, "frame", GST_TYPE_SAMPLE, sample, NULL); gst_sample_unref (sample); } m = gst_message_new_element (GST_OBJECT (zbar), s); gst_element_post_message (GST_ELEMENT (zbar), m); } else if (zbar->attach_frame) GST_WARNING_OBJECT (zbar, "attach-frame=true has no effect if message=false"); } out: /* clean up */ zbar_image_scanner_recycle_image (zbar->scanner, image); zbar_image_destroy (image); return GST_FLOW_OK; } static gboolean gst_zbar_start (GstBaseTransform * base) { GstZBar *zbar = GST_ZBAR (base); /* start the cache if enabled (e.g. for filtering dupes) */ zbar_image_scanner_enable_cache (zbar->scanner, zbar->cache); return TRUE; } static gboolean gst_zbar_stop (GstBaseTransform * base) { GstZBar *zbar = GST_ZBAR (base); /* stop the cache if enabled (e.g. for filtering dupes) */ zbar_image_scanner_enable_cache (zbar->scanner, zbar->cache); return TRUE; } static gboolean plugin_init (GstPlugin * plugin) { GST_DEBUG_CATEGORY_INIT (zbar_debug, "zbar", 0, "zbar"); return gst_element_register (plugin, "zbar", GST_RANK_NONE, GST_TYPE_ZBAR); } GST_PLUGIN_DEFINE (GST_VERSION_MAJOR, GST_VERSION_MINOR, zbar, "zbar barcode scanner", plugin_init, VERSION, GST_LICENSE, GST_PACKAGE_NAME, GST_PACKAGE_ORIGIN);