I wish to draw a few lines on top of video using NvDsLineMeta. I tested it with deepstream-test1-app by inserting the line information manually to NvDsLineMeta. It doesn’t work like what I expect. May I know how we draw a line with NvDsLineMeta without creating a new plugin.
#include <gst/gst.h>
#include <glib.h>
#include "gstnvdsmeta.h"
#define MAX_DISPLAY_LEN 64
#define PGIE_CLASS_ID_VEHICLE 0
#define PGIE_CLASS_ID_PERSON 2
gint frame_number = 0;
gchar pgie_classes_str[4][32] = { "Vehicle", "TwoWheeler", "Person",
"Roadsign"
};
/* osd_sink_pad_buffer_probe will extract metadata received on OSD sink pad
* and update params for drawing rectangle, object information etc. */
static void generate_line_meta(gpointer data)
{ guint l_index, num_lines;
//NvOSD_LineParams *line_param = NULL;
NvDsLineMeta *meta = (NvDsLineMeta *) data;
meta->num_lines = 1.0;
meta->batch_id = 1.0;
num_lines = meta->num_lines;
NvOSD_LineParams *line_param = (NvOSD_LineParams *) g_malloc0 (sizeof (NvOSD_LineParams));
meta->line_params[0] = g_malloc0 (sizeof (NvOSD_LineParams));
meta->line_params[1] = g_malloc0 (sizeof (NvOSD_LineParams));
//line_param = & (meta->line_params[0]);
line_param = g_malloc0 (sizeof (NvOSD_LineParams));
//g_print("x1 = %d \n", line_param->x1);
line_param->x1 = 100;
// //g_print ("Linex1 b4 = %d \n", line_param->x1 );
line_param->y1 = 100;
line_param->x2 = 400;
line_param->y2 = 400;
line_param->line_width = 10;
line_param->line_color.red = 1.0;
line_param->line_color.green = 0.0;
line_param->line_color.blue = 0.0;
line_param->line_color.alpha = 1.0;
meta->line_params[0] = line_param;
meta->line_params[1] = line_param;
//g_print ("Test %d\n", meta->line_params[0].x1);
}
static GstPadProbeReturn
osd_sink_pad_buffer_probe (GstPad * pad, GstPadProbeInfo * info,
gpointer u_data)
{
GstMeta *gst_meta = NULL;
NvDsMeta *nvdsmeta = NULL;
gpointer state = NULL;
static GQuark _nvdsmeta_quark = 0;
GstBuffer *buf = (GstBuffer *) info->data; //Put all the data from the probe to GstBuffer buf
NvDsFrameMeta *frame_meta = NULL;
NvDsLineMeta *line_meta = NULL;
guint num_rects = 0, rect_index = 0;
NvDsObjectParams *obj_meta = NULL;
NvOSD_LineParams *line_param = NULL;
guint i = 0;
NvOSD_TextParams *txt_params = NULL;
guint vehicle_count = 0;
guint person_count = 0;
if (!_nvdsmeta_quark)
_nvdsmeta_quark = g_quark_from_static_string (NVDS_META_STRING); //NVDS_META_STRING = nvdsmeta, get a quark from nvdsmeta, if NULL, create a new quark to nvdsmeta.
while ((gst_meta = gst_buffer_iterate_meta (buf, &state))) { //&state = NULL, Get the the gst_meta from the current buffer. Iterate the buffer to get NvDsMeta.
if (gst_meta_api_type_has_tag (gst_meta->info->api, _nvdsmeta_quark)) { //To find the gst_meta with quark tag (nvdsmeta), so that it return TRUE for nvdsmeta.
nvdsmeta = (NvDsMeta *) gst_meta;
/* We are interested only in intercepting Meta of type
* "NVDS_META_FRAME_INFO" as they are from our infer elements. */
if (nvdsmeta->meta_type == NVDS_META_FRAME_INFO) { //There are still alot of information from NvDsMeta nvdsmeta, set meta_type to NVDS_META_FRAME_INFO only
frame_meta = (NvDsFrameMeta *) nvdsmeta->meta_data; //Set nvdsmeta->(gpointer)meta_data to frame_meta.
if (frame_meta == NULL) {
g_print ("NvDsFrameMeta contained NULL meta \n");
return GST_PAD_PROBE_OK;
}
/* We reset the num_strings here as we plan to iterate through the
* the detected objects and form our own strings.
* The pipeline generated strings shall be discarded.
*/
frame_meta->num_strings = 0;
num_rects = frame_meta->num_rects;
/* This means we have num_rects in frame_meta->obj_params,
* now lets iterate through them */
for (rect_index = 0; rect_index < num_rects; rect_index++) {
/* Now using above information we need to form a text that should
* be displayed on top of the bounding box, so lets form it here. */
obj_meta = (NvDsObjectParams *) & frame_meta->obj_params[rect_index];
txt_params = &(obj_meta->text_params);
/*
if (txt_params->display_text)
g_free (txt_params->display_text);
txt_params->display_text = g_malloc0 (MAX_DISPLAY_LEN);
g_snprintf (txt_params->display_text, MAX_DISPLAY_LEN, "%s %d",
pgie_classes_str[obj_meta->class_id], obj_meta->tracking_id );*/
if (obj_meta->class_id == PGIE_CLASS_ID_VEHICLE)
vehicle_count++;
if (obj_meta->class_id == PGIE_CLASS_ID_PERSON)
person_count++;
/* Now set the offsets where the string should appear */
txt_params->x_offset = obj_meta->rect_params.left;
txt_params->y_offset = obj_meta->rect_params.top - 25;
/* Font , font-color and font-size */
txt_params->font_params.font_name = "Arial";
txt_params->font_params.font_size = 10;
txt_params->font_params.font_color.red = 1.0;
txt_params->font_params.font_color.green = 1.0;
txt_params->font_params.font_color.blue = 1.0;
txt_params->font_params.font_color.alpha = 1.0;
/* Text background color */
txt_params->set_bg_clr = 1;
txt_params->text_bg_clr.red = 0.0;
txt_params->text_bg_clr.green = 0.0;
txt_params->text_bg_clr.blue = 0.0;
txt_params->text_bg_clr.alpha = 1.0;
frame_meta->num_strings++;
}
}
NvDsMeta *gst_line_meta = NULL;
NvDsLineMeta *line_meta = (NvDsLineMeta *) g_malloc0 (sizeof (NvDsLineMeta));
generate_line_meta (line_meta);
//g_print ("line = %d\n", line_meta->line_params[0]->x1);
gst_line_meta = gst_buffer_add_nvds_meta (buf, line_meta, NULL);
if (nvdsmeta->meta_type == NVDS_META_LINE_INFO)
g_print ("In2\n");
//g_print ("In2\n");
}
}
/*g_print ("Frame Number = %d Number of objects = %d "
"Vehicle Count = %d Person Count = %d\n",
frame_number, num_rects, vehicle_count, person_count);*/
frame_number++;
return GST_PAD_PROBE_OK;
}
static gboolean
bus_call (GstBus * bus, GstMessage * msg, gpointer data)
{
GMainLoop *loop = (GMainLoop *) data;
switch (GST_MESSAGE_TYPE (msg)) {
case GST_MESSAGE_EOS:
g_print ("End of stream\n");
g_main_loop_quit (loop);
break;
case GST_MESSAGE_ERROR:{
gchar *debug;
GError *error;
gst_message_parse_error (msg, &error, &debug);
g_printerr ("ERROR from element %s: %s\n",
GST_OBJECT_NAME (msg->src), error->message);
if (debug)
g_printerr ("Error details: %s\n", debug);
g_free (debug);
g_error_free (error);
g_main_loop_quit (loop);
break;
}
default:
break;
}
return TRUE;
}
int
main (int argc, char *argv[])
{
GMainLoop *loop = NULL;
GstElement *pipeline = NULL, *source = NULL, *h264parser = NULL,
*decoder = NULL, *sink = NULL, *pgie = NULL, *nvvidconv = NULL, *dsexample = NULL,
*nvosd = NULL, *tracker = NULL;
GstBus *bus = NULL;
guint bus_watch_id;
gulong osd_probe_id = 0;
GstPad *osd_sink_pad = NULL;
/* Check input arguments */
if (argc != 2) {
g_printerr ("Usage: %s <H264 filename>\n", argv[0]);
return -1;
}
/* Standard GStreamer initialization */
gst_init (&argc, &argv);
loop = g_main_loop_new (NULL, FALSE);
/* Create gstreamer elements */
/* Create Pipeline element that will form a connection of other elements */
pipeline = gst_pipeline_new ("dstest1-pipeline");
/* Source element for reading from the file */
source = gst_element_factory_make ("filesrc", "file-source");
/* Since the data format in the input file is elementary h264 stream,
* we need a h264parser */
h264parser = gst_element_factory_make ("h264parse", "h264-parser");
/* Use nvdec_h264 for hardware accelerated decode on GPU */
decoder = gst_element_factory_make ("nvdec_h264", "nvh264-decoder");
/* Use nvinfer to run inferencing on decoder's output,
* behaviour of inferencing is set through config file */
pgie = gst_element_factory_make ("nvinfer", "primary-nvinference-engine");
/* Use nvtracker to tracker the result*/
tracker = gst_element_factory_make ("nvtracker", "nvidia-tracker");
/* Use convertor to convert from NV12 to RGBA as required by nvosd */
nvvidconv = gst_element_factory_make ("nvvidconv", "nvvideo-converter");
/* Use convertor to convert from NV12 to RGBA as required by nvosd */
//dsexample = gst_element_factory_make ("cairo", "dsexample_testing");
/* Create OSD to draw on the converted RGBA buffer */
nvosd = gst_element_factory_make ("nvosd", "nv-onscreendisplay");
/* Finally render the osd output */
sink = gst_element_factory_make ("nveglglessink", "nvvideo-renderer");
if (!pipeline || !source || !h264parser || !decoder || !pgie || !tracker
|| !nvvidconv || !nvosd || !sink) {
g_printerr ("One element could not be created. Exiting.\n");
return -1;
}
/* we set the input filename to the source element */
g_object_set (G_OBJECT (source), "location", argv[1], NULL);
/* Set all the necessary properties of the nvinfer element,
* the necessary ones are : */
g_object_set (G_OBJECT (pgie),
"config-file-path", "dstest1_pgie_config.txt", NULL);
/* we set the input tracking configuration into tracking element */
g_object_set (G_OBJECT (tracker), "tracker-width", 640, "tracker-height", 368,
"tracker-algorithm", 1, "iou-threshold", 0.9, NULL);
//g_object_set (G_OBJECT (dsexample), "full-frame", 1, NULL);
/* we set the osd properties here */
//g_object_set (G_OBJECT (nvosd), "font-size", 45, NULL);
/* we add a message handler */
bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
bus_watch_id = gst_bus_add_watch (bus, bus_call, loop);
gst_object_unref (bus);
/* Set up the pipeline */
/* we add all elements into the pipeline */
gst_bin_add_many (GST_BIN (pipeline),
source, h264parser, decoder, pgie, tracker,
nvvidconv, nvosd, sink, NULL);
/* we link the elements together */
/* file-source -> h264-parser -> nvh264-decoder ->
* nvinfer -> nvtracker -> nvvidconv -> nvosd -> video-renderer */
if (!gst_element_link_many (source, h264parser, decoder, pgie, tracker,
nvvidconv, nvosd, sink, NULL)) {
g_printerr ("Elements could not be linked. Exiting.\n");
return -1;
}
/* Lets add probe to get informed of the meta data generated, we add probe to
* the sink pad of the osd element, since by that time, the buffer would have
* had got all the metadata. */
osd_sink_pad = gst_element_get_static_pad (nvosd, "sink");
if (!osd_sink_pad)
g_print ("Unable to get sink pad\n");
else
osd_probe_id = gst_pad_add_probe (osd_sink_pad, GST_PAD_PROBE_TYPE_BUFFER,
osd_sink_pad_buffer_probe, NULL, NULL);
/* Set the pipeline to "playing" state */
g_print ("Now playing: %s\n", argv[1]);
gst_element_set_state (pipeline, GST_STATE_PLAYING);
/* Wait till pipeline encounters an error or EOS */
g_print ("Running...\n");
g_main_loop_run (loop);
/* Out of the main loop, clean up nicely */
g_print ("Returned, stopping playback\n");
gst_element_set_state (pipeline, GST_STATE_NULL);
g_print ("Deleting pipeline\n");
gst_object_unref (GST_OBJECT (pipeline));
g_source_remove (bus_watch_id);
g_main_loop_unref (loop);
return 0;
}
