The comprehensive code looks like this:
static GstPadProbeReturn tiler_src_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;
NvDsFrameMeta *frame_meta = NULL;
guint num_rects = 0, rect_index = 0;
NvDsObjectParams *obj_meta = NULL;
NvOSD_TextParams *txt_params = NULL;
GstNvStreamMeta *streammeta = NULL;
if (!_nvdsmeta_quark)
_nvdsmeta_quark = g_quark_from_static_string (NVDS_META_STRING);
if (probe_counter == 0) {
gettimeofday (&start_time, NULL);
} else if (probe_counter == FPS_PRINT_INTERVAL) {
struct timeval cur_time;
gettimeofday (&cur_time, NULL);
g_print ("FPS for the last %d batches: %.2f\n", FPS_PRINT_INTERVAL,
FPS_PRINT_INTERVAL / ((cur_time.tv_sec - start_time.tv_sec) +
(cur_time.tv_usec - start_time.tv_usec) / 1e6));
probe_counter = 0;
start_time = cur_time;
}
probe_counter++;
streammeta = gst_buffer_get_nvstream_meta (buf);
while ((gst_meta = gst_buffer_iterate_meta (buf, &state))) {
if (gst_meta_api_type_has_tag (gst_meta->info->api, _nvdsmeta_quark)) {
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) {
guint vehicle_count = 0;
guint person_count = 0;
frame_meta = (NvDsFrameMeta *) nvdsmeta->meta_data;
if (frame_meta == NULL) {
g_print ("NvDS Meta 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 = (char * )(g_malloc0) (MAX_DISPLAY_LEN);
g_snprintf (txt_params->display_text, MAX_DISPLAY_LEN, "%s ",
pgie_classes_str[obj_meta->class_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++;
}
/* Enable this print by setting environment variable GST_DEBUG=4
* before running the app. */
GST_INFO ("Source %d Frame Number = %lu Number of objects = %d "
"Vehicle Count = %d Person Count = %d", frame_meta->stream_id,
streammeta->stream_frame_num[frame_meta->batch_id],
num_rects, vehicle_count, person_count);
}
}
}
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_WARNING:
{
gchar *debug;
GError *error;
gst_message_parse_warning (msg, &error, &debug);
g_printerr ("WARNING from element %s: %s\n",
GST_OBJECT_NAME (msg->src), error->message);
g_free (debug);
g_printerr ("Warning: %s\n", error->message);
g_error_free (error);
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;
}
case GST_MESSAGE_ELEMENT:
{
if (gst_nvmessage_is_stream_eos (msg)) {
guint stream_id;
if (gst_nvmessage_parse_stream_eos (msg, &stream_id)) {
g_print ("Got EOS from stream %d\n", stream_id);
}
}
break;
}
default:
break;
}
return TRUE;
}
static void cb_newpad (GstElement * decodebin, GstPad * decoder_src_pad, gpointer data)
{
GstCaps *caps = gst_pad_query_caps (decoder_src_pad, NULL);
const GstStructure *str = gst_caps_get_structure (caps, 0);
const gchar *name = gst_structure_get_name (str);
GstElement *source_bin = (GstElement *) data;
GstCapsFeatures *features = gst_caps_get_features (caps, 0);
/* Need to check if the pad created by the decodebin is for video and not
* audio. */
if (!strncmp (name, "video", 5)) {
/* Link the decodebin pad only if decodebin has picked nvidia
* decoder plugin nvdec_*. We do this by checking if the pad caps contain
* NVMM memory features. */
if (gst_caps_features_contains (features, GST_CAPS_FEATURES_NVMM)) {
/* Get the source bin ghost pad */
GstPad *bin_ghost_pad = gst_element_get_static_pad (source_bin, "src");
if (!gst_ghost_pad_set_target (GST_GHOST_PAD (bin_ghost_pad),
decoder_src_pad)) {
g_printerr ("Failed to link decoder src pad to source bin ghost pad\n");
}
gst_object_unref (bin_ghost_pad);
} else {
g_printerr ("Error: Decodebin did not pick nvidia decoder plugin.\n");
}
}
}
static GstElement * create_source_bin (guint index, gchar * uri)
{
GstElement *bin = NULL, *uri_decode_bin = NULL;
gchar bin_name[16] = { };
g_snprintf (bin_name, 15, "source-bin-%02d", index);
/* Create a source GstBin to abstract this bin's content from the rest of the
* pipeline */
bin = gst_bin_new (bin_name);
/* Source element for reading from the uri.
* We will use decodebin and let it figure out the container format of the
* stream and the codec and plug the appropriate demux and decode plugins. */
uri_decode_bin = gst_element_factory_make ("uridecodebin", "uri-decode-bin");
if (!bin || !uri_decode_bin) {
g_printerr ("One element in source bin could not be created.\n");
return NULL;
}
/* We set the input uri to the source element */
g_object_set (G_OBJECT (uri_decode_bin), "uri", uri, NULL);
/* Connect to the "pad-added" signal of the decodebin which generates a
* callback once a new pad for raw data has beed created by the decodebin */
g_signal_connect (G_OBJECT (uri_decode_bin), "pad-added",
G_CALLBACK (cb_newpad), bin);
gst_bin_add (GST_BIN (bin), uri_decode_bin);
/* We need to create a ghost pad for the source bin which will act as a proxy
* for the video decoder src pad. The ghost pad will not have a target right
* now. Once the decode bin creates the video decoder and generates the
* cb_newpad callback, we will set the ghost pad target to the video decoder
* src pad. */
if (!gst_element_add_pad (bin, gst_ghost_pad_new_no_target ("src",
GST_PAD_SRC))) {
g_printerr ("Failed to add ghost pad in source bin\n");
return NULL;
}
return bin;
}
GstFlowReturn new_sample(GstAppSink *appsink, gpointer data) {
static int framecount = 0;
framecount++;
GstSample *sample = gst_app_sink_pull_sample(appsink);
GstCaps *caps = gst_sample_get_caps(sample);
GstBuffer *buffer = gst_sample_get_buffer(sample);
const GstStructure *info = gst_sample_get_info(sample);
qDebug() <<" ---- Read frame and convert to opencv format ---------------" << QString::number(framecount);
GstMapInfo map;
gst_buffer_map (buffer, &map, GST_MAP_READ);
// convert gstreamer data to OpenCV Mat, you could actually
// resolve height / width from caps...
Mat frame(Size(1280, 720), CV_8UC3, (char*)map.data, Mat::AUTO_STEP);
int frameSize = map.size;
qDebug() << " TODO: synchronize this.... ";
frameQueue.push_back(frame);
gst_buffer_unmap(buffer, &map);
// show caps on first frame
if (framecount == 1) {
g_print ("%s\n", gst_caps_to_string(caps));
}
gst_sample_unref (sample);
return GST_FLOW_OK;
}
int main() {
std::deque<cv::Mat> frameQueue;
int frameNo=0;
GMainLoop *loop = NULL;
GstElement *pipeline = NULL, *streammux = NULL, *sink = NULL, *pgie = NULL,
*nvvidconv = NULL, *nvosd = NULL, *tiler = NULL;
GstBus *bus = NULL;
guint bus_watch_id;
GstPad *tiler_src_pad = NULL;
guint i, num_sources;
guint tiler_rows, tiler_columns;
guint pgie_batch_size;
num_sources = 1;
gchar vp = 'file:///home/XYZ/sample_720p.h264';
gchar *m = &vp;
gchar** n = &m;
gchar*** p = &n;
// std::cout << &p << &vp << &m << &n;
qDebug() << " Starting ... ";
/* Standard GStreamer initialization */
gst_init (0, p);
/* Standard GStreamer initialization */
// gst_init (0, );
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 ("dstest3-pipeline");
/* Create nvstreammux instance to form batches from one or more sources. */
streammux = gst_element_factory_make ("nvstreammux", "stream-muxer");
if (!pipeline || !streammux) {
g_printerr ("One element could not be created. Exiting.\n");
// return -1;
}
gst_bin_add (GST_BIN (pipeline), streammux);
//for (i = 0; i < num_sources; i++) {
GstPad *sinkpad, *srcpad;
gchar pad_name[16] = { };
GstElement *source_bin = create_source_bin (0, "file:///home/sigmind/sample_720p.h264");
if (!source_bin) {
g_printerr ("Failed to create source bin. Exiting.\n");
// return -1;
}
gst_bin_add (GST_BIN (pipeline), source_bin);
g_snprintf (pad_name, 15, "sink_%u", i);
sinkpad = gst_element_get_request_pad (streammux, pad_name);
if (!sinkpad) {
g_printerr ("Streammux request sink pad failed. Exiting.\n");
// return -1;
}
srcpad = gst_element_get_static_pad (source_bin, "src");
if (!srcpad) {
g_printerr ("Failed to get src pad of source bin. Exiting.\n");
//return -1;
}
if (gst_pad_link (srcpad, sinkpad) != GST_PAD_LINK_OK) {
g_printerr ("Failed to link source bin to stream muxer. Exiting.\n");
//return -1;
}
gst_object_unref (srcpad);
gst_object_unref (sinkpad);
// }
/* Use nvinfer to infer on batched frame. */
pgie = gst_element_factory_make ("nvinfer", "primary-nvinference-engine");
/* Use nvtiler to composite the batched frames into a 2D tiled array based
* on the source of the frames. */
tiler = gst_element_factory_make ("nvmultistreamtiler", "nvtiler");
/* Use convertor to convert from NV12 to RGBA as required by nvosd */
nvvidconv = gst_element_factory_make ("nvvidconv", "nvvideo-converter");
/* 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");
sink = gst_element_factory_make ("appsink", "appsink");
gst_app_sink_set_emit_signals((GstAppSink*)sink, true);
gst_app_sink_set_drop((GstAppSink*)sink, true);
gst_app_sink_set_max_buffers((GstAppSink*)sink, 1);
GstAppSinkCallbacks callbacks = { NULL, new_preroll, new_sample };
gst_app_sink_set_callbacks (GST_APP_SINK(sink), &callbacks, NULL, NULL);
if (!pgie || !tiler || !nvvidconv || !nvosd || !sink) {
g_printerr ("One element could not be created. Exiting.\n");
//return -1;
}
g_object_set (G_OBJECT (streammux), "width", MUXER_OUTPUT_WIDTH, "height",
MUXER_OUTPUT_HEIGHT, "batch-size", num_sources,
"batched-push-timeout", MUXER_BATCH_TIMEOUT_USEC, NULL);
/* Configure the nvinfer element using the nvinfer config file. */
g_object_set (G_OBJECT (pgie),
"config-file-path", "/home/XYZ/Downloads/DeepStream_Release/sources/apps/sample_apps/deepstream-test3/dstest3_pgie_config.txt", NULL);
/* Override the batch-size set in the config file with the number of sources. */
g_object_get (G_OBJECT (pgie), "batch-size", &pgie_batch_size, NULL);
if (pgie_batch_size != num_sources) {
g_printerr
("WARNING: Overriding infer-config batch-size (%d) with number of sources (%d)\n",
pgie_batch_size, num_sources);
g_object_set (G_OBJECT (pgie), "batch-size", num_sources, NULL);
}
tiler_rows = (guint) sqrt (num_sources);
tiler_columns = (guint) ceil (1.0 * num_sources / tiler_rows);
/* we set the tiler properties here */
g_object_set (G_OBJECT (tiler), "rows", tiler_rows, "columns", tiler_columns,
"width", TILED_OUTPUT_WIDTH, "height", TILED_OUTPUT_HEIGHT, NULL);
/* we set the osd properties here */
g_object_set (G_OBJECT (nvosd), "font-size", 15, NULL);
/* we add a message handler */
bus = gst_pipeline_get_bus (GST_PIPELINE (pipeline));
bus_watch_id = gst_bus_add_watch (bus, bus_call, NULL);
gst_object_unref (bus);
/* Set up the pipeline */
/* we add all elements into the pipeline */
gst_bin_add_many (GST_BIN (pipeline), pgie, tiler, nvvidconv, nvosd, sink,
NULL);
/* we link the elements together
* nvstreammux -> nvinfer -> nvtiler -> nvvidconv -> nvosd -> video-renderer */
if (!gst_element_link_many (streammux, pgie, tiler, 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. */
tiler_src_pad = gst_element_get_static_pad (pgie, "src");
if (!tiler_src_pad)
g_print ("Unable to get src pad\n");
else
gst_pad_add_probe (tiler_src_pad, GST_PAD_PROBE_TYPE_BUFFER,
tiler_src_pad_buffer_probe, NULL, NULL);
/* Set the pipeline to "playing" state */
g_print ("Now playing:");
g_print ("\n");
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);
while(1) {
// g_main_loop_run (loop);
g_main_iteration(false);
if (frameQueue.size() > 0) {
Mat frameSink = frameQueue.front();
std::cout << "Width : " << frameSink.size().width << std::endl;
std::cout << "Height: " << frameSink.size().height << std::endl;
imshow("edges", frameSink);
cv::waitKey(30);
frameQueue.clear();
}
}
/* 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;
}
It works good untill the line imshow(“edges”, frameSink) comes in execution, showing Segmentation Fault.
If I comment the line out, it correctly prints GBUS Message from the line
GST_INFO ("Source %d Frame Number = %lu Number of objects = %d "
“Vehicle Count = %d Person Count = %d”, frame_meta->stream_id,
streammeta->stream_frame_num[frame_meta->batch_id],
num_rects, vehicle_count, person_count);
Any help is appreciated.