如何使用Deepstream SDK拍摄视频并提取jpg格式的帧

gst-launch-1.0 v4l2src ! video/x-raw,width=1920,height=1080,framerate=30/1 ! nvvidconv ! video/x-raw(memory:NVMM),width=1920,height=1080,format=I420 ! nvjpegenc ! filesink location=output.jpg

#include <gst/gst.h>

static GstElement *pipeline, *source, *capsfilter, *converter, *encoder, *sink;

static void pad_added_handler(GstElement *src, GstPad *new_pad, gpointer user_data) {
    GstPad *sink_pad = gst_element_get_static_pad(GST_ELEMENT(user_data), "sink");
    GstPadLinkReturn ret;
    GstCaps *new_pad_type = NULL;

    new_pad_type = gst_pad_get_current_caps(new_pad);
    GstStructure *new_pad_struct = gst_caps_get_structure(new_pad_type, 0);
    const gchar *new_pad_type_name = gst_structure_get_name(new_pad_struct);

    g_print("Received new pad '%s' from '%s':\n", GST_OBJECT_NAME(new_pad), GST_ELEMENT_NAME(src));

    if (g_str_has_prefix(new_pad_type_name, "video/x-raw")) {
        ret = gst_pad_link(new_pad, sink_pad);
        if (GST_PAD_LINK_FAILED(ret)) {
            g_print("Type is '%s' but link failed.\n", new_pad_type_name);
        } else {
            g_print("Link succeeded (type '%s').\n", new_pad_type_name);
        }
    } else {
        g_print("It has type '%s' which is not raw video. Ignoring.\n", new_pad_type_name);
    }

    if (new_pad_type != NULL)
        gst_caps_unref(new_pad_type);
    gst_object_unref(sink_pad);
}

int main(int argc, char *argv[]) {
    gst_init(&argc, &argv);

    pipeline = gst_pipeline_new("video-pipeline");
    source = gst_element_factory_make("v4l2src", "video-source");
    capsfilter = gst_element_factory_make("capsfilter", "caps-filter");
    converter = gst_element_factory_make("videoconvert", "converter");
    encoder = gst_element_factory_make("nvjpegenc", "encoder");
    sink = gst_element_factory_make("filesink", "sink");

    g_object_set(G_OBJECT(capsfilter), "caps", gst_caps_from_string("video/x-raw, format=(string)I420"));

    gst_bin_add_many(GST_BIN(pipeline), source, capsfilter, converter, encoder, sink, NULL);
    gst_element_link_many(capsfilter, converter, encoder, sink, NULL);

    g_signal_connect(source, "pad-added", G_CALLBACK(pad_added_handler), converter);

    gst_element_set_state(pipeline, GST_STATE_PLAYING);

    GstBus *bus = gst_element_get_bus(pipeline);
    GstMessage *msg = gst_bus_timed_pop_filtered(bus, GST_CLOCK_TIME_NONE,
        static_cast<GstMessageType>(GST_MESSAGE_ERROR | GST_MESSAGE_EOS));

    if (msg != NULL)
        gst_message_unref(msg);

    gst_object_unref(bus);
    gst_element_set_state(pipeline, GST_STATE_NULL);
    gst_object_unref(pipeline);
    return 0;
}