C++有一个简单的GStreamer例子吗？

Question

我正在寻找使用视频流的GStreamer的简单例子...

我想创建一个简单的例子（显示视频输出）incl。编制说明。

Answer 1

这将是GStreamer管道的源代码videotestsec ! autovideosink。它会显示一个不错的视频输出...

先决条件 确保您安装了GStreamer和gcc。

添加下面的源代码到helloworld.c

#include <gst/gst.h> 
#include <glib.h> 


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_free (debug); 

     g_printerr ("Error: %s\n", error->message); 
     g_error_free (error); 

     g_main_loop_quit (loop); 
     break; 
    } 
    default: 
     break; 
    } 

    return TRUE; 
} 



int main (int argc, char *argv[]) 
{ 
    GMainLoop *loop; 

    GstElement *pipeline, *videotestsrcm, *autovideosinkm; 
    GstBus *bus; 
    guint bus_watch_id; 

    /* Initialisation */ 
    gst_init (&argc, &argv); 

    loop = g_main_loop_new (NULL, FALSE); 


    /* Create gstreamer elements */ 
    pipeline = gst_pipeline_new ("videotest-pipeline"); 
    videotestsrcm = gst_element_factory_make ("videotestsrc", "testsource"); 
    autovideosinkm = gst_element_factory_make ("autovideosink", "videosink"); 

    if (!pipeline || !videotestsrcm || !autovideosinkm) { 
    g_printerr ("One element could not be created. Exiting.\n"); 
    return -1; 
    } 

    /* Set up the pipeline */ 

    /* 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); 


    /* we add all elements into the pipeline */ 
    gst_bin_add_many (GST_BIN (pipeline), 
        videotestsrcm, autovideosinkm, NULL); 

    /* we link the elements together */ 
    /* videotestsrcm -> autovideosinkm */ 
    gst_element_link (videotestsrcm, autovideosinkm); 


    /* Set the pipeline to "playing" state*/ 
    g_print ("Now set pipeline in state playing"); 
    gst_element_set_state (pipeline, GST_STATE_PLAYING); 


    /* Iterate */ 
    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; 
} 

编译

gcc -Wall helloworld.c -o helloworld $(pkg-config --cflags --libs gstreamer-1.0) 

运行它

./helloworld