gstreamer向appsrc傳送幀畫面的程式碼
阿新 • • 發佈:2019-01-23
這個程式碼可以正常執行,黑白畫面交替:
#include <gst/gst.h> #define VIDEO_WIDTH 384 #define VIDEO_HEIGHT 288 #define VIDEO_FORMAT "RGB16" #define PIXEL_SIZE 2 static void cb_need_data (GstElement *appsrc, guint unused_size, gpointer user_data) { static gboolean white = FALSE; static GstClockTime timestamp = 0; GstBuffer *buffer; guint size; GstFlowReturn ret; size = VIDEO_WIDTH * VIDEO_HEIGHT * PIXEL_SIZE; buffer = gst_buffer_new_allocate (NULL, size, NULL); /* this makes the image black/white */ gst_buffer_memset (buffer, 0, white ? 0xFF : 0x00, size); white = !white; GST_BUFFER_PTS (buffer) = timestamp; GST_BUFFER_DURATION (buffer) = gst_util_uint64_scale_int (1, GST_SECOND, 2); timestamp += GST_BUFFER_DURATION (buffer); g_signal_emit_by_name (appsrc, "push-buffer", buffer, &ret); gst_buffer_unref (buffer); if (ret != GST_FLOW_OK) { /* something wrong, stop pushing */ g_main_loop_quit (loop); } } gint main (gint argc, gchar *argv[]) { GstElement *pipeline, *appsrc, *conv, *videosink; GMainLoop *loop; /* init GStreamer */ gst_init (NULL, NULL); loop = g_main_loop_new (NULL, FALSE); /* setup pipeline */ pipeline = gst_pipeline_new ("pipeline"); appsrc = gst_element_factory_make ("appsrc", "source"); conv = gst_element_factory_make ("videoconvert", "conv"); videosink = gst_element_factory_make ("xvimagesink", "videosink"); /* setup */ g_object_set (G_OBJECT (appsrc), "caps", gst_caps_new_simple ("video/x-raw", "format", G_TYPE_STRING, VIDEO_FORMAT, "width", G_TYPE_INT, VIDEO_WIDTH, "height", G_TYPE_INT, VIDEO_HEIGHT, "framerate", GST_TYPE_FRACTION, 0, 1, NULL), NULL); gst_bin_add_many (GST_BIN (pipeline), appsrc, conv, videosink, NULL); gst_element_link_many (appsrc, conv, videosink, NULL); /* setup appsrc */ g_object_set (G_OBJECT (appsrc), "stream-type", 0, "format", GST_FORMAT_TIME, NULL); g_signal_connect (appsrc, "need-data", G_CALLBACK (cb_need_data), NULL); /* play */ gst_element_set_state (pipeline, GST_STATE_PLAYING); g_main_loop_run (loop); /* clean up */ gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (GST_OBJECT (pipeline)); g_main_loop_unref (loop); return 0; }