使用带有c API的gstreamer显示图像

我尝试使用c API执行gstreamer管道来显示图像我使用此gst-launch命令

gst-launch filesrc location="pluto.jpg" ! jpegdec ! ffmpegcolorspace ! videobalance saturation=0 ! freeze ! ximagesink 

当我尝试它它工作正常但当我尝试将其转换为C代码它不起作用有人可以帮助我吗?

 #include  int main(int argc, char *argv[]) { GstElement *pipeline, *jpdec, *imgf, *cod, *source, *sink; GstBus *bus; GstMessage *msg; GstStateChangeReturn ret; /* Initialize GStreamer */ gst_init (&argc, &argv); /* Create the elements */ source = gst_element_factory_make ("filesrc", "source"); sink = gst_element_factory_make ("ximagesink", "sink"); jpdec = gst_element_factory_make ("jpegdec", "jdec"); imgf = gst_element_factory_make ("imagefreeze", "freeze"); cod = gst_element_factory_make ("ffmpegcolorspace", "ffmdec"); /* Create the empty pipeline */ pipeline = gst_pipeline_new ("test-pipeline"); if (!pipeline || !source || !sink || !jpdec || !imgf || !cod) { g_printerr ("Not all elements could be created.\n"); return -1; } /* Build the pipeline */ gst_bin_add_many (GST_BIN (pipeline), source, jpdec, cod, imgf, sink, NULL); if (gst_element_link (source, sink) != TRUE) { g_printerr ("Elements could not be linked.\n"); gst_object_unref (pipeline); return -1; } /* Modify the source's properties */ g_object_set (G_OBJECT (source), "location","pluto.jpg", NULL); /* Start playing */ ret = gst_element_set_state (pipeline, GST_STATE_PLAYING); if (ret == GST_STATE_CHANGE_FAILURE) { g_printerr ("Unable to set the pipeline to the playing state.\n"); gst_object_unref (pipeline); return -1; } /* Wait until error or EOS */ bus = gst_element_get_bus (pipeline); msg = gst_bus_timed_pop_filtered (bus, GST_CLOCK_TIME_NONE, GST_MESSAGE_ERROR | GST_MESSAGE_EOS); /* Parse message */ if (msg != NULL) { GError *err; gchar *debug_info; switch (GST_MESSAGE_TYPE (msg)) { case GST_MESSAGE_ERROR: gst_message_parse_error (msg, &err, &debug_info); g_printerr ("Error received from element %s: %s\n", GST_OBJECT_NAME (msg->src), err->message); g_printerr ("Debugging information: %s\n", debug_info ? debug_info : "none"); g_clear_error (&err); g_free (debug_info); break; case GST_MESSAGE_EOS: g_print ("End-Of-Stream reached.\n"); break; default: /* We should not reach here because we only asked for ERRORs and EOS */ g_printerr ("Unexpected message received.\n"); break; } gst_message_unref (msg); } /* Free resources */ gst_object_unref (bus); gst_element_set_state (pipeline, GST_STATE_NULL); gst_object_unref (pipeline); return 0; } 

有我用来播放图像的c代码
当我编译代码我没有错误,但当我运行它我有这个错误:

 (test:5355): GStreamer-CRITICAL **: gst_caps_get_structure: assertion `GST_IS_CAPS (caps)' failed (test:5355): GStreamer-CRITICAL **: gst_structure_get_int: assertion `structure != NULL' failed Error received from element sink: Failed to create output image buffer of 0x0 pixels Debugging information: ximagesink.c(472): gst_ximagesink_ximage_new (): /GstPipeline:test-pipeline/GstXImageSink:sink: could not get shared memory of 0 bytes 

你的gst_element_link错了。 就像是:

 if (gst_element_link_many (source, jpdec, cod, imgf, sink, NULL) != TRUE) 

应该管用。

这些错误可能是xvimagesink中的一个错误,但你错误地使用它。 请随时报告bugzilla.gnome.org中有关这些断言的错误,以防它们与1.0一起发生。