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运行效果

 

介绍

     GStreamer 带有一组将音频转换为视频的元素。他们 可用于科学可视化或为您的音乐增添趣味 player 的本教程展示了：

          • 如何启用音频可视化

          • 如何选择可视化元素

     启用音频可视化实际上非常简单。设置相应的标志，当纯音频流为 found，它将实例化必要的元素来创建和显示可视化。

 

GStreamer相关运行库

INCLUDEPATH += D:/Software/GStreamer/1.0/mingw_x86_64/include/gstreamer-1.0/gst
INCLUDEPATH += D:/Software/GStreamer/1.0/mingw_x86_64/include
INCLUDEPATH += D:/Software/GStreamer/1.0/mingw_x86_64/include/gstreamer-1.0
INCLUDEPATH += D:/Software/GStreamer/1.0/mingw_x86_64/include/glib-2.0
INCLUDEPATH += D:/Software/GStreamer/1.0/mingw_x86_64/lib/glib-2.0/includeLIBS += D:/Software/GStreamer/1.0/mingw_x86_64/lib/gstreamer-1.0.lib
LIBS += D:/Software/GStreamer/1.0/mingw_x86_64/lib/glib-2.0.lib
LIBS += D:/Software/GStreamer/1.0/mingw_x86_64/lib/gobject-2.0.lib

 

源码

#include <gst/gst.h>/* playbin的flag */
typedef enum
{GST_PLAY_FLAG_VIS           = (1 << 3) /* 在没有视频流时启用可视化渲染。 */
} GstPlayFlags;/* 如果这是可视化元素，则返回TRUE */
static gboolean filter_vis_features (GstPluginFeature *feature, gpointer data)
{GstElementFactory *factory;if (!GST_IS_ELEMENT_FACTORY (feature))return FALSE;factory = GST_ELEMENT_FACTORY (feature);if (!g_strrstr (gst_element_factory_get_klass (factory), "Visualization"))return FALSE;return TRUE;
}int main(int argc, char *argv[])
{/* d初始化Streamer */gst_init (&argc, &argv);/* 获取所有可视化插件的列表 */GList *list = gst_registry_feature_filter (gst_registry_get (), filter_vis_features, FALSE, NULL);/* 打印他们的名字 */GstElementFactory *selected_factory = NULL;g_print("Available visualization plugins:\n");for (GList *walk = list; walk != NULL; walk = g_list_next (walk)){GstElementFactory *factory = GST_ELEMENT_FACTORY (walk->data);const gchar *name = gst_element_factory_get_longname (factory);g_print("  %s\n", name);if (selected_factory == NULL || g_str_has_prefix (name, "GOOM")){selected_factory = factory;}}if (!selected_factory) { g_print ("No visualization plugins found!\n"); return -1; }/* 我们现在已经为可视化元素选择了一个工厂 */g_print ("Selected '%s'\n", gst_element_factory_get_longname (selected_factory));GstElement *vis_plugin = gst_element_factory_create (selected_factory, NULL);if (!vis_plugin){return -1;}/* 构建管道 */GstElement *pipeline = gst_parse_launch ("playbin uri=http://radio.hbr1.com:19800/ambient.ogg", NULL);/* 设置可视化标志 */guint flags;g_object_get (pipeline, "flags", &flags, NULL);flags |= GST_PLAY_FLAG_VIS;g_object_set (pipeline, "flags", flags, NULL);/* 为playbin设置vis插件 */g_object_set (pipeline, "vis-plugin", vis_plugin, NULL);/* 开始播放 */gst_element_set_state (pipeline, GST_STATE_PLAYING);/* 等待直到错误或结束 */GstBus *bus = gst_element_get_bus (pipeline);GstMessage *msg = gst_bus_timed_pop_filtered (bus, GST_CLOCK_TIME_NONE, (GstMessageType)(GST_MESSAGE_ERROR | GST_MESSAGE_EOS));/* 释放资源 */if (msg != NULL){ gst_message_unref (msg); }gst_plugin_feature_list_free (list);gst_object_unref (bus);gst_element_set_state (pipeline, GST_STATE_NULL);gst_object_unref (pipeline);return 0;
}

 

关注

笔者 - jxd