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如何在 gst-launch 的 textoverlay 管道中设置多行文本？

我想建立一个管道，并希望多行文本垂直和水平居中。我能做1行。

我不确定如何指定换行符。

gst-launch-1.0 videotestsrc pattern=0 horizontal-speed=0 is-live=1 \
    ! textoverlay text="PLEASE <b>STAND</b> <span foreground=\"blue\" size=\"x-large\">\nBY</span>Next <u>under-line</u>" valignment=center halignment=center font-desc="Sans, 24" \ ... other pipes ...

我想基本上有2行以上。两者都相对于彼此和整个屏幕垂直和水平对齐。

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1 回答 1

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我不知道如何在参数中传递换行符gst-launch，但您可以使用 C 代码实现相同的目的。下面是示例：

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

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

  GstElement *pipeline, *source, *overlay, *sink;

  gst_init(&argc, &argv);

  loop = g_main_loop_new(NULL, FALSE);

  // initialize elements
  pipeline = gst_pipeline_new("audio-player");
  source = gst_element_factory_make("videotestsrc", "source");
  overlay = gst_element_factory_make("textoverlay", "overlay");
  sink = gst_element_factory_make("autovideosink", "sink");

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

  g_object_set(G_OBJECT(overlay), "text", "blebleble\nble", NULL);
  g_object_set(G_OBJECT(overlay), "font-desc", "Sans, 24", NULL);
  g_object_set(G_OBJECT(overlay), "halignment", 1, NULL);
  g_object_set(G_OBJECT(overlay), "valignment", 1, NULL);

  // add elements to pipeline
  gst_bin_add_many(GST_BIN(pipeline), source, overlay, sink, NULL);

  // link elements
  gst_element_link(source, overlay);
  gst_element_link_many(overlay, sink, NULL);

  gst_element_set_state(pipeline, GST_STATE_PLAYING);

  g_main_loop_run(loop);

  // cleanup
  gst_element_set_state(pipeline, GST_STATE_NULL);
  gst_object_unref(GST_OBJECT(pipeline));
  g_main_loop_unref(loop);

  return 0;
}
于 2019-08-01T13:14:12.440 回答