Gstreamer學習筆記：GStreamer Debugging

Refer to: http://developer.ridgerun.com/wiki/index.php/GStreamer_Debugging

Create DOT file to see exact pipeline and capabilities used（使用 gst dump 出 pipeline 構成圖）

In order to generate a DOT file, set the GST_DEBUG_DUMP_DOT_DIR environment variable to point to the folder where you want the .dot files to be stored.

1) Install “dot” tool on your host machine…to do so simply install graphviz:

sudo apt-get install graphviz

2) On your target board, set the environment dot dump variable:
　創建用於存放數據的目錄： /root

export GST_DEBUG_DUMP_DOT_DIR=/root
mkdir -p $GST_DEBUG_DUMP_DOT_DIR

3) Run your pipeline, a .dot file will be generated according to each of the state changes that occur showing how the caps are negotiated during the process.

4) Convert the dot files to PNG image files or SVG graphics files

dot -Tpng input.dot > output.png

dot -Tsvg input.dot > output.svg

Using SVG allows you to infinitely zoom to be able to read all the text. You can use inkscape to view and edit SVG files.

例如：

export GST_DEBUG_DUMP_DOT_DIR=./dot
mkdir -p $GST_DEBUG_DUMP_DOT_DIR
gst-launch-1.0 playbin uri=file:///traile.mp4
cd ./dot
dot -Tpng 0.00.00.171600734-gst-launch.PAUSED_PLAYING.dot > pipeline.png
eog pipeline.png