Refer to the GStreamer Tutorial on Debugging tools for more information.
DSL uses GStreamer's built-in logging with a single GST_CATEGORY labeled DSL.
The environment variable, GST_DEBUG, controls the current logging level for both GStreamer and DSL.
The below example sets a default level of WARNING=2 for all categories.
export GST_DEBUG=2
Log level values: NONE=0,ERROR=1, WARNING=2, FIXME=3, INFO=4, DEBUG=5
Levels are "lower-level-inclusive" with WARNING=2 including ERROR=1 and so forth.
DSL, all GStreamer modules, and plugins define their own unique category allowing log levels to be set for each.
export GST_DEBUG=1,DSL:3
DSL takes advantage of GStreamer's capability to output graph files. These are .dot files, readable with
free programs like GraphViz. Pipeline Graphs describe the topology of your DSL pipeline, along with the
caps negotiated in each link.
GStreamer creates the information when a Pipeline transitions into states of GST_STATE_READY, GST_STATE_PAUSED and GST_STATE_PLAYING when the following environment variable is set.
export GST_DEBUG_DUMP_DOT_DIR=./.dot
mkdir -p $GST_DEBUG_DUMP_DOT_DIR
The DSL Pipeline API provides two services dsl_pipeline_dump_to_dot and dsl_pipeline_dump_to_dot_with_ts to dump the informatin to file, best called from a dsl_state_change_listener_cb
after building and running a pipeline you'll find .dot files under the ./.dot directory with the format of
<timestamp>-pipeline-ready.dot
<timestamp>-pipeline-playing.dot
Use the following command to convert a .dot. file to a .png file for viewing.
dot -Tpng 0.00.13.747142702-pipeline-ready.dot > pipeline.png