GST_DEBUG: Comma-separated list of debug categories and levels, e.g:
GST_DEBUG=totem:4,typefind:5
GST_DEBUG_NO_COLOR: When this environment variable is set, coloured debug output is disabled. This might come handy when saving the debug output to a file.
GST_DEBUG_DUMP_DOT_DIR: When set to a filesystem path, store dot files of pipeline graphs there.
GST_REGISTRY: Path of the plugin registry file. The default is ~/.gstreamer-1.0/registry-CPU.xml where CPU is the machine/cpu type GStreamer was compiled for, e.g. 'i486', 'i686', 'x86-64', 'ppc', etc. Check the output of uname -i and uname -m for details.
GST_REGISTRY_UPDATE: Set to "no" to force GStreamer to assume that no plugins have changed, have been added or have been removed. This will make GStreamer skip the initial check to determine whether a rebuild of the registry cache is required or not. This may be useful in embedded environments where the installed plugins never change. Do not use this option in any other setup.
GST_PLUGIN_PATH: Specifies a list of directories to scan for additional plugins. These take precedence over the system plugins.
GST_PLUGIN_SYSTEM_PATH: Specifies a list of plugins that are always loaded by default. If not set, this defaults to the system-installed path, and the plugins installed in the user's home directory
OIL_CPU_FLAGS: Useful liboil environment variable. Set OIL_CPU_FLAGS=0 when valgrind or other debugging tools trip over liboil's CPU detection. Quite a few important GStreamer plugins like videotestsrc, audioconvert and audioresample use liboil.
G_DEBUG: This is a useful GLib environment variable. Set G_DEBUG=fatal_warnings to make GStreamer programs abort when a critical warning such as an assertion failure occurs. This is useful if you want to find out which part of the code caused that warning to be triggered and under what circumstances. Simply set G_DEBUG as mentioned above and run the program under gdb (or let it core dump). Then get a stack trace in the usual way.