This is a tool to query a plugin or an element about its properties.
To query the information about the element mad, you would specify:
gst-inspect mad
Below is the output of a query for the osssink element:
Factory Details: Rank: secondary (128) Long-name: Audio Sink (OSS) Klass: Sink/Audio Description: Output to a sound card via OSS Author: Erik Walthinsen <omega@cse.ogi.edu>, Wim Taymans <wim.taymans@chello.be> Plugin Details: Name: ossaudio Description: OSS (Open Sound System) support for GStreamer Filename: /home/wim/gst/head/gst-plugins-good/sys/oss/.libs/libgstossaudio.so Version: 1.0.0.1 License: LGPL Source module: gst-plugins-good Source release date: 2012-09-25 12:52 (UTC) Binary package: GStreamer Good Plug-ins git Origin URL: Unknown package origin GObject +----GInitiallyUnowned +----GstObject +----GstElement +----GstBaseSink +----GstAudioBaseSink +----GstAudioSink +----GstOssSink Pad Templates: SINK template: 'sink' Availability: Always Capabilities: audio/x-raw format: { S16LE, U16LE, S8, U8 } layout: interleaved rate: [ 1, 2147483647 ] channels: 1 audio/x-raw format: { S16LE, U16LE, S8, U8 } layout: interleaved rate: [ 1, 2147483647 ] channels: 2 channel-mask: 0x0000000000000003 Element Flags: no flags set Element Implementation: Has change_state() function: gst_audio_base_sink_change_state Clocking Interaction: element is supposed to provide a clock but returned NULL Element has no indexing capabilities. Element has no URI handling capabilities. Pads: SINK: 'sink' Implementation: Has chainfunc(): gst_base_sink_chain Has custom eventfunc(): gst_base_sink_event Has custom queryfunc(): gst_base_sink_sink_query Has custom iterintlinkfunc(): gst_pad_iterate_internal_links_default Pad Template: 'sink' Element Properties: name : The name of the object flags: readable, writable String. Default: "osssink0" parent : The parent of the object flags: readable, writable Object of type "GstObject" sync : Sync on the clock flags: readable, writable Boolean. Default: true max-lateness : Maximum number of nanoseconds that a buffer can be late before it is dropped (-1 unlimited) flags: readable, writable Integer64. Range: -1 - 9223372036854775807 Default: -1 qos : Generate Quality-of-Service events upstream flags: readable, writable Boolean. Default: false async : Go asynchronously to PAUSED flags: readable, writable Boolean. Default: true ts-offset : Timestamp offset in nanoseconds flags: readable, writable Integer64. Range: -9223372036854775808 - 9223372036854775807 Default: 0 enable-last-sample : Enable the last-sample property flags: readable, writable Boolean. Default: false last-sample : The last sample received in the sink flags: readable Boxed pointer of type "GstSample" blocksize : Size in bytes to pull per buffer (0 = default) flags: readable, writable Unsigned Integer. Range: 0 - 4294967295 Default: 4096 render-delay : Additional render delay of the sink in nanoseconds flags: readable, writable Unsigned Integer64. Range: 0 - 18446744073709551615 Default: 0 throttle-time : The time to keep between rendered buffers flags: readable, writable Unsigned Integer64. Range: 0 - 18446744073709551615 Default: 0 buffer-time : Size of audio buffer in microseconds, this is the minimum latency that the sink reports flags: readable, writable Integer64. Range: 1 - 9223372036854775807 Default: 200000 latency-time : The minimum amount of data to write in each iteration in microseconds flags: readable, writable Integer64. Range: 1 - 9223372036854775807 Default: 10000 provide-clock : Provide a clock to be used as the global pipeline clock flags: readable, writable Boolean. Default: true slave-method : Algorithm to use to match the rate of the masterclock flags: readable, writable Enum "GstAudioBaseSinkSlaveMethod" Default: 1, "skew" (0): resample - GST_AUDIO_BASE_SINK_SLAVE_RESAMPLE (1): skew - GST_AUDIO_BASE_SINK_SLAVE_SKEW (2): none - GST_AUDIO_BASE_SINK_SLAVE_NONE can-activate-pull : Allow pull-based scheduling flags: readable, writable Boolean. Default: false alignment-threshold : Timestamp alignment threshold in nanoseconds flags: readable, writable Unsigned Integer64. Range: 1 - 18446744073709551614 Default: 40000000 drift-tolerance : Tolerance for clock drift in microseconds flags: readable, writable Integer64. Range: 1 - 9223372036854775807 Default: 40000 discont-wait : Window of time in nanoseconds to wait before creating a discontinuity flags: readable, writable Unsigned Integer64. Range: 0 - 18446744073709551614 Default: 1000000000 device : OSS device (usually /dev/dspN) flags: readable, writable String. Default: "/dev/dsp"
To query the information about a plugin, you would do:
gst-inspect gstelements