[gst-devel] gstreamer: Wim Taymans : Add message to request a state change
Edward Hervey
bilboed at gmail.com
Thu Feb 19 10:47:39 CET 2009
Hi,
This looks really neat. A few comments though.
If the commit is not done to the master branch, is it possible to have
that in the subject ? Something like the following:
"<module> [<branchname>]: <author> : <subject>"
What happens for gigantic push with plenty of commits ? I did one a
day or two ago in gst-plugins-bad.
It might be better to have a message-only (i.e. everything down to
'---') version for the current commit list, and use the ones with
patches on another mailing list. In fact... I'm wondering if we
shouldn't create new mailing lists now that we've switched to git, I can
have them created within the day on freedesktop.org. Something like
gst-commits at ... and gst-commits-full at ...
Edward
On Thu, 2009-02-19 at 00:54 +0200, felipe.contreras at gmail.com wrote:
> Module: gstreamer
> Branch: master
> Commit: 4b986a4a94c436a3d1dac443ad8da374fe38b6eb
> URL: http://cgit.freedesktop.org/gstreamer/gstreamer/commit/?id=4b986a4a94c436a3d1dac443ad8da374fe38b6eb
>
> Author: Wim Taymans <wim.taymans at collabora.co.uk>
> Date: Wed Feb 18 15:31:55 2009 +0100
>
> Add message to request a state change
>
> Add a GST_MESSAGE_REQUEST_STATE that can be posted by element when they would
> like to have the application change the state of the pipeline. the primary use
> case is to pause the pipeline when an audio mixer is mixing a higher priority
> stream but it can also be used for other purposes.
>
> Add some docs and a unit test.
>
> Implement the REQUEST_STATE message in gst-launch.
>
> API: gst_message_new_request_state()
> API: gst_message_parse_request_state()
> API: GST_MESSAGE_REQUEST_STATE
>
> ---
>
> docs/design/part-messages.txt | 4 +++
> docs/gst/gstreamer-sections.txt | 2 +
> gst/gstmessage.c | 52 +++++++++++++++++++++++++++++++++++++++
> gst/gstmessage.h | 8 ++++++
> tests/check/gst/gstmessage.c | 17 ++++++++++++
> tools/gst-launch.c | 47 ++++++++++++++++++++++++-----------
> 6 files changed, 115 insertions(+), 15 deletions(-)
>
> diff --git a/docs/design/part-messages.txt b/docs/design/part-messages.txt
> index aa5f218..cd53e10 100644
> --- a/docs/design/part-messages.txt
> +++ b/docs/design/part-messages.txt
> @@ -128,4 +128,8 @@ Message types
> Posted by elements when the latency in a pipeline changed and a new global
> latency should be calculated by the pipeline or application.
>
> + GST_MESSAGE_REQUEST_STATE:
>
> + Posted by elements when they want to change the state of the pipeline they
> + are in. A typical use case would be an audio sink that requests the pipeline
> + to pause in order to play a higher priority stream.
> diff --git a/docs/gst/gstreamer-sections.txt b/docs/gst/gstreamer-sections.txt
> index b07d371..751d8e9 100644
> --- a/docs/gst/gstreamer-sections.txt
> +++ b/docs/gst/gstreamer-sections.txt
> @@ -1089,6 +1089,8 @@ gst_message_parse_async_start
> gst_message_new_async_done
> gst_message_new_structure_change
> gst_message_parse_structure_change
> +gst_message_new_request_state
> +gst_message_parse_request_state
> <SUBSECTION Standard>
> GstMessageClass
> GST_MESSAGE
> diff --git a/gst/gstmessage.c b/gst/gstmessage.c
> index df9b5e1..78305bd 100644
> --- a/gst/gstmessage.c
> +++ b/gst/gstmessage.c
> @@ -111,6 +111,7 @@ static GstMessageQuarks message_quarks[] = {
> {GST_MESSAGE_LATENCY, "latency", 0},
> {GST_MESSAGE_ASYNC_START, "async-start", 0},
> {GST_MESSAGE_ASYNC_DONE, "async-done", 0},
> + {GST_MESSAGE_REQUEST_STATE, "request-state", 0},
> {0, NULL, 0}
> };
>
> @@ -933,6 +934,35 @@ gst_message_new_latency (GstObject * src)
> }
>
> /**
> + * gst_message_new_request_state:
> + * @src: The object originating the message.
> + * @state: The new requested state
> + *
> + * This message can be posted by elements when they want to have their state
> + * changed. A typical use case would be an audio server that wants to pause the
> + * pipeline because a higher priority stream is being played.
> + *
> + * Returns: The new requst state message.
> + *
> + * MT safe.
> + *
> + * Since: 0.10.23
> + */
> +GstMessage *
> +gst_message_new_request_state (GstObject * src, GstState state)
> +{
> + GstMessage *message;
> + GstStructure *structure;
> +
> + structure = gst_structure_empty_new ("GstMessageRequestState");
> + gst_structure_id_set (structure,
> + GST_QUARK (NEW_STATE), GST_TYPE_STATE, (gint) state, NULL);
> + message = gst_message_new_custom (GST_MESSAGE_REQUEST_STATE, src, structure);
> +
> + return message;
> +}
> +
> +/**
> * gst_message_get_structure:
> * @message: The #GstMessage.
> *
> @@ -1431,3 +1461,25 @@ gst_message_parse_async_start (GstMessage * message, gboolean * new_base_time)
> g_value_get_boolean (gst_structure_id_get_value (message->structure,
> GST_QUARK (NEW_BASE_TIME)));
> }
> +
> +/**
> + * gst_message_parse_request_state:
> + * @message: A valid #GstMessage of type GST_MESSAGE_REQUEST_STATE.
> + * @state: Result location for the requested state or NULL
> + *
> + * Extract the requested state from the request_state message.
> + *
> + * MT safe.
> + *
> + * Since: 0.10.23
> + */
> +void
> +gst_message_parse_request_state (GstMessage * message, GstState * state)
> +{
> + g_return_if_fail (GST_IS_MESSAGE (message));
> + g_return_if_fail (GST_MESSAGE_TYPE (message) == GST_MESSAGE_REQUEST_STATE);
> +
> + if (state)
> + *state = g_value_get_enum (gst_structure_id_get_value (message->structure,
> + GST_QUARK (NEW_STATE)));
> +}
> diff --git a/gst/gstmessage.h b/gst/gstmessage.h
> index ad13ac0..b1b5b5c 100644
> --- a/gst/gstmessage.h
> +++ b/gst/gstmessage.h
> @@ -81,6 +81,9 @@ typedef struct _GstMessageClass GstMessageClass;
> * pipeline. Since: 0.10.13
> * @GST_MESSAGE_LATENCY: Posted by elements when their latency changes. The
> * pipeline will calculate and distribute a new latency. Since: 0.10.12
> + * @GST_MESSAGE_REQUEST_STATE: Posted by elements when they want the pipeline to
> + * change state. This message is a suggestion to the application which can
> + * decide to perform the state change on (part of) the pipeline. Since: 0.10.23.
> * @GST_MESSAGE_ANY: mask for all of the above messages.
> *
> * The different message types that are available.
> @@ -113,6 +116,7 @@ typedef enum
> GST_MESSAGE_LATENCY = (1 << 19),
> GST_MESSAGE_ASYNC_START = (1 << 20),
> GST_MESSAGE_ASYNC_DONE = (1 << 21),
> + GST_MESSAGE_REQUEST_STATE = (1 << 22),
> GST_MESSAGE_ANY = ~0
> } GstMessageType;
>
> @@ -383,6 +387,10 @@ GstMessage * gst_message_new_structure_change (GstObject * src, GstStructureCh
> void gst_message_parse_structure_change (GstMessage *message, GstStructureChangeType *type,
> GstElement **owner, gboolean *busy);
>
> +/* REQUEST_STATE */
> +GstMessage * gst_message_new_request_state (GstObject * src, GstState state);
> +void gst_message_parse_request_state (GstMessage * message, GstState *state);
> +
> /* custom messages */
> GstMessage * gst_message_new_custom (GstMessageType type,
> GstObject * src,
> diff --git a/tests/check/gst/gstmessage.c b/tests/check/gst/gstmessage.c
> index b2a03f2..39bae40 100644
> --- a/tests/check/gst/gstmessage.c
> +++ b/tests/check/gst/gstmessage.c
> @@ -186,8 +186,25 @@ GST_START_TEST (test_parsing)
> void gst_message_parse_warning (GstMessage *message, GError **gerror, gchar **debug);
> */
>
> + /* GST_MESSAGE_REQUEST_STATE */
> + {
> + GstState state;
>
> + state = GST_STATE_PAUSED;
>
> + message = gst_message_new_request_state (NULL, state);
> + fail_if (message == NULL);
> + fail_unless (GST_MESSAGE_TYPE (message) == GST_MESSAGE_REQUEST_STATE);
> + fail_unless (GST_MESSAGE_SRC (message) == NULL);
> +
> + /* set some wrong values to check if the parse method overwrites them
> + * with the good values */
> + state = GST_STATE_READY;
> + gst_message_parse_request_state (message, &state);
> + fail_unless (state == GST_STATE_PAUSED);
> +
> + gst_message_unref (message);
> + }
> }
>
> GST_END_TEST;
> diff --git a/tools/gst-launch.c b/tools/gst-launch.c
> index d23f1c7..3930eae 100644
> --- a/tools/gst-launch.c
> +++ b/tools/gst-launch.c
> @@ -523,7 +523,7 @@ event_loop (GstElement * pipeline, gboolean blocking, GstState target_state)
> gint percent;
>
> gst_message_parse_buffering (message, &percent);
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, "%s %d%% \r", _("buffering..."), percent);
>
> /* no state management needed for live pipelines */
> @@ -535,7 +535,7 @@ event_loop (GstElement * pipeline, gboolean blocking, GstState target_state)
> buffering = FALSE;
> /* if the desired state is playing, go back */
> if (target_state == GST_STATE_PLAYING) {
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr,
> _("Done buffering, setting pipeline to PLAYING ...\n"));
> gst_element_set_state (pipeline, GST_STATE_PLAYING);
> @@ -545,8 +545,9 @@ event_loop (GstElement * pipeline, gboolean blocking, GstState target_state)
> /* buffering busy */
> if (buffering == FALSE && target_state == GST_STATE_PLAYING) {
> /* we were not buffering but PLAYING, PAUSE the pipeline. */
> - if(!quiet)
> - fprintf (stderr, _("Buffering, setting pipeline to PAUSED ...\n"));
> + if (!quiet)
> + fprintf (stderr,
> + _("Buffering, setting pipeline to PAUSED ...\n"));
> gst_element_set_state (pipeline, GST_STATE_PAUSED);
> }
> buffering = TRUE;
> @@ -559,6 +560,21 @@ event_loop (GstElement * pipeline, gboolean blocking, GstState target_state)
> gst_bin_recalculate_latency (GST_BIN (pipeline));
> break;
> }
> + case GST_MESSAGE_REQUEST_STATE:
> + {
> + GstState state;
> + gchar *name = gst_object_get_path_string (GST_MESSAGE_SRC (message));
> +
> + gst_message_parse_request_state (message, &state);
> +
> + fprintf (stderr, _("Setting state to %s as requested by %s...\n"),
> + gst_element_state_get_name (state), name);
> +
> + gst_element_set_state (pipeline, state);
> +
> + g_free (name);
> + break;
> + }
> case GST_MESSAGE_APPLICATION:{
> const GstStructure *s;
>
> @@ -567,7 +583,7 @@ event_loop (GstElement * pipeline, gboolean blocking, GstState target_state)
> if (gst_structure_has_name (s, "GstLaunchInterrupt")) {
> /* this application message is posted when we caught an interrupt and
> * we need to stop the pipeline. */
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Interrupt: Stopping pipeline ...\n"));
> /* return TRUE when we caught an interrupt */
> res = TRUE;
> @@ -728,7 +744,7 @@ main (int argc, char *argv[])
> gst_bin_add (GST_BIN (real_pipeline), pipeline);
> pipeline = real_pipeline;
> }
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Setting pipeline to PAUSED ...\n"));
> ret = gst_element_set_state (pipeline, GST_STATE_PAUSED);
>
> @@ -739,12 +755,13 @@ main (int argc, char *argv[])
> event_loop (pipeline, FALSE, GST_STATE_VOID_PENDING);
> goto end;
> case GST_STATE_CHANGE_NO_PREROLL:
> - if(!quiet)
> - fprintf (stderr, _("Pipeline is live and does not need PREROLL ...\n"));
> + if (!quiet)
> + fprintf (stderr,
> + _("Pipeline is live and does not need PREROLL ...\n"));
> is_live = TRUE;
> break;
> case GST_STATE_CHANGE_ASYNC:
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Pipeline is PREROLLING ...\n"));
> caught_error = event_loop (pipeline, TRUE, GST_STATE_PAUSED);
> if (caught_error) {
> @@ -754,7 +771,7 @@ main (int argc, char *argv[])
> state = GST_STATE_PAUSED;
> /* fallthrough */
> case GST_STATE_CHANGE_SUCCESS:
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Pipeline is PREROLLED ...\n"));
> break;
> }
> @@ -767,7 +784,7 @@ main (int argc, char *argv[])
> GstClockTime tfthen, tfnow;
> GstClockTimeDiff diff;
>
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Setting pipeline to PLAYING ...\n"));
>
> if (gst_element_set_state (pipeline,
> @@ -804,24 +821,24 @@ main (int argc, char *argv[])
> /* iterate mainloop to process pending stuff */
> while (g_main_context_iteration (NULL, FALSE));
>
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Setting pipeline to PAUSED ...\n"));
> gst_element_set_state (pipeline, GST_STATE_PAUSED);
> if (!caught_error)
> gst_element_get_state (pipeline, &state, &pending, GST_CLOCK_TIME_NONE);
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Setting pipeline to READY ...\n"));
> gst_element_set_state (pipeline, GST_STATE_READY);
> gst_element_get_state (pipeline, &state, &pending, GST_CLOCK_TIME_NONE);
>
> end:
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Setting pipeline to NULL ...\n"));
> gst_element_set_state (pipeline, GST_STATE_NULL);
> gst_element_get_state (pipeline, &state, &pending, GST_CLOCK_TIME_NONE);
> }
>
> - if(!quiet)
> + if (!quiet)
> fprintf (stderr, _("Freeing pipeline ...\n"));
> gst_object_unref (pipeline);
>
>
>
>
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