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GStreamer 0.10 Core Reference Manual | ![]() |
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GstPipelineGstPipeline — Top-level bin with clocking and bus management functionality. |
#include <gst/gst.h> GstPipeline; enum GstPipelineFlags; GstElement* gst_pipeline_new (const gchar *name); void gst_pipeline_auto_clock (GstPipeline *pipeline); GstBus* gst_pipeline_get_bus (GstPipeline *pipeline); GstClock* gst_pipeline_get_clock (GstPipeline *pipeline); GstClockTime gst_pipeline_get_last_stream_time (GstPipeline *pipeline); gboolean gst_pipeline_set_clock (GstPipeline *pipeline, GstClock *clock); void gst_pipeline_set_new_stream_time (GstPipeline *pipeline, GstClockTime time); void gst_pipeline_use_clock (GstPipeline *pipeline, GstClock *clock); gboolean gst_pipeline_get_auto_flush_bus (GstPipeline *pipeline); void gst_pipeline_set_auto_flush_bus (GstPipeline *pipeline, gboolean auto_flush);
In almost all cases, you'll want to use a GstPipeline when creating a filter graph. The GstPipeline will manage the selection and distribution of a global clock as well as provide a GstBus to the application.
The pipeline will also use the selected clock to calculate the stream time of the pipeline.
When sending a seek event to a GstPipeline, it will make sure that the pipeline is properly PAUSED and resumed as well as update the new stream time after the seek.
gst_pipeline_new()
is used to create a pipeline. when you are done with
the pipeline, use gst_object_unref()
to free its resources including all
added GstElement objects (if not otherwise referenced).
typedef struct { GstClock *fixed_clock; /* fixed clock if any */ GstClockTime stream_time; GstClockTime delay; } GstPipeline;
The GstPipeline structure.
GstClock *fixed_clock ; |
The fixed clock of the pipeline, used when GST_PIPELINE_FLAG_FIXED_CLOCK is set. |
GstClockTime stream_time ; |
The stream time of the pipeline. |
GstClockTime delay ; |
Extra delay added to base time to compensate for delay when setting elements to PLAYING. |
typedef enum { GST_PIPELINE_FLAG_FIXED_CLOCK = (GST_BIN_FLAG_LAST << 0), /* padding */ GST_PIPELINE_FLAG_LAST = (GST_BIN_FLAG_LAST << 4) } GstPipelineFlags;
Pipeline flags
GST_PIPELINE_FLAG_FIXED_CLOCK |
this pipeline works with a fixed clock |
GST_PIPELINE_FLAG_LAST |
offset to define more flags |
GstElement* gst_pipeline_new (const gchar *name);
Create a new pipeline with the given name.
name : |
name of new pipeline |
Returns : | newly created GstPipeline MT safe. |
void gst_pipeline_auto_clock (GstPipeline *pipeline);
Let the pipeline select a clock automatically.
MT safe.
pipeline : |
the pipeline |
GstBus* gst_pipeline_get_bus (GstPipeline *pipeline);
Gets the GstBus of this pipeline.
pipeline : |
the pipeline |
Returns : | a GstBus MT safe. |
GstClock* gst_pipeline_get_clock (GstPipeline *pipeline);
Gets the current clock used by the pipeline.
pipeline : |
the pipeline |
Returns : | a GstClock |
GstClockTime gst_pipeline_get_last_stream_time (GstPipeline *pipeline);
Gets the last stream time of the pipeline. If the pipeline is PLAYING, the returned time is the stream time used to configure the elements in the PAUSED->PLAYING state. If the pipeline is PAUSED, the returned time is the stream time when the pipeline was paused.
pipeline : |
the pipeline |
Returns : | a GstClockTime MT safe. |
gboolean gst_pipeline_set_clock (GstPipeline *pipeline, GstClock *clock);
Set the clock for the pipeline. The clock will be distributed to all the elements managed by the pipeline.
pipeline : |
the pipeline |
clock : |
the clock to set |
Returns : | TRUE if the clock could be set on the pipeline. MT safe. |
void gst_pipeline_set_new_stream_time (GstPipeline *pipeline, GstClockTime time);
Set the new stream time of the pipeline. The stream time is used to
set the base time on the elements (see @gst_element_set_base_time()
)
in the PAUSED->PLAYING state transition.
Setting time
to GST_CLOCK_TIME_NONE will disable the pipeline's management
of element base time. The application will then be responsible for
performing base time distribution. This is sometimes useful if you want to
synchronize capture from multiple pipelines, and you can also ensure that the
pipelines have the same clock.
MT safe.
pipeline : |
the pipeline |
time : |
the new stream time to set |
void gst_pipeline_use_clock (GstPipeline *pipeline, GstClock *clock);
Force the pipeline to use the given clock. The pipeline will always use the given clock even if new clock providers are added to this pipeline.
MT safe.
pipeline : |
the pipeline |
clock : |
the clock to use |
gboolean gst_pipeline_get_auto_flush_bus (GstPipeline *pipeline);
pipeline : |
a GstPipeline |
Returns : | whether the pipeline will automatically flush its bus when going from READY to NULL state or not. MT safe. |
Since 0.10.4
void gst_pipeline_set_auto_flush_bus (GstPipeline *pipeline, gboolean auto_flush);
Usually, when a pipeline goes from READY to NULL state, it automatically flushes all pending messages on the bus, which is done for refcounting purposes, to break circular references. This means that applications that update state using (async) bus messages (e.g. do certain things when a pipeline goes from PAUSED to READY) might not get to see messages when the pipeline is shut down, because they might be flushed before they can be dispatched in the main thread. This behaviour can be disabled using this function.
MT safe.
pipeline : |
a GstPipeline |
auto_flush : |
whether or not to automatically flush the bus when the pipeline goes from READY to NULL state |
Since 0.10.4
auto-flush-bus
" property"auto-flush-bus" gboolean : Read / Write
Whether or not to automatically flush all messages on the
pipeline's bus when going from READY to NULL state. Please see
gst_pipeline_set_auto_flush_bus()
for more information on this option.
Default value: TRUE
Since 0.10.4
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