GstParse

GstParse — Get a pipeline from a text pipeline description

Synopsis


#include <gst/gst.h>


GQuark              gst_parse_error_quark               (void);
#define             GST_PARSE_ERROR
enum                GstParseError;
GstElement*         gst_parse_launch                    (const gchar *pipeline_description,
                                                         GError **error);
GstElement*         gst_parse_launchv                   (const gchar **argv,
                                                         GError **error);
GstElement*         gst_parse_bin_from_description      (const gchar *bin_description,
                                                         gboolean ghost_unconnected_pads,
                                                         GError **err);


Description

These function allow to create a pipeline based on the syntax used in the gst-launch utillity.

Details

gst_parse_error_quark ()

GQuark              gst_parse_error_quark               (void);

Get the error quark used by the parsing subsystem.

Returns : the quark of the parse errors.

GST_PARSE_ERROR

#define GST_PARSE_ERROR gst_parse_error_quark ()

Get access to the error quark of the parse subsystem.


enum GstParseError

typedef enum
{
  GST_PARSE_ERROR_SYNTAX,
  GST_PARSE_ERROR_NO_SUCH_ELEMENT,
  GST_PARSE_ERROR_NO_SUCH_PROPERTY,
  GST_PARSE_ERROR_LINK,
  GST_PARSE_ERROR_COULD_NOT_SET_PROPERTY,
  GST_PARSE_ERROR_EMPTY_BIN,
  GST_PARSE_ERROR_EMPTY
} GstParseError;

The different parsing errors that can occur.

GST_PARSE_ERROR_SYNTAX A syntax error occured.
GST_PARSE_ERROR_NO_SUCH_ELEMENT The description contained an unknown element
GST_PARSE_ERROR_NO_SUCH_PROPERTY An element did not have a specified property
GST_PARSE_ERROR_LINK There was an error linking two pads.
GST_PARSE_ERROR_COULD_NOT_SET_PROPERTY There was an error setting a property
GST_PARSE_ERROR_EMPTY_BIN An empty bin was specified.
GST_PARSE_ERROR_EMPTY An empty description was specified

gst_parse_launch ()

GstElement*         gst_parse_launch                    (const gchar *pipeline_description,
                                                         GError **error);

Create a new pipeline based on command line syntax. Please note that you might get a return value that is not NULL even though the error is set. In this case there was a recoverable parsing error and you can try to play the pipeline.

pipeline_description : the command line describing the pipeline
error : the error message in case of an erroneous pipeline.
Returns : a new element on success, NULL on failure. If more than one toplevel element is specified by the pipeline_description, all elements are put into a GstPipeline, which than is returned.

gst_parse_launchv ()

GstElement*         gst_parse_launchv                   (const gchar **argv,
                                                         GError **error);

Create a new element based on command line syntax. error will contain an error message if an erroneuos pipeline is specified. An error does not mean that the pipeline could not be constructed.

argv : null-terminated array of arguments
error : pointer to a GError
Returns : a new element on success and NULL on failure.

gst_parse_bin_from_description ()

GstElement*         gst_parse_bin_from_description      (const gchar *bin_description,
                                                         gboolean ghost_unconnected_pads,
                                                         GError **err);

This is a convenience wrapper around gst_parse_launch() to create a GstBin from a gst-launch-style pipeline description. See gst_parse_launch() and the gst-launch man page for details about the syntax. Ghost pads on the bin for unconnected source or sink pads within the bin can automatically be created (but only a maximum of one ghost pad for each direction will be created; if you expect multiple unconnected source pads or multiple unconnected sink pads and want them all ghosted, you will have to create the ghost pads yourself).

bin_description : command line describing the bin
ghost_unconnected_pads : whether to automatically create ghost pads for unconnected source or sink pads within the bin
err : where to store the error message in case of an error, or NULL
Returns : a newly-created bin, or NULL if an error occurred.

Since 0.10.3