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GStreamer 0.10 Core Reference Manual | ![]() |
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Top | Description |
#include <gst/gst.h> GQuark gst_parse_error_quark (void
); #define GST_PARSE_ERROR enum GstParseError; GstParseContext; enum GstParseFlags; GstElement * gst_parse_launch (const gchar *pipeline_description
,GError **error
); GstElement * gst_parse_launch_full (const gchar *pipeline_description
,GstParseContext *context
,GstParseFlags flags
,GError **error
); GstElement * gst_parse_launchv (const gchar **argv
,GError **error
); GstElement * gst_parse_launchv_full (const gchar **argv
,GstParseContext *context
,GstParseFlags flags
,GError **error
); GstElement * gst_parse_bin_from_description (const gchar *bin_description
,gboolean ghost_unlinked_pads
,GError **err
); GstElement * gst_parse_bin_from_description_full (const gchar *bin_description
,gboolean ghost_unlinked_pads
,GstParseContext *context
,GstParseFlags flags
,GError **err
); GstParseContext * gst_parse_context_new (void
); void gst_parse_context_free (GstParseContext *context
); gchar ** gst_parse_context_get_missing_elements (GstParseContext *context
);
These function allow to create a pipeline based on the syntax used in the gst-launch utility (see man-page for syntax documentation).
Please note that these functions take several measures to create somewhat dynamic pipelines. Due to that such pipelines are not always reusable (set the state to NULL and back to PLAYING).
GQuark gst_parse_error_quark (void
);
Get the error quark used by the parsing subsystem.
Returns : |
the quark of the parse errors. |
#define GST_PARSE_ERROR gst_parse_error_quark ()
Get access to the error quark of the parse subsystem.
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.
A syntax error occured. | |
The description contained an unknown element | |
An element did not have a specified property | |
There was an error linking two pads. | |
There was an error setting a property | |
An empty bin was specified. | |
An empty description was specified |
typedef enum { GST_PARSE_FLAG_NONE = 0, GST_PARSE_FLAG_FATAL_ERRORS = (1 << 0) } GstParseFlags;
Parsing options.
Do not use any special parsing options. | |
Always return NULL when an error occurs (default behaviour is to return partially constructed bins or elements in some cases) |
Since 0.10.20
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.
|
the command line describing the pipeline |
|
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. [transfer full]
|
GstElement * gst_parse_launch_full (const gchar *pipeline_description
,GstParseContext *context
,GstParseFlags flags
,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.
|
the command line describing the pipeline |
|
a parse context allocated with
gst_parse_context_new() , or NULL . [allow-none]
|
|
parsing options, or GST_PARSE_FLAG_NONE |
|
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 then is returned. [transfer full]
|
Since 0.10.20
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.
|
null-terminated array of arguments. [in][array zero-terminated=1] |
|
pointer to a GError |
Returns : |
a new element on success and NULL on failure. [transfer full]
|
GstElement * gst_parse_launchv_full (const gchar **argv
,GstParseContext *context
,GstParseFlags flags
,GError **error
);
Create a new element based on command line syntax.
error
will contain an error message if an erroneous pipeline is specified.
An error does not mean that the pipeline could not be constructed.
|
null-terminated array of arguments. [in][array zero-terminated=1] |
|
a parse context allocated with
gst_parse_context_new() , or NULL . [allow-none]
|
|
parsing options, or GST_PARSE_FLAG_NONE |
|
pointer to a GError (which must be initialised to NULL ) |
Returns : |
a new element on success; on failure, either NULL
or a partially-constructed bin or element will be returned and error will
be set (unless you passed GST_PARSE_FLAG_FATAL_ERRORS in flags , then
NULL will always be returned on failure). [transfer full]
|
Since 0.10.20
GstElement * gst_parse_bin_from_description (const gchar *bin_description
,gboolean ghost_unlinked_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 unlinked 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 unlinked source pads or multiple unlinked sink pads
and want them all ghosted, you will have to create the ghost pads
yourself).
|
command line describing the bin |
|
whether to automatically create ghost pads for unlinked source or sink pads within the bin |
|
where to store the error message in case of an error, or NULL |
Returns : |
a newly-created bin, or NULL if an error occurred. [transfer full] |
Since 0.10.3
GstElement * gst_parse_bin_from_description_full (const gchar *bin_description
,gboolean ghost_unlinked_pads
,GstParseContext *context
,GstParseFlags flags
,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 unlinked 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 unlinked source pads or multiple unlinked sink pads
and want them all ghosted, you will have to create the ghost pads
yourself).
|
command line describing the bin |
|
whether to automatically create ghost pads for unlinked source or sink pads within the bin |
|
a parse context allocated with
gst_parse_context_new() , or NULL . [transfer none][allow-none]
|
|
parsing options, or GST_PARSE_FLAG_NONE |
|
where to store the error message in case of an error, or NULL |
Returns : |
a newly-created bin, or NULL if an error occurred. [transfer full] |
Since 0.10.20
GstParseContext * gst_parse_context_new (void
);
Allocates a parse context for use with gst_parse_launch_full()
or
gst_parse_launchv_full()
.
Free-function: gst_parse_context_free
Returns : |
a newly-allocated parse context. Free with
gst_parse_context_free() when no longer needed. [transfer full]
|
Since 0.10.20
void gst_parse_context_free (GstParseContext *context
);
Frees a parse context previously allocated with gst_parse_context_new()
.
|
a GstParseContext. [transfer full] |
Since 0.10.20
gchar ** gst_parse_context_get_missing_elements
(GstParseContext *context
);
Retrieve missing elements from a previous run of gst_parse_launch_full()
or gst_parse_launchv_full()
. Will only return results if an error code
of GST_PARSE_ERROR_NO_SUCH_ELEMENT
was returned.
|
a GstParseContext |
Returns : |
a
NULL-terminated array of element factory name strings of missing
elements. Free with g_strfreev() when no longer needed. [transfer full][array zero-terminated=1][element-type gchar*]
|
Since 0.10.20