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Functions
Description
These function allow to create a pipeline based on the syntax used in the gst-launch-1.0 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).
Functions
gst_parse_error_quark ()
GQuark
gst_parse_error_quark (void);
Get the error quark used by the parsing subsystem.
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.
Parameters
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.
[transfer floating][nullable]
gst_parse_launch_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.
Parameters
pipeline_description |
the command line describing the pipeline |
|
context |
a parse context allocated with
|
[allow-none] |
flags |
parsing options, or GST_PARSE_FLAG_NONE |
|
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
then is returned (unless the GST_PARSE_FLAG_PLACE_IN_BIN flag is set, in
which case they are put in a GstBin instead).
[transfer floating][nullable]
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 erroneous pipeline is specified.
An error does not mean that the pipeline could not be constructed.
Parameters
argv |
null-terminated array of arguments. |
[in][array zero-terminated=1] |
error |
pointer to a GError |
gst_parse_launchv_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.
Parameters
argv |
null-terminated array of arguments. |
[in][array zero-terminated=1] |
context |
a parse context allocated with
|
[allow-none] |
flags |
parsing options, or GST_PARSE_FLAG_NONE |
|
error |
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 floating][nullable]
gst_parse_bin_from_description ()
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).
Parameters
bin_description |
command line describing the bin |
|
ghost_unlinked_pads |
whether to automatically create ghost pads for unlinked source or sink pads within the bin |
|
err |
where to store the error message in case of an error, or |
Returns
a
newly-created bin, or NULL if an error occurred.
[transfer floating][type Gst.Bin][nullable]
gst_parse_bin_from_description_full ()
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).
Parameters
bin_description |
command line describing the bin |
|
ghost_unlinked_pads |
whether to automatically create ghost pads for unlinked source or sink pads within the bin |
|
context |
a parse context allocated with
|
[transfer none][allow-none] |
flags |
parsing options, or GST_PARSE_FLAG_NONE |
|
err |
where to store the error message in case of an error, or |
Returns
a newly-created
element, which is guaranteed to be a bin unless
GST_FLAG_NO_SINGLE_ELEMENT_BINS was passed, or NULL if an error
occurred.
[transfer floating][type Gst.Element][nullable]
gst_parse_context_new ()
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][nullable]
gst_parse_context_copy ()
GstParseContext *
gst_parse_context_copy (const GstParseContext *context);
Copies the context
.
gst_parse_context_free ()
void
gst_parse_context_free (GstParseContext *context);
Frees a parse context previously allocated with gst_parse_context_new().
gst_parse_context_get_missing_elements ()
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.
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*][nullable]
Types and Values
GST_PARSE_ERROR
#define GST_PARSE_ERROR gst_parse_error_quark ()
Get access to the error quark of the parse subsystem.
enum GstParseError
The different parsing errors that can occur.
enum GstParseFlags
Parsing options.
Members
|
Do not use any special parsing options. |
||
|
Always return |
||
|
If a bin only has a single element, just return the element. |
||
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If more than one toplevel element is described by the pipeline description string, put them in a GstBin instead of a GstPipeline. (Since 1.10) |