Make it possible to add API specific flags to the ALLOCATION query. This makes
it possible to also check what kinds of subfeatures of the metadata API are
supported.
Add a method that memory implementations can call to initialize the standard
GstMemory structure.
Move the parent handling in the _free handler.
Rearrange some internal function parameters so that the order is consistent.
Add more memory examples
Move the locking methods from GstMemory to GstMiniObject.
Add a miniobject flag to enable LOCKABLE objects. LOCKABLE objects can
use the lock/unlock API to control the access to the object.
Add a minobject flag that allows you to lock an object in readonly mode.
Modify the _is_writable() method to check the shared counter for LOCKABLE
objects. This allows us to control writability separately from the refcount for
LOCKABLE objects.
The NO_SHARE flag does not influence the exclusiveness of the buffer initially
but only if a _share operation can be done. Otherwise, we would not be able to
WRITE map a buffer memory because it would have a share count of at least 2.
We implement the locking in gst_memory_map with the lock flags, make matching
flags the same number so that we can use the map flags directly as lock flags.
Expose the internally used methods for locking and unlocking the object. Pass
the access mode to the unlock function for extra checks and because we need it
for the EXCLUSIVE locks.
Make some new defines to specify the desired locking.
Add a new EXCLUSIVE lock mode which will increment the shared counter. Objects
with a shared counter > 1 will not be lockable in WRITE mode.
Improve parallel installability in setups like jhbuild by
providing versioned variants of some environment variables:
GST_REGISTRY_1_0
GST_PLUGIN_PATH_1_0
GST_PLUGIN_SYSTEM_PATH_1_0
GST_PLUGIN_SCANNER_1_0
will now be checked before checking the unversioned ones.
https://bugzilla.gnome.org/show_bug.cgi?id=679407
We added a minimum length of three letters originally so we would
fail to recognise DOS/Windows-style filenames as valid URIs (as we
should). Two should be just fine as well.
Make GstSeekFlag to GstSegmentFlag conversion explicit, and
set only those seek flags in the segment flags which are
mapped. This makes sure we don't have extraneous flags
littering our segment flag field, which also fixes the
debug printing/serialisation of segment events in the
debug log.
Visual C++ does not have isnan(), so add fallback to
math-compat.h (could use _isnan() in this case, but
this makes it work for all cases where isnan is missing).
https://bugzilla.gnome.org/show_bug.cgi?id=679112
Make a gst_buffer_append_region() function that allows you to append a memory
region from one buffer to another. This is a more general version of
gst_buffer_append().
If we have a file called Foo\Bar.ogg, there is no way to pass
that filename properly to filesrc in gst_parse_launch(), since
gst_parse_unescape() will just unescape \x to x.
Not cherry-picking this into 0.10 since there are apparently
apps that work around this problem and which would break if
we fixed it there too.
https://bugzilla.gnome.org/show_bug.cgi?id=673319
Take into account that not all fields might be valid (though they
are valid in the GDateTime structure). But we should just return
unordered if the set fields don't match. Also, don't check
microseconds when comparing datetimes, since we don't serialise
those by default if they're available. This ensures date times are
still regarded as equal after serialising+deserialising.
Some tag parsers and writers use same datetime format based on ISO 8601.
We can reduce some code by creating some general functions for it.
API: gst_date_time_to_iso8601_string()
API: gst_date_time_new_from_iso8601_string()
https://bugzilla.gnome.org/show_bug.cgi?id=678031
Now that TOCs are refcounted and have a GType, we can just
stuff a ref of the TOC directly into the various toc
event/message/query structures and get rid of lots of
cracktastic GstStructure <-> GstToc serialisation and
deserialisation code. We lose some TOC sanity checking
in the process, but that should really be done when
it's being created anyway.
Let's keep it simple for now:
gst_toc_setter_reset_toc() -> gst_toc_setter_reset()
gst_toc_setter_get_toc_copy() -> removed
gst_toc_setter_get_toc() -> returns a ref now
gst_toc_setter_get_toc_entry_copy() -> removed,
use TOC functions instead
gst_toc_setter_get_toc_entry() -> removed,
use TOC functions instead
gst_toc_setter_add_toc_entry() -> removed,
to avoid problems with (refcount-dependent)
writability of TOC; use TOC functions instead
So mini objects don't have to poke into the GstMiniObject part
of the structure. Saves lines of code, and seems slightly cleaner.
We don't have proper OO hierarchies or methods here after all.
These changes are to clean up syntax issues such as missing colons,
missing spaces, etc., and minor issues such as argument names in
headers not matching the implementation and/or documentation.
When 2 weak refs are added, the array is not resized big enough.
Simplify the weak ref handling code.
Free memory when we remove all weak refs.
Allow installing the same weak ref multiple times, like in gobject.
The size field is used by subclasses to store the total allocated size of the
memory for this miniobject. Because miniobject doesn't really do anything with
this field we can move it to the subclasses.
Add the running-time of the buffer that caused the async operation to complete
to the async-done message.
Update bin to handle the new async-done message.
Use the new RESET_TIME message to reset the start-time of the pipeline to the
requested time.
Make basesink request a new running-time when the flush-stop message tells it to
insteasd of waiting for preroll.
Add a new message to reset the pipeline running_time. Currently reseting the
pipeline can only be requested in the async_done message which means that the
pipeline needs to be prerolled. It is better to move this to a separate message.
Remove constructors we don't want:
gst_date_time_new_ymd_h() because we don't want to
support hour-only for now;
gst_date_time_new_ymd_hm() because we don't want to
add constructors with time info where the caller doesn't
have to think about what timezone the time is in.
Lots of compulsive clean-up. Docs fixes. Replace
has_minute() and has_hour() with has_time().
In order to deserialise and re-serialise dates and date times
from tags properly, we need to be able to express partial
dates (e.g. YYYY or YYYY-MM) and date times.
We only support partial date times where all the more
significant fields above the first unset field are set
(e.g. YYYY-00-DD is not supported).
Calling _get_foo() when foo is not set is not allowed
any more, callers need to check which fields are set
first.
https://bugzilla.gnome.org/show_bug.cgi?id=677757
Make the gst_bin_remove_func more like the add_func. Check if the element we try
to remove from the bin has the bin as the parent and set the parent flag to NULL
immediately, this allows us to avoid concurrent remove operations without using
the UNPARENTING element flag. After we unparented the element from the bin, we
update the bin state and remove the element from the list. Finally we unlink
all the pads.
This avoids a race condition where the element could still claim to have the
bin as the parent while the bin didn't have a pointer to the element anymore.
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=647759
In the dispose handler we first need to release all the request pads and then
remove the remaining pads. This is because it is possible that releasing the
request pad might also cleanly remove some of the other dynamic pads, like
what rtpsession does.
https://bugzilla.gnome.org/show_bug.cgi?id=677436
Context: Latency configuration should not be
messed up because of not-linked pads. In general,
one return FALSE on latency distribution causes
the "overall" pipeline latency configuration to
fail. This shows up as noise in logs (warning).
Conflicts:
gst/gstpad.c
Otherwise a pipeline where one sticky event fails to be sent will
never forward EOS events downstream. This can cause pipelines to
wait forever for EOS on errors.
The linking behaviour of external variables that are not initialized
in the compilation unit where they are defined is undefined. On OS X
this causes a linking failure when statically linking GStreamer.
When the bin does an upward state change, try to avoid doing a downward state
change on the child and vice versa.
Add some more unit tests for this fix.
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=621833
Make GstPluginFeature opaque until we have time to
clean it up a little. Only GstElementFactory and
GstTypefindFactory derive from it, and they are
opaque already, and we currently don't support
custom plugin features in the registry anyway.
They can be used to select snapping behavior (to previous, next, or
nearest location, where relevant) when seeking.
The seeking implementation (eg, demuxer) may currently ignore some
or all of these flags.
It's only used internally, most other users will likely
want to use gst_registry_find_plugin() directly instead
(and if not, they can easily walk the list and doing the
strcmp themselves).
There's no reason anyone would want to derive from this, so
just make opaque until we manage to make all the private bits
private properly (which I'm not doing right now because it's
more invasive and I have registry modifications locally which
touch all that code as well).
This is an implementation detail really, and it's not
clear what anyone would do with this. It's unused as
far as I'm aware, so just remove it for now.
Rename the _get_value_array() functions to _get_g_value_array() and reintroduce
the former to operate on plain unboxed c datatypes (like in 0.10). The _g_value
variants are for bindings while the _value ones are more suited to processing
in elements.
Reset the buffer not after we acquire but before we release into the pool. This
makes sure that the pool only has buffers in a clean state and that we can set
extra metadata on buffers in the acquire method. this means that we need to
remove an argument from the method.
Add a new LOCKED flag to the metadata. Refuse removing LOCKED metadata from
a buffer.
Mark the metadata from the bufferpool LOCKED.
Add unit test for LOCKED flag
Ass serialize and deserialize functions for GstSegment so that gdp and
gst_structure_to_string show the segment values. We convert to a GstSegment
first to make things easier..
Fixes https://bugzilla.gnome.org/show_bug.cgi?id=674100
Add gst_element_class_{add,set}_metadata() variants for static strings,
so we can avoid unnecessary g_strdup()s.
API: gst_element_class_add_static_metadata()
API: gst_element_class_set_static_metadata()
After a writer has written to its reserved write location, it can only make the
location available for reading if all of the writers with lower locations have
finished.
Fix a race where the reader would see the updated the tail pointer before the
write could write the data into the queue. Fix this by having a separate reader
tail pointer that is only incremented after the writer wrote the data.
Remove GST_MAJORMINOR and replace it by GST_API_VERSION
Also set GST_VERSION_{MAJOR,MINOR,MICRO,NANO} explicitely
now.
All versions are at 1.0.0 now for the release soon but
API/ABI can still change until the 1.0.0 release.
Next release versions until 1.0.0 will be 0.10.9X and
these will be release candidates. GST_VERSION_* will
nonetheless stay at 1.0.0.0.
gst_buffer_take_memory -> gst_buffer_insert_memory because insert is what the
method does.
Make all methods deal with ranges so that we can replace, merge, remove and map
a certain subset of the memory in a buffer. With the new methods we can make
some code nicer and reuse more code. Being able to deal with a subset of the
buffer memory allows us to optimize more cases later (most notably RTP headers
and payload that could be in different memory objects).
Make some more convenient macros that call the more generic range methods.
Add gst_buffer_append() which appends the memory blocks from one buffer to
another. Remove the old inefficient _merge() and _join() methods which forced a
premature memcpy in most cases.
Remove the _is_span() and _span() methods they are not needed anymore now that
we can _append(). Merging and spanning will be delayed until mapping or maybe
not at all when the element can deal with the different memory blocks.
Remove the const from the GstCaps in get/set_param. set_param modifies
the refcount of the caps.
Don't increment the refcount of the caps result of get_param like we
do with other objects.
Update some annotiations.
Improve the docs of the get/pull_range functions, define the lifetime of the
buffer in case of errors and short reads.
Make sure the code does what the docs say.
Make it possible to wrap all kinds of memory by exposing all properties to
gst_buffer_new_wrapped_full(). This makes it possible to also create writable
memory without a free function or memory with extra padding.
Make it so that one can specify a buffer for get/pull_range where the downstream
element should write into. When passing NULL, upstream should allocate a buffer,
like in 0.10.
We also need to change the probes a little because before the pull probe, there
could already be a buffer passed. This then allows us to use the same PROBE
macro for before and after pulling.
While we're at the probes, make the query probe more powerful by handling the
GST_PAD_PROBE_DROP return value. Returning _DROP from a query probe will now
return TRUE upstream and will not forward the probe to the peer or handler.
Also handle _DROP for get/pull_range properly by not dispatching to the
peer/handler or by generating EOS when the probe returns DROP and no buffer.
Make filesrc handle the non-NULL buffer passed in the get_range function and
skip the allocation in that case, writing directly into the downstream provided
buffer.
Update tests because now we need to make sure to not pass a random value in the
buffer pointer to get/pull_range
Separate the bufferpool and allocator hints in the allocation query, some
of the values don't always make sense together.
Keep the bufferpool and its configuration together.
Keep the allocator and its parameters together.
Allow for multiple bufferpool configurations in the query.
Group the extra allocation parameters in a GstAllocationParams structure to make
it easier to deal with them and so that we can extend them later if needed.
Make gst_buffer_new_allocate() take the GstAllocationParams for added
functionality.
Add boxed type for GstAllocationParams.
Change gst_allocator_alloc() so that we can also spicify flags and padding.
Add 2 new flags to mark the memory 0 prefixed/padded. This allows us to
remove some resizes in the base classes.
When allocating memory, memset prefix and padding with 0 when the flags tell
us to.
On resize, clear the zero padding flags if we can't guarantee the memory is
still 0 filled.
Update tests.
Negotiating padding is needed on second thought so include it in the
ALLOCATION query.
Make the bufferpool take padding into account when allocating.
Make basesrc take padding into account.
Use padding and prefix when allocating in basetransform.
Also register queries with a QueryType that allows us to check if the event is
sent in the right direction. Add a serialized query type because we will need
this for the allocation query.
Remove the QueryTypeDefinition stuff, it is not used anymore and we now use
custom queries and separate API for them.
Update defs.
Rename _do_simplify() to _simplify(). The name was introduced as a replacement
method for a deprecated method but we can now rename it again.
Fix some docs.
Make gst_caps_do_simplify() take ownership of the input caps and produce a
simplified output caps. This removes the requirement of having writable input
caps and the method can make the caps writable only when needed.
Rework some caps operations so they don't rely on writable caps but instead take
ownership of the input caps and do _make_writable() only when needed.
Remove some const from caps functions, it does not make much sense for
refcounted objects and does not allow us to return a refcount to the const input
caps.
Rework the base classes fixate vmethods to not operate on the caps in-place.
All this saves us around 30% of caps and structure copy and new operations.
Make a helper function check_sticky to check and push pending sticky events.
Move the handling of the result of pushing the sticky event inside the
push_event function, we need to mark the event as received when it was pushed
correctly.
Move the sticky events code outside of gst_pad_push_event_unchecked and
make it purely handle sending the event to the peer.
when pushing a sticky event, first store it on the pad. Then check and push any
pending sticky events when we get a serialized or sticky event on a srcpad. This
fixes the issue where sticky events are not pushed when an event is pushed.
There isn't really any need to provide public API for that. It's not
used anywhere in practice, and we aim to provide an API that works
for GstCaps, not some kind of generic set manipulation API based on
GValue. Making this private also makes it easier to optimise this
later. We can always put it back if someone actually needs it.
Because gst_pad_get_pad_template_caps() returns ANY when there is no template,
the query caps function should also return ANY when there is no template (and no
pad current caps) instead of EMPTY.
Split out the registration of the metadata API and its implementation. Make a
GType for each metadata API. This allows us to store extra information with the
API type such as the tags.
Change the buffer API so that we can get the metadata using the API GType.
Change the query API so that we use the metadata API GType in the allocation
query instead of a string.
Update netaddress and unit tests
Add support for adding tags to the metadata. with some standard keys, this
should make it possible to describe what the metadata refers to. We should be
able to use this information to decide if a transformation destroys the metadata
or not.
lseek() returns the offset if successful, and this is != 0 and
does not indicate an error. And if it does actually fail, don't
return FALSE (0) as an int, but -1. None of these things are
likely to have made a difference, ever. I don't think the offset
seek can ever actually happen, the current file position and the
current offset should always be increased in lock step, unless
there was an error in which case we'd just error out.
After a writer has written to its reserved write location, it can only make the
location available for reading if all of the writers with lower locations have
finished.
Fix a race where the reader would see the updated the tail pointer before the
write could write the data into the queue. Fix this by having a separate reader
tail pointer that is only incremented after the writer wrote the data.
Flesh out the transform method. Add a type and extra info to the transform
function so that implementation can transform the metadata.
Remove the copy function and replace with the more generic transform.
Make it possible to configure a GDestroyNotify and user_data for
gst_memory_new_wrapped() this allows for more flexible wrapping of foreign
memory blocks.
Don't use the duration in the segment for calculating clipping values.
The duration is expressed in stream time and clipping is done on unrelated
timestamp values.
This used to be interesting for elements that used the segment structure to
implement seeking because then they would use stream-time for the segment
start/stop values and the duration could be used as a fallback when the stop
position was not set. Now that the complete segment event is passed between
elements we cannot do this anymore because some elements might store the
duration and start/stop values with different time bases in the segment.
When we have no chain function or when we are operating the pad in the wrong
mode, emit a critical instead of posting an error message. This is certainly a
programming error and we cannot always post a message (like when the pad has no
parent)
Rename _is_writable() with _is_exclusive because the writability does not depend
on the amount of references to the memory object anymore.
Add accessor macros for the memory flags.
Rename the GstBuffer _peek_memory() method to _get_memory() and return a
reference to the memory now that we can do this without affecting writability
of the memory object. Make it possible to also make this function merge the
buffer memory.
Add methods to replace memory in a buffer. Make some convience macros for the
buffer memory functions.
Fix unit tests.
Make an _init method where the parent mini-object and other fields are
initialized.
Check that the passed structure doesn't already have a parent.
Use the _new_custom () constructors
__registry_reuse_plugin_scanner is only defined when
GST_DISABLE_REGISTRY is not defined.
gstregistry.c: In function 'gst_registry_scan_plugin_file':
gstregistry.c:1131:8: error: '__registry_reuse_plugin_scanner' undeclared (first use in this function)
https://bugzilla.gnome.org/show_bug.cgi?id=667284
Fix annoying gst_type_find_register() function signature. A simple
string with comma-separated extensions works just as well and saves
lines of code, casts, relocations and ultimately kittens.
Place the allocator object in the ALLOCATION query instead of the name. This
allows us to exchange allocators that are not in the global pool of allocators.
Update elements for the new api
Add refcounting to the GstAllocator object.
Remove const from functions because the allocator is refcounted now.
Rename the vmethods for consistency
Expose the constructor for GstAllocator and add a destroy notify for the
user_data. This should make it possible to create allocators that are not
registered and shared globally along with the possibility to destroy them
properly.
Update defs with new symbols.
Remove trace, we use debug log for that
Make alloc trace simpler, removing some methods.
Activate alloc trace with a GST_TRACE=3 environment variable.
Dump leaked objects atexit.
Provide an offset in the object where the GType can be found so that more
verbose info can be given for objects.
Remove -T option from gst-launch because tracing is now triggered with the
environment variable.
We don't use the sticky event index anymore, ordering of the events are how they
were sent initially.
Add some more padding between the event numbers so that we can insert new events
later.
Since GValueArray is deprecated. It's all only internal anywhere here,
but if we use GstValueArray the option strings get serialized nicely
in the debug logs at least.
This is now bindings firendly as _new is just a classic c convenience and all
the work is done in a constructor. As a side effect _new never fails.
Fix the tests.
int and int64 ranges can now have an optional step (defaulting to 1).
Members of the range are those values within the min and max bounds
which are a multiple of this step.
https://bugzilla.gnome.org/show_bug.cgi?id=665294
We introduced our own when GLib didn't want to add a GType
for GError. But now that there is one, we can use GLib's
unconditionally and remove our version.
Make the memory object simply manage the data pointer and the maxsize and move
the offset and size handling to common functionality.
Use the READONLY flag to set a readonly lock.
Remove the data and size fields from the unmap method. We need an explicit
resize operation instead of using the unmap function.
Make internal helper lock and unlock functions.
Update unit test and users of the old API.
This has to be handled explicitely by elements to
make sure that they support all the metas passed
in the allocation query.
Metas have to supported explicitely, otherwise the
query will fail. All elements in a chain need to
support a specific meta to allow its usage.
Which we had to add because GLib didn't have it
back in the day. Port everything to plain old
G_TYPE_DATE, which is also a boxed type. Ideally
we'd just use GDateTime for everything, but it
doesn't support not setting some of the fields
unfortuntely (which would be very useful for
tag handling in general, if we could express
2012-01 for example).
https://bugzilla.gnome.org/show_bug.cgi?id=666351
Count how many mappings are currently active and also with what access pattern.
Update the design doc with restrictions on the access patterns for nested
mappings.
Check if nested mappings obey the access mode restrictions of the design doc.
Add various unit tests to check the desired behaviour.
Make an unmap call with a different data pointer than the map call update the
offset field. This allows for both offset and size adjustements in the unmap
call.
There are many good use cases for GstIndex and we want
to add it back again in some form, but possibly not with
the current API, which is very powerful (maybe too powerful),
but also a bit confusing. At the very least we'd need to
make the API bindings-friendly.
Add a GstControlBinding class. This is a preparation for making the
controlsources generate double valued control curves and do the gparamspec
mapping in the control binding. Now the API in GstObject is again mostly
for convenience.
Conflicts:
libs/gst/base/gstbasetransform.c
libs/gst/controller/gstinterpolationcontrolsource.c
libs/gst/controller/gstlfocontrolsource.c
plugins/elements/gstfilesrc.c
Dit not merge controller or basetransform changes.
Mark all metadata on the allocated buffers with a POOLED flag. When a buffer
returns to the pool, remove all metadata that did not have the POOLED flag. This
makes sure that we never leave unknown metadata to the buffers in the pool.
Add a singleton for ANY and EMPTY caps and make the GST_CAPS_ANY and
GST_CAPS_NONE point to them. This makes the API more consistent now
that the macro does not magically create a ref. It also solves some leaks in
places where the macro was used to register a padtemplate.
Move most of the code to a GstTimedValueControlSource. Split out the trigger
'interpolation mode' to a new control source class. Move tests and examples to
new api. Update docs.
Fixes#610338
An extra application preset dir help to organize presets created for special
purposes. Fixes#660760
API: gst_preset_set_app_dir(), gst_preset_get_app_dir()
Add private replacements for deprecated functions such as
g_mutex_new(), g_mutex_free(), g_cond_new() etc., mostly
to avoid the deprecation warnings. We can't change most of
these in 0.10 because they're part of our API and ABI.
Add a new simple miniobject that is a combination of a GstBuffer, GstCaps,
GstSegment and other arbitrary info organized in a GstStructure. This object can
be used to exchange samples between an element and the application or for
storing album art in tags etc.
Use GstFlowReturn to internally pass events between pads.
When we sticky events cause an error, translate this error into a GstFlowReturn.
Caps events will, for example, generate a NOT_NEGOTIATED return when the event
function returns an error.
This allows us then to refuse sending buffers if one of the sticky events is
refused and generate a correct error return value.
If we are dealing with a blocking probe, only then check if one the
blocking flags of the hook matches.
Add some more debug.
Make the pad unit test less racy.
This check is correct but unfortunately it's impossible to implement
in a threadsafe way because the caps could have changed in the meantime.
Fixes bug #659606.
Add a new event flag for sticky events so that multiple events of that type can
be stored on a pad at the same time. Change the _get_sticky_event() function to
loop over the multiple events of a type.
Change the foreach function to make it possible to removed and modify the sticky
events on a pad.
Use an variable size array now to store the events. This could later be
optimized some more.
When the foreach function told us to remove the buffer from the list, decrease
the length of the array or else we might read past the last item in the array.
Rewrite sticky events, trying to make it a bit more simple.
When sticky events are pushed on a srcpad, store them in the sticky event
array and mark the event with received = FALSE.
When the sticky event is successfully sent to the peer pad, make
received = TRUE.
Keep a PENDING_EVENTS pad flag that is set when one of the events is in
the received = FALSE state for some reason.
when activating a sinkpad, mark all events received = FALSE on the peer
srcpad.
When pushing a buffer, check the PENDING_EVENTS flag and if it is set, push all
events to the peer pad first.
Add _full variants of the pad function setters that take a destroy notify.
Make some macros that make the old method name pass NULL to this new
function.
Add the pad mode to the activate function so that we can reuse the same function
for all activation modes. This makes the core logic smaller and allows for some
elements to make their activation code easier. It would allow us to add more
scheduling modes later without having to add more activate functions.
Turns some boolean arguments in the scheduling query to flags, which are easier
to extend and makes the code easier to read.
Make extra methods for configuring and querying the supported scheduling modes.
This should make it easier to add new modes later.
Add a new pad flag NEED_PARENT that ensures that the parent of a pad is
reffed and not NULL when the event, query and internal links functions
are called.
When a pad is added to an element automatically make sure the NEED_PARENT flag
is enabled.
fix the proxy functions for query_accept_caps and query_caps to use the pad
forward helper functions which correctly forwards on the internally linked pads.
Remove the getcaps function on the pad and use the CAPS query for
the same effect.
Add PROXY_CAPS to the pad flags. This instructs the default caps event and query
handlers to pass on the CAPS related queries and events. This simplifies a lot
of elements that passtrough caps negotiation.
Make two utility functions to proxy caps queries and aggregate the result. Needs
to use the pad forward function instead later.
Make the _query_peer_ utility functions use the gst_pad_peer_query() function to
make sure the probes are emited properly.
Make that implizit with attaching/detaching controlsources. This is a lot easier
and has less invalid state (controlled property without control source).
No one but filesrc used that API. Should probably be replaced by
requiring an "uri" property instead, and then objects can do a
notify on that. Also removed interface structure padding, it's
not needed.
This make the controller even more lightweight (no extra object, no extra lock,
less indirections). For object that don't use the controller the only 'overhead'
is a 3 unused fields in the gst_object structure.
