For metas where order might be significant if multiple metas are
attached to the same buffer, so store a sequence number with the
meta when adding it to the buffer. This allows users of the meta
to make sure metas are processed in the right order.
We need a 64-bit integer for the sequence number here in the API,
a 32-bit one might overflow too easily with high packet/buffer
rates. We could do it rtp-seqnum style of course, but that's a
bit of a pain.
We could also make it so that gst_buffer_add_meta() just keeps metas in
order or rely on the order we add the metas in, but that seems too
fragile overall, when buffers (incl. metas) get merged or split.
Also add a compare function for easier sorting.
We store the seqnum in the MetaItem struct here and not in the
GstMeta struct since there's no padding in the GstMeta struct.
We could add a private struct to GstMeta before the start of
GstMeta, but that's what MetaItem effectively is implementation-
wise. We can still change this later if we want, since it's all
private.
Fixes#262
Thi introduces new APIs to post a `DEVICE_CHANGED` message on the
bus so the application is notifies when a device is modified. For
example, if the "defaultness" of a device was changed or any property
that can be changed at any time. Atomically changing the device
object notifying that way allow us to abtract away the internal threads.
New APIS:
- gst_message_new_device_changed
- gst_message_parse_device_changed
- gst_device_provider_device_changed
The hook->hook_id is a gulong for which there are no portability issues
when tracing in printf format with %lu. So use %lu and remove the upcast
to 64 bit. This makes the code more consistent with everything else
tracing that hook_id and other gulong id.
This was added in 7fdb15d6a2 but it is wrong. (scope call) is for
closures that only have to stay valid for the scope of the call, but the
tag merge function has to stay valid for the whole lifetime of the
application instead.
There's no appropriate scope annotation for that so we have to skip
these functions for now.
GstDeviceProvider has a started_count private variable counter,
and the gst_device_provider_start() documentation emphasizes the
importance of balancing the start and stop calls.
However, when starting a provider that is already started, the
current code will never increment the counter more than once.
So you start it twice, but it will have start_count 1, which is the
maximum value it will ever see.
Then when you stop it twice, on the 2nd stop, after decrementing the
counter in gst_device_provider_stop():
else if (provider->priv->started_count < 1) {
g_critical
("Trying to stop a GstDeviceProvider %s which is already stopped",
GST_OBJECT_NAME (provider));
and the program is killed.
Fix this by incrementing the counter when starting a device provider that
was already started.
This is racy if the state lock of the parent bin is not taken. The
parent bin might've just checked the flag in another thread and as the
next step proceed to change the child element's state.
We need to take the state lock here to ensure that we're
not currently just before setting the state of this child
element. Otherwise it can happen that we removed the element
here and e.g. set it to NULL state, and shortly afterwards
have another thread set it to a higher state again as part of
a state change for the whole bin.
When adding an element to the bin this is not needed as we
require callers to always ensure after adding to the bin that
the new element is set to the correct state.
There was a dead assignment used outside of the bin/pipeline creation
which was confusing (and unused). Just move that variable to
where it is actually used.
(Note that that variable was not needed outside of that block since
the refactoring done in 2b33d33185 )
Fix corruption of meta list head when removing metas at the beginning
during iteration. Linked list handling in gst_buffer_foreach_meta
failed to track the previous entry and update the correct next pointer
when removing items from beyond the head of the list, resulting in
arbitrary list pointer corruption.
Closes#332
Currently in Python it would become a signed 64 bit value but should
actually be an unsigned 32 bit value with all bits set.
This is the same problem as with GST_MESSAGE_TYPE_ANY.
See https://bugzilla.gnome.org/show_bug.cgi?id=732633
We won't be able to do ASSERT_CRITICAL, but the main body of the tests
are still valid, and given we ship GStreamer with this configuration, it
is important to be able to run some tests against it.
Allows determining from downstream what the expected bitrate of a stream
may be which is useful in queue2 for setting time based limits when
upstream does not provide timing information.
Implement bitrate query handling in queue2
https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/issues/60
A pointer to a hook in this list can easily not be unique, given both
the slice-allocator reusing memory, and the OS re-using freed blocks
in malloc.
By doing many repeated add and remove of probes, this becomes very easily
reproduced.
Instead use hook_id, which *is* unique for a added GHook.
This is based on g_clear_object(). Basically, you can use this instead
of using gst_mini_object_unref (which needs to be preceded by a NULL-check).
Also fixes#275
