Custom meta is backed by a GstStructure, and does not require
that users of the API expose their GstMeta implementation as
public API for other components to make use of it.
In addition, it provides a simpler interface by ignoring the
impl vs. api distinction that the regular API exposes.
This new API is meant to be the meta counterpart to custom events
and messages, and to be more convenient than the lower-level API
when the absolute best performance isn't a requirement.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/609>
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
gstharness.c: Use G_GSIZE_FORMAT instead of hard-coding %zu
error: unknown conversion type character 'z' in format [-Werror=format]
gst-inspect.c: GPid is void* on non-UNIX, and we only use it on UNIX
error: initialization makes pointer from integer without a cast [-Werror]
gstmeta.c: Use and then discard value
error: value computed is not used [-Werror=unused-value]
With this, gstreamer builds with -Werror on MinGW
Existing test for iterating/removing buffer meta data was insufficient
to detect linked list corruption when removing multiple items, and could
also suffer from such corruption in attempting to count remaining items.
Modified the one test and added several others to exercise multiple
scenarios.
Validates fix for issue #332.
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
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
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.
Require the memory implementations to implement a share operation. This allows
us to remove the fallback share implementation which uses a different allocator
implementation and complicates things too much.
Update design doc a bit.
Replace subbuffer and copy vmethods by a more generic transform function that
can then be parametrised by transform specific data. This should allow us to
implement make-writable and more future transform functions.
Make separate api for getting and adding metadata. This allows us to pass extra
parameters to the init functions when creating metadata, which is needed for
specific API implementations.
Add beginnings of memory metadata.
