GitLab

Having a NULL caps in a GValue is legal and we should handle it
properly for comparisons.

Before that commit `{test, }` wouldn't be accepted as an array
because of the trailing coma, the commit fixes that.

At the same time, the code has been refactored to avoid special casing
the first element of the list, making `{,}` or `<,>` valid lists.

Looks like it's been removed from glib.devhelp2 on Fedora 31.

Fix #508

This allows an element to not require implementing transform or
transform_ip.

There can only be a single waiter: on the streaming thread.

There can only be a single waiter: on the streaming thread.

... and immediately return FLUSHING from the streaming thread instead of
waiting potentially forever.

Fixes gstreamer/gstreamer#516

We kept the start time around and subtracted it everywhere for "easy of
debugging", but we don't do anything like this anywhere else and it
only complicates the code unnecessarily.

fixate() will return empty caps if it gets empty caps passed and assert
early if any caps are provided as there's no meaningful way of fixating
any caps.

truncate() and simplify() will return the input caps in case of
any/empty caps as before, but slightly optimized and as documented
behaviour.

Also add tests for this and a few other operations behaviour on
empty/any caps.

This is not an API breakage, as implementors are already
expected to return a GstFlowReturn

Required to avoid broken log string on Windows but missed
in the commit of 493a3261

The format modifier for thread-id prints hex value without "0x" prefix on Windows.

.. instead of looking things up by thread id from a GHashTable,
which also happens to have no locking around insertion/lookup.

gst-inspect-1.0 segfaults on tracing logs where it fails to find
element stats. So on the pipelines where we get the following WARNING
during execution will afterwards crash with a segfault as the
g_ptr_array has a index for it but it is just a NULL pointer.

WARN default gst-stats.c:444:do_message_stats: no element stats found for ix=X

An example of an pipeline which can reproducibly create a trace log
where this occurs would be this

GST_DEBUG="GST_TRACER:7" GST_TRACERS="stats;rusage;latency" gst-launch-1.0 videotestsrc num-buffers=120 ! autovideosink &> trace.log
gst-stats-1.0 trace.log

Add the equation to the debug message to make it easier for non-GStreamer
experts to understand why their pipeline has latency.

That's the minimum version of GLib we require right now.

Fixes gstreamer/gstreamer#514

The clocksync element is a generic element that can be
placed in a pipeline to synchronise passing buffers to the
clock at that point. This is similar to 'identity sync=true',
but because it isn't GstBaseTransform-based, it can process
GstBufferLists without breaking them into separate GstBuffers

g_log_writer_supports_color() was introduced since GLib 2.50.0
which is slightly higher version than our minimum required GLib version.

We do not have a way to know the format modifiers to use with string
functions provided by the system. `G_GUINT64_FORMAT` and other string
modifiers only work for glib string formatting functions. We cannot
use them for string functions provided by the stdlib. See:
https://developer.gnome.org/glib/stable/glib-Basic-Types.html#glib-Basic-Types.description

F.ex.:

```
 ../tools/gst-stats.c:921:11: error: too many arguments for format [-Werror=format-extra-args]
   printf ("Number of Buffers passed: %" G_GUINT64_FORMAT "\n", num_buffers);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../tools/gst-stats.c:922:11: error: unknown conversion type character 'l' in format [-Werror=format=]
   printf ("Number of Events sent: %" G_GUINT64_FORMAT "\n", num_events);
           ^~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /builds/nirbheek/cerbero/cerbero-build/dist/windows_x86_64/include/glib-2.0/glib/gtypes.h:32,
                 from /builds/nirbheek/cerbero/cerbero-build/dist/windows_x86_64/include/glib-2.0/glib/galloca.h:32,
                 from /builds/nirbheek/cerbero/cerbero-build/dist/windows_x86_64/include/glib-2.0/glib.h:30,
                 from ../gst/gst.h:27,
                 from ../tools/tools.h:28,
                 from ../tools/gst-stats.c:30:
/builds/nirbheek/cerbero/cerbero-build/dist/windows_x86_64/lib/glib-2.0/include/glibconfig.h:69:28: note: format string is defined here
 #define G_GUINT64_FORMAT "llu"
                            ^
```

and

```
../tests/misc/netclock-replay.c: In function 'main':
../tests/misc/netclock-replay.c:98:23: error: unknown conversion type character 'l' in format [-Werror=format=]
     if (sscanf (line, "%" G_GUINT64_FORMAT " %" G_GUINT64_FORMAT " %"
                       ^~~
In file included from /builds/nirbheek/cerbero/cerbero-build/dist/windows_x86/include/glib-2.0/glib/gtypes.h:32,
                 from /builds/nirbheek/cerbero/cerbero-build/dist/windows_x86/include/glib-2.0/glib/galloca.h:32,
                 from /builds/nirbheek/cerbero/cerbero-build/dist/windows_x86/include/glib-2.0/glib.h:30,
                 from ../tests/misc/../../libs/gst/net/gstntppacket.c:38,
                 from ../tests/misc/netclock-replay.c:31:
/builds/nirbheek/cerbero/cerbero-build/dist/windows_x86/lib/glib-2.0/include/glibconfig.h:69:28: note: format string is defined here
 #define G_GUINT64_FORMAT "llu"
                            ^
```

This is needed for upgrading glib inside Cerbero which builds with
`-Werror` on Windows:
gstreamer/cerbero!419

Seems unnecessary to print the parent name for every
element in the pipeline graph, it's clear from the
graph what the parent element is and it's hard to
imagine a case where this is useful info rather than
just distracting spam. So far this was only done for
pads, but we should just do it for everything.

A buffer to be skipped wasn't unref'd in gst_base_parse_chain().

Fixes #406

When the user sets filters, we should not trace ref counts of object that
are not traced. This optimizes the tracer by potentially avoiding
generating useless backtraces.

Otherwise an application cannot rely on a subsequent call to e.g. gst_pad_query_duration() succeeding.

Previously we would use the object lock only for storing the sync
handler and its user_data in a local variable, then unlock it and only
then call the sync handler. Between unlocking and calling the sync
handler it might be unset and the user_data be freed, causing it to be
called with a freed pointer.

To prevent this add a refcounting wrapper struct around the sync
handler, hold the object lock while retrieving it and increasing the
reference count and only actually free it once the reference count
reaches zero.

As a side-effect we can now also allow to actually replace the sync
handler. Previously it was only allowed to clear it after initially
setting it according to the docs, but the code still allowed to clear it
and then set a different one.

Fixes gstreamer/gstreamer#506

Fixing markdown syntax

Keep the ANY caps empty internally when appending and merging
caps/structures. Previously, an ANY caps could end up containing
internal structures, which could be fetched by the user, and gave the
caps a non-zero length.

Also, made sure that `gst_caps_set_features_simple` frees the features
if caps is empty.

Fixed gst_caps_is_strictly_equal() to take into account whether either of
the caps are ANY caps. Previously, two ANY caps could be considered not
strictly equal if one of them still contained some remnant *internal*
structure (this can happen if an ANY caps has emerged from an append or
merge operation). Also, an ANY caps with no remnant internal structures
was considered strictly equal to an EMPTY caps. Similarly, a non-ANY caps
was considered strictly equal to an ANY caps if its remnant internal
structures happened to match.

Also changed gst_caps_is_fixed to take into account that an ANY caps
should not be considered fixed even if it contains a single remnant
internal fixed structure. This affects gst_caps_is_equal(), which uses a
separate method if both caps are fixed. Previously, this meant that a
non-ANY fixed caps was considered equal to an ANY caps if it contained a
single matching remnant internal structure.

Added some tests for these two equality methods, which covers the above
examples, as well as asserts existing behaviour.

Fixes #496

This has the same function as the negotiate() functions in various other
base classes and is required to be able to completely re-implement
submit_input_buffer() in subclasses.

When we do not have any information about DTSs we shouldn't try to make
them up, moreover after seeking `segment->start` has nothing to do with
the next buffer timing (and is probably after the actual buffer timestamp)
and since, since gstreamer/gstreamer@fa831247
we do:

```
if (buffer->dts > buffer->dts)
    buffer->pts = buffer->dts
```

we end up setting `buffer->pts = segment->start` which is plain
broken and leads to downstream decoder accept the first buffer
as it will be inside the segment (its pts==segment->start) which
basically means accurate seeking behaves mostly the same way as
keyframe seeks.

Fixes gstreamer/gstreamer#492

POSIX defines CLOCK_MONOTONIC to always be a macro, so I think
it's safe to assume that CLOCK_TAI will also be.

GST_CLOCK_TYPE_TAI is GStreamer abstraction for CLOCK_TAI. Main
motivation for this patch is support for transmission offloading features
- when network packets are timestamped with the time they are deemed to
be actually transmitted. Linux API for that requires that time to be
in CLOCK_TAI coordinate.

With GST_CLOCK_TYPE_TAI, applications can use CLOCK_TAI directly on
their pipelines, avoiding the need to cross timestamp packet times. By
leveraging system's CLOCK_TAI, applications also don't need to keep track
of leap seconds - less burden for them. Just keep system's CLOCK_TAI
accurate and use it.

bin: Don't consider having a group-id or being STREAM_START if we have not a single STREAM_START message

This would cause us to set GST_GROUP_ID_INVALID as group-id in the
aggregated STREAM_START message if there are no sinks at all or none of
them have a STREAM_START message, which is simply wrong.

If we have not a single STREAM_START message then the bin should not be
considered STREAM_START.

They are optional on STREAM_START messages/events but if available
should have at least a valid value.

For STREAM_GROUP_DONE events don't allow creating it with an invalid
group id as this does not make any sense.

This allows start-time selection in gst_aggregator_pad_chain_internal()
to actually work as that code assumes it to be -1 for actually
overriding the value.

Fixes gstreamer/gstreamer#500

child and bin were switched.

gstreamer/gstreamer!354