Otherwise decklink seems to hold onto the latest frame and may cause a
flash in the output if the played sequence has a framerate less than the
video output.
Scenario is play for N seconds, pause, flushing seek to some other position,
play again. Each of the play sequences would normally start at 0 with
the decklink time. As a result, the latest frame from the previous sequence
is kept alive waiting for it's timestamp to pass before either dropping
(if a subsequent frame in the new sequence overrides it) or displayed
causing the out of place frame to be displayed.
This is also supported by the debug logs from the decklink video sink
element where a ScheduledFrameCompleted() callback would not occur for
the frame until the above had happened.
It was timing related as to whether the frame was displayed based
on the decklink refresh cycle (which seems to be 16ms here),
when the frame was scheduled by the sink and the difference between
the 'time since vblank' of the two play requests (and thus start times
of scheduled playback).
If the "output-cc" property is set to TRUE and there is CC present
in the VBI Ancillary Data, they will be extracted and set on the
outgoing buffer as GstVideoCaptionMeta.
Only CDP packets are supported.
https://bugzilla.gnome.org/show_bug.cgi?id=773863
There is no log of gst_decklink_com_thread () which initializes COM.
The initialization part is not valid with #ifdef MSC_VER.
Windows binaries are built with gcc.
As with other codes, it was avoidable by setting it to G_OS_WIN32
instead of MSC_VER.
https://bugzilla.gnome.org/show_bug.cgi?id=794652
There is no fixed limitation for the number of devices on the
decklink API side according to BlackMagic. Many PC motherboards
are able support 6 decklink cards each with up to 8 inputs so
a limit of 16 might well be too low.
https://bugzilla.gnome.org/show_bug.cgi?id=777239
Sometimes we might get an audio packet without a corresponding video
frame. In these cases, the stream and hardware reference timestamps
would be missing, because they're called on the video frame. Instead of
potentially breaking stuff downstream that might depend on these, we now
extrapolate them.
https://bugzilla.gnome.org/show_bug.cgi?id=792042
When we receive a video or audio buffer, we calculate the next stream
time based on the current stream time + buffer duration. If the next
buffer's stream time is after that, we issue a warning.
This happens because the stream time incoming from Decklink should be
really constant and without gaps. If there is a gap, it means that
something went wrong, e.g. the internal buffer pool is empty (too many
buffers queued up downstream).
https://bugzilla.gnome.org/show_bug.cgi?id=781776
Sometimes we might get an audio packet without a corresponding video
frame. In these cases, the stream and hardware reference timestamps
would be missing, because they're called on the video frame. Instead of
potentially breaking stuff downstream that might depend on these, we now
extrapolate them.
https://bugzilla.gnome.org/show_bug.cgi?id=792042
Not only if the video sink is set to PLAYING so far. Also give more
useful debug output about why we don't start, and don't start if already
started.
Also refactor the function to early-return instead of having a huge
if-else block over the whole function.
https://bugzilla.gnome.org/show_bug.cgi?id=790114
The Decklink and GstAudioBaseSink APIs don't fit very well together,
which causes various problems due to inaccuracies in the clock
calculations and the actual ringbuffer and GStreamer's copy getting of
sync.
Problems are audio drop-outs and A/V sync getting wrong after
pausing/seeking.
https://bugzilla.gnome.org/show_bug.cgi?id=790114
The "fields" flag is ignored because currently GStreamer doesn't support
having only top or only bottom fields inside a frame. The "drop frame"
flag is ignored because some occurrences have been spotted where it
wasn't set while it should have been. In practice, when we have 29.97 or
59.94 FPS, it's always drop-frame.
https://bugzilla.gnome.org/show_bug.cgi?id=790112
When we receive a video or audio buffer, we calculate the next stream
time based on the current stream time + buffer duration. If the next
buffer's stream time is after that, we issue a warning.
This happens because the stream time incoming from Decklink should be
really constant and without gaps. If there is a gap, it means that
something went wrong, e.g. the internal buffer pool is empty (too many
buffers queued up downstream).
https://bugzilla.gnome.org/show_bug.cgi?id=781776
If we drop many frames at once, printing one message per video frame and
one per audio packet would cause a lot of disk IO. Just print a total at
the end.
https://bugzilla.gnome.org/show_bug.cgi?id=788780
The buffer itself is 128 bytes into the allocated memory area, to be
able to store the size and other metadata before it. Freeing the buffer
directly will make malloc moderately unhappy.
HRESULT is unsigned long on Windows, but the Decklink headers define
it to 'int' on Linux. Confusingly, the defines that talk about the
possible return values for it use long constants. The easy fix would
be to change the linux/LinuxCOM.h header, but that's copied from the
decklink SDK.
Change the logging to always upcast to unsigned long while printing
HRESULT for consistency across platforms.
gstdecklinkvideosrc.cpp:425:7: warning: format '%x' expects argument of type 'unsigned int', but argument 8 has type 'HRESULT {aka long int}' [-Wformat]
[and so on]
gstdecklinkaudiosink.cpp:155:19: error: conflicting type attributes specified for 'virtual HRESULT GStreamerAudioOutputCallback::QueryInterface(const IID&, void**)'
In file included from /var/lib/jenkins/workspace/cerbero-cross-mingw32/workdir/mingw/w32/bin/../lib/gcc/i686-w64-mingw32/4.7.3/../../../../i686-w64-mingw32/include/objbase.h:153:0,
from /var/lib/jenkins/workspace/cerbero-cross-mingw32/workdir/mingw/w32/bin/../lib/gcc/i686-w64-mingw32/4.7.3/../../../../i686-w64-mingw32/include/ole2.h:16,
from /var/lib/jenkins/workspace/cerbero-cross-mingw32/workdir/mingw/w32/bin/../lib/gcc/i686-w64-mingw32/4.7.3/../../../../i686-w64-mingw32/include/windows.h:94,
from /var/lib/jenkins/workspace/cerbero-cross-mingw32/workdir/mingw/w32/bin/../lib/gcc/i686-w64-mingw32/4.7.3/../../../../i686-w64-mingw32/include/rpc.h:16,
from win/DeckLinkAPI.h:27,
from gstdecklink.h:35,
from gstdecklinkaudiosink.h:27,
from gstdecklinkaudiosink.cpp:25:
/var/lib/jenkins/workspace/cerbero-cross-mingw32/workdir/mingw/w32/bin/../lib/gcc/i686-w64-mingw32/4.7.3/../../../../i686-w64-mingw32/include/unknwn.h:67:25: error: overriding 'virtual HRESULT IUnknown::QueryInterface(const IID&, void**)'
(and many more)
https://ci.gstreamer.net/job/cerbero-cross-mingw32/6407/console
The default memory allocator of the decklink library allocates
a fixed pool of buffers, and the number of buffers is unknown.
This makes it impossible do useful queuing downstream. The new
memory allocator can create an unlimited number of buffers,
giving all queuing features one would expect from a live source.
https://bugzilla.gnome.org/show_bug.cgi?id=782556
