The purpose of being able to flush the buffer pool is only to
unlock any blocked operation. Doing streamoff/streamon had the
side effect of turning off and on the camera. As we do a flush_start
/ flush_stop sequence when shutting down, that would cause a really
quick sequence of streamoff/streamon/streamoff/close which was
causing some cameras to stop working.
https://bugzilla.gnome.org/show_bug.cgi?id=783945
The code relied on the list compare function to fixate the caps
but if the caps only has one structure, the compare function will
never get called. Capture device for which there is only one
structure in the caps would then get some assertion and later
fail badly.
Instead, fixate before inserting into the list and split the reading
and the fixation of the structures.
try_fmt will update the caps colorimetry and interlace-mode. Before this
call, those field are missing. The caps equality check was always
failing when a spurious reconfigure event was received.
These have been copy pasted all over the place and are not used anymore.
All object have it's own category now. This fixes build warning since
the VP9 decoder had vp8 category declared.
Whenever we import from downstream pool (userptr or dmabuf-import), we
should copy over the flags and timestamp, otherwise downstream will not
get proper synchronization or will not be able to notice frames that has
corruption in it.
https://bugzilla.gnome.org/show_bug.cgi?id=785680
Removes the FIXME/Question in the buffer pool and add a ref to the
element in the GstAllocator too. This ref is strictly required to keep
the GstV4l2Object structure around.
The library has started preventing a lot of interesting use cases,
like CREATE_BUFS, DMABuf, usage of TRY_FMT. As the libv4l2 is totally
inactive and not maintained, we decided to disable it. As a convenience
we added a run-time environment that let you enable it for testing.
GST_V4L2_USE_LIBV4L2=1
This of course only works if you have enabled libv4l2 at build time.
While not documented, gst_video_colorimetry_matches() only accepts well
known names. Looking at the code and unit test, this seems to be on
purpose, so fixing by parsing the string and compating the colorimetry
structures.
The subclass negotiated function will call set_format, if that fails the
pool will not be created. We ended up with an assertion.
GStreamer-CRITICAL **: gst_buffer_pool_set_active: assertion 'GST_IS_BUFFER_POOL (pool)' failed
In this commit, we enabled skip_try_fmt_probes quirk in order to speed
up the start which is known to be disastrously slow with certain USB
cameras.
This has the side effect that we needed to rewrite the entire
negotiation process in a way that we iterate over the possible caps
until we find one that works.
The new negotiation method consist of extracting a preferred structure
from the peer caps and using this to fixate and sort the caps. To
reflect the old behaviour, we sort all resolution strictly bigger
to the preferred one with the closes one first. The rest is appended,
keeping the same order. We then normalize the caps in case there was
some list of interlace-mode or colorimetry left. We finally iterate
over all fixed caps and try it. 99% of the time, the first or the
second one should work, whit the result of a single S_FMT being issues.
From there, it will be relatively easy to introduce new negotiation
algorithm. The current algorithm is made for optimal image quality
with a scaling sink that sets it's window resolution as preference.
This the case if for:
v4l2src ! videoconvert ! videoscale ! ximagesink
Other strategy would be needed to optimize for non-scaling sink like
ximagesink or kmssink when the driver does not scale.
https://bugzilla.gnome.org/show_bug.cgi?id=785156
skip_try_fmt_probes quirk is set, V4L2 object will not probe for
interlace-mode and colorimetry to avoid relying on try_fmt. This quirk
will be used by v4l2src to avoid desastrous startup time with slow
USB webcams.
When this quirk is enabled, caller will have to iterate over the
negotiated caps as it may contains unsupported formats. If the peer
didn't choose a specific interlace-mode, or colorimetry, the value
chosen by the driver is set into the caps. For this reason, when this
mode is enabled, gst_v4l2_object_set_format() will require writable
caps.
https://bugzilla.gnome.org/show_bug.cgi?id=785156
According to the spec,TRY_FMT cannot return EBUSY, though it can
return EINVAL if it was not possible to update the format to
something supported.
https://bugzilla.gnome.org/show_bug.cgi?id=785156
This is in preparation for removing slow TRY_FMT probes for
colorimetry. As we won't have tried that colorimetry we cannot
assume the driver will accept it.
https://bugzilla.gnome.org/show_bug.cgi?id=785156
This is in preparation from removing the slow TRY_FMT probes for
interlacing. As we won't have tried that interlace-mode already
we need to validate that the driver isn't refusing it.
https://bugzilla.gnome.org/show_bug.cgi?id=785156
Add a couple of useful debug traces , they happened to be useful to
debug/investigate a 4K video playback issue with v4l2, so let's make these
changes more permanent.
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
https://bugzilla.gnome.org/show_bug.cgi?id=785109
Since 1.6, the transfer function for BT2020 has been changed from BT709
to BT2020_12. It's the same function, but with more precision. As a side
effect, the V4L2 colorpsace didn't match GStreamer colorspace. When
GStreamer ended up making a guess, it would not match anything supported
by V4L2 anymore. This this by using BT2020_12 for BT2020 colorspace and
BT2020 transfer function in replacement of BT709 whenever a 4K
resolution is detected.
The pixel aspect ratio is documented to not change unless the TV
Standard is changed. So this mean that this will be uniform across all
possible format and resolutions.
https://bugzilla.gnome.org/show_bug.cgi?id=784674
First step of a larger cleanup, all function from v4l2_calls are in fact
methods on GstV4l2Object. This split makes the code really confusing.
This also remove no longer unused macros.
Before that, each m2m node would be wrapped as a single, multi-format
decoder element. As a unique name was needed, we where using the device
name, which changes between re-boots. This led to unpredictable element
names. In this patch, we generate an element per codec, using
v4l2<codec>dec name. If there is multiple decoder for the same format,
the following elements will be named v4l2<node><codec>dec.
https://bugzilla.gnome.org/show_bug.cgi?id=784908
When resurrecting a buffer, the subsequent free call can result
in the group-released handler being called again, which causes
a recursive loop. This patch blocks the signal handler during
the time that it executes, ensuring that the loop will not occur.
https://bugzilla.gnome.org/show_bug.cgi?id=759292
Increasing this number fix a buffer starvation problem I'm hitting
with a "v4l2src ! kmssink" pipeline.
kmssink requests 2 buffer as it keeps a reference on the last rendered
one. So we were allocating 3 buffers for the pipeline.
Once the first 2 buffers have been pushed we ended up with:
- one buffer queued in v4l2
- one being pushed
- one kept as last rendered
If this 3rd buffer is released after that v4l2 used the first one to
capture we end up with a buffer starvation problem as no buffer is currently
queued in v4l2 for capture.
Fixing this by adding one extra buffer to the pipeline so when one
buffer is being pushed downstream the other can already be queued to
capture the next frame.
We were already adding 3 buffers if downstream didn't reply to the
allocation query. I reduced this number to 2 to compensate the extra
buffer which is now always added.
https://bugzilla.gnome.org/show_bug.cgi?id=783049
