gst_v4l2_open() is called by gst_v4l2_device_provider_probe_device(),
where the GstV4l2Object is created without an associated GstElement.
If gst_v4l2_open() fails, it raises a bus message, but without an
element, a precondition check fails on
gst_element_message_full_with_details() generating a crash if running
with fatal-warnings debug mode.
GstV4l2Error is a helper to raise error bus messages when it is
appropiated. This patch changes the direct bus messages to this
helper, and the elements will actually send the error message.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/694>
When using this mode each frame is split in two fields, each one being
transferred using its own buffer.
This is implemented with the V4L2_FIELD_ALTERNATE field format in v4l2.
This mode is enabled using a caps filter such as
"v4l2src ! video/x-raw\(format:Interlaced\)"
Here are the main changes related to this feature:
- use the INTERLACED caps feature with this mode.
- in this mode both fields of a given frame have the same sequence/offset
so adjust the algorithm checking for lost field/frame accordingly.
- double pool's min number of buffers as each frame requires 2 buffers.
Fix#504
Co-authored-by: Zeeshan Ali <zeenix@collabora.co.uk>
Lower the verbosity of the 'sync' log message emitted
each buffer from gst_v4l2src_create down to LOG(6)
from INFO(4). This brings the logging behavior of
v4l2src closer to the GStreamer guidelines, which
recommend the INFO level be reserved for rare or
one-off messages.
The caps features were lost when sorting caps structures in
gst_v4l2src_fixate(). This was breaking alternate as
GST_CAPS_FEATURE_FORMAT_INTERLACED was removed from the caps.
Always initially use try_format(), delaying set_format() to when the
allocation is being negotiated. This avoid having two code paths, and
will be help adding support for properly importing buffers of specific
strides and offsets.
https://bugzilla.gnome.org/show_bug.cgi?id=583890
Some camera firmware crash is TRY_FMT is called during streaming. As a
side effect. This try and detect that the same format as currently
running is about to be tried, and skip renegotiation.
https://bugzilla.gnome.org/show_bug.cgi?id=796789
The g_list_insert_sorted() will behave like prepend when the compare
function returns 0. In our case, we want to maintain the order hence
append. This fixes this issue and improve the sorting algorithm to make
a 10x10 prefered over 10x200 with a preference of 10x8 (and similar
cases which was badly handled). This fixes generally fixes issue were a
sub-optimal format / size is picked.
https://bugzilla.gnome.org/show_bug.cgi?id=792435
This way we can pass the pad name instead of the element for tracing
which helps identifying which v4l2object is used withing M2M element
like decoder, encoder and transform. For the reference, pads are name
<parent-name>:<pad-name>.
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.
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.
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
Unlike former definitions of LOG_CAPS, the current implementation simply
expands to GST_DEBUG_OBJECT. The LOG_CAPS macro is rarely used and most
uses duplicate already existing GST_DEBUG_OBJECT lines. Therefore, the
caps are often printed twice which unnecessarily clutters the debug log.
Replace LOG_CAPS calls with GST_DEBUG_OBJECT, remove LOG_CAPS calls, and
delete the definition of LOG_CAPS.
https://bugzilla.gnome.org/show_bug.cgi?id=776899
v4l2src will renegotiate only if the format have changed. As of now,
it's not possible to change the allocationw without resetting the
camera. To avoid unwanted side effect, simply keep the old allocation
if no renegotiation is taking place. This fixes assertion and possible
failures in USERPTR or DMABUF import mode (when using downstream pools).
https://bugzilla.gnome.org/show_bug.cgi?id=754042
The v4l2 device restarts the sequence counter in case of streamoff/streamon,
the GST offset values are supposed to increment strictly monotonic, so
adjust the sequence counter/offset values in case of caps
renegotiation.
https://bugzilla.gnome.org/show_bug.cgi?id=745441
In case of v4l2 driver filled offset/sequence values add frame
loss detection (and write a warning message).
Move offset meta data setting and frame loss checking after the
timestamp adjustment code to get proper timestamps for the
warning message.
https://bugzilla.gnome.org/show_bug.cgi?id=745441
Allow renegotiation to happen when buffers have returned after an allocation
query. As the allocation query is serialized, all buffers from the pool
should have returned and we can stop it to create a new one for the
new format
https://bugzilla.gnome.org/show_bug.cgi?id=682770
This allow skipping buffer flagged with ERROR that has no payload.
This is typical behaviour when a recovererable error occured during
capture in the driver, but that no valid data was ever written into that
buffer. This patch also translate V4L2_BUF_FLAG_ERROR into
GST_BUFFER_FLAG_CORRUPTED. Hence decoding error produce
by decoder due to missing frames will now be correctly marked. Finally,
this fixes a buffer leak when EOS is reached.
https://bugzilla.gnome.org/show_bug.cgi?id=740040
Rather than try and guess interlace support as part of checking supported
sizes, look for interlace support specifically in its own function.
As a cleanup, use V4L2_FIELD_ANY when probing sizes, which should result in
the driver doing the right thing.
With my capture setup, this gets me the following sample caps:
For 1080i resolution:
video/x-raw, format=(string)YUY2, width=(int)1920, height=(int)1080, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)interleaved, framerate=(fraction){ 25/1, 30/1 }
For 720p resolution:
video/x-raw, format=(string)YUY2, width=(int)1280, height=(int)720, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive, framerate=(fraction){ 50/1, 60/1 }
For 576i/p resolution (both possible at the point of query):
video/x-raw, format=(string)YUY2, width=(int)720, height=(int)576, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string){ progressive, interleaved }, framerate=(fraction){ 25/1, 50/1 }
This, in turn, makes 576i work correctly; with the old code,
the caps would be interlace-mode=progressive for interlaced video.
https://bugzilla.gnome.org/show_bug.cgi?id=726194
Even though the UVC driver do a great deal of effort to prevent bad
timestamp to be sent to userspace, there still exist UVC hardware that
are so buggy that the timestamp endup nearly random. This code detect
and ignore timestamp from these drivers, making these camera usable.
This has been tested on both invalid and valid cameras, making sure it
does not trigger for valid cameras.
https://bugzilla.gnome.org/show_bug.cgi?id=732910
Before we would hit an assertion "'gst_buffer_pool_is_active (bpool)' failed"
if the internal pool was not used to push buffer downstrea, hence not
given to the baseclass.
https://bugzilla.gnome.org/show_bug.cgi?id=732912
Calculation of num_buffers (the max latency in buffers) was
up-side-down. If we can allcoate, then our maximum latency match
pool maximum number of buffers. Also renamed it to max latency. Finally
introduced a min_latency for clarity.
This moves away from copying information and store everything inside
the GstVideoInfo structure. The alignement exposed by v4l2 api
is now handled using proper offset.
Return a buffer from an otherpool has unwanted side effects that lead to leaks and
prevents deactivating the pool. Instead, we change the _process() API so it can
replace the internal buffer with the buffer from the downstream pool. This implied
moving from _fill() to _create() method in the src.
For format like mpegts, width and height is rarely in the negotiated caps. This
patch fixes failure when setting format, and prevent introducing width, height,
framerate and format to the caps when fixating.
https://bugzilla.gnome.org/show_bug.cgi?id=725860
