Commit graph

109 commits

Author SHA1 Message Date
Haihua Hu
1c488626da v4l2src: fix cannot reuse current caps when fixate caps in negotiation
when regotiation happens, v4l2src will check if it can reuse current caps,
but we need check if current caps is subset of all query caps from downstream
instead of check it with query caps one by one.

Assuming that the current caps is not the subset of first caps from query caps,
it will go to try fmt. when try fmt success, v4l2src will make pending_set_fmt
to TRUE and going to reset.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4500>
2023-05-01 15:05:26 +00:00
Nicolas Dufresne
e709e2d97c meson: Add a wrap file for libgudev
And allow fallback to it.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4447>
2023-04-19 22:47:19 +00:00
Nicolas Dufresne
2e76371666 v4l2: Fix use after free of fmtdesc part 2
Add missing code in merge commit e890e6e8d8
("v4l2: Fix use after free of fmtdesc"). The v4l2object code was
missing.

Related to https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4317

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4411>
2023-04-13 13:54:32 -04:00
Nicolas Dufresne
e890e6e8d8 v4l2: Fix use after free of fmtdesc
The decoder needs to force another enumeration of the format. For
this it was clearing the v4l2object insternal list, leaving a fmtdesc
pointer pointing to freed memory. This patch clears the fmtdesc pointer
that has just been free. It also makes sure the probe function does not
use the cached formats list. The probe function will restore the current
fmtdesc pointer based on the currently configured pixelformat.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4317>
2023-04-13 15:32:14 +00:00
Nicolas Dufresne
3a17200638 v4l2: videodec: Prefer acquired caps over anything downstream
As we don't have anything smart in the fixation process, we may endup with
a format that has a lower bitdepth, even if downstream can handle higher
depth. it is notably the case when negotiating with deinterlace, which places
is non-passthrough caps before its passthrough one. This makes the generic
fixation prefer the formats natively supported by deinterlace element over
the HW 10bit format. As some HW can downscale 10bit to 8bit, this can break
10bit decoding.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4317>
2023-04-13 15:32:13 +00:00
Nicolas Dufresne
89854fd2f3 v4l2: videodec: Remove leading space in comment
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4317>
2023-04-13 15:32:13 +00:00
Shengqi Yu
8cf21fe744 v4l2object: Add support for YVU420M format
This is a multi-planar format with planes non contiguous in memory. It
is intended to be used only in drivers and applications that support the
multi-planar API.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4287>
2023-03-31 13:42:05 +00:00
Michael Tretter
a11f811155 v4l2object: mark jpeg as parsed
Assuming that V4L2 CAPTURE devices always use one buffer per JPEG image, we can
always mark JPEGs provided by a V4L2 element as parsed.

The V4L2 elements require that JPEG images sent to V4L2 OUTPUT devices must
always be parsed.

This is necessary to link a V4L2 CAPTURE device with a V4L2 OUTPUT device
without explicitly marking the stream as parsed or adding a jpegparse into the
pipeline.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4229>
2023-03-21 14:58:15 +00:00
Tim-Philipp Müller
0fc568c6b1 gst-plugins-good: re-indent with GNU indent 2.2.12
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/4182>
2023-03-17 03:18:54 +00:00
Khem Raj
817339c4de v4l2: Define ioctl_req_t for posix/linux case
this is an issue seen with musl based linux distros e.g. alpine [1]
musl is not going to change this since it breaks ABI/API interfaces
Newer compilers are stringent ( e.g. clang16 ) which can now detect
signature mismatches in function pointers too, existing code warned but
did not error with older clang

Fixes
gstv4l2object.c:544:23: error: incompatible function pointer types assigning to 'gint (*)(gint, ioctl_req_t, ...)' (aka 'int (*)(int, unsigned long, ...)') from 'int (int, int, ...)' [-Wincompatible-function-pointer-types]
    v4l2object->ioctl = ioctl;
                      ^ ~~~~~

[1] https://gitlab.alpinelinux.org/alpine/aports/-/issues/7580

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3950>
2023-02-14 20:36:28 +00:00
Pawel Stawicki
492d2b6498 v4l2h264dec: Fix Raspberry Pi4 will not play video in application
Ensure object v4l2object->pool will be released by
correctly releasing the temporary thread-safety lock

Fixes issue #1729

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3786>
2023-01-25 16:07:50 +00:00
Tim-Philipp Müller
f6950b4537 v4l2: drop use of GSlice
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3695>
2023-01-24 15:25:07 +00:00
Nicolas Dufresne
c4cd94f465 v4l2src: Fix crash in renegotiation
This regression was introduce by fix for making buffer pool thread safe. When
we renegotiate, the pool will be setup after we set the format. But the code
has been simplified to only get the pool once before, which caused a null
pointer deref.

Fixes 94ba019 ("v4l2: Fix SIGSEGV on 'change state' during 'format change'")
Related to !3481
Fixes #1626

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3513>
2022-12-02 19:25:52 +00:00
Pawel Stawicki
94ba019397 v4l2: Fix SIGSEGV on 'change state' during 'format change'
Ensure all access to v4l2object->pool imply taking a lock and a hard ref on the pool

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3481>
2022-12-01 12:47:54 +00:00
Elliot Chen
63ff99ca8e v4l2: bypass check some transfer types in colorimetry
v4l2 will report fail for some streams whose colorimetry value such as 2:4:8:3.
Can bypass check these transfer types in colorimetry to avoid error.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3440>
2022-11-23 13:06:29 +00:00
Nicolas Dufresne
5980fb76e7 video: Add arbitrary tile dimensions support
In current tile representation, only tiles with power of two
width and height in bytes are supported. This limitation
prevents adding more complex tiles formats.

In this patch, we deprecate tile_ws and tile_hs from GstVideoFormatInfo and
replace if with an array of GstVideoTileInfo. Each plane tiles are then
described with their pixels width/height, line stride and total size.
The helper gst_video_format_info_get_tile_sizes() that depends on the
deprecated API is also being removed. This can simply be removed as it wasn't
in any stable release yet.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3424>
2022-11-18 22:59:29 +00:00
F. Duncanh
d77fe9495a v4l2videodec: Fixes three H.264/HEVC ITU conformance tests
Postpone the cleanup of any consecutive sequence of lost frames
which starts at frame 0, until frame 100 is dequeued from driver.

This allows fluster tests JVT/CVWP2_TOSHIBA_E, JVC/CVWP3_TOSHIBA_E
and HEVC/POC_A_Bossen_3 that sends out-of-order frames to successfully
complete  (e.g., test of Amphion vpu driver).

Fixes #1569

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3398>
2022-11-16 10:00:03 +00:00
Elliot Chen
e76e98d109 v4l2videodec: add cap negotiation fail check in the capture configuration change
The capture configuration change may cause negotiation fail.
Need to check it to avoid enter the endless loop.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2960>
2022-09-17 21:21:22 +00:00
Thibault Saunier
6a4425e46a meson: Call pkgconfig.generate in the loop where we declare plugins dependencies
Removing some copy pasted code

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2970>
2022-09-01 21:17:35 +00:00
Jianhui Dai
625e74100d v4l2allocator: Fix invalid imported dmabuf fd
Fix a typo that set userptr to dmabuf fd. It leads to failure of
dmabuf-import io-mode.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2935>
2022-08-24 09:59:14 +00:00
Nicolas Dufresne
d126f65485 v4l2bufferpool: Fix debug trace
The tracing of the buffer pointer was done on the secondary pointer, which
does not match with other traces of the same buffer. This made the trace
confusing and less useful.

Fixes #1379

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2893>
2022-08-16 14:33:24 +00:00
fduncanh
197b72f32a v4l2object.c: add support for Apple's full-range bt709 colorspace variant
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2793>
2022-07-26 15:14:41 +00:00
Elliot Chen
e0564b04c6 v4l2: fix the critical log when unreference the buffer with no data
In the trick mode, driver may queue a valid buffer follow by an
empty buffer which has no valid data to indicate EOS.For the empty
buffer whose memory is multi-plane, need to resize it before
unreference it.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2731>
2022-07-25 16:44:05 +08:00
fduncanh
735723c230 v4l2videodec: replace multiple decoder bug warnings with single one
Achieve this by dropping frames after a drain if the driver failed to so.
This works around RaspberryPi driver issue [1].

[1] https://github.com/raspberrypi/linux/issues/5059#issuecomment-

Fixes #1103

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2518>
2022-07-02 23:56:00 +00:00
fduncanh
dfeb8198e4 v4l2videodec: replace multiple decoder bug warnings by a single warning
(warning due to incorrectly dropped frames at initial caps adjustment)

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2517>
2022-06-29 19:50:15 +00:00
Nicolas Dufresne
7c40fcb66e v4l2videodec: Fix activation of internal pool
If the driver does not support VIDIOC_CREATE_BUFS ioctl, the pool
configuration may get changed, which requires a validation. This would
fail to activate a pool in a case it shouldn't normally fail unless we
are out of memory.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2456>
2022-06-28 16:19:53 +00:00
Hou Qi
7f2fb3b783 v4l2: Reset transfer in gst_v4l2_object_acquire_format()
get_colorspace() checks input caps transfer when mapping V4L2_XFER_FUNC_709
back to V4L2_COLORSPACE_BT2020 and GST_VIDEO_TRANSFER_BT2020_12. After
receiving source change event, decoder will G_FMT and S_FMT again. So need
to reset transfer when acquiring format to avoid using the old transfer.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2475>
2022-05-26 17:09:28 +00:00
Nicolas Dufresne
6d6ebbbb36 v4l2videodec: Fix missing handling of resolution-change
The pool process function may poll and get the resolution-change event
whenever it is not possible to share our buffers. This typically happen
when downstream does not support GstVideoMeta.

Not handling this would cause the decoder thread to exit silently and the
pipeline to stall.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2457>
2022-05-24 18:02:12 +00:00
Nicolas Dufresne
4e441417b8 v4l2videodec: Downgrade to info resolution-change trace
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2457>
2022-05-24 18:02:12 +00:00
Hou Qi
85b53bb65d v4l2: set default resolution if caps has no such information
Output may attemp to set the width and height to zero values if
caps has no such information, which will cause capture get invalid
dimensions. Then decoder reports negotiation failure.

So need to set default resolution if caps has no such information.
Real values can be set again until source change event is signaled.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2400>
2022-05-20 12:23:40 +00:00
Nicolas Dufresne
522f19e013 v4l2videoenc: Setup crop rectangle if needed
Hantro H1 and Rockchip VEPU2 drivers will pad the width/height to a
multiple of 16. In order to obtain the right JPEG size, the image needs
to be cropped using the S_SELECTION API. This support is added as best
effort since older drivers may emulate this by looking at the capture
queue width/height.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2329>
2022-05-07 11:35:14 +00:00
Xavier Claessens
b99ecc78ca Replace gst-i18n-*.h with gi18n-lib.h
GLib guarantees libintl is always present, using proxy-libintl as
last resort. There is no need to mock gettex API any more.

This fix static build on Windows because G_INTL_STATIC_COMPILATION must
be defined before including libintl.h, and glib does it for us as part
as including glib.h.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2028>
2022-04-19 18:01:06 +00:00
Hou Qi
8dcb8a28af v4l2videodec: copy colorimetry values to output_state caps
This is to avoid transcoding negotiation fail between v4l2h265dec
and v4l2h264enc caused by colorimetry mismatch.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2192>
2022-04-18 13:17:55 +00:00
Ming Qian
dce02a870e v4l2: Add NV12_8L128 in gst_v4l2_object_get_caps_info
It should be included in
<https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1379>

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2158>
2022-04-13 07:20:58 +00:00
Ming Qian
6af66167d0 v4l2: Add a missed break
Fix a typo that miss a break in the switch statement

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2158>
2022-04-13 07:20:58 +00:00
Ming Qian
2861bd9456 v4l2: Add NV12_8L128 and NV12_10BE_8L128
These formats are used by i.MX 8QXP/8QM VPU.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1379>
2022-03-22 00:41:39 +00:00
Hou Qi
b962126b06 v4l2videodec: set frame duration according to framerate
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1953>
2022-03-16 14:15:04 +00:00
Hou Qi
738dbf1cb7 v4l2videodec: safely retrun from video_dec_loop with stream unlock
This is to avoid decoder hang when doing trick play between
different resolutions.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1960>
2022-03-16 02:13:00 +00:00
Damian Hobson-Garcia
70086fda22 v4l2src: Add support for cropping at capture source input
Add properties to control input cropping in the V4L2 device.
The input cropping is applied before composing the result to the
capture buffer.  By default the capture size will be set to the same
size as the crop region, but it can be scaled to a different output
frame size if supported by the V4L2 device.
If scaling is not supported, the cropped image will
be composed as is into the top-left corner of the capture buffer.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1089>
2022-03-11 15:02:08 +00:00
Damian Hobson-Garcia
ceff3e8ff7 v4l2object: Add function to get crop regions from device
Get the current crop bounding region from the V4L2 device so
that it can be provided to applications and used to validate
crop settings. Also make the default crop region available so
that it can be used to reset the crop when appropriate.

Uses the selection API when available with fallback to the crop
API for older kernels.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1089>
2022-03-11 15:02:08 +00:00
Damian Hobson-Garcia
25f240993c v4l2object: rename crop function to reflect its usage
The gst_v4l2_object_set_crop() is used for removing buffer
alignment padding. Give it a name that better reflects
that usage.  This helps to distinguish from cropping of the
input image (e.g. cropping at the image sensor on a captre
device), which can be  unrelated to the memory buffer padding,
especially if scaling is involved.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1089>
2022-03-11 15:02:08 +00:00
Hou Qi
fa6f34d595 v4l2bufferpool: Fix race condition between qbuf and pool streamoff
There is a chance that pool->buffers[index] sets BUFFER_STATE_QUEUED, but
it has not been queued yet which makes pool->buffers[index] still NULL.
At this time, if pool_streamff release all buffers with BUFFER_STATE_QUEUED
state regardless of whether the buffer is NULL or not, it will cause segfault.

To fix this, also check buffer when streamoff release buffer.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1842>
2022-03-07 15:14:15 +00:00
Damian Hobson-Garcia
2f410f26bf v4l2src: Reset the compose window to the default after setting format
When the size of V4L2 capture or output is changes with VIDIOC_S_FMT,
the device is only required to update the compisition window to fit
inside the new frame size.  This can result in captured data only being
updated on a portion of the frame after a resize.

Update the composition window to the default value determined by the
V4L2 device driver whenever the format is changed to make sure that
all image data is composed to its full size.

Fixes #765

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1806>
2022-03-03 13:28:31 +00:00
Ming Qian
24eb35f113 v4l2videodec : enable resolution change
The dynamic resolution changes when
the sequence starts when the decoder detects a coded frame with one or
more of the following parameters different from those previously
established (and reflected by corresponding queries):
1.coded resolution (OUTPUT width and height),
2.visible resolution (selection rectangles),
3.the minimum number of buffers needed for decoding,
4.bit-depth of the bitstream has been changed.

Although gstreamer parser has parsed the stream resolution.
but there are some case that we need to handle resolution change event.
1. bit-depth is different from the negotiated format.
2. the capture buffer count can meet the demand
3. there are some hardware limitations that the decoded resolution may
be larger than the display size. For example, the stream size is
1920x1080, but some vpu may decode it to 1920x1088.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1381>
2022-03-01 00:00:50 +00:00
Ming Qian
fe56af607b v4l2videodec : refactor the setup process of capture
v4l2videodec do some refactoring so that it can support
dynamic resolution change event.

1.wrap the setup process of capture as a function,
as decoder need setup the capture again when
dynamic resolution change event is received.

2.move the function "remove_padding"

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1381>
2022-03-01 00:00:50 +00:00
Nicolas Dufresne
e2b2ff26c9 v4l2transform: Handle caps changes
As this element is single threaded, we only need to stop the objects to
allow changing the format again. Fixes assertion notably on shutdown and
on some other situation where the format may be set twice without
actually activating the element.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1567>
2022-02-20 22:32:55 +00:00
Nicolas Dufresne
d394b8b4bd v4l2object: Avoid crash on early failure
This happens while an external error lead to an early shutdown.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1567>
2022-02-20 22:32:55 +00:00
Nicolas Dufresne
ec9585d148 video4linux2: Add MM21 support
This enables mtk-vcodec and MDP driver from mainline Linux kernel.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1567>
2022-02-20 22:32:55 +00:00
Nicolas Dufresne
bab9041c4b Port plugins to gst_video_format_info_extrapolate_stride()
This reduces code duplication and simplify addition of new
pixel formats into related plugins.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1567>
2022-02-20 22:32:55 +00:00
Rouven Czerwinski
748c5f3579 gstv4l2tuner: return NULL if no norm set
If the video4linux device supports norms but has no norm set, norm is
returned as an uninitialized variable after the ioctl call, leading to
gst_v4l2_tuner_get_norm_by_std_id() returning a random norm from the
supported norms. Catch this case and instead return NULL to indicate
that no norm is setup.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1625>
2022-02-20 21:38:40 +00:00
Tim Mooney
54a1f60077 v4l2: include <sys/ioccom.h> on Illumos
Needed for _IOR/_IORW

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1524>
2022-02-18 21:34:49 +00:00
Nicolas Dufresne
ecfbd33dbe video4linux2: Sync kernel headers against 5.16.0
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/965>
2022-01-21 19:32:30 +00:00
Nicolas Dufresne
01857d7941 v4l2videdec: Fix race condition between drain and state changes
This is due to an unsafe usage of the pad task. We didn't ensure proper
ownership of the task. That race involved the task being released too early,
and was detected, luckily, by the glib mutex implementationt that
reported the mutex being disposed while being locked.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1478>
2022-01-21 16:36:50 +00:00
Wim Taymans
9aaef931bf v4l2: handle 0x0 sizes gracefully
Also ignore 0x0 sizes in the fallback case and assume the size can be
anything between 1x1 and MAXxMAX.

This fixes the case where a width=0, height=0 caps are created. Whith
this patch the caps will contain width=[1,MAX], height=[1,MAX].

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1396>
2021-11-29 15:35:36 +01:00
Trung Do
a87be69ce5 v4l2: Update fmt if padded height is greater than fmt height
If padded height is greater, buffer bytesused could be larger than plane length,
and cause VIDIOC_QBUF failure.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1355>
2021-11-16 10:46:29 -05:00
James Cowgill
1e27ea63af v4l2: Record buffer states in pool to fix dequeue race
The `gst_v4l2_buffer_pool_dqbuf` function contains this ominous comment:

    /* get our GstBuffer with that index from the pool, if the buffer was
     * outstanding we have a serious problem.
     */
    outbuf = pool->buffers[group->buffer.index];

Unfortunately it is common for buffers in _output_ buffer pools to be
both queued and outstanding at the same time. This can happen if the
upstream element keeps a reference to the buffer, or in an encoder
element itself when it keeps a reference to the input buffer for each
frame.

Since the current code doesn't handle this case properly we can end up
with crashes in other elements such as:

    (gst-launch-1.0:32559): CRITICAL **: 17:33:35.740: gst_video_frame_map_id: assertion 'GST_IS_BUFFER (buffer)' failed

and:

    (gst-launch-1.0:231): GStreamer-CRITICAL **: 00:16:20.882: write map requested on non-writable buffer

Both these crashes are caused by a race condition related to releasing
the same buffer twice from two different threads. If a buffer is queued
and outstanding this situation is possible:

**Thread 1**
- Calls `gst_buffer_unref` decrementing the reference count to zero.
- The core GstBufferPool object marks the buffer non-outstanding.
- Calls the V4L2 release buffer function.
- If the buffer is _not_ queued:
  - Release it back to the free pool (containing non-queued buffers).

**Thread 2**
- Dequeues the queued output buffer.
  - Marks the buffer as not queued.
- If the buffer is _not_ outstanding:
  - Calls the V4L2 release buffer function.
  - Release it back to the free pool (containing non-queued buffers).

If both of these threads run at exactly the same time there is a small
window where the buffer is marked both not outstanding and not queued
but before it has been released. In this case the buffer will be freed
twice causing the above crashes.

Unfortunately the variable recording whether a buffer is outstanding is
part of the core `GstBuffer` object and is managed by `GstBufferPool` so
it's not as straightforward as adding a mutex. Instead we can fix this
by additionally recording the buffer state in `GstV4l2BufferPool`, and
handle "internal" and "external" buffer release separately so we can
detect when a buffer becomes not outstanding.

In the new solution:
- The "external" buffer pool release and the "dqbuf" functions
  atomically update the buffer state and determine if a buffer is still
  queued or outstanding.
- Subsequent code and a new
  `gst_v4l2_buffer_pool_complete_release_buffer` function can proceed to
  release (or not) a buffer knowing that it's not racing with another
  thread.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1010>
2021-11-11 22:30:31 +00:00
Haihua Hu
a66124a79c v4l2bufferpool: set video alignment of video meta
need apply video alignment info on video meta, downstream
element can get buffer alignment from video meta

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1326>
2021-11-09 13:32:46 +00:00
Sebastian Dröge
d2f66106a8 v4l2: Support bools for setting extra-controls
They're just mapped to 0 / 1 and can already be set as integers, but
being able to set them as booleans seems useful.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1308>
2021-11-04 15:21:40 +00:00
Thibault Saunier
5ff769d731 Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00