Because there might be more than a single call to CreateSurfaces,
we cannot assume that the index relative to the number of surfaces
requested in a single call matches the v4l2 index.
Grab the base index (as returned by the kernel) when allocating
buffers and use it for memory mapping and addressing them in v4l2.
This avoids memory-mapping the first (index 0) buffer multiple times
in that scenario instead of the n-th allocated buffer (in the n-th
call in the sequence).
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
The V4L2 API does not currently provide a way to liberate allocated
buffers one by one (which would fit well with DestroySurfaces in
VAAPI). Moreover, streaming needs to be off before liberating
buffers is allowed.
As a result, output an capture buffers can only be liberated when
destroying the decoding context, all at once, such as implemented
in this patch.
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Since the V4L2 ioctl is called QUERYBUF, it makes more sense to
call the associated function with the same name.
Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
void * can be assigned from and stored to any pointer type without any
warning. Remove the explicit casts.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
The cedrus_data structure carries the old name. In order to migrate to the
new name, let's rename it to request_data.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
The sunxi_cedrus.h header contains a bunch of defines prefixed with
SUNXI_CEDRUS.
As part as the ongoing migration to a more generic name, change that prefix
for V4L2_REQUEST, and the header file to request.h
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
As part of our renaming effort, Rename the libva hooks names to mention
request instead of SunxiCedrus
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
The libva only provides the reference images needed to decode the current
picture, but not the full DPB. However, some codecs need that whole DPB in
order to decode a picture.
For example, the Allwinner hardware codec has an internal SRAM, with each
picture getting a slot in that SRAM, and during each decoding process, some
metadata will then be generated from that SRAM content to a separate
buffer. Therefore, each frames must be located at the same SRAM position
each time so that the metadata are then re-used properly.
However, since libva will only pass a few reference images, we can end up
in a situation where multiple, subsequent, frames will have the same
reference images set, but might all be used as reference later on and
cannot therefore be located at the same position.
And from a more theorical point of view, Linux expects a full blown DPB in
its H264 control.
In order to work around this, we can create a shadow of the DPB by simply
maintaining a list of 16 decoded images, each associated with their
VAPictureH264 and an age. This age is the last time we used that frame as
reference. When a new picture is decoded, either we assign it to a free
slot, or we reuse the slot from the frame that hasn't been used as a
reference for the longest time.
This is a much simpler approach than the one documented in the H264 spec,
but this shouldn't really be a problem since we don't handle the reference
frames ourselves, but just re-use the one from the libva, and taken from
the bitstream before. As such, frames that are not supposed to be used for
reference will not be anymore, their age will not increase, and therefore
after a while we will garbage-collect their slot to store a much newer
frame.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
The coding style has been a bit erratic. Enforce the linux kernel coding
style by reusing their .clang-format file, running clang-format on the
source, and ignoring the few shortcomings that clang-format has at the
moment (especially on aligning the define values).
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
This long structure name makes it quite difficult to fit within the 80
characters limit. Shorten it.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
This patch introduces the support of MPEG4 video decoding. It basically
just copies data from VA's frame/slice headers data structures to v4l's
MPEG4 frame header extended controls data structures.
This patch introduces the support of MPEG2 video decoding. It basically
just copies data from VA's frame/slice headers data structures to v4l's
MPEG2 frame header extended controls data structures.
This VA backend uses v4l2's Frame API proposal to interface with the
"sunxi-cedrus" video driver on Allwinner SoC. Only a few parts of the
code are really dependent on sunxi-cedrus and this VA backend could be
reused for other v4l drivers using the Frame API.
Paul Kocialkowski