Applications are expected to fill V4L2_CID_MPEG_VIDEO_H264_SCALING_MATRIX
if a non-flat scaling matrix applies to the picture. This is the case if
SPS scaling_matrix_present_flag or PPS pic_scaling_matrix_present_flag
are set, and should be handled by applications.
On one hand, the PPS bitstream syntax element signals the presence of a
Picture scaling matrix modifying the Sequence (SPS) scaling matrix.
On the other hand, our flag should indicate if the scaling matrix
V4L2 control is applicable to this request.
Rename the flag from PPS_FLAG_PIC_SCALING_MATRIX_PRESENT to
PPS_FLAG_SCALING_MATRIX_PRESENT, to avoid mixing this flag with
bitstream syntax element pic_scaling_matrix_present_flag,
and clarify the meaning of our flag.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The H.264 specification requires in section 7.4.3 "Slice header semantics",
that the following values shall be the same in all slice headers:
pic_parameter_set_id
frame_num
field_pic_flag
bottom_field_flag
idr_pic_id
pic_order_cnt_lsb
delta_pic_order_cnt_bottom
delta_pic_order_cnt[ 0 ]
delta_pic_order_cnt[ 1 ]
sp_for_switch_flag
slice_group_change_cycle
These bitstream fields are part of the slice header, and therefore
passed redundantly on each slice. The purpose of the redundancy
is to make the codec fault-tolerant in network scenarios.
This is of course not needed to be reflected in the V4L2 controls,
given the bitstream has already been parsed by applications.
Therefore, move the redundant fields to the per-frame decode
parameters control (DECODE_PARAMS).
Field 'pic_parameter_set_id' is simply removed in this case,
because the PPS control must currently contain the active PPS.
Syntax elements dec_ref_pic_marking() and those related
to pic order count, remain invariant as well, and therefore,
the fields dec_ref_pic_marking_bit_size and pic_order_cnt_bit_size
are also common to all slices.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Currently, the SLICE_BASED and FRAME_BASED modes documentation
is misleading and not matching the intended use-cases.
Drop non-required fields SLICE_PARAMS 'start_byte_offset' and
DECODE_PARAMS 'num_slices' and clarify the decoding modes in the
documentation.
On SLICE_BASED mode, a single slice is expected per OUTPUT buffer,
and therefore 'start_byte_offset' is not needed (since the offset
to the slice is the start of the buffer).
This mode requires the use of CAPTURE buffer holding, and so
the number of slices shall not be required.
On FRAME_BASED mode, the devices are expected to take care of slice
parsing. Neither SLICE_PARAMS are required (and shouldn't be
exposed by frame-based drivers), nor the number of slices.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The SLICE_PARAMS control is intended for slice-based
devices. In this mode, the OUTPUT buffer contains
a single slice, and so the buffer's plane payload size
can be used to query the slice size.
To reduce the API surface drop the size from the
SLICE_PARAMS control.
A follow-up change will remove other members in SLICE_PARAMS
so we don't need to add padding fields here.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
DPB entry PicNum maximum value is 2*MaxFrameNum for interlaced
content (field_pic_flag=1).
As specified, MaxFrameNum is 2^(log2_max_frame_num_minus4 + 4)
and log2_max_frame_num_minus4 is in the range of 0 to 12,
which means pic_num should be a 32-bit field.
The v4l2_h264_dpb_entry struct needs to be padded to avoid a hole,
which might be also useful to allow future uAPI extensions.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
As discussed recently, the current interface for the
Decoded Picture Buffer is not enough to properly
support field coding.
This commit introduces enough semantics to support
frame and field coding, and to signal how DPB entries
are "used for reference".
Reserved fields will be added by a follow-up commit.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Slice header syntax element 'first_mb_in_slice' can point
to the last macroblock, currently the field can only reference
65536 macroblocks which is insufficient for 8K videos.
Although unlikely, a 8192x4320 video (where macroblocks are 16x16),
would contain 138240 macroblocks on a frame.
As per the H264 specification, 'first_mb_in_slice' can be up to
PicSizeInMbs - 1, so increase the size of the field to 32-bits.
Note that v4l2_ctrl_h264_slice_params struct will be modified
in a follow-up commit, and so we defer its 64-bit padding.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
The prediction weight parameters are only required under
certain conditions, which depend on slice header parameters.
As specified in section 7.3.3 Slice header syntax, the prediction
weight table is present if:
((weighted_pred_flag && (slice_type == P || slice_type == SP)) || \
(weighted_bipred_idc == 1 && slice_type == B))
Given its size, it makes sense to move this table to its control,
so applications can avoid passing it if the slice doesn't specify it.
Before this change struct v4l2_ctrl_h264_slice_params was 960 bytes.
With this change, it's 188 bytes and struct v4l2_ctrl_h264_pred_weight
is 772 bytes.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
When dealing with interlaced frames, reference lists must tell if
each particular reference is meant for top or bottom field. This info
is currently not provided at all in the H264 related controls.
Change reference lists to hold a structure, which specifies
an index into the DPB array and the field/frame specification
for the picture.
Currently the only user of these lists is Cedrus which is just compile
fixed here. Actual usage of will come in a following commit.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Building those list is a standard procedure described in section
'8.2.4 Decoding process for reference picture lists construction' of
the H264 specification.
We already have 2 drivers needing the same logic (hantro and rkvdec) and
I suspect we will soon have more.
Let's provide generic helpers to create those lists.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Using the field information attached to v4l2 buffers is not enough to
determine the type of field referenced by a DPB entry: the decoded
frame might contain the full picture (both top and bottom fields)
but the reference only point to one of them.
Let's add new V4L2_H264_DPB_ENTRY_FLAG_ flags to express that.
[Keep only 2 flags and add some details about they mean]
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Those lists can be extracted from the dpb, let's simplify userspace
life and build that list kernel-side (generic helpers will be provided
for drivers that need this list).
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Reviewed-by: Ezequiel Garcia <ezequiel@collabora.com>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Stateless decoders have different expectations about the
start code that is prepended on H264 slices. Add a
menu control to express the supported start code types
(including no start code).
Drivers are allowed to support only one start code type,
but they can support both too.
Note that this is independent of the H264 decoding mode,
which specifies the granularity of the decoding operations.
Either in frame-based or slice-based mode, this new control
will allow to define the start code expected on H264 slices.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Some stateless decoders don't support per-slice decoding granularity
(or at least not in a way that would make them efficient or easy to use).
Expose a menu to control the supported decoding modes. Drivers are
allowed to support only one decoding but they can support both too.
To fully specify the decoding operation, we need to introduce
a start_byte_offset, to indicate where slices start.
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The V4L2_PIX_FMT_H264_SLICE_RAW name was originally suggested
because the pixel format would represent H264 slices without any
start code.
However, as we will now introduce a start code menu control,
give the pixel format a more meaningful name, while it's
still early enough to do so.
Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
The H264_SLICE_RAW format is meant to hold the parsed slice data without
the start code. This will be needed by stateless decoders.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Ezequiel Garcia
Jernej Skrabec
Boris Brezillon
Jonas Karlman
Maxime Ripard