Re: [PATCH v5 04/17] media: uapi: HEVC: Add missing fields in HEVC controls

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hey Benjamin,

On 25.04.2022 18:16, Benjamin Gaignard wrote:

Le 25/04/2022 à 15:54, Sebastian Fricke a écrit :
On 07.04.2022 17:29, Benjamin Gaignard wrote:
Complete the HEVC controls with missing fields from H.265 specifications.
Even if these fields aren't used by the current mainlined drivers
they will be need for (at least) rkvdec driver.

s/be need/be required/
or
s/be need/be needed/

s/rkvdec/the rkvdec/


Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
---
.../media/v4l/ext-ctrls-codec.rst             | 19 +++++++++++++++++++
include/media/hevc-ctrls.h                    |  6 +++++-
2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
index 4cd7c541fc30..dbb08603217b 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -2661,6 +2661,16 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
    :stub-columns: 0
    :widths:       1 1 2

+    * - __u8
+      - ``video_parameter_set_id``
+      - Specifies the value of the vps_video_parameter_set_id of the active VPS +        as descibed in section "7.4.3.2.1 General sequence parameter set RBSP semantics"
+        of H.265 specifications.
+    * - __u8
+      - ``seq_parameter_set_id``
+      - Provides an identifier for the SPS for reference by other syntax elements +        as descibed in section "7.4.3.2.1 General sequence parameter set RBSP semantics"
+        of H.265 specifications.
    * - __u16
      - ``pic_width_in_luma_samples``
      -
@@ -2800,6 +2810,9 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
    :stub-columns: 0
    :widths:       1 1 2

+    * - __u8
+      - ``pic_parameter_set_id``
+      - Identifies the PPS for reference by other syntax elements.
    * - __u8
      - ``num_extra_slice_header_bits``
      -
@@ -3026,6 +3039,12 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
    * - __u8
      - ``ref_idx_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX]``
      - The list of L1 reference elements as indices in the DPB.
+    * - __u16
+      - ``short_term_ref_pic_set_size``
+      - Specifies the size of short-term reference pictures set included in the SPS.

s/size of/size of the/

Section 7.4.8 depicts that the st_ref_pic_set syntax
structure can be part of the SPS or the slice header.

I think we should mention that we talk about the size of the st_ref_pic_set
syntax structure from section 7.4.8 of the specification.
+    * - __u16
+      - ``long_term_ref_pic_set_size``
+      - Specifies the size of long-term reference pictures set include in the SPS.

s/size of/size of the/

Can we make this a bit more helpful? The specification doesn't contain
a similar structure to `st_ref_pic_set` for long term pictures. So, as a
programmer this leaves me guessing:
- Which syntax structure's size are we talking about?
- Does this correlate to any of the existing sections of the
specification?
Because in the end, I feel like this documentation should be able to
help a programmer to provide the correct data for the uABI.

I will reword it like that:

  * - __u16
    - ``short_term_ref_pic_set_size``
    - Specifies the size, in bits, of the short-term reference pictures set, described as st_ref_pic_set()

Just ...

s/reference pictures set/reference picture set/

     in the specification, included in the slice header (section 7.3.6.1).

s/slice header/slice header or SPS/



* - __u16
   - ``long_term_ref_pic_set_size``
   - Specifies the size, in bits, of the long-term reference pictures set include in the slice header.

s/reference pictures set/reference picture set/

Looking at the documentation it looks like: s/slice header/slice header or SPS/
(For example in section 7.3.6.1:
```
if( long_term_ref_pics_present_flag ) {
  if( num_long_term_ref_pics_sps > 0 )
    num_long_term_sps
  num_long_term_pics
  for( i = 0; i < num_long_term_sps + num_long_term_pics; i++ ) {
    ...
```
)

... and then it looks very good!

Greetings,
Sebastian

     It is the number of bits in the conditional block if( long_term_ref_pics_present_flag ) {...}
     in section 7.3.6.1 of the specification.

Benjamin



Greetings,
Sebastian

    * - __u8
      - ``padding``
      - Applications and drivers must set this to zero.
diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
index 01ccda48d8c5..a329e086a89a 100644
--- a/include/media/hevc-ctrls.h
+++ b/include/media/hevc-ctrls.h
@@ -58,6 +58,8 @@ enum v4l2_mpeg_video_hevc_start_code {
/* The controls are not stable at the moment and will likely be reworked. */
struct v4l2_ctrl_hevc_sps {
    /* ISO/IEC 23008-2, ITU-T Rec. H.265: Sequence parameter set */
+    __u8    video_parameter_set_id;
+    __u8    seq_parameter_set_id;
    __u16    pic_width_in_luma_samples;
    __u16    pic_height_in_luma_samples;
    __u8    bit_depth_luma_minus8;
@@ -108,6 +110,7 @@ struct v4l2_ctrl_hevc_sps {

struct v4l2_ctrl_hevc_pps {
    /* ISO/IEC 23008-2, ITU-T Rec. H.265: Picture parameter set */
+    __u8    pic_parameter_set_id;
    __u8    num_extra_slice_header_bits;
    __u8    num_ref_idx_l0_default_active_minus1;
    __u8    num_ref_idx_l1_default_active_minus1;
@@ -199,7 +202,8 @@ struct v4l2_ctrl_hevc_slice_params {
    __u32    slice_segment_addr;
    __u8    ref_idx_l0[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
    __u8    ref_idx_l1[V4L2_HEVC_DPB_ENTRIES_NUM_MAX];
-
+    __u16    short_term_ref_pic_set_size;
+    __u16    long_term_ref_pic_set_size;
    __u8    padding;

    /* ISO/IEC 23008-2, ITU-T Rec. H.265: Weighted prediction parameter */
--
2.32.0





[Index of Archives]     [Linux Driver Development]     [Linux Driver Backports]     [DMA Engine]     [Linux GPIO]     [Linux SPI]     [Video for Linux]     [Linux USB Devel]     [Linux Coverity]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [Yosemite Backpacking]
  Powered by Linux