[RFC 4/7] media: uapi: h264: increase size of fields

Ezequiel Garcia
2020-06-23T18:29:19Z

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.

DPB entry PicNum maximum value is 2*MaxFrameNum for interlaced
content (field_pic_flag=1).

Therefore, increase 'first_mb_in_slice' and 'pic_num'.

The v4l2_h264_dpb_entry struct needs to be padded to avoid a hole,
which will be useful to allow future uAPI extensions.

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>
---
.../userspace-api/media/v4l/ext-ctrls-codec.rst | 7 +++++--
drivers/media/v4l2-core/v4l2-ctrls.c | 9 +++++++++
include/media/h264-ctrls.h | 6 ++++--
include/media/v4l2-h264.h | 2 +-
4 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
index 0808a36777b6..e3b5a28fb965 100644
--- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
@@ -1772,7 +1772,7 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
* - __u32
- ``header_bit_size``
-
- * - __u16
+ * - __u32
- ``first_mb_in_slice``
-
* - __u8
@@ -2046,7 +2046,10 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
* - __u16
- ``frame_num``
-
- * - __u16
+ * - __u8
+ - ``reserved[6]``
+ - Applications and drivers must set this to zero.
+ * - __u32
- ``pic_num``
-
* - __s32
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 6abd023f10c7..a751c14f9c22 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1734,6 +1734,7 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
struct v4l2_ctrl_mpeg2_slice_params *p_mpeg2_slice_params;
struct v4l2_ctrl_vp8_frame_header *p_vp8_frame_header;
struct v4l2_ctrl_h264_slice_params *p_h264_slice_params;
+ struct v4l2_ctrl_h264_decode_params *p_h264_dec_params;
struct v4l2_ctrl_hevc_sps *p_hevc_sps;
struct v4l2_ctrl_hevc_pps *p_hevc_pps;
struct v4l2_ctrl_hevc_slice_params *p_hevc_slice_params;
@@ -1808,6 +1809,14 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
}
break;
case V4L2_CTRL_TYPE_H264_DECODE_PARAMS:
+ p_h264_dec_params = p;
+
+ for (i = 0; i < V4L2_H264_NUM_DPB_ENTRIES; i++) {
+ struct v4l2_h264_dpb_entry *dpb_entry =
+ &p_h264_dec_params->dpb[i];
+
+ zero_reserved(*dpb_entry);
+ }
break;

case V4L2_CTRL_TYPE_VP8_FRAME_HEADER:
diff --git a/include/media/h264-ctrls.h b/include/media/h264-ctrls.h
index c6cbf178c1c9..a938d16b901c 100644
--- a/include/media/h264-ctrls.h
+++ b/include/media/h264-ctrls.h
@@ -161,7 +161,8 @@ struct v4l2_ctrl_h264_slice_params {
/* Offset in bits to slice_data() from the beginning of this slice. */
__u32 header_bit_size;

- __u16 first_mb_in_slice;
+ __u32 first_mb_in_slice;
+
__u8 slice_type;
__u8 pic_parameter_set_id;
__u8 colour_plane_id;
@@ -208,7 +209,8 @@ struct v4l2_ctrl_h264_slice_params {
struct v4l2_h264_dpb_entry {
__u64 reference_ts;
__u16 frame_num;
- __u16 pic_num;
+ __u8 reserved[6];
+ __u32 pic_num;
/* Note that field is indicated by v4l2_buffer.field */
__s32 top_field_order_cnt;
__s32 bottom_field_order_cnt;
diff --git a/include/media/v4l2-h264.h b/include/media/v4l2-h264.h
index bc9ebb560ccf..1a5f26fc2a9a 100644
--- a/include/media/v4l2-h264.h
+++ b/include/media/v4l2-h264.h
@@ -33,7 +33,7 @@ struct v4l2_h264_reflist_builder {
struct {
s32 pic_order_count;
int frame_num;
- u16 pic_num;
+ u32 pic_num;
u16 longterm : 1;
} refs[V4L2_H264_NUM_DPB_ENTRIES];
s32 cur_pic_order_count;
--
2.26.0.rc2