Re: [PATCH v4 14/15] media: uapi: Change data_bit_offset definition

Nicolas Dufresne
2022-04-06T20:37:41Z

Le lundi 28 février 2022 à 15:08 +0100, Benjamin Gaignard a écrit :
> 'F.7.3.6.1 General slice segment header syntax' section of HEVC
> specification describes that a slice header always end byte aligned,
> therefore we only need to provide the data offset in byte.
>
> Signed-off-by: Benjamin Gaignard <benjamin.gaignard@collabora.com>
> ---
> Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 4 ++--
> drivers/staging/media/sunxi/cedrus/cedrus_h265.c | 2 +-
> include/media/hevc-ctrls.h | 4 ++--
> 3 files changed, 5 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 1aa2a7399e76..c8602c1e706e 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
> @@ -2986,8 +2986,8 @@ enum v4l2_mpeg_video_hevc_size_of_length_field -
> - ``bit_size``
> - Size (in bits) of the current slice data.
> * - __u32
> - - ``data_bit_offset``
> - - Offset (in bits) to the video data in the current slice data.
> + - ``data_byte_offset``
> + - Offset (in bytes) to the video data in the current slice data.
> * - __u32
> - ``num_entry_point_offsets``
> - Specifies the number of entry point offset syntax elements in the slice header.
> diff --git a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> index 8ab2d9c6f048..3e43b7cc2f57 100644
> --- a/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> +++ b/drivers/staging/media/sunxi/cedrus/cedrus_h265.c
> @@ -405,7 +405,7 @@ static void cedrus_h265_setup(struct cedrus_ctx *ctx,
> /* Initialize bitstream access. */
> cedrus_write(dev, VE_DEC_H265_TRIGGER, VE_DEC_H265_TRIGGER_INIT_SWDEC);
>
> - cedrus_h265_skip_bits(dev, slice_params->data_bit_offset);
> + cedrus_h265_skip_bits(dev, slice_params->data_byte_offset / 8);

Did you mean the following instead ?

+ cedrus_h265_skip_bits(dev, slice_params->data_byte_offset * 8);

>
> /* Bitstream parameters. */
>
> diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h
> index c50205083573..51bdf38ea0c3 100644
> --- a/include/media/hevc-ctrls.h
> +++ b/include/media/hevc-ctrls.h
> @@ -296,7 +296,7 @@ struct v4l2_hevc_pred_weight_table {
> * V4L2_CTRL_FLAG_DYNAMIC_ARRAY flag must be set when using it.
> *
> * @bit_size: size (in bits) of the current slice data
> - * @data_bit_offset: offset (in bits) to the video data in the current slice data
> + * @data_byte_offset: offset (in bytes) to the video data in the current slice data
> * @num_entry_point_offsets: specifies the number of entry point offset syntax
> * elements in the slice header.
> * @nal_unit_type: specifies the coding type of the slice (B, P or I)
> @@ -340,7 +340,7 @@ struct v4l2_hevc_pred_weight_table {
> */
> struct v4l2_ctrl_hevc_slice_params {
> __u32 bit_size;
> - __u32 data_bit_offset;
> + __u32 data_byte_offset;
> __u32 num_entry_point_offsets;
> /* ISO/IEC 23008-2, ITU-T Rec. H.265: NAL unit header */
> __u8 nal_unit_type;