Messages in this thread | | | Date | Wed, 1 Jun 2022 18:33:22 +0200 | Subject | Re: [PATCH v6 16/17] media: uapi: Change data_bit_offset definition | From | Benjamin Gaignard <> |
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Le 01/06/2022 à 18:17, Jernej Škrabec a écrit : > Dne nedelja, 29. maj 2022 ob 08:45:57 CEST je Jernej Škrabec napisal(a): >> Dne petek, 27. maj 2022 ob 16:31:33 CEST je Benjamin Gaignard napisal(a): >>> 'F.7.3.6.1 General slice segment header syntax' section of HEVC >>> specification describes that a slice header always end aligned on >>> byte boundary, therefore we only need to provide the data offset in bytes. >>> >>> 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 48a8825a001b..37079581c661 100644 >>> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst >>> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst >>> @@ -3008,8 +3008,8 @@ 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 411601975124..835454239f73 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); >> While it's true that actual data starts on 8-bit aligned address, Cedrus for >> some reason needs offset which points at the end of the header, before >> alignment. There is very simple way to determine that, but unfortunately > this >> means reading source buffer. >> >> In short, above code won't work. I'll provide a fix. > Please include following fix http://ix.io/3Z8x otherwise Cedrus will fail to > decode slice. > > Other than fix in previous e-mail and this one, code looks good and I'll be > able to add missing functionality to Cedrus without much trouble in follow up > series.
Thanks for the patch it will be in version 7.
Regards, Benjamin
> > Best regards, > Jernej > >>> >>> /* Bitstream parameters. */ >>> >>> diff --git a/include/media/hevc-ctrls.h b/include/media/hevc-ctrls.h >>> index 9abca1a75bd4..936ff693967b 100644 >>> --- a/include/media/hevc-ctrls.h >>> +++ b/include/media/hevc-ctrls.h >>> @@ -312,7 +312,7 @@ 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) >>> @@ -356,7 +356,7 @@ 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; >>> -- >>> 2.32.0 >>> >>> >> >> >
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