From 4245232fa6ca58f79710732bd16cefe78b8b8bc4 Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Tue, 25 Aug 2020 05:52:31 +0200 Subject: media: uapi: h264: Increase size of 'first_mb_in_slice' field 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 Tested-by: Jonas Karlman Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'Documentation') diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst index 591d3d35c429..a417a1ae50d5 100644 --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst @@ -1774,7 +1774,7 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - * - __u32 - ``header_bit_size`` - - * - __u16 + * - __u32 - ``first_mb_in_slice`` - * - __u8 -- cgit v1.2.3