From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E70553CA4B3; Wed, 15 Jul 2026 08:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784103940; cv=none; b=szKRkBEPtxwaer+gtFHV6VcA/gStJM+QRW/yNIN7Jao7SsXTjuBeYXOdYmdClpymktOvKqw+MCrSibaINtSrWVEklzRf3HRxu5LMuZc2qz1c36C72fgMqiW1f8tmLR7e4cMMmWR8tl9ZSnZWlfHJMV/TfMQJ8m/QqN7CTaoXe2I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784103940; c=relaxed/simple; bh=VA489iJmfvSIIS6zCkGAI+diWfCh9Aow6uBb+2qStsk=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=bAVdNx25sGj+4o8engkqIILnnttqinpSj0OydhR9qBPrVMyCayIJ8dzfNShici6B5zPhC9q+lGTxAJ5LHAIj8Ooii+voYhILmh4cCOjaWvDMHsMI5TQDCnTLUrZ8wCoFha/zQdy5YJWpsng6yFEa0tvM0XDmG+BDObG7whLkrbg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iYNV30ep; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iYNV30ep" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5A1AC1F000E9; Wed, 15 Jul 2026 08:25:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784103938; bh=7Kg9E7GsmDh7hENS97sqL6GD8dmTGG/hPjBDQLQ/ZXQ=; h=Date:From:Subject:To:Cc:References:In-Reply-To; b=iYNV30epQQrHm1bY7vwyrG/UzwpT/XeHBVm9qdwrKS+x67ggCWy1i/rtFuUGL26tr 25IpjMn1OeBD4Lo6PvIeEx6hlHtpEFHkWfHLxrFhKtE3mGfzFGECmqqRQuw8nn4psM 24FxPeBENh+BwQe+XMnleA+eYidCzJNSf2NceTONTX+EDD71jGeoDe8whuAMmOorFu LuHZG4rHaUDLGQBtA4pZmZ66STkxaGXB6v+dY5rXFTpGFwV/4b4OiGI8JmoYPl8AzB I+djbKSzXtD9XbEQTSOrgMKeNuLbkHL0OcbgMFcnvXYE00vcJrUGyOZcYzxHEyLpxf dPsI5XQDaNwUQ== Message-ID: Date: Wed, 15 Jul 2026 10:25:34 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Hans Verkuil Subject: Re: [PATCH v2 1/3] media: uapi: Introduce new control for video encoder ROI To: Deepa Guthyappa Madivalara , Mauro Carvalho Chehab , Vikash Garodia , Dikshita Agarwal , Abhinav Kumar , Bryan O'Donoghue Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, kernel test robot References: <20260714-enc_roi_enable-v2-0-63683f9dbcef@oss.qualcomm.com> <20260714-enc_roi_enable-v2-1-63683f9dbcef@oss.qualcomm.com> Content-Language: en-US, nl In-Reply-To: <20260714-enc_roi_enable-v2-1-63683f9dbcef@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 14/07/2026 21:00, Deepa Guthyappa Madivalara wrote: > Add custom control, V4L2_CID_MPEG_VIDEO_ROI_MB_DELTA_QP for > video encoder Region of Interest to allow applications to specify > different quality levels for specific regions in video frames. Define > V4L2_CID_MPEG_VIDEO_ROI_MB_SIZE to retrieve supported MB size based on > codec from the hardware encoder and set the corresponding ROI MB delta_qp > map that adjusts quantization relative to the frame QP's base value. > > This enables use cases like prioritizing quality for faces in video > conferencing or important objects in surveillance footage while reducing > bitrate for less critical areas. > > Signed-off-by: Deepa Guthyappa Madivalara > --- > Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 14 ++++++++++++++ > .../userspace-api/media/v4l/videodev2.h.rst.exceptions | 1 + > .../userspace-api/media/v4l/vidioc-g-ext-ctrls.rst | 4 ++++ > Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst | 6 ++++++ > include/media/v4l2-ctrls.h | 1 + > include/uapi/linux/v4l2-controls.h | 2 ++ > include/uapi/linux/videodev2.h | 3 +++ > 7 files changed, 31 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > index ab865a1a6ba929f1725ce2ab0fd3aeee4a69329a..1995e7335fb29611151c61561df577f2bdac7a48 100644 > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > @@ -1674,6 +1674,20 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - > Codecs need to always use the specified range, rather then a HW custom range. > Applicable to encoders > > +``V4L2_CID_MPEG_VIDEO_ROI_MB_DELTA_QP (integer)`` integer -> __s8 > + This custom control is used to set ROI MB map delta_Qp for whole frame. Why is this a 'custom' control? This looks like a standard control to me. Or do you perhaps mean that the value is HW dependent? > + The frame is divided into grid with MB Size returned from querying The frame is divided into a grid of MB Size by MB Size pixels (MB Size is obtained from querying ``V4L2_CID_MPEG_VIDEO_ROI_MB_SIZE``). > + V4L2_CID_MPEG_VIDEO_ROI_MB_SIZE. Each block is configured with delta_Qp > + in raster order. The valid range for delta_Qp is encoder dependent. > + Applicable to encoders. > + > +``V4L2_CID_MPEG_VIDEO_ROI_MB_SIZE (integer)`` > + This read-only control returns the MB Size for ROI MB delta_Qp map. > + Its valid range depends on encoder supported codec format. > + Example: For H.264, 16 is returned for 16x16 MB size. > + For HEVC, 32 is returned for 32x32 MB size. > + Depending on the size returned, delta_Qp Map is set to the encoder. Sorry, it's not clear what you mean with that last sentence. Is it possible to have codecs with non-square macroblocks? E.g. 32x16? Regards, Hans > + > .. raw:: latex > > \normalsize > diff --git a/Documentation/userspace-api/media/v4l/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/v4l/videodev2.h.rst.exceptions > index 6182b4e2d2ee002c0d3562e1cc3bc2fd9c4286d6..b036ed3ec2f0744175cad1cbc4e73fe828e0c955 100644 > --- a/Documentation/userspace-api/media/v4l/videodev2.h.rst.exceptions > +++ b/Documentation/userspace-api/media/v4l/videodev2.h.rst.exceptions > @@ -141,6 +141,7 @@ replace symbol V4L2_CTRL_TYPE_STRING :c:type:`V4L.v4l2_ctrl_type` > replace symbol V4L2_CTRL_TYPE_U16 :c:type:`V4L.v4l2_ctrl_type` > replace symbol V4L2_CTRL_TYPE_U32 :c:type:`V4L.v4l2_ctrl_type` > replace symbol V4L2_CTRL_TYPE_U8 :c:type:`V4L.v4l2_ctrl_type` > +replace symbol V4L2_CTRL_TYPE_S8 :c:type:`V4L.v4l2_ctrl_type` > replace symbol V4L2_CTRL_TYPE_MPEG2_SEQUENCE :c:type:`V4L.v4l2_ctrl_type` > replace symbol V4L2_CTRL_TYPE_MPEG2_PICTURE :c:type:`V4L.v4l2_ctrl_type` > replace symbol V4L2_CTRL_TYPE_MPEG2_QUANTISATION :c:type:`V4L.v4l2_ctrl_type` > diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > index b8698b85bd808979fc590715125f689880e5a30e..8d5eec357509700c9a582b98c14843bb5e483be0 100644 > --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > @@ -185,6 +185,10 @@ still cause this situation. > - ``p_u32`` > - A pointer to a matrix control of unsigned 32-bit values. Valid if > this control is of type ``V4L2_CTRL_TYPE_U32``. > + * - __s8 * > + - ``p_s8`` > + - A pointer to a matrix control of signed 8-bit values. Valid if > + this control is of type ``V4L2_CTRL_TYPE_S8``. > * - __s32 * > - ``p_s32`` > - A pointer to a matrix control of signed 32-bit values. Valid if > diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst > index 82c8b52e771ce9301491b3f752e501a8fe7e2434..57e1652ae72e0324742142446acf32a16b94941c 100644 > --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst > +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst > @@ -425,6 +425,12 @@ See also the examples in :ref:`control`. > - any > - An unsigned 32-bit valued control ranging from minimum to maximum > inclusive. The step value indicates the increment between values. > + * - ``V4L2_CTRL_TYPE_S8`` > + - any > + - any > + - any > + - A signed 8-bit valued control ranging from minimum to maximum > + inclusive. The step value indicates the increment between values. > * - ``V4L2_CTRL_TYPE_MPEG2_QUANTISATION`` > - n/a > - n/a > diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h > index 327976b14d50b73a631e4d2ed95d9f4d146c45ab..a1806ddbc797efa52e83cd3f685ef70d5b5483d2 100644 > --- a/include/media/v4l2-ctrls.h > +++ b/include/media/v4l2-ctrls.h > @@ -64,6 +64,7 @@ union v4l2_ctrl_ptr { > s32 *p_s32; > s64 *p_s64; > u8 *p_u8; > + s8 *p_s8; > u16 *p_u16; > u32 *p_u32; > char *p_char; > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h > index affec0ab4781507be761cb791ff737460acf9cb7..00a2c48630bd198faa9a2b833a9aa346d8357555 100644 > --- a/include/uapi/linux/v4l2-controls.h > +++ b/include/uapi/linux/v4l2-controls.h > @@ -920,6 +920,8 @@ enum v4l2_mpeg_video_av1_level { > }; > > #define V4L2_CID_MPEG_VIDEO_AVERAGE_QP (V4L2_CID_CODEC_BASE + 657) > +#define V4L2_CID_MPEG_VIDEO_ROI_MB_DELTA_QP (V4L2_CID_CODEC_BASE + 658) > +#define V4L2_CID_MPEG_VIDEO_ROI_MB_SIZE (V4L2_CID_CODEC_BASE + 659) > > /* MPEG-class control IDs specific to the CX2341x driver as defined by V4L2 */ > #define V4L2_CID_CODEC_CX2341X_BASE (V4L2_CTRL_CLASS_CODEC | 0x1000) > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index eda4492e40dc14a90a230601d8e23b0e13845d34..1e307781645543960e4b73ba46fdf83279fda4dd 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -1880,6 +1880,7 @@ struct v4l2_ext_control { > __s64 value64; > char __user *string; > __u8 __user *p_u8; > + __s8 __user *p_s8; > __u16 __user *p_u16; > __u32 __user *p_u32; > __s32 __user *p_s32; > @@ -1957,6 +1958,7 @@ enum v4l2_ctrl_type { > V4L2_CTRL_TYPE_U8 = 0x0100, > V4L2_CTRL_TYPE_U16 = 0x0101, > V4L2_CTRL_TYPE_U32 = 0x0102, > + V4L2_CTRL_TYPE_S8 = 0x0103, > V4L2_CTRL_TYPE_AREA = 0x0106, > V4L2_CTRL_TYPE_RECT = 0x0107, > > @@ -1993,6 +1995,7 @@ enum v4l2_ctrl_type { > V4L2_CTRL_TYPE_AV1_TILE_GROUP_ENTRY = 0x281, > V4L2_CTRL_TYPE_AV1_FRAME = 0x282, > V4L2_CTRL_TYPE_AV1_FILM_GRAIN = 0x283, > + > }; > > /* Used in the VIDIOC_QUERYCTRL ioctl for querying controls */ >