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 9B9A83CEB8A; Thu, 10 Sep 2026 07:37:31 +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=1789025863; cv=none; b=PlQTq59F7YB5gGBYBt5Rkb7TLVVh2LwxSdn/+Yz95zUHxqNZ+tCAQi8EAJYCN/sLmNmGWE4SnQ50/7b96uqXif2srdmAMOeiEHh7th5T1FcoaAxLnTCRDifQzxXxlm151X4+ouw50NOy7CHr9pKzMhFAqUzy7USSTWiokfUuDC8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789025863; c=relaxed/simple; bh=M1RydW3VCEQcH9Tz132yCnyBPxqFQb5vqUdyR4ATkC4=; h=Message-ID:Date:MIME-Version:From:Subject:To:Cc:References: In-Reply-To:Content-Type; b=gKyCcrVuYGqC6BWfUy2eNghQ0whl8xoCRKDK50KJD5KgS+OMES9ua8Engba6G0OZSum9AndPEmgYIfXQ6SLic/drpY2pWmNEl0spXU7IGtN73473fnupH/Yz8sNZcFDikS5pi7g9j4JRd5Ol8OFgPqUNS7j/AQ6KpxL4vK51Hj4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DfJrZuT/; 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="DfJrZuT/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 967101F00893; Thu, 10 Sep 2026 07:37:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789025848; bh=TXmB+a2+yLPSWFMIr/KVskMQgZnxP07M03tdVqNRxYk=; h=Date:From:Subject:To:Cc:References:In-Reply-To; b=DfJrZuT/DswaNgKtMgm6kFheB/cqKZf4w//ybI/Eog8reivV93MHH0S9g1k52il1U Z5aKFFLlXFEVn6PBnv6r7wnhNtUFzbgliZJmhzCNyNpkYMgS3iPuIO0EwudMWVEe7i WtH01OcW2MTr1Orr7HJgdNC7pgZ4tW602/PT7pMjHOMiErc2TiyI/RNyaGoUhvbmeZ JwgnP900Xv8G2N+oF76RL2prHNWKTKe1N4jfxIDu8lyl2hKCa9lQpxEpclG/Gu/0FW TfBRyKuW4ELjVkHPieO60YnuqLIYs7VzPXRTdeWHvy6OpqahGBBLcwvAiWgR4lCGWS m1BK0drOJ7rXQ== Message-ID: <790e3c11-1ba5-4e2f-a072-4deb4f384c3d@kernel.org> Date: Thu, 10 Sep 2026 09:37:24 +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 v5 1/5] 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: <20260815-enc_roi_enable-v5-0-ded944f0fc7f@oss.qualcomm.com> <20260815-enc_roi_enable-v5-1-ded944f0fc7f@oss.qualcomm.com> Content-Language: en-US, nl In-Reply-To: <20260815-enc_roi_enable-v5-1-ded944f0fc7f@oss.qualcomm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 15/08/2026 21:22, Deepa Guthyappa Madivalara wrote: > Add custom control, V4L2_CID_MPEG_VIDEO_ROI_MB_DELTA_QP for A small terminology issue: custom -> array Custom controls are driver-specific controls. But this adds a standard array control. Please check this series for the use of 'custom' and replace it with 'array'. > 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 > --- > .../userspace-api/media/v4l/ext-ctrls-codec.rst | 19 +++++++++++++++++++ > .../media/v4l/videodev2.h.rst.exceptions | 1 + > .../userspace-api/media/v4l/vidioc-g-ext-ctrls.rst | 4 ++++ > .../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 | 2 ++ > 7 files changed, 35 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..c16b1c5cd1c02b7f66b5f13433eb039eb615b35e 100644 > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst > @@ -1674,6 +1674,25 @@ 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 (__s8)`` __s8 -> __s8 array Otherwise it is not clear that this is a compound control containing an array. > + This custom control is used to set ROI MB map delta_Qp for the whole frame. Here is another use of 'custom' were 'array' is meant. > + 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``). 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) > + A read-only control that reports the MB Size used for the ROI delta_QP map. > + The supported MB Size depends on the encoder codec. > + Only square MBs are supported. The value returned represents the > + width and height of each block in pixels. The ROI delta_QP map provided > + through the ROI control must use the MB Size reported by this control. > + The number of entries in the ROI delta_QP array is determined by the > + frame dimensions and the reported MB Size. For example, for a QCIF frame > + (176x144) if reported MB Size is 16, the delta_QP array must contain > + 99 entries (176 x 144 / 16 x 16). What happens if the width/height is not nicely dividable by 16? E.g. 1920x1080. > + > .. 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 d78328152b7552f8f0d30a9e2f7c104bfd4b70d3..fe5f8992389c32d8f35f432229ef2f734002644e 100644 > --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > @@ -188,6 +188,10 @@ 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 5373dba640fae3d19247ab1c74ba336e05dc0fe0..95d8369e0d3d1e434978b9e576e0ef122691c65c 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -1884,6 +1884,7 @@ 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; > @@ -1961,6 +1962,7 @@ 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, > > Hmm, I see that patch 2/5 adds the v4l2-core changes for the new controls. Can you rework patches 1 and 2? It is much easier to review if the first patch adds V4L2_CTRL_TYPE_S8 support in both headers, documentation and v4l2-core, and the second patch does the same for the new controls. Currently the patches mix adding the new type and new controls, and that's actually hard to review. Regards, Hans