From: ming qian <ming.qian@oss.nxp.com>
To: Nicolas Dufresne <nicolas@ndufresne.ca>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
Ming Qian <ming.qian@nxp.com>,
mchehab@kernel.org
Cc: shawnguo@kernel.org, robh+dt@kernel.org, s.hauer@pengutronix.de,
kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com,
xiahong.bao@nxp.com, eagle.zhou@nxp.com, tao.jiang_2@nxp.com,
imx@lists.linux.dev, linux-media@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] media: v4l2-ctrls: Add average qp control
Date: Mon, 6 May 2024 10:28:01 +0800 [thread overview]
Message-ID: <5fbe3159-8ded-4d56-a778-db65d029b77a@oss.nxp.com> (raw)
In-Reply-To: <46ea74867fee6f0dbefb4c2d24a682d15beb41e7.camel@ndufresne.ca>
Hi Nicolas,
> Le mercredi 24 avril 2024 à 12:03 +0200, Hans Verkuil a écrit :
>> On 29/03/2024 10:23, Ming Qian wrote:
>>> Add a control V4L2_CID_MPEG_VIDEO_AVERAGE_QP to report the average qp
>>> value of current encoded frame.
>>>
>>> Signed-off-by: Ming Qian <ming.qian@nxp.com>
>>> ---
>>> Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst | 4 ++++
>>> drivers/media/v4l2-core/v4l2-ctrls-defs.c | 5 +++++
>>> include/uapi/linux/v4l2-controls.h | 2 ++
>>> 3 files changed, 11 insertions(+)
>>>
>>> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>>> index 2a165ae063fb..cef20b3f54ca 100644
>>> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>>> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-codec.rst
>>> @@ -1653,6 +1653,10 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type -
>>> Quantization parameter for a P frame for FWHT. Valid range: from 1
>>> to 31.
>>>
>>> +``V4L2_CID_MPEG_VIDEO_AVERAGE_QP (integer)``
>>> + This read-only control returns the average qp value of the currently
>>> + encoded frame. Applicable to the H264 and HEVC encoders.
>>
>> qp -> QP
>>
>> Why is this applicable to H264/HEVC only? I think it is fine for any codec.
>
> Same question, though we should document the range, which will differ per-
> codecs. We should also document to always use the specified range, rather then a
> HW custom range. This way we don't endup with issues we have hit with other ill-
> defined controls.
>
> Nicolas
Thanks for the tip, I will add a description of the value range in V3
patch.
>
>>
>> This needs to document that the value applies to the last dequeued buffer
>> (VIDIOC_DQBUF).
>>
>>> +
>>> .. raw:: latex
>>>
>>> \normalsize
>>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
>>> index 8696eb1cdd61..88e86e4e539d 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
>>> @@ -972,6 +972,7 @@ const char *v4l2_ctrl_get_name(u32 id)
>>> case V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES: return "Use LTR Frames";
>>> case V4L2_CID_FWHT_I_FRAME_QP: return "FWHT I-Frame QP Value";
>>> case V4L2_CID_FWHT_P_FRAME_QP: return "FWHT P-Frame QP Value";
>>> + case V4L2_CID_MPEG_VIDEO_AVERAGE_QP: return "Average QP value";
>>
>> value -> Value
>>
>> Also move it up two lines so that it follows V4L2_CID_MPEG_VIDEO_USE_LTR_FRAMES
>> rather than FWHT controls.
>>
>>>
>>> /* VPX controls */
>>> case V4L2_CID_MPEG_VIDEO_VPX_NUM_PARTITIONS: return "VPX Number of Partitions";
>>> @@ -1507,6 +1508,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>>> *max = 0xffffffffffffLL;
>>> *step = 1;
>>> break;
>>> + case V4L2_CID_MPEG_VIDEO_AVERAGE_QP:
>>> + *type = V4L2_CTRL_TYPE_INTEGER;
>>> + *flags |= V4L2_CTRL_FLAG_VOLATILE | V4L2_CTRL_FLAG_READ_ONLY;
>>
>> Drop the volatile flag, this isn't a volatile value.
>>
>>> + break;
>>> case V4L2_CID_PIXEL_RATE:
>>> *type = V4L2_CTRL_TYPE_INTEGER64;
>>> *flags |= V4L2_CTRL_FLAG_READ_ONLY;
>>> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
>>> index 99c3f5e99da7..974fd254e573 100644
>>> --- a/include/uapi/linux/v4l2-controls.h
>>> +++ b/include/uapi/linux/v4l2-controls.h
>>> @@ -898,6 +898,8 @@ enum v4l2_mpeg_video_av1_level {
>>> V4L2_MPEG_VIDEO_AV1_LEVEL_7_3 = 23
>>> };
>>>
>>> +#define V4L2_CID_MPEG_VIDEO_AVERAGE_QP (V4L2_CID_CODEC_BASE + 657)
>>> +
>>> /* MPEG-class control IDs specific to the CX2341x driver as defined by V4L2 */
>>> #define V4L2_CID_CODEC_CX2341X_BASE (V4L2_CTRL_CLASS_CODEC | 0x1000)
>>> #define V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE (V4L2_CID_CODEC_CX2341X_BASE+0)
>>
>> Regards,
>>
>> Hans
>>
>
prev parent reply other threads:[~2024-05-06 2:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-29 9:23 [PATCH 1/2] media: v4l2-ctrls: Add average qp control Ming Qian
2024-03-29 9:23 ` [PATCH 2/2] media: amphion: Report the average qp of current encoded frame Ming Qian
2024-04-24 10:07 ` Hans Verkuil
2024-04-04 18:14 ` [PATCH 1/2] media: v4l2-ctrls: Add average qp control Nicolas Dufresne
2024-04-07 2:43 ` ming qian
2024-04-24 10:03 ` Hans Verkuil
2024-05-01 19:55 ` Nicolas Dufresne
2024-05-06 2:28 ` ming qian [this message]
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