From: Nicolas Dufresne <nicolas@ndufresne.ca>
To: 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,
ming.qian@oss.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: Wed, 01 May 2024 15:55:46 -0400 [thread overview]
Message-ID: <46ea74867fee6f0dbefb4c2d24a682d15beb41e7.camel@ndufresne.ca> (raw)
In-Reply-To: <25a33db9-3bc1-4d90-83d4-0bdbea9bc5d8@xs4all.nl>
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
>
> 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
>
next prev parent reply other threads:[~2024-05-01 19:55 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 [this message]
2024-05-06 2:28 ` ming qian
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