Re: [PATCH v2 2/9] media: cedrus: h264: Support profile and level controls

From: Ezequiel Garcia <ezequiel@collabora.com>
To: "Jernej Škrabec" <jernej.skrabec@siol.net>,
	linux-media@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: kernel@collabora.com, Jonas Karlman <jonas@kwiboo.se>,
	Hans Verkuil <hverkuil@xs4all.nl>,
	Nicolas Dufresne <nicolas.dufresne@collabora.com>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Maxime Ripard <mripard@kernel.org>,
	Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Subject: Re: [PATCH v2 2/9] media: cedrus: h264: Support profile and level controls
Date: Tue, 17 Nov 2020 16:40:09 -0300	[thread overview]
Message-ID: <22e909c7fe5722a7edf0828521c5a43f79ab70e3.camel@collabora.com> (raw)
In-Reply-To: <1725677.6jS8d4RcRb@kista>

On Tue, 2020-11-17 at 20:24 +0100, Jernej Škrabec wrote:
> Hi Ezequiel,
> 
> sorry for late review.
> 
> First of all, this patch doesn't break anything. However, see comment below.
> 
> Dne petek, 13. november 2020 ob 22:51:14 CET je Ezequiel Garcia napisal(a):
> > Cedrus supports H.264 profiles from Baseline to High,
> > up to Level 5.1, except for the Extended profile
> > 
> > Expose the V4L2_CID_MPEG_VIDEO_H264_PROFILE and
> > V4L2_CID_MPEG_VIDEO_H264_LEVEL so that userspace can
> > query the driver for the supported profiles and levels.
> > 
> > Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
> > ---
> >  drivers/staging/media/sunxi/cedrus/cedrus.c | 21 +++++++++++++++++++++
> >  1 file changed, 21 insertions(+)
> > 
> > diff --git a/drivers/staging/media/sunxi/cedrus/cedrus.c b/drivers/staging/
> media/sunxi/cedrus/cedrus.c
> > index 9a102b7c1bb9..8b0e97752d27 100644
> > --- a/drivers/staging/media/sunxi/cedrus/cedrus.c
> > +++ b/drivers/staging/media/sunxi/cedrus/cedrus.c
> > @@ -103,6 +103,27 @@ static const struct cedrus_control cedrus_controls[] = 
> {
> >  		.codec		= CEDRUS_CODEC_H264,
> >  		.required	= false,
> >  	},
> > +	{
> > +		.cfg = {
> > +			.id	= 
> V4L2_CID_MPEG_VIDEO_H264_PROFILE,
> > +			.min	= 
> V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE,
> > +			.def	= 
> V4L2_MPEG_VIDEO_H264_PROFILE_MAIN,
> > +			.max	= 
> V4L2_MPEG_VIDEO_H264_PROFILE_HIGH,
> > +			.menu_skip_mask =
> > +				
> BIT(V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED),
> > +		},
> > +		.codec		= CEDRUS_CODEC_H264,
> > +		.required	= false,
> > +	},
> > +	{
> > +		.cfg = {
> > +			.id = V4L2_CID_MPEG_VIDEO_H264_LEVEL,
> > +			.min = V4L2_MPEG_VIDEO_H264_LEVEL_1_0,
> > +			.max = V4L2_MPEG_VIDEO_H264_LEVEL_5_1,
> 
> I went through several datasheets and only newer ones (H6, H616) state max. 
> supported level, which is 4.2. Please change it in next revision.
> 
> After that, you can add
> Reviewed-by: Jernej Skrabec <jernej.skrabec@siol.net>
> 

Note that I used level 5.1 based on a commit from you:
"""
    media: cedrus: h264: Fix 4K decoding on H6

    Due to unknown reason, H6 needs larger intraprediction buffer for 4K
    videos than other SoCs. This was discovered by playing 4096x2304 video,
    which is maximum what H6 VPU is supposed to support.
"""

I guessed this meant it supported level 5 or higher.
(Now that I think about it, I meant at least H6, does).

According to https://en.wikipedia.org/wiki/Advanced_Video_Coding#Levels,
level 4.2 is up to 2,048×1,080@60.0.

Frankly, I'm open to put whatever value makes you happy.

Thanks,
Ezequiel

> Best regards,
> Jernej
> 
> > +		},
> > +		.codec		= CEDRUS_CODEC_H264,
> > +		.required	= false,
> > +	},
> >  	{
> >  		.cfg = {
> >  			.id	= V4L2_CID_MPEG_VIDEO_HEVC_SPS,
> > -- 
> > 2.27.0
> > 
> > 
> 
> 