Re: [PATCH v7, 04/15] media: mtk-vcodec: Read max resolution from dec_capability

[Chen-Yu Tsai <wenst@chromium.org>]

Hi,

On Mon, Feb 28, 2022 at 04:29:15PM -0500, Nicolas Dufresne wrote:
> Hi Yunfei,
> 
> this patch does not work unless userland calls enum_framesizes, which is
> completely optional. See comment and suggestion below.
> 
> Le mercredi 23 février 2022 à 11:39 +0800, Yunfei Dong a écrit :
> > Supported max resolution for different platforms are not the same: 2K
> > or 4K, getting it according to dec_capability.
> > 
> > Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> > Reviewed-by: Tzung-Bi Shih<tzungbi@google.com>
> > ---
> >  .../platform/mtk-vcodec/mtk_vcodec_dec.c      | 29 +++++++++++--------
> >  .../platform/mtk-vcodec/mtk_vcodec_drv.h      |  4 +++
> >  2 files changed, 21 insertions(+), 12 deletions(-)
> > 
> > diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
> > index 130ecef2e766..304f5afbd419 100644
> > --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
> > +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
> > @@ -445,7 +447,7 @@ static int vidioc_vdec_s_fmt(struct file *file, void *priv,
> >  		return -EINVAL;
> >  
> >  	q_data->fmt = fmt;
> > -	vidioc_try_fmt(f, q_data->fmt);
> > +	vidioc_try_fmt(ctx, f, q_data->fmt);
> >  	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
> >  		q_data->sizeimage[0] = pix_mp->plane_fmt[0].sizeimage;
> >  		q_data->coded_width = pix_mp->width;
> > @@ -545,6 +547,9 @@ static int vidioc_enum_framesizes(struct file *file, void *priv,
> >  				fsize->stepwise.min_height,
> >  				fsize->stepwise.max_height,
> >  				fsize->stepwise.step_height);
> > +
> > +		ctx->max_width = fsize->stepwise.max_width;
> > +		ctx->max_height = fsize->stepwise.max_height;
> 
> The spec does not require calling enum_fmt, so changing the maximum here is
> incorrect (and fail with GStreamer). If userland never enum the framesizes, the
> resolution get limited to 1080p.
> 
> As this only depends and the OUTPUT format and the device being open()
> (condition being dev_capability being set and OUTPUT format being known / not
> VP8), you could initialize the cxt max inside s_fmt(OUTPUT) instead, which is a
> mandatory call. I have tested this change to verify this:
> 
> 
> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
> index 044e3dfbdd8c..3e7c571526a4 100644
> --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c
> @@ -484,6 +484,14 @@ static int vidioc_vdec_s_fmt(struct file *file, void *priv,
>  	if (fmt == NULL)
>  		return -EINVAL;
>  
> +	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE &&
> +	    !(ctx->dev->dec_capability & VCODEC_CAPABILITY_4K_DISABLED) &&
> +	    fmt->fourcc != V4L2_PIX_FMT_VP8_FRAME) {
> +		mtk_v4l2_debug(3, "4K is enabled");
> +		ctx->max_width = VCODEC_DEC_4K_CODED_WIDTH;
> +		ctx->max_height = VCODEC_DEC_4K_CODED_HEIGHT;
> +	}
> +
>  	q_data->fmt = fmt;
>  	vidioc_try_fmt(ctx, f, q_data->fmt);
>  	if (f->type == V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE) {
> @@ -574,15 +582,9 @@ static int vidioc_enum_framesizes(struct file *file, void *priv,
>  
>  		fsize->type = V4L2_FRMSIZE_TYPE_STEPWISE;
>  		fsize->stepwise = dec_pdata->vdec_framesizes[i].stepwise;
> -		if (!(ctx->dev->dec_capability &
> -				VCODEC_CAPABILITY_4K_DISABLED) &&
> -				fsize->pixel_format != V4L2_PIX_FMT_VP8_FRAME) {
> -			mtk_v4l2_debug(3, "4K is enabled");
> -			fsize->stepwise.max_width =
> -					VCODEC_DEC_4K_CODED_WIDTH;
> -			fsize->stepwise.max_height =
> -					VCODEC_DEC_4K_CODED_HEIGHT;
> -		}
> +		fsize->stepwise.max_width = ctx->max_width;
> +		fsize->stepwise.max_height = ctx->max_height;
> +

Recent testing on ChromeOS suggests this doesn't work. The spec implies
that querying capabilities could happen before the output format is set.
And also, supported frame sizes are detected for each given format,
which may not be the one current set.

So the if block above has to be reintroduced in some form. I'll take a
look at this.


Regards
ChenYu

>  		mtk_v4l2_debug(1, "%x, %d %d %d %d %d %d",
>  				ctx->dev->dec_capability,
>  				fsize->stepwise.min_width,
> @@ -592,8 +594,6 @@ static int vidioc_enum_framesizes(struct file *file, void *priv,
>  				fsize->stepwise.max_height,
>  				fsize->stepwise.step_height);
>  
> -		ctx->max_width = fsize->stepwise.max_width;
> -		ctx->max_height = fsize->stepwise.max_height;
>  		return 0;
>  	}
>  
> 
> 
> >  		return 0;
> >  	}
> >  

[...]