[PATCH v2 12/25] media: atmel: atmel-isc-base: fix bytesperline value for planar formats

Jacopo Mondi jacopo at jmondi.org
Mon Dec 6 08:38:15 PST 2021


Hi Eugen

On Fri, Nov 12, 2021 at 04:24:56PM +0200, Eugen Hristev wrote:
> The bytesperline field of the pixfmt should be only for the first plane
> in case of planar formats like YUV420 or YUV422.
> The bytesperline is used by the driver to compute the framesize.
> We have to report a different bpp (bytes per pixel) to v4l2 in bytesperline
> than the actual bpp.
> For example for YUV420, the real bpp is 12, but the first plane has only
> 8 bpp. Thus we report a bytesperline 8*width instead of 12*width.
> However, for real framezise we have to compute 12*width*height.
> Hence added a new variable to hold this information and to correctly
> compute the frame size.

Using single planar API for multiplanar format is really painful :(

>
> Signed-off-by: Eugen Hristev <eugen.hristev at microchip.com>
> ---
>  drivers/media/platform/atmel/atmel-isc-base.c | 19 +++++++++++++++++--
>  drivers/media/platform/atmel/atmel-isc.h      |  4 ++++
>  2 files changed, 21 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
> index 2cb8446ff90c..d0542b97a391 100644
> --- a/drivers/media/platform/atmel/atmel-isc-base.c
> +++ b/drivers/media/platform/atmel/atmel-isc-base.c
> @@ -654,6 +654,7 @@ static int isc_try_configure_rlp_dma(struct isc_device *isc, bool direct_dump)
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED8;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 8;
> +		isc->try_config.bpp_v4l2 = 8;
>  		break;
>  	case V4L2_PIX_FMT_SBGGR10:
>  	case V4L2_PIX_FMT_SGBRG10:
> @@ -663,6 +664,7 @@ static int isc_try_configure_rlp_dma(struct isc_device *isc, bool direct_dump)
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED16;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_SBGGR12:
>  	case V4L2_PIX_FMT_SGBRG12:
> @@ -672,24 +674,28 @@ static int isc_try_configure_rlp_dma(struct isc_device *isc, bool direct_dump)
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED16;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_RGB565:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_RGB565;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED16;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_ARGB444:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_ARGB444;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED16;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_ARGB555:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_ARGB555;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED16;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_ABGR32:
>  	case V4L2_PIX_FMT_XBGR32:
> @@ -697,42 +703,49 @@ static int isc_try_configure_rlp_dma(struct isc_device *isc, bool direct_dump)
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED32;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 32;
> +		isc->try_config.bpp_v4l2 = 32;
>  		break;
>  	case V4L2_PIX_FMT_YUV420:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_YYCC;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_YC420P;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PLANAR;
>  		isc->try_config.bpp = 12;
> +		isc->try_config.bpp_v4l2 = 8; /* only first plane */
>  		break;
>  	case V4L2_PIX_FMT_YUV422P:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_YYCC;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_YC422P;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PLANAR;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 8; /* only first plane */

This could have also been described with by adding to the format a
subsampling factor for the CbCr plane and fixing the bpp to 8 as it
describes the first plane. In this way you could avoid setting
bpp_v4l2 for all formats that do not need it.

Something like a simple subsampling multiplier would do for planar YUV
formats, more complicated schemes would probably needed for other
formats.

                420:
                bpp = 8
                subsampling = 12
                bytesperline = w * bpp  >> 3
                sizeimage = w * h * subsampling >> 3

                422:
                bpp = 8
                subsampling = 16
                bytesperline = w * bpp  >> 3
                sizeimage = w * h * subsampling >> 3

                444:
                bpp = 8
                subsampling = 24
                bytesperline = w * bpp  >> 3
                sizeimage = w * h * subsampling >> 3

You would anyway need to set subsampling = 8 in other formats or
either
        sizeimage = w * h * (subsampling ? subsampling : 8) >> 3

which is not super nice ;)

As you wish though, this is driver code, so anything goes

Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
   j




>  		break;
>  	case V4L2_PIX_FMT_YUYV:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_YCYC | ISC_RLP_CFG_YMODE_YUYV;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED32;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_UYVY:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_YCYC | ISC_RLP_CFG_YMODE_UYVY;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED32;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_VYUY:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_YCYC | ISC_RLP_CFG_YMODE_VYUY;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED32;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	case V4L2_PIX_FMT_GREY:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_DATY8;
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED8;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 8;
> +		isc->try_config.bpp_v4l2 = 8;
>  		break;
>  	case V4L2_PIX_FMT_Y16:
>  		isc->try_config.rlp_cfg_mode = ISC_RLP_CFG_MODE_DATY10 | ISC_RLP_CFG_LSH;
> @@ -742,6 +755,7 @@ static int isc_try_configure_rlp_dma(struct isc_device *isc, bool direct_dump)
>  		isc->try_config.dcfg_imode = ISC_DCFG_IMODE_PACKED16;
>  		isc->try_config.dctrl_dview = ISC_DCTRL_DVIEW_PACKED;
>  		isc->try_config.bpp = 16;
> +		isc->try_config.bpp_v4l2 = 16;
>  		break;
>  	default:
>  		return -EINVAL;
> @@ -990,8 +1004,9 @@ static int isc_try_fmt(struct isc_device *isc, struct v4l2_format *f,
>  		pixfmt->height = isc->max_height;
>
>  	pixfmt->field = V4L2_FIELD_NONE;
> -	pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp) >> 3;
> -	pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
> +	pixfmt->bytesperline = (pixfmt->width * isc->try_config.bpp_v4l2) >> 3;
> +	pixfmt->sizeimage = ((pixfmt->width * isc->try_config.bpp) >> 3) *
> +			     pixfmt->height;
>
>  	if (code)
>  		*code = mbus_code;
> diff --git a/drivers/media/platform/atmel/atmel-isc.h b/drivers/media/platform/atmel/atmel-isc.h
> index 32448ccfc636..07fa6dbf8460 100644
> --- a/drivers/media/platform/atmel/atmel-isc.h
> +++ b/drivers/media/platform/atmel/atmel-isc.h
> @@ -102,6 +102,9 @@ struct isc_format {
>  			configuration.
>   * @fourcc:		Fourcc code for this format.
>   * @bpp:		Bytes per pixel in the current format.
> + * @bpp_v4l2:		Bytes per pixel in the current format, for v4l2.
> +			This differs from 'bpp' in the sense that in planar
> +			formats, it refers only to the first plane.
>   * @rlp_cfg_mode:	Configuration of the RLP (rounding, limiting packaging)
>   * @dcfg_imode:		Configuration of the input of the DMA module
>   * @dctrl_dview:	Configuration of the output of the DMA module
> @@ -112,6 +115,7 @@ struct fmt_config {
>
>  	u32			fourcc;
>  	u8			bpp;
> +	u8			bpp_v4l2;
>
>  	u32			rlp_cfg_mode;
>  	u32			dcfg_imode;
> --
> 2.25.1
>



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