diff mbox series

[v6,2/8] media: v4l: Add definition for Allwinner's MB32-tiled NV12 format

Message ID 20180725100256.22833-3-paul.kocialkowski@bootlin.com (mailing list archive)
State New, archived
Headers show
Series Cedrus driver for the Allwinner Video Engine, using media requests | expand

Commit Message

Paul Kocialkowski July 25, 2018, 10:02 a.m. UTC
This introduces support for Allwinner's MB32-tiled NV12 format, where
each plane is divided into macroblocks of 32x32 pixels. Hence, the size
of each plane has to be aligned to 32 bytes. The pixels inside each
macroblock are coded as they would be if the macroblock was a single
plane, line after line.

The MB32-tiled NV12 format is used by the video engine on Allwinner
platforms: it is the default format for decoded frames (and the only one
available in the oldest supported platforms).

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
---
 Documentation/media/uapi/v4l/pixfmt-reserved.rst | 15 ++++++++++++++-
 drivers/media/v4l2-core/v4l2-ioctl.c             |  1 +
 include/uapi/linux/videodev2.h                   |  1 +
 3 files changed, 16 insertions(+), 1 deletion(-)

Comments

Hans Verkuil Aug. 4, 2018, 11:42 a.m. UTC | #1
On 07/25/2018 12:02 PM, Paul Kocialkowski wrote:
> This introduces support for Allwinner's MB32-tiled NV12 format, where
> each plane is divided into macroblocks of 32x32 pixels. Hence, the size
> of each plane has to be aligned to 32 bytes. The pixels inside each
> macroblock are coded as they would be if the macroblock was a single
> plane, line after line.
> 
> The MB32-tiled NV12 format is used by the video engine on Allwinner
> platforms: it is the default format for decoded frames (and the only one
> available in the oldest supported platforms).
> 
> Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> ---
>  Documentation/media/uapi/v4l/pixfmt-reserved.rst | 15 ++++++++++++++-
>  drivers/media/v4l2-core/v4l2-ioctl.c             |  1 +
>  include/uapi/linux/videodev2.h                   |  1 +
>  3 files changed, 16 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
> index 38af1472a4b4..9a68b6a787bf 100644
> --- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst
> +++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
> @@ -243,7 +243,20 @@ please make a proposal on the linux-media mailing list.
>  	It is an opaque intermediate format and the MDP hardware must be
>  	used to convert ``V4L2_PIX_FMT_MT21C`` to ``V4L2_PIX_FMT_NV12M``,
>  	``V4L2_PIX_FMT_YUV420M`` or ``V4L2_PIX_FMT_YVU420``.
> -
> +    * .. _V4L2-PIX-FMT-MB32-NV12:
> +
> +      - ``V4L2_PIX_FMT_MB32_NV12``
> +      - 'MN12'
> +      - Two-planar NV12-based format used by the Allwinner video engine
> +        hardware, with 32x32 tiles for the luminance plane and 32x64 tiles
> +        for the chrominance plane. Each tile is a linear pixel data
> +        representation within its own bounds. Each tile follows the previous
> +        one linearly (as in, from left to right, top to bottom).

as in, -> as in:

> +
> +        The frame dimensions are aligned to match an integer number of
> +        tiles, resulting in 32-aligned resolutions for the luminance plane
> +        and 16-aligned resolutions for the chrominance plane (with 2x2
> +        subsampling).
>  
>  .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
>  
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 68e914b83a03..7e1c200de10d 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1331,6 +1331,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
>  		case V4L2_PIX_FMT_SE401:	descr = "GSPCA SE401"; break;
>  		case V4L2_PIX_FMT_S5C_UYVY_JPG:	descr = "S5C73MX interleaved UYVY/JPEG"; break;
>  		case V4L2_PIX_FMT_MT21C:	descr = "Mediatek Compressed Format"; break;
> +		case V4L2_PIX_FMT_MB32_NV12:	descr = "Allwinner tiled NV12 format"; break;

"Allwinner Tiled NV12 Format"

If it is Allwinner specific, then that should be in the PIX_FMT name as well:
something like V4L2_PIX_FMT_ALLWINNER_MB32_NV12 or perhaps SUNXI_MB32_NV12.

On the other hand, you could also see this as a variant of e.g. V4L2_PIX_FMT_NV12MT
or V4L2_PIX_FMT_NV12MT_16X16. In that case it is not necessarily Allwinner specific
since other devices might choose this format. You can go either way, as long
as it is consistent.

>  		default:
>  			WARN(1, "Unknown pixelformat 0x%08x\n", fmt->pixelformat);
>  			if (fmt->description[0])
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index d171361ed9b3..453d27142e31 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -670,6 +670,7 @@ struct v4l2_pix_format {
>  #define V4L2_PIX_FMT_Z16      v4l2_fourcc('Z', '1', '6', ' ') /* Depth data 16-bit */
>  #define V4L2_PIX_FMT_MT21C    v4l2_fourcc('M', 'T', '2', '1') /* Mediatek compressed block mode  */
>  #define V4L2_PIX_FMT_INZI     v4l2_fourcc('I', 'N', 'Z', 'I') /* Intel Planar Greyscale 10-bit and Depth 16-bit */
> +#define V4L2_PIX_FMT_MB32_NV12 v4l2_fourcc('M', 'N', '1', '2') /* Allwinner tiled NV12 format */
>  
>  /* 10bit raw bayer packed, 32 bytes for every 25 pixels, last LSB 6 bits unused */
>  #define V4L2_PIX_FMT_IPU3_SBGGR10	v4l2_fourcc('i', 'p', '3', 'b') /* IPU3 packed 10-bit BGGR bayer */
> 

Regards,

	Hans
Paul Kocialkowski Aug. 7, 2018, 4:40 p.m. UTC | #2
Hi,

On Sat, 2018-08-04 at 13:42 +0200, Hans Verkuil wrote:
> On 07/25/2018 12:02 PM, Paul Kocialkowski wrote:
> > This introduces support for Allwinner's MB32-tiled NV12 format, where
> > each plane is divided into macroblocks of 32x32 pixels. Hence, the size
> > of each plane has to be aligned to 32 bytes. The pixels inside each
> > macroblock are coded as they would be if the macroblock was a single
> > plane, line after line.
> > 
> > The MB32-tiled NV12 format is used by the video engine on Allwinner
> > platforms: it is the default format for decoded frames (and the only one
> > available in the oldest supported platforms).
> > 
> > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
> > ---
> >  Documentation/media/uapi/v4l/pixfmt-reserved.rst | 15 ++++++++++++++-
> >  drivers/media/v4l2-core/v4l2-ioctl.c             |  1 +
> >  include/uapi/linux/videodev2.h                   |  1 +
> >  3 files changed, 16 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
> > index 38af1472a4b4..9a68b6a787bf 100644
> > --- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst
> > +++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
> > @@ -243,7 +243,20 @@ please make a proposal on the linux-media mailing list.
> >  	It is an opaque intermediate format and the MDP hardware must be
> >  	used to convert ``V4L2_PIX_FMT_MT21C`` to ``V4L2_PIX_FMT_NV12M``,
> >  	``V4L2_PIX_FMT_YUV420M`` or ``V4L2_PIX_FMT_YVU420``.
> > -
> > +    * .. _V4L2-PIX-FMT-MB32-NV12:
> > +
> > +      - ``V4L2_PIX_FMT_MB32_NV12``
> > +      - 'MN12'
> > +      - Two-planar NV12-based format used by the Allwinner video engine
> > +        hardware, with 32x32 tiles for the luminance plane and 32x64 tiles
> > +        for the chrominance plane. Each tile is a linear pixel data
> > +        representation within its own bounds. Each tile follows the previous
> > +        one linearly (as in, from left to right, top to bottom).
> 
> as in, -> as in:

Thanks!

> > +
> > +        The frame dimensions are aligned to match an integer number of
> > +        tiles, resulting in 32-aligned resolutions for the luminance plane
> > +        and 16-aligned resolutions for the chrominance plane (with 2x2
> > +        subsampling).
> >  
> >  .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
> >  
> > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> > index 68e914b83a03..7e1c200de10d 100644
> > --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> > @@ -1331,6 +1331,7 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
> >  		case V4L2_PIX_FMT_SE401:	descr = "GSPCA SE401"; break;
> >  		case V4L2_PIX_FMT_S5C_UYVY_JPG:	descr = "S5C73MX interleaved UYVY/JPEG"; break;
> >  		case V4L2_PIX_FMT_MT21C:	descr = "Mediatek Compressed Format"; break;
> > +		case V4L2_PIX_FMT_MB32_NV12:	descr = "Allwinner tiled NV12 format"; break;
> 
> "Allwinner Tiled NV12 Format"
> 
> If it is Allwinner specific, then that should be in the PIX_FMT name as well:
> something like V4L2_PIX_FMT_ALLWINNER_MB32_NV12 or perhaps SUNXI_MB32_NV12.
> 
> On the other hand, you could also see this as a variant of e.g. V4L2_PIX_FMT_NV12MT
> or V4L2_PIX_FMT_NV12MT_16X16. In that case it is not necessarily Allwinner specific
> since other devices might choose this format. You can go either way, as long
> as it is consistent.

I think it is fair to say that the format is Allwinner-specific and
unlikely to be found elsewhere. It is not actually very well described
by "MB32" since the chroma tiles have a different pixel size than the
luma tiles (16x64).

It would probably be clearer to just call the format:
V4L2_PIX_FMT_SUNXI_TILED_NV12

Cheers,

Paul

> >  		default:
> >  			WARN(1, "Unknown pixelformat 0x%08x\n", fmt->pixelformat);
> >  			if (fmt->description[0])
> > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> > index d171361ed9b3..453d27142e31 100644
> > --- a/include/uapi/linux/videodev2.h
> > +++ b/include/uapi/linux/videodev2.h
> > @@ -670,6 +670,7 @@ struct v4l2_pix_format {
> >  #define V4L2_PIX_FMT_Z16      v4l2_fourcc('Z', '1', '6', ' ') /* Depth data 16-bit */
> >  #define V4L2_PIX_FMT_MT21C    v4l2_fourcc('M', 'T', '2', '1') /* Mediatek compressed block mode  */
> >  #define V4L2_PIX_FMT_INZI     v4l2_fourcc('I', 'N', 'Z', 'I') /* Intel Planar Greyscale 10-bit and Depth 16-bit */
> > +#define V4L2_PIX_FMT_MB32_NV12 v4l2_fourcc('M', 'N', '1', '2') /* Allwinner tiled NV12 format */
> >  
> >  /* 10bit raw bayer packed, 32 bytes for every 25 pixels, last LSB 6 bits unused */
> >  #define V4L2_PIX_FMT_IPU3_SBGGR10	v4l2_fourcc('i', 'p', '3', 'b') /* IPU3 packed 10-bit BGGR bayer */
> > 
> 
> Regards,
> 
> 	Hans
diff mbox series

Patch

diff --git a/Documentation/media/uapi/v4l/pixfmt-reserved.rst b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
index 38af1472a4b4..9a68b6a787bf 100644
--- a/Documentation/media/uapi/v4l/pixfmt-reserved.rst
+++ b/Documentation/media/uapi/v4l/pixfmt-reserved.rst
@@ -243,7 +243,20 @@  please make a proposal on the linux-media mailing list.
 	It is an opaque intermediate format and the MDP hardware must be
 	used to convert ``V4L2_PIX_FMT_MT21C`` to ``V4L2_PIX_FMT_NV12M``,
 	``V4L2_PIX_FMT_YUV420M`` or ``V4L2_PIX_FMT_YVU420``.
-
+    * .. _V4L2-PIX-FMT-MB32-NV12:
+
+      - ``V4L2_PIX_FMT_MB32_NV12``
+      - 'MN12'
+      - Two-planar NV12-based format used by the Allwinner video engine
+        hardware, with 32x32 tiles for the luminance plane and 32x64 tiles
+        for the chrominance plane. Each tile is a linear pixel data
+        representation within its own bounds. Each tile follows the previous
+        one linearly (as in, from left to right, top to bottom).
+
+        The frame dimensions are aligned to match an integer number of
+        tiles, resulting in 32-aligned resolutions for the luminance plane
+        and 16-aligned resolutions for the chrominance plane (with 2x2
+        subsampling).
 
 .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
 
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 68e914b83a03..7e1c200de10d 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1331,6 +1331,7 @@  static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 		case V4L2_PIX_FMT_SE401:	descr = "GSPCA SE401"; break;
 		case V4L2_PIX_FMT_S5C_UYVY_JPG:	descr = "S5C73MX interleaved UYVY/JPEG"; break;
 		case V4L2_PIX_FMT_MT21C:	descr = "Mediatek Compressed Format"; break;
+		case V4L2_PIX_FMT_MB32_NV12:	descr = "Allwinner tiled NV12 format"; break;
 		default:
 			WARN(1, "Unknown pixelformat 0x%08x\n", fmt->pixelformat);
 			if (fmt->description[0])
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index d171361ed9b3..453d27142e31 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -670,6 +670,7 @@  struct v4l2_pix_format {
 #define V4L2_PIX_FMT_Z16      v4l2_fourcc('Z', '1', '6', ' ') /* Depth data 16-bit */
 #define V4L2_PIX_FMT_MT21C    v4l2_fourcc('M', 'T', '2', '1') /* Mediatek compressed block mode  */
 #define V4L2_PIX_FMT_INZI     v4l2_fourcc('I', 'N', 'Z', 'I') /* Intel Planar Greyscale 10-bit and Depth 16-bit */
+#define V4L2_PIX_FMT_MB32_NV12 v4l2_fourcc('M', 'N', '1', '2') /* Allwinner tiled NV12 format */
 
 /* 10bit raw bayer packed, 32 bytes for every 25 pixels, last LSB 6 bits unused */
 #define V4L2_PIX_FMT_IPU3_SBGGR10	v4l2_fourcc('i', 'p', '3', 'b') /* IPU3 packed 10-bit BGGR bayer */