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From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: "sandy.huang" <hjc@rock-chips.com>
Cc: dri-devel@lists.freedesktop.org,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <maxime.ripard@bootlin.com>,
	Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
	Daniel Vetter <daniel@ffwll.ch>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 01/36] drm/fourcc: Add 2 plane YCbCr 10bit format support
Date: Mon, 23 Sep 2019 21:30:49 +0300	[thread overview]
Message-ID: <20190923183049.GR1208@intel.com> (raw)
In-Reply-To: <82664d48-36de-15fd-3b30-a12907e5bfcd@rock-chips.com>

On Mon, Sep 23, 2019 at 06:05:22AM -0700, sandy.huang wrote:
> 
> 在 2019/9/23 上午5:53, Ville Syrjälä 写道:
> > On Mon, Sep 23, 2019 at 08:38:50PM +0800, Sandy Huang wrote:
> >> diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
> >> index 3feeaa3..5fe89e9 100644
> >> --- a/include/uapi/drm/drm_fourcc.h
> >> +++ b/include/uapi/drm/drm_fourcc.h
> >> @@ -266,6 +266,21 @@ extern "C" {
> >>   #define DRM_FORMAT_P016		fourcc_code('P', '0', '1', '6') /* 2x2 subsampled Cr:Cb plane 16 bits per channel */
> >>   
> >>   /*
> >> + * 2 plane YCbCr 10bit
> >> + * index 0 = Y plane, [9:0] Y
> >> + * index 1 = Cr:Cb plane, [19:0] Cr:Cb little endian
> >> + * or
> >> + * index 1 = Cb:Cr plane, [19:0] Cb:Cr little endian
> > What does "little endian" even mean for these?
> 
> It's Inherited from the following define, the difference is 8bit and 10bit.
> /*
>   * 2 plane YCbCr
>   * index 0 = Y plane, [7:0] Y
>   * index 1 = Cr:Cb plane, [15:0] Cr:Cb little endian
>   * or
>   * index 1 = Cb:Cr plane, [15:0] Cb:Cr little endian
>   */
> #define DRM_FORMAT_NV12        fourcc_code('N', 'V', '1', '2') /* 2x2 
> subsampled Cr:Cb plane */
> #define DRM_FORMAT_NV21        fourcc_code('N', 'V', '2', '1') /* 2x2 
> subsampled Cb:Cr plane */
> #define DRM_FORMAT_NV16        fourcc_code('N', 'V', '1', '6') /* 2x1 
> subsampled Cr:Cb plane */
> #define DRM_FORMAT_NV61        fourcc_code('N', 'V', '6', '1') /* 2x1 
> subsampled Cb:Cr plane */
> #define DRM_FORMAT_NV24        fourcc_code('N', 'V', '2', '4') /* 
> non-subsampled Cr:Cb plane */
> #define DRM_FORMAT_NV42        fourcc_code('N', 'V', '4',

Something not aligned to bytes can't have its endianness defined the
same way as these. Just doesn't make sense.

>
> 
> 
> >
> >> + */
> >> +
> >> +#define DRM_FORMAT_NV12_10	fourcc_code('N', 'A', '1', '2') /* 2x2 subsampled Cr:Cb plane */
> >> +#define DRM_FORMAT_NV21_10	fourcc_code('N', 'A', '2', '1') /* 2x2 subsampled Cb:Cr plane */
> >> +#define DRM_FORMAT_NV16_10	fourcc_code('N', 'A', '1', '6') /* 2x1 subsampled Cr:Cb plane */
> >> +#define DRM_FORMAT_NV61_10	fourcc_code('N', 'A', '6', '1') /* 2x1 subsampled Cb:Cr plane */
> >> +#define DRM_FORMAT_NV24_10	fourcc_code('N', 'A', '2', '4') /* non-subsampled Cr:Cb plane */
> >> +#define DRM_FORMAT_NV42_10	fourcc_code('N', 'A', '4', '2') /* non-subsampled Cb:Cr plane */
> >> +
> >> +/*
> >>    * 3 plane YCbCr
> >>    * index 0: Y plane, [7:0] Y
> >>    * index 1: Cb plane, [7:0] Cb
> >> -- 
> >> 2.7.4
> >>
> >>
> >>
> >> _______________________________________________
> >> dri-devel mailing list
> >> dri-devel@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 

-- 
Ville Syrjälä
Intel

  reply	other threads:[~2019-09-23 18:30 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1569242365-182133-1-git-send-email-hjc@rock-chips.com>
2019-09-23 12:38 ` [PATCH 01/36] drm/fourcc: Add 2 plane YCbCr 10bit format support Sandy Huang
2019-09-23 12:53   ` Ville Syrjälä
2019-09-23 13:05     ` sandy.huang
2019-09-23 18:30       ` Ville Syrjälä [this message]
2019-09-24  6:47         ` sandy.huang
2019-09-23 13:06   ` Daniel Vetter
2019-09-24  6:46     ` sandy.huang
2019-09-24  7:00       ` sandy.huang
     [not found]       ` <20190924101200.GA8715@arm.com>
2019-09-25  8:09         ` sandy.huang
2019-09-25 11:23       ` Daniel Vetter
2019-09-23 12:38 ` [PATCH 02/36] drm/rockchip: use bpp instead of cpp for drm_format_info Sandy Huang
2019-09-23 12:38 ` [PATCH 03/36] drm/i915: " Sandy Huang
2019-09-23 12:38 ` [PATCH 04/36] drm: exynos: " Sandy Huang

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