Hi Geert,

On Monday 29 August 2011 13:20:44 Geert Uytterhoeven wrote:

On Mon, Aug 29, 2011 at 13:08, Laurent Pinchart wrote:

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On Monday 29 August 2011 13:04:15 Geert Uytterhoeven wrote:

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On Mon, Aug 29, 2011 at 12:09, Laurent Pinchart wrote:

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On Monday 29 August 2011 11:36:07 Geert Uytterhoeven wrote:

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On Mon, Aug 29, 2011 at 10:50, Laurent Pinchart wrote:

[...]

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If my understanding is now correct, a V4L2 planar YUV type where Y, U
and V components are stored in separate byte-oriented planes, with
each plane storing Y, U or V components packed (such as
http://linuxtv.org/downloads/v4l- dvb-apis/V4L2-PIX-FMT-YUV422P.html),
would be of neither FB_TYPE_PLANES nor FB_TYPE_PACKED. The same would
be true for an RGB format where each component is stored in a
separate plane with each plane sotring R, G or B packed.

Indeed. Currently this cannot be represented.

Good, at least I now understand the situation :-)

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For ideas from the past, see e.g.
http://comments.gmane.org/gmane.linux.fbdev.devel/10951.

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If the above is correct, what FB_TYPE_* should a driver report when
using FB_VISUAL_FOURCC with V4L2_PIX_FMT_YUV422P
(http://linuxtv.org/downloads/v4l- dvb-apis/V4L2-PIX-FMT-YUV422P.html)
or V4L2_PIX_FMT_NV12
(http://linuxtv.org/downloads/v4l-dvb-apis/re25.html) for instance ?

We need new types for those. Or always use FOURCC for them.

My proposal currently defined FB_VISUAL_FOURCC. What about adding
FB_TYPE_FOURCC as well ?

That may make sense.
When will the driver report FB_{TYPE,VISUAL}_FOURCC?
  - When using a mode that cannot be represented in the legacy way,

Definitely.

  - But what with modes that can be represented? Legacy software cannot
    handle FB_{TYPE,VISUAL}_FOURCC.

My idea was to use FB_{TYPE,VISUAL}_FOURCC only when the mode is configured 
using the FOURCC API. If FBIOPUT_VSCREENINFO is called with a non-FOURCC 
format, the driver will report non-FOURCC types and visuals.

-- 
Regards,

Laurent Pinchart