Hi Guennadi,
On Thursday 26 January 2012 16:59:23 Guennadi Liakhovetski wrote:
> On Wed, 25 Jan 2012, Laurent Pinchart wrote:
> > The function returns the minimum size of an image for a given number of
> > bytes per line (as per the V4L2 specification), width and format.
> >
> > Signed-off-by: Laurent Pinchart <[email protected]>
> > ---
> >
> > drivers/media/video/soc_mediabus.c | 18 ++++++++++++++++++
> > include/media/soc_mediabus.h | 2 ++
> > 2 files changed, 20 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/media/video/soc_mediabus.c
> > b/drivers/media/video/soc_mediabus.c index a707314..3f47774 100644
> > --- a/drivers/media/video/soc_mediabus.c
> > +++ b/drivers/media/video/soc_mediabus.c
> > @@ -397,6 +397,24 @@ s32 soc_mbus_bytes_per_line(u32 width, const struct
> > soc_mbus_pixelfmt *mf)
> >
> > }
> > EXPORT_SYMBOL(soc_mbus_bytes_per_line);
> >
> > +s32 soc_mbus_image_size(u32 bytes_per_line, u32 height,
> > + const struct soc_mbus_pixelfmt *mf)
>
> What do you think about making mf the first parameter? :-)
I copied the parameters order from soc_mbus_bytes_per_line(). I like having
the format first, so I'll change that for soc_mbus_image_size().
> > +{
> > + if (mf->layout == SOC_MBUS_LAYOUT_PACKED)
> > + return bytes_per_line * height;
> > +
> > + switch (mf->packing) {
> > + case SOC_MBUS_PACKING_2X8_PADHI:
> > + case SOC_MBUS_PACKING_2X8_PADLO:
> > + return bytes_per_line * height * 2;
> > + case SOC_MBUS_PACKING_1_5X8:
> > + return bytes_per_line * height * 3 / 2;
>
> Hm, confused. Why have you decided to calculate the size based on packing
> and not on layout?
Because planar YUV 4:2:0, 4:2:2 and 4:4:4 formats would all use
SOC_MBUS_LAYOUT_Y_U_V. I could create SOC_MBUS_LAYOUT_2Y_U_V and
SOC_MBUS_LAYOUT_4Y_U_V instead. As existing planar formats all have a
bits_per_sample value of 8, mf->packing was already used by
soc_mbus_bytes_per_line() (before my patches) to compute the total line size
in bytes, so I thought it made sense to reuse it in soc_mbus_image_size().
--
Regards,
Laurent Pinchart
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