Hi Laurent,
Am Montag, den 25.08.2014, 17:13 +0200 schrieb Laurent Pinchart:
[...]
> > > > +static inline unsigned int v4l2_sizeimage(const struct v4l2_pixfmt
> > > > *fmt,
> > > > + unsigned int width,
> > > > + unsigned int height)
> > > > +{
> > > > + return width * height * fmt->bpp_image / 8;
> > >
> > > Ditto: return height * v4l2_bytesperline(fmt, width);
> >
> > I can't use v4l2_bytesperline because that might be zero for macroblock
> > tiled formats and uses the wrong bpp value for planar formats with
> > subsampled chroma.
> >
> > This nearly works:
> > return height * DIV_ROUND_UP(width * fmt->bpp_image, 8)
>
> Isn't that exactly height * v4l2_bytesperline(fmt, width) ?
Only if bpp_image == bpp_line ...
> > For the planar 4:2:0 subsampled formats and Y41P (bpp_image == 12),
> > width has to be even, so that is ok.
> > Most other formats have a bpp_image that is divisible by 8, but there
> > are the 4:1:0 subsampled formats (bpp_image == 9). Those would round up
> > width to a multiple of eight, even though it only has to be a multiple
> > of four. I'd fall back to:
> >
> > if (fmt->bpp_image == fmt->bpp_line) {
> > return height * DIV_ROUND_UP(width * fmt->bpp_image, 8);
... as is the case here. I'll use v4l2_bytesperline, then.
> > } else {
> > /* we know that v4l2_bytesperline doesn't round for planar */
> > return height * width * fmt->bpp_image / 8;
> > }
>
> Isn't that growing slightly too big for an inline function ?
Yes, I think this is slightly over the edge. Is room for a function to
accompany the preexisting v4l2_fill_pix_format (say,
v4l2_fill_pix_format_size) to set both the bytesperline and sizeimage
values in a struct v4l2_pix_format?
Also, is anybody bothered by the v4l2_pix_format / v4l2_pixfmt
similarity in name?
regards
Philipp
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