On Monday 25 August 2014 13:38:45 Hans Verkuil wrote: > Hi Philipp, > > I have to think a bit more about the format names, but in the meantime I > have two other suggestions: > > On 08/25/2014 12:33 PM, Philipp Zabel wrote: > > This patch adds an array of V4L2 pixel formats and descriptions that can > > be used by drivers so that each driver doesn't have to provide its own > > slightly different format descriptions for VIDIOC_ENUM_FMT. I've started working on this recently as well, so I can only agree with the idea. > > Each array entry also includes two bits per pixel values (for a single > > line and one for the whole image) that can be used to determine the > > v4l2_pix_format bytesperline and sizeimage values and whether the format > > is planar or compressed. > > > > Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > > --- > > I have started to convert some drivers on a boring train ride, but it > > occurred to me that I probably should get some feedback before carrying > > on with this: > > http://git.pengutronix.de/?p=pza/linux.git;a=shortlog;h=refs/heads/topic/ > > media-pixfmt > > --- > > > > drivers/media/v4l2-core/v4l2-common.c | 488 +++++++++++++++++++++++++++++ > > include/media/v4l2-common.h | 44 +++ > > 2 files changed, 532 insertions(+) > > > > diff --git a/drivers/media/v4l2-core/v4l2-common.c > > b/drivers/media/v4l2-core/v4l2-common.c index ccaa38f..41692df 100644 > > --- a/drivers/media/v4l2-core/v4l2-common.c > > +++ b/drivers/media/v4l2-core/v4l2-common.c > > @@ -533,3 +533,491 @@ void v4l2_get_timestamp(struct timeval *tv) > > > > tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC; > > > > } > > EXPORT_SYMBOL_GPL(v4l2_get_timestamp); > > > > + > > +static const struct v4l2_pixfmt v4l2_pixfmts[] = { > > <snip> > > > +}; > > + > > +const struct v4l2_pixfmt *v4l2_pixfmt_by_fourcc(u32 fourcc) > > +{ > > + int i; > > + > > + for (i = 0; i < ARRAY_SIZE(v4l2_pixfmts); i++) { > > + if (v4l2_pixfmts[i].pixelformat == fourcc) > > + return v4l2_pixfmts + i; > > + } > > + > > + return NULL; > > +} > > +EXPORT_SYMBOL_GPL(v4l2_pixfmt_by_fourcc); > > + > > +int v4l2_fill_fmtdesc(struct v4l2_fmtdesc *f, u32 fourcc) > > +{ > > + const struct v4l2_pixfmt *fmt; > > + > > + fmt = v4l2_pixfmt_by_fourcc(fourcc); > > + if (!fmt) > > + return -EINVAL; > > + > > + strlcpy((char *)f->description, fmt->name, sizeof(f->description)); > > + f->pixelformat = fmt->pixelformat; > > + f->flags = (fmt->bpp_image == 0) ? V4L2_FMT_FLAG_COMPRESSED : 0; > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(v4l2_fill_fmtdesc); > > diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h > > index 48f9748..27b084f 100644 > > --- a/include/media/v4l2-common.h > > +++ b/include/media/v4l2-common.h > > @@ -204,4 +204,48 @@ const struct v4l2_frmsize_discrete > > *v4l2_find_nearest_format(> > > void v4l2_get_timestamp(struct timeval *tv); > > > > +/** > > + * struct v4l2_pixfmt - internal V4L2 pixel format description > > + * @name: format description to be returned by enum_fmt > > + * @pixelformat: v4l2 pixel format fourcc > > + * @bpp_line: bits per pixel, averaged over a line (of the first plane > > + * for planar formats), used to calculate bytesperline > > + * Zero for compressed and macroblock tiled formats. > > + * @bpp_image: bits per pixel, averaged over the whole image. This is > > used to > > + * calculate sizeimage for uncompressed formats. > > + * Zero for compressed formats. > > I would add a 'planes' field as well for use with formats that use > non-contiguous planes. > > > + */ > > +struct v4l2_pixfmt { > > + const char *name; > > + u32 pixelformat; > > + u8 bpp_line; > > + u8 bpp_image; > > +}; > > + > > +const struct v4l2_pixfmt *v4l2_pixfmt_by_fourcc(u32 fourcc); > > +int v4l2_fill_fmtdesc(struct v4l2_fmtdesc *f, u32 fourcc); > > + > > +static inline unsigned int v4l2_bytesperline(const struct v4l2_pixfmt > > *fmt, + unsigned int width) > > +{ > > + return width * fmt->bpp_line / 8; > > Round up: return (width * fmt->bpp_line + 7) / 8; DIV_ROUND_UP(width * fmt->bpp_line, 8) ? > > +} > > + > > +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); > > > +} > > + > > +static inline bool v4l2_pixfmt_is_planar(const struct v4l2_pixfmt *fmt) > > +{ > > + return fmt->bpp_line && (fmt->bpp_line != fmt->bpp_image); > > +} > > + > > +static inline bool v4l2_pixfmt_is_compressed(const struct v4l2_pixfmt > > *fmt) > > +{ > > + return fmt->bpp_image == 0; > > +} > > + > > > > #endif /* V4L2_COMMON_H_ */ -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
