Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
Hi Guennadi, Am Dienstag, den 26.08.2014, 22:18 +0200 schrieb Guennadi Liakhovetski: > Hi Philipp, > > On Mon, 25 Aug 2014, 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. > > In case you missed it, soc-camera is doing something rather similar along > the lines of: > > drivers/media/platform/soc_camera/soc_mediabus.c > include/media/soc_mediabus.h > > Feel free to re-use. thank you for the pointer. It is unfortunate that there is a bit of overlap in the names, but not much in the rest of the information. I don't see how the data could be reused in a meaningful way, but maybe I should try to match the patterns. I like the idea of soc_mbus_find_fmtdesc being called with a driver specific lookup array. Although that currently causes drivers to again duplicate all the names, it side-steps the issue of a linear lookup in a large global array. Maybe a helper to fill this driver specific array from the global array would be a good idea for consistency? What is the reason for the separation between struct soc_mbus_lookup and struct soc_mbus pixelformat (as opposed to including enum v4l2_mbus_pixelcode in struct soc_mbus_pixelformat directly)? regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
Hi Philipp,
On Mon, 25 Aug 2014, 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.
In case you missed it, soc-camera is doing something rather similar along
the lines of:
drivers/media/platform/soc_camera/soc_mediabus.c
include/media/soc_mediabus.h
Feel free to re-use.
Thanks
Guennadi
>
> 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
> ---
> 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[] = {
> + {
> + .name = "8-bit RGB 3-3-2",
> + .pixelformat = V4L2_PIX_FMT_RGB332,
> + .bpp_line = 8,
> + .bpp_image = 8,
> + }, {
> + .name = "16-bit RGB 4-4-4",
> + .pixelformat = V4L2_PIX_FMT_RGB444,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit ARGB 4-4-4-4",
> + .pixelformat = V4L2_PIX_FMT_ARGB444,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit XRGB 4-4-4-4",
> + .pixelformat = V4L2_PIX_FMT_XRGB444,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit RGB 5-5-5",
> + .pixelformat = V4L2_PIX_FMT_RGB555,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit ARGB 1-5-5-5",
> + .pixelformat = V4L2_PIX_FMT_ARGB555,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit XRGB 1-5-5-5",
> + .pixelformat = V4L2_PIX_FMT_XRGB555,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit RGB 5-6-5",
> + .pixelformat = V4L2_PIX_FMT_RGB565,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit RGB 5-5-5 BE",
> + .pixelformat = V4L2_PIX_FMT_RGB555X,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "16-bit RGB 5-6-5 BE",
> + .pixelformat = V4L2_PIX_FMT_RGB565X,
> + .bpp_line = 16,
> + .bpp_image = 16,
> + }, {
> + .name = "18-bit BGR 6-6-6",
> + .pixelformat = V4L2_PIX_FMT_BGR666,
> + .bpp_line = 18,
> + .bpp_image = 18,
> + }, {
> + .name = "24-bit BGR 8-8-8",
> + .pixelformat = V4L2_PIX_FMT_BGR24,
> + .bpp_line = 24,
> + .bpp_image = 24,
> + }, {
> + .name = "24-bit RGB 8-8-8",
> + .pixelformat = V4L2_PIX_FMT_RGB24,
> + .bpp_line = 24,
> + .bpp_image = 24,
> + }, {
> + .name = "32-bit BGR 8-8-8-8",
> + .pixelformat = V4L2_PIX_FMT_BGR32,
> + .bpp_line = 32,
> + .bpp_image = 32,
> + }, {
> + .name = "32-bit BGRA 8-8-8-8",
> + .pixelformat = V4L2_PIX_FMT_ABGR32,
> + .bpp_line = 32,
> + .bpp_image = 32,
> + }, {
> + .name = "32-bit BGRX 8-8-8-8",
> + .pixelformat = V4L2_PIX_FMT_XBGR32,
> + .bpp_line = 32,
> + .bpp_image = 32,
> + }, {
> + .name = "32-bit RGB 8-8-8-8",
> + .pixelformat = V4L2_PIX_FMT_RGB32,
> + .bpp_line = 32,
> + .bpp_image = 32,
> + }, {
> + .name = "32-bit ARGB 8-8-8-8",
> + .pixelformat = V4L2_PIX_FMT_ARGB32,
> + .bpp_line = 32,
> + .bpp_image = 32,
> + }, {
> + .name = "32-bit XRGB 8-8-8-8",
> + .pixelformat = V4L2_PIX_FMT_XRGB32,
> + .bpp_line = 32,
> + .bpp_image = 32,
> + }, {
> +
Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
Hi Laurent, Am Montag, den 25.08.2014, 17:47 +0200 schrieb Laurent Pinchart: > > 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? > > That sounds sensible to me, provided it would be used by drivers of course. I > wouldn't remove v4l2_bytesperline() and v4l2_sizeimage(), as the values might > be needed by drivers in places where a v4l2_pix_format structure isn't > available. I think about four of the drivers I've looked at so far could use such a function, but it probably won't be useful for the majority. > > Also, is anybody bothered by the v4l2_pix_format / v4l2_pixfmt > > similarity in name? > > How about renaming v4l2_pixfmt to v4l2_pix_format_info ? Thanks, but v4l2_pix_format is a userspace API structure. I fear renaming v4l2_pixfmt to v4l2_pix_format_anything would rather strengthen that association, while I'd like to achieve the opposite. regards Philipp -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
Hi Philipp,
On Monday 25 August 2014 17:41:17 Philipp Zabel wrote:
> 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 ...
Oops, I've missed that subtle difference, sorry.
> >> 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?
That sounds sensible to me, provided it would be used by drivers of course. I
wouldn't remove v4l2_bytesperline() and v4l2_sizeimage(), as the values might
be needed by drivers in places where a v4l2_pix_format structure isn't
available.
> Also, is anybody bothered by the v4l2_pix_format / v4l2_pixfmt
> similarity in name?
How about renaming v4l2_pixfmt to v4l2_pix_format_info ?
--
Regards,
Laurent Pinchart
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Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
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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Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
On Monday 25 August 2014 14:50:53 Philipp Zabel wrote:
> Hi Hans,
>
> Am Montag, den 25.08.2014, 13:38 +0200 schrieb Hans Verkuil:
> > Hi Philipp,
> >
> > I have to think a bit more about the format names, but in the meantime I
> > have
> > two other suggestions:
> Thank you, I haven't spent much thought about the actual descriptions
> yet. Most are just transcribed from the comments in videodev2.h without
> looking at the names used in the drivers.
>
> [...]
>
> > > +/**
> > > + * 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.
>
> Good point, I'll add that.
>
> [...]
>
> > > +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;
>
> Right, I should use DIV_ROUND_UP(width * fmt->bpp_line, 8) here.
>
> > > +}
> > > +
> > > +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) ?
> 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);
> } 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 ?
--
Regards,
Laurent Pinchart
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Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
Hi Hans,
Am Montag, den 25.08.2014, 13:38 +0200 schrieb Hans Verkuil:
> Hi Philipp,
>
> I have to think a bit more about the format names, but in the meantime I have
> two other suggestions:
Thank you, I haven't spent much thought about the actual descriptions
yet. Most are just transcribed from the comments in videodev2.h without
looking at the names used in the drivers.
[...]
> > +/**
> > + * 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.
Good point, I'll add that.
[...]
> > +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;
Right, I should use DIV_ROUND_UP(width * fmt->bpp_line, 8) here.
> > +}
> > +
> > +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)
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);
} else {
/* we know that v4l2_bytesperline doesn't round for planar */
return height * width * fmt->bpp_image / 8;
}
regards
Philipp
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Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
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
> > ---
> > 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[] = {
>
>
>
> > +};
> > +
> > +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 unsubsc
Re: [RFC] [media] v4l2: add V4L2 pixel format array and helper functions
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.
>
> 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
> ---
> 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[] = {
> +};
> +
> +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;
> +}
> +
> +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,
Hans
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