Re: [PATCH] libv4lconvert: by default, offer the original format to the client
Em Fri, 10 Mar 2017 17:00:59 -0800
Troy Kisky escreveu:
> On 3/10/2017 12:53 PM, Mauro Carvalho Chehab wrote:
> > The libv4lconvert part of libv4l was meant to provide a common
> > place to handle weird proprietary formats. With time, we also
> > added support to other standard formats, in order to help
> > V4L2 applications that are not performance sensitive to support
> > all V4L2 formats.
> >
> > Yet, the hole idea is to let userspace to decide to implement
> > their own format conversion code when it needs either more
> > performance or more quality than what libv4lconvert provides.
> >
> > In other words, applications should have the right to decide
> > between using a libv4lconvert emulated format or to implement
> > the decoding themselves for non-proprietary formats,
> > as this may have significative performance impact.
> >
> > At the application side, deciding between them is just a matter
> > of looking at the V4L2_FMT_FLAG_EMULATED flag.
> >
> > Yet, we don't want to have a miriad of format converters
> > everywhere for the proprietary formats, like V4L2_PIX_FMT_KONICA420,
> > V4L2_PIX_FMT_SPCA501, etc. So, let's offer only the emulated
> > variant for those weird stuff.
> >
> > So, this patch changes the libv4lconvert behavior, for
> > all non-proprietary formats, including Bayer, to offer both
> > the original format and the emulated ones.
> >
> > Signed-off-by: Mauro Carvalho Chehab
> > ---
> > lib/libv4lconvert/libv4lconvert.c | 17 -
> > 1 file changed, 8 insertions(+), 9 deletions(-)
> >
> > diff --git a/lib/libv4lconvert/libv4lconvert.c
> > b/lib/libv4lconvert/libv4lconvert.c
> > index da718918b030..d87d6b91a838 100644
> > --- a/lib/libv4lconvert/libv4lconvert.c
> > +++ b/lib/libv4lconvert/libv4lconvert.c
> > @@ -118,10 +118,10 @@ static const struct v4lconvert_pixfmt
> > supported_src_pixfmts[] = {
> > { V4L2_PIX_FMT_OV511,0, 7, 7, 1 },
> > { V4L2_PIX_FMT_OV518,0, 7, 7, 1 },
> > /* uncompressed bayer */
> > - { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 1 },
> > - { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 1 },
> > - { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 1 },
> > - { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 1 },
> > + { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 0 },
> > + { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 0 },
> > + { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 0 },
> > + { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 0 },
> > { V4L2_PIX_FMT_STV0680, 8, 8, 8, 1 },
> > /* compressed bayer */
> > { V4L2_PIX_FMT_SPCA561, 0, 9, 9, 1 },
> > @@ -178,7 +178,7 @@ struct v4lconvert_data
> > *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri
> > /* This keeps tracks of devices which have only formats for which apps
> >most likely will need conversion and we can thus safely add software
> >processing controls without a performance impact. */
>
>
> The bottom part seems unwanted.
> Before, if any source format did not need conversion then
> always_needs_conversion = 0
> else always_needs_conversion = 1
>
> Now
> if any source format needs conversion then always_needs_conversion = 1
> else always_needs_conversion = 0
Hmm... you're right. I dropped that part at "PATH v2".
I also added a patch improving the documentation about this logic,
with is not too clear, IMHO.
Thanks,
Mauro
Re: [PATCH] libv4lconvert: by default, offer the original format to the client
On 3/10/2017 12:53 PM, Mauro Carvalho Chehab wrote:
> The libv4lconvert part of libv4l was meant to provide a common
> place to handle weird proprietary formats. With time, we also
> added support to other standard formats, in order to help
> V4L2 applications that are not performance sensitive to support
> all V4L2 formats.
>
> Yet, the hole idea is to let userspace to decide to implement
> their own format conversion code when it needs either more
> performance or more quality than what libv4lconvert provides.
>
> In other words, applications should have the right to decide
> between using a libv4lconvert emulated format or to implement
> the decoding themselves for non-proprietary formats,
> as this may have significative performance impact.
>
> At the application side, deciding between them is just a matter
> of looking at the V4L2_FMT_FLAG_EMULATED flag.
>
> Yet, we don't want to have a miriad of format converters
> everywhere for the proprietary formats, like V4L2_PIX_FMT_KONICA420,
> V4L2_PIX_FMT_SPCA501, etc. So, let's offer only the emulated
> variant for those weird stuff.
>
> So, this patch changes the libv4lconvert behavior, for
> all non-proprietary formats, including Bayer, to offer both
> the original format and the emulated ones.
>
> Signed-off-by: Mauro Carvalho Chehab
> ---
> lib/libv4lconvert/libv4lconvert.c | 17 -
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/lib/libv4lconvert/libv4lconvert.c
> b/lib/libv4lconvert/libv4lconvert.c
> index da718918b030..d87d6b91a838 100644
> --- a/lib/libv4lconvert/libv4lconvert.c
> +++ b/lib/libv4lconvert/libv4lconvert.c
> @@ -118,10 +118,10 @@ static const struct v4lconvert_pixfmt
> supported_src_pixfmts[] = {
> { V4L2_PIX_FMT_OV511,0, 7, 7, 1 },
> { V4L2_PIX_FMT_OV518,0, 7, 7, 1 },
> /* uncompressed bayer */
> - { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 1 },
> - { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 1 },
> - { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 1 },
> - { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 1 },
> + { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 0 },
> + { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 0 },
> + { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 0 },
> + { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 0 },
> { V4L2_PIX_FMT_STV0680, 8, 8, 8, 1 },
> /* compressed bayer */
> { V4L2_PIX_FMT_SPCA561, 0, 9, 9, 1 },
> @@ -178,7 +178,7 @@ struct v4lconvert_data
> *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri
> /* This keeps tracks of devices which have only formats for which apps
> most likely will need conversion and we can thus safely add software
> processing controls without a performance impact. */
The bottom part seems unwanted.
Before, if any source format did not need conversion then
always_needs_conversion = 0
else always_needs_conversion = 1
Now
if any source format needs conversion then always_needs_conversion = 1
else always_needs_conversion = 0
Seems like it should be 2 separate patches even if I'm wrong.
> - int always_needs_conversion = 1;
> + int always_needs_conversion = 0;
>
> if (!data) {
> fprintf(stderr, "libv4lconvert: error: out of memory!\n");
> @@ -208,10 +208,9 @@ struct v4lconvert_data
> *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri
> if (j < ARRAY_SIZE(supported_src_pixfmts)) {
> data->supported_src_formats |= 1ULL << j;
> v4lconvert_get_framesizes(data, fmt.pixelformat, j);
> - if (!supported_src_pixfmts[j].needs_conversion)
> - always_needs_conversion = 0;
> - } else
> - always_needs_conversion = 0;
> + if (supported_src_pixfmts[j].needs_conversion)
> + always_needs_conversion = 1;
> + }
> }
>
> data->no_formats = i;
>
Re: [PATCH] libv4lconvert: by default, offer the original format to the client
Hi Mauro,
On Fri, Mar 10, 2017 at 05:53:26PM -0300, Mauro Carvalho Chehab wrote:
> The libv4lconvert part of libv4l was meant to provide a common
> place to handle weird proprietary formats. With time, we also
> added support to other standard formats, in order to help
> V4L2 applications that are not performance sensitive to support
> all V4L2 formats.
>
> Yet, the hole idea is to let userspace to decide to implement
> their own format conversion code when it needs either more
> performance or more quality than what libv4lconvert provides.
>
> In other words, applications should have the right to decide
> between using a libv4lconvert emulated format or to implement
> the decoding themselves for non-proprietary formats,
> as this may have significative performance impact.
>
> At the application side, deciding between them is just a matter
> of looking at the V4L2_FMT_FLAG_EMULATED flag.
>
> Yet, we don't want to have a miriad of format converters
^ myriad
> everywhere for the proprietary formats, like V4L2_PIX_FMT_KONICA420,
> V4L2_PIX_FMT_SPCA501, etc. So, let's offer only the emulated
> variant for those weird stuff.
>
> So, this patch changes the libv4lconvert behavior, for
> all non-proprietary formats, including Bayer, to offer both
> the original format and the emulated ones.
>
> Signed-off-by: Mauro Carvalho Chehab
> ---
> lib/libv4lconvert/libv4lconvert.c | 17 -
> 1 file changed, 8 insertions(+), 9 deletions(-)
>
> diff --git a/lib/libv4lconvert/libv4lconvert.c
> b/lib/libv4lconvert/libv4lconvert.c
> index da718918b030..d87d6b91a838 100644
> --- a/lib/libv4lconvert/libv4lconvert.c
> +++ b/lib/libv4lconvert/libv4lconvert.c
> @@ -118,10 +118,10 @@ static const struct v4lconvert_pixfmt
> supported_src_pixfmts[] = {
> { V4L2_PIX_FMT_OV511,0, 7, 7, 1 },
> { V4L2_PIX_FMT_OV518,0, 7, 7, 1 },
> /* uncompressed bayer */
> - { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 1 },
> - { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 1 },
> - { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 1 },
> - { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 1 },
> + { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 0 },
> + { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 0 },
> + { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 0 },
> + { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 0 },
> { V4L2_PIX_FMT_STV0680, 8, 8, 8, 1 },
> /* compressed bayer */
> { V4L2_PIX_FMT_SPCA561, 0, 9, 9, 1 },
> @@ -178,7 +178,7 @@ struct v4lconvert_data
> *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri
> /* This keeps tracks of devices which have only formats for which apps
> most likely will need conversion and we can thus safely add software
> processing controls without a performance impact. */
Does the comment require updating?
With these,
Acked-by: Sakari Ailus
> - int always_needs_conversion = 1;
> + int always_needs_conversion = 0;
>
> if (!data) {
> fprintf(stderr, "libv4lconvert: error: out of memory!\n");
> @@ -208,10 +208,9 @@ struct v4lconvert_data
> *v4lconvert_create_with_dev_ops(int fd, void *dev_ops_pri
> if (j < ARRAY_SIZE(supported_src_pixfmts)) {
> data->supported_src_formats |= 1ULL << j;
> v4lconvert_get_framesizes(data, fmt.pixelformat, j);
> - if (!supported_src_pixfmts[j].needs_conversion)
> - always_needs_conversion = 0;
> - } else
> - always_needs_conversion = 0;
> + if (supported_src_pixfmts[j].needs_conversion)
> + always_needs_conversion = 1;
> + }
> }
>
> data->no_formats = i;
--
Kind regards,
Sakari Ailus
e-mail: sakari.ai...@iki.fi XMPP: sai...@retiisi.org.uk
[PATCH] libv4lconvert: by default, offer the original format to the client
The libv4lconvert part of libv4l was meant to provide a common
place to handle weird proprietary formats. With time, we also
added support to other standard formats, in order to help
V4L2 applications that are not performance sensitive to support
all V4L2 formats.
Yet, the hole idea is to let userspace to decide to implement
their own format conversion code when it needs either more
performance or more quality than what libv4lconvert provides.
In other words, applications should have the right to decide
between using a libv4lconvert emulated format or to implement
the decoding themselves for non-proprietary formats,
as this may have significative performance impact.
At the application side, deciding between them is just a matter
of looking at the V4L2_FMT_FLAG_EMULATED flag.
Yet, we don't want to have a miriad of format converters
everywhere for the proprietary formats, like V4L2_PIX_FMT_KONICA420,
V4L2_PIX_FMT_SPCA501, etc. So, let's offer only the emulated
variant for those weird stuff.
So, this patch changes the libv4lconvert behavior, for
all non-proprietary formats, including Bayer, to offer both
the original format and the emulated ones.
Signed-off-by: Mauro Carvalho Chehab
---
lib/libv4lconvert/libv4lconvert.c | 17 -
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/lib/libv4lconvert/libv4lconvert.c
b/lib/libv4lconvert/libv4lconvert.c
index da718918b030..d87d6b91a838 100644
--- a/lib/libv4lconvert/libv4lconvert.c
+++ b/lib/libv4lconvert/libv4lconvert.c
@@ -118,10 +118,10 @@ static const struct v4lconvert_pixfmt
supported_src_pixfmts[] = {
{ V4L2_PIX_FMT_OV511,0, 7, 7, 1 },
{ V4L2_PIX_FMT_OV518,0, 7, 7, 1 },
/* uncompressed bayer */
- { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 1 },
- { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 1 },
- { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 1 },
- { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 1 },
+ { V4L2_PIX_FMT_SBGGR8, 8, 8, 8, 0 },
+ { V4L2_PIX_FMT_SGBRG8, 8, 8, 8, 0 },
+ { V4L2_PIX_FMT_SGRBG8, 8, 8, 8, 0 },
+ { V4L2_PIX_FMT_SRGGB8, 8, 8, 8, 0 },
{ V4L2_PIX_FMT_STV0680, 8, 8, 8, 1 },
/* compressed bayer */
{ V4L2_PIX_FMT_SPCA561, 0, 9, 9, 1 },
@@ -178,7 +178,7 @@ struct v4lconvert_data *v4lconvert_create_with_dev_ops(int
fd, void *dev_ops_pri
/* This keeps tracks of devices which have only formats for which apps
most likely will need conversion and we can thus safely add software
processing controls without a performance impact. */
- int always_needs_conversion = 1;
+ int always_needs_conversion = 0;
if (!data) {
fprintf(stderr, "libv4lconvert: error: out of memory!\n");
@@ -208,10 +208,9 @@ struct v4lconvert_data *v4lconvert_create_with_dev_ops(int
fd, void *dev_ops_pri
if (j < ARRAY_SIZE(supported_src_pixfmts)) {
data->supported_src_formats |= 1ULL << j;
v4lconvert_get_framesizes(data, fmt.pixelformat, j);
- if (!supported_src_pixfmts[j].needs_conversion)
- always_needs_conversion = 0;
- } else
- always_needs_conversion = 0;
+ if (supported_src_pixfmts[j].needs_conversion)
+ always_needs_conversion = 1;
+ }
}
data->no_formats = i;
--
2.9.3
