[libcamera-devel,v2,03/10] libcamera: v4l2_subdevice: Extend [gs]etFormat() to specify format type
diff mbox series

Message ID 20200316214310.27665-4-laurent.pinchart@ideasonboard.com
State Superseded
Headers show
Series
  • Simple pipeline handler
Related show

Commit Message

Laurent Pinchart March 16, 2020, 9:43 p.m. UTC 
The V4L2 subdevice API exposes ACTIVE and TRY formats, but the
V4L2Subdevice getFormat() and setFormat() operations only apply on
ACTIVE formats. Extend them to support TRY formats as well.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
---
 src/libcamera/include/v4l2_subdevice.h | 11 +++++++++--
 src/libcamera/v4l2_subdevice.cpp       | 23 +++++++++++++++++++----
 2 files changed, 28 insertions(+), 6 deletions(-)

Comments

Jacopo Mondi March 17, 2020, 12:22 p.m. UTC | #1 
HI Laurent,

On Mon, Mar 16, 2020 at 11:43:03PM +0200, Laurent Pinchart wrote:
> The V4L2 subdevice API exposes ACTIVE and TRY formats, but the
> V4L2Subdevice getFormat() and setFormat() operations only apply on
> ACTIVE formats. Extend them to support TRY formats as well.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> ---
>  src/libcamera/include/v4l2_subdevice.h | 11 +++++++++--
>  src/libcamera/v4l2_subdevice.cpp       | 23 +++++++++++++++++++----
>  2 files changed, 28 insertions(+), 6 deletions(-)
>
> diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h
> index 9c077674f997..4a04eadfb1f9 100644
> --- a/src/libcamera/include/v4l2_subdevice.h
> +++ b/src/libcamera/include/v4l2_subdevice.h
> @@ -32,6 +32,11 @@ struct V4L2SubdeviceFormat {
>  class V4L2Subdevice : public V4L2Device
>  {
>  public:
> +	enum Whence {
> +		ActiveFormat,
> +		TryFormat,
> +	};

Just wondering if
        ActiveFormat = V4L2_SUBDEV_FORMAT_ACTIVE,
        TryFormat = V4L2_SUBDEV_FORMAT_TRY

would not save you the ternary operator in set/get functions

> +
>  	explicit V4L2Subdevice(const MediaEntity *entity);
>  	V4L2Subdevice(const V4L2Subdevice &) = delete;
>  	V4L2Subdevice &operator=(const V4L2Subdevice &) = delete;
> @@ -46,8 +51,10 @@ public:
>
>  	ImageFormats formats(unsigned int pad);
>
> -	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format);
> -	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format);
> +	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> +		      Whence whence = ActiveFormat);
> +	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> +		      Whence whence = ActiveFormat);

This mimics the V4L2 APIs, so it's certainly safe, but considering the
use case for TRY is actually to set a try format to then get it back
to see how the driver changed it, have you considered a tryFormat()
function that does both steps in one call ?

>
>  	static V4L2Subdevice *fromEntityName(const MediaDevice *media,
>  					     const std::string &entity);
> diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
> index 8b9da81e8ab3..fb9bdbce2610 100644
> --- a/src/libcamera/v4l2_subdevice.cpp
> +++ b/src/libcamera/v4l2_subdevice.cpp
> @@ -95,6 +95,15 @@ const std::string V4L2SubdeviceFormat::toString() const
>   * any device left open will be closed, and any resources released.
>   */
>
> +/**
> + * \enum V4L2Subdevice::Whence
> + * \brief Specify the type of format for getFormat() and setFormat() operations
> + * \var V4L2Subdevice::ActiveFormat
> + * \brief The format operation applies to ACTIVE formats
> + * \var V4L2Subdevice::TryFormat
> + * \brief The format operation applies to TRY formats
> + */
> +
>  /**
>   * \brief Create a V4L2 subdevice from a MediaEntity using its device node
>   * path
> @@ -184,12 +193,15 @@ ImageFormats V4L2Subdevice::formats(unsigned int pad)
>   * \brief Retrieve the image format set on one of the V4L2 subdevice pads
>   * \param[in] pad The 0-indexed pad number the format is to be retrieved from
>   * \param[out] format The image bus format
> + * \param[in] whence The format to retrieve, ACTIVE or TRY
>   * \return 0 on success or a negative error code otherwise
>   */
> -int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
> +int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> +			     Whence whence)
>  {
>  	struct v4l2_subdev_format subdevFmt = {};
> -	subdevFmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> +	subdevFmt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
> +			: V4L2_SUBDEV_FORMAT_TRY;
>  	subdevFmt.pad = pad;
>
>  	int ret = ioctl(VIDIOC_SUBDEV_G_FMT, &subdevFmt);
> @@ -211,6 +223,7 @@ int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
>   * \brief Set an image format on one of the V4L2 subdevice pads
>   * \param[in] pad The 0-indexed pad number the format is to be applied to
>   * \param[inout] format The image bus format to apply to the subdevice's pad
> + * \param[in] whence The format to set, ACTIVE or TRY

Here and above "ActiveFormat or TryFormat".
If you could cross-reference to the enum it's even better

Thanks
  j

>   *
>   * Apply the requested image format to the desired media pad and return the
>   * actually applied format parameters, as \ref V4L2Subdevice::getFormat would
> @@ -218,10 +231,12 @@ int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
>   *
>   * \return 0 on success or a negative error code otherwise
>   */
> -int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format)
> +int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> +			     Whence whence)
>  {
>  	struct v4l2_subdev_format subdevFmt = {};
> -	subdevFmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> +	subdevFmt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
> +			: V4L2_SUBDEV_FORMAT_TRY;
>  	subdevFmt.pad = pad;
>  	subdevFmt.format.width = format->size.width;
>  	subdevFmt.format.height = format->size.height;
> --
> Regards,
>
> Laurent Pinchart
>
> _______________________________________________
> libcamera-devel mailing list
> libcamera-devel@lists.libcamera.org
> https://lists.libcamera.org/listinfo/libcamera-devel
Laurent Pinchart March 17, 2020, 8:17 p.m. UTC | #2 
Hi Jacopo,

On Tue, Mar 17, 2020 at 01:22:43PM +0100, Jacopo Mondi wrote:
> On Mon, Mar 16, 2020 at 11:43:03PM +0200, Laurent Pinchart wrote:
> > The V4L2 subdevice API exposes ACTIVE and TRY formats, but the
> > V4L2Subdevice getFormat() and setFormat() operations only apply on
> > ACTIVE formats. Extend them to support TRY formats as well.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
> > ---
> >  src/libcamera/include/v4l2_subdevice.h | 11 +++++++++--
> >  src/libcamera/v4l2_subdevice.cpp       | 23 +++++++++++++++++++----
> >  2 files changed, 28 insertions(+), 6 deletions(-)
> >
> > diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h
> > index 9c077674f997..4a04eadfb1f9 100644
> > --- a/src/libcamera/include/v4l2_subdevice.h
> > +++ b/src/libcamera/include/v4l2_subdevice.h
> > @@ -32,6 +32,11 @@ struct V4L2SubdeviceFormat {
> >  class V4L2Subdevice : public V4L2Device
> >  {
> >  public:
> > +	enum Whence {
> > +		ActiveFormat,
> > +		TryFormat,
> > +	};
> 
> Just wondering if
>         ActiveFormat = V4L2_SUBDEV_FORMAT_ACTIVE,
>         TryFormat = V4L2_SUBDEV_FORMAT_TRY
> 
> would not save you the ternary operator in set/get functions

I would prefer keeping the ternary operator below for clarity, but your
proposal could help the compiler optimizing the code. However, that
requires pulling the V4L2 kernel headers in here. Do you think it's
worth it ?

> > +
> >  	explicit V4L2Subdevice(const MediaEntity *entity);
> >  	V4L2Subdevice(const V4L2Subdevice &) = delete;
> >  	V4L2Subdevice &operator=(const V4L2Subdevice &) = delete;
> > @@ -46,8 +51,10 @@ public:
> >
> >  	ImageFormats formats(unsigned int pad);
> >
> > -	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format);
> > -	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format);
> > +	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> > +		      Whence whence = ActiveFormat);
> > +	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> > +		      Whence whence = ActiveFormat);
> 
> This mimics the V4L2 APIs, so it's certainly safe, but considering the
> use case for TRY is actually to set a try format to then get it back
> to see how the driver changed it, have you considered a tryFormat()
> function that does both steps in one call ?

No, because setFormat() does so already :-) It returns the formats that
was actually set.

> >
> >  	static V4L2Subdevice *fromEntityName(const MediaDevice *media,
> >  					     const std::string &entity);
> > diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
> > index 8b9da81e8ab3..fb9bdbce2610 100644
> > --- a/src/libcamera/v4l2_subdevice.cpp
> > +++ b/src/libcamera/v4l2_subdevice.cpp
> > @@ -95,6 +95,15 @@ const std::string V4L2SubdeviceFormat::toString() const
> >   * any device left open will be closed, and any resources released.
> >   */
> >
> > +/**
> > + * \enum V4L2Subdevice::Whence
> > + * \brief Specify the type of format for getFormat() and setFormat() operations
> > + * \var V4L2Subdevice::ActiveFormat
> > + * \brief The format operation applies to ACTIVE formats
> > + * \var V4L2Subdevice::TryFormat
> > + * \brief The format operation applies to TRY formats
> > + */
> > +
> >  /**
> >   * \brief Create a V4L2 subdevice from a MediaEntity using its device node
> >   * path
> > @@ -184,12 +193,15 @@ ImageFormats V4L2Subdevice::formats(unsigned int pad)
> >   * \brief Retrieve the image format set on one of the V4L2 subdevice pads
> >   * \param[in] pad The 0-indexed pad number the format is to be retrieved from
> >   * \param[out] format The image bus format
> > + * \param[in] whence The format to retrieve, ACTIVE or TRY
> >   * \return 0 on success or a negative error code otherwise
> >   */
> > -int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
> > +int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> > +			     Whence whence)
> >  {
> >  	struct v4l2_subdev_format subdevFmt = {};
> > -	subdevFmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > +	subdevFmt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
> > +			: V4L2_SUBDEV_FORMAT_TRY;
> >  	subdevFmt.pad = pad;
> >
> >  	int ret = ioctl(VIDIOC_SUBDEV_G_FMT, &subdevFmt);
> > @@ -211,6 +223,7 @@ int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
> >   * \brief Set an image format on one of the V4L2 subdevice pads
> >   * \param[in] pad The 0-indexed pad number the format is to be applied to
> >   * \param[inout] format The image bus format to apply to the subdevice's pad
> > + * \param[in] whence The format to set, ACTIVE or TRY
> 
> Here and above "ActiveFormat or TryFormat".
> If you could cross-reference to the enum it's even better

I'll fix that. It seems to require either V4L2Subdevice::ActiveFormat,
or \ref V4L2Subdevice::ActiveFormat "ActiveFormat". I'll go for the
latter.

> >   *
> >   * Apply the requested image format to the desired media pad and return the
> >   * actually applied format parameters, as \ref V4L2Subdevice::getFormat would
> > @@ -218,10 +231,12 @@ int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
> >   *
> >   * \return 0 on success or a negative error code otherwise
> >   */
> > -int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format)
> > +int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
> > +			     Whence whence)
> >  {
> >  	struct v4l2_subdev_format subdevFmt = {};
> > -	subdevFmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
> > +	subdevFmt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
> > +			: V4L2_SUBDEV_FORMAT_TRY;
> >  	subdevFmt.pad = pad;
> >  	subdevFmt.format.width = format->size.width;
> >  	subdevFmt.format.height = format->size.height;

Patch
diff mbox series 

diff --git a/src/libcamera/include/v4l2_subdevice.h b/src/libcamera/include/v4l2_subdevice.h
index 9c077674f997..4a04eadfb1f9 100644
--- a/src/libcamera/include/v4l2_subdevice.h
+++ b/src/libcamera/include/v4l2_subdevice.h
@@ -32,6 +32,11 @@  struct V4L2SubdeviceFormat {
 class V4L2Subdevice : public V4L2Device
 {
 public:
+	enum Whence {
+		ActiveFormat,
+		TryFormat,
+	};
+
 	explicit V4L2Subdevice(const MediaEntity *entity);
 	V4L2Subdevice(const V4L2Subdevice &) = delete;
 	V4L2Subdevice &operator=(const V4L2Subdevice &) = delete;
@@ -46,8 +51,10 @@  public:
 
 	ImageFormats formats(unsigned int pad);
 
-	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format);
-	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format);
+	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
+		      Whence whence = ActiveFormat);
+	int setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
+		      Whence whence = ActiveFormat);
 
 	static V4L2Subdevice *fromEntityName(const MediaDevice *media,
 					     const std::string &entity);
diff --git a/src/libcamera/v4l2_subdevice.cpp b/src/libcamera/v4l2_subdevice.cpp
index 8b9da81e8ab3..fb9bdbce2610 100644
--- a/src/libcamera/v4l2_subdevice.cpp
+++ b/src/libcamera/v4l2_subdevice.cpp
@@ -95,6 +95,15 @@  const std::string V4L2SubdeviceFormat::toString() const
  * any device left open will be closed, and any resources released.
  */
 
+/**
+ * \enum V4L2Subdevice::Whence
+ * \brief Specify the type of format for getFormat() and setFormat() operations
+ * \var V4L2Subdevice::ActiveFormat
+ * \brief The format operation applies to ACTIVE formats
+ * \var V4L2Subdevice::TryFormat
+ * \brief The format operation applies to TRY formats
+ */
+
 /**
  * \brief Create a V4L2 subdevice from a MediaEntity using its device node
  * path
@@ -184,12 +193,15 @@  ImageFormats V4L2Subdevice::formats(unsigned int pad)
  * \brief Retrieve the image format set on one of the V4L2 subdevice pads
  * \param[in] pad The 0-indexed pad number the format is to be retrieved from
  * \param[out] format The image bus format
+ * \param[in] whence The format to retrieve, ACTIVE or TRY
  * \return 0 on success or a negative error code otherwise
  */
-int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
+int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
+			     Whence whence)
 {
 	struct v4l2_subdev_format subdevFmt = {};
-	subdevFmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
+	subdevFmt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
+			: V4L2_SUBDEV_FORMAT_TRY;
 	subdevFmt.pad = pad;
 
 	int ret = ioctl(VIDIOC_SUBDEV_G_FMT, &subdevFmt);
@@ -211,6 +223,7 @@  int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
  * \brief Set an image format on one of the V4L2 subdevice pads
  * \param[in] pad The 0-indexed pad number the format is to be applied to
  * \param[inout] format The image bus format to apply to the subdevice's pad
+ * \param[in] whence The format to set, ACTIVE or TRY
  *
  * Apply the requested image format to the desired media pad and return the
  * actually applied format parameters, as \ref V4L2Subdevice::getFormat would
@@ -218,10 +231,12 @@  int V4L2Subdevice::getFormat(unsigned int pad, V4L2SubdeviceFormat *format)
  *
  * \return 0 on success or a negative error code otherwise
  */
-int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format)
+int V4L2Subdevice::setFormat(unsigned int pad, V4L2SubdeviceFormat *format,
+			     Whence whence)
 {
 	struct v4l2_subdev_format subdevFmt = {};
-	subdevFmt.which = V4L2_SUBDEV_FORMAT_ACTIVE;
+	subdevFmt.which = whence == ActiveFormat ? V4L2_SUBDEV_FORMAT_ACTIVE
+			: V4L2_SUBDEV_FORMAT_TRY;
 	subdevFmt.pad = pad;
 	subdevFmt.format.width = format->size.width;
 	subdevFmt.format.height = format->size.height;