[libcamera-devel] [PATCH 3/3] libcamera: v4l2_device: Add support for META_CAPTURE devices

[Laurent Pinchart]

Hi Jacopo,

On Tue, Feb 26, 2019 at 11:04:41AM +0100, Jacopo Mondi wrote:
> On Mon, Feb 25, 2019 at 09:49:39PM +0200, Laurent Pinchart wrote:
> > On Mon, Feb 25, 2019 at 10:31:13AM +0100, Jacopo Mondi wrote:
> >> On Fri, Feb 22, 2019 at 01:22:37AM +0200, Laurent Pinchart wrote:
> >>> On Tue, Feb 19, 2019 at 05:56:20PM +0100, Jacopo Mondi wrote:
> >>>> Add support for devices that provides video meta-data to v4l2_device.cpp
> >>>
> >>> s/provides/provide/
> >>> s/to v4l2_device.cpp/to the V4L2Device class/ or just drop this part
> >>>
> >>>> Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
> >>>> ---
> >>>>  src/libcamera/include/v4l2_device.h |  4 ++++
> >>>>  src/libcamera/v4l2_device.cpp       | 12 ++++++++++--
> >>>>  2 files changed, 14 insertions(+), 2 deletions(-)
> >>>>
> >>>> diff --git a/src/libcamera/include/v4l2_device.h b/src/libcamera/include/v4l2_device.h
> >>>> index 1d31d1b403bc..52eb6785cc15 100644
> >>>> --- a/src/libcamera/include/v4l2_device.h
> >>>> +++ b/src/libcamera/include/v4l2_device.h
> >>>> @@ -53,6 +53,10 @@ struct V4L2Capability final : v4l2_capability {
> >>>>  		return device_caps() & (V4L2_CAP_VIDEO_CAPTURE |
> >>>>  					V4L2_CAP_VIDEO_CAPTURE_MPLANE);
> >>>>  	}
> >>>> +	bool isMeta() const
> >>>> +	{
> >>>> +		return device_caps() & V4L2_CAP_META_CAPTURE;
> >>>
> >>> How about META_OUTPUT ? We will need that for the ImgU parameters. It
> >>> would make sense to have 4 helpers, isVideo(), isMeta(), isCapture(),
> >>> isOutput().
> >>
> >> META_OUTPUT went in in v4.20, our headers come from v4.19 iirc
> 
> I was wrong. The the patch that introduces META_OUTPUT went in in
> v4.20-7 in the media tree, but hit Linus' tree in the 5.0 merge
> window.

Indeed, my bad.

> > Feel free to update them :-) Doesn't the IPU3 parameters queue use
> > META_OUTPUT ?
> 
> I would wait another week or so and update headers to the 5.0 version,
> once v5.0 is released.

That's fine with me, but you'll have to change the API introduced by
this patch, and may fail to catch all required changes, so there's a
small risk of introducting a bug. Up to you, but I don't think the V4L2
headers will change between v5.0-rc8 and v5.0, so updating them doesn't
seem to be a problem to me.

> It's not blocking IPU3 support anyway.
> 
> >>>> +	}
> >>>>  	bool isOutput() const
> >>>>  	{
> >>>>  		return device_caps() & (V4L2_CAP_VIDEO_OUTPUT |
> >>>> diff --git a/src/libcamera/v4l2_device.cpp b/src/libcamera/v4l2_device.cpp
> >>>> index 24e115554a99..7fe6476bf035 100644
> >>>> --- a/src/libcamera/v4l2_device.cpp
> >>>> +++ b/src/libcamera/v4l2_device.cpp
> >>>> @@ -79,6 +79,12 @@ LOG_DEFINE_CATEGORY(V4L2)
> >>>>   * \return True if the device can output video frames
> >>>>   */
> >>>>
> >>>> +/**
> >>>> + * \fn bool V4L2Capability::isMeta()
> >>>> + * \brief Identify if the device is capable of providing video meta-data
> >>>> + * \return True if the device can provide video meta-data
> >>>> + */
> >>>> +
> >>>>  /**
> >>>>   * \fn bool V4L2Capability::hasStreaming()
> >>>>   * \brief Determine if the device can perform Streaming I/O
> >>>> @@ -280,7 +286,7 @@ int V4L2Device::open()
> >>>>  		<< "Opened device " << caps_.bus_info() << ": "
> >>>>  		<< caps_.driver() << ": " << caps_.card();
> >>>>
> >>>> -	if (!caps_.isCapture() && !caps_.isOutput()) {
> >>>> +	if (!caps_.isCapture() && !caps_.isOutput() && !caps_.isMeta()) {
> >>>>  		LOG(V4L2, Debug) << "Device is not a supported type";
> >>>>  		return -EINVAL;
> >>>>  	}
> >>>> @@ -294,10 +300,12 @@ int V4L2Device::open()
> >>>>  		bufferType_ = caps_.isMultiplanar()
> >>>>  			    ? V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE
> >>>>  			    : V4L2_BUF_TYPE_VIDEO_CAPTURE;
> >>>> -	else
> >>>> +	else if (caps_.isOutput())
> >>>>  		bufferType_ = caps_.isMultiplanar()
> >>>>  			    ? V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE
> >>>>  			    : V4L2_BUF_TYPE_VIDEO_OUTPUT;
> >>>> +	else
> >>>> +		bufferType_ = V4L2_BUF_TYPE_META_CAPTURE;
> >>>>
> >>>>  	/*
> >>>>  	 *  We wait for Read notifications on CAPTURE devices (POLLIN), and

-- 
Regards,

Laurent Pinchart