NekoCWD/libcamera
NekoCWD/libcamera
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages 7 Wiki Activity Actions

libcamera: v4l2_device: Move start of frame detection to V4L2Device

Browse source 
The V4L2_EVENT_FRAME_SYNC event may occur on both V4L2 video-devices
(V4L2VideoDevice) and sub-devices (V4L2Subdevice). Move the start of
frame detection to the common base class of the two, V4L2Device.

There is no functional change.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
This commit is contained in:
Niklas Söderlund 2020-10-18 03:47:23 +02:00
parent 68d2c41835
commit 3d624b745b
4 changed files with 87 additions and 84 deletions
Download patch file Download diff file Expand all files Collapse all files

76
src/libcamera/v4l2_device.cpp
View file

@ -16,6 +16,8 @@
#include <sys/syscall.h>
#include <unistd.h>
#include <libcamera/event_notifier.h>
#include "libcamera/internal/log.h"
#include "libcamera/internal/sysfs.h"
#include "libcamera/internal/utils.h"
@ -52,7 +54,8 @@ LOG_DEFINE_CATEGORY(V4L2)
* at open() time, and the \a logTag to prefix log messages with.
*/
V4L2Device::V4L2Device(const std::string &deviceNode)
: deviceNode_(deviceNode), fd_(-1)
: deviceNode_(deviceNode), fd_(-1), fdEventNotifier_(nullptr),
frameStartEnabled_(false)
{
}
@ -87,7 +90,7 @@ int V4L2Device::open(unsigned int flags)
return ret;
}
fd_ = ret;
setFd(ret);
listControls();
@ -117,6 +120,10 @@ int V4L2Device::setFd(int fd)
fd_ = fd;
fdEventNotifier_ = new EventNotifier(fd_, EventNotifier::Exception);
fdEventNotifier_->activated.connect(this, &V4L2Device::eventAvailable);
fdEventNotifier_->setEnabled(false);
return 0;
}
@ -130,6 +137,8 @@ void V4L2Device::close()
if (!isOpen())
return;
delete fdEventNotifier_;
if (::close(fd_) < 0)
LOG(V4L2, Error) << "Failed to close V4L2 device: "
<< strerror(errno);
@ -395,6 +404,40 @@ std::string V4L2Device::devicePath() const
return path;
}
/**
* \brief Enable or disable frame start event notification
* \param[in] enable True to enable frame start events, false to disable them
*
* This function enables or disables generation of frame start events. Once
* enabled, the events are signalled through the frameStart signal.
*
* \return 0 on success, a negative error code otherwise
*/
int V4L2Device::setFrameStartEnabled(bool enable)
{
if (frameStartEnabled_ == enable)
return 0;
struct v4l2_event_subscription event{};
event.type = V4L2_EVENT_FRAME_SYNC;
unsigned long request = enable ? VIDIOC_SUBSCRIBE_EVENT
: VIDIOC_UNSUBSCRIBE_EVENT;
int ret = ioctl(request, &event);
if (enable && ret)
return ret;
fdEventNotifier_->setEnabled(enable);
frameStartEnabled_ = enable;
return ret;
}
/**
* \var V4L2Device::frameStart
* \brief A Signal emitted when capture of a frame has started
*/
/**
* \brief Perform an IOCTL system call on the device node
* \param[in] request The IOCTL request code
@ -518,4 +561,33 @@ void V4L2Device::updateControls(ControlList *ctrls,
}
}
/**
* \brief Slot to handle V4L2 events from the V4L2 device
* \param[in] notifier The event notifier
*
* When this slot is called, a V4L2 event is available to be dequeued from the
* device.
*/
void V4L2Device::eventAvailable([[maybe_unused]] EventNotifier *notifier)
{
struct v4l2_event event{};
int ret = ioctl(VIDIOC_DQEVENT, &event);
if (ret < 0) {
LOG(V4L2, Error)
<< "Failed to dequeue event, disabling event notifier";
fdEventNotifier_->setEnabled(false);
return;
}
if (event.type != V4L2_EVENT_FRAME_SYNC) {
LOG(V4L2, Error)
<< "Spurious event (" << event.type
<< "), disabling event notifier";
fdEventNotifier_->setEnabled(false);
return;
}
frameStart.emit(event.u.frame_sync.frame_sequence);
}
} /* namespace libcamera */