hyperion.ng/libsrc/grabber/amlogic/AmlogicGrabber.cpp

// STL includes
#include <algorithm>
#include <cassert>
#include <iostream>

// Linux includes
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>

// Local includes
#include <utils/Logger.h>
#include <grabber/AmlogicGrabber.h>


// Flags copied from 'include/linux/amlogic/amports/amvideocap.h' at https://github.com/codesnake/linux-amlogic
#define AMVIDEOCAP_IOC_MAGIC 'V'
#define AMVIDEOCAP_IOW_SET_WANTFRAME_WIDTH  _IOW(AMVIDEOCAP_IOC_MAGIC, 0x02, int)
#define AMVIDEOCAP_IOW_SET_WANTFRAME_HEIGHT _IOW(AMVIDEOCAP_IOC_MAGIC, 0x03, int)

#if HAVE_AML_HEADER
	#include <amcodec/amports/amstream.h>
#else
	// Flags copied from 'include/linux/amlogic/amports/amvstream.h' at https://github.com/codesnake/linux-amlogic
	#define AMSTREAM_IOC_MAGIC   'S'
	#define AMSTREAM_IOC_GET_VIDEO_DISABLE   _IOR(AMSTREAM_IOC_MAGIC,   0x48, unsigned long)
#endif

AmlogicGrabber::AmlogicGrabber(const unsigned width, const unsigned height)
	: Grabber("AMLOGICGRABBER", qMax(160u, width), qMax(160u, height)) // Minimum required width or height is 160
	, _amlogicCaptureDev(-1)
{
	Debug(_log, "constructed(%d x %d)",_width,_height);
}

AmlogicGrabber::~AmlogicGrabber()
{
	if (_amlogicCaptureDev != -1)
	{
		if (close(_amlogicCaptureDev) == -1)
		{
			Error(_log, "Failed to close device (%d - %s)", errno, strerror(errno));
		}
		_amlogicCaptureDev = -1;
	}
}


bool AmlogicGrabber::isVideoPlaying()
{
	const QString videoDevice = "/dev/amvideo";

	// Open the video device
	int video_fd = open(QSTRING_CSTR(videoDevice), O_RDONLY);
	if (video_fd < 0)
	{
		Error(_log, "Failed to open video device(%s): %d - %s", QSTRING_CSTR(videoDevice), errno, strerror(errno));
		return false;
	}

	// Check the video disabled flag
	int videoDisabled;
	if (ioctl(video_fd, AMSTREAM_IOC_GET_VIDEO_DISABLE, &videoDisabled) == -1)
	{
		Error(_log, "Failed to retrieve video state from device: %d - %s", errno, strerror(errno));
		close(video_fd);
		return false;
	}

	// Make sure to close the device after use
	close(video_fd);

	return videoDisabled == 0;
}

int AmlogicGrabber::grabFrame(Image<ColorRgb> & image)
{
	// TODO crop resulting image accroding member _videoMode
	// TODO add croping

	// Make sure video is playing, else there is nothing to grab
	if (!isVideoPlaying())
	{
		return -1;
	}

	// If the device is not open, attempt to open it
	if (_amlogicCaptureDev == -1)
	{
		_amlogicCaptureDev = open("/dev/amvideocap0", O_RDONLY, 0);

		// If the device is still not open, there is something wrong
		if (_amlogicCaptureDev == -1)
		{
			Error(_log,"Failed to open the AMLOGIC device (%d - %s):", errno, strerror(errno));
			return -1;
		}
	}


	if (ioctl(_amlogicCaptureDev, AMVIDEOCAP_IOW_SET_WANTFRAME_WIDTH,  _width)  == -1 ||
		ioctl(_amlogicCaptureDev, AMVIDEOCAP_IOW_SET_WANTFRAME_HEIGHT, _height) == -1)
	{
		// Failed to configure frame width
		Error(_log,"Failed to configure capture size (%d - %s)", errno, strerror(errno));
		close(_amlogicCaptureDev);
		_amlogicCaptureDev = -1;
		return -1;
	}

	// Read the snapshot into the memory
	void * image_ptr = _image.memptr();
	const ssize_t bytesToRead = _width * _height * sizeof(ColorBgr);

	const ssize_t bytesRead   = pread(_amlogicCaptureDev, image_ptr, bytesToRead, 0);
	if (bytesRead == -1)
	{
		Error(_log,"Read of device failed: %d - %s", errno, strerror(errno));
		close(_amlogicCaptureDev);
		_amlogicCaptureDev = -1;
		return -1;
	}
	else if (bytesToRead != bytesRead)
	{
		// Read of snapshot failed
		Error(_log,"Capture failed to grab entire image [bytesToRead(%d) != bytesRead(%d)]", bytesToRead, bytesRead);
		close(_amlogicCaptureDev);
		_amlogicCaptureDev = -1;
		return -1;
	}

	// For now we always close the device now and again
	static int readCnt = 0;
	++readCnt;
	if (readCnt > 20)
	{
		close(_amlogicCaptureDev);
		_amlogicCaptureDev = -1;
		readCnt = 0;
	}
	
	_imageResampler.setHorizontalPixelDecimation(_width);
	_imageResampler.setVerticalPixelDecimation(_height);
	_imageResampler.processImage((const uint8_t*)image_ptr, _width, _height, 3, PIXELFORMAT_BGR24, image);

	return 0;
}