myvtm/Other/libmediadeviceinfo/linux/videodevice_info_linux.cpp

#include "../imediadeviceinfo.h"

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/ioctl.h>
#include <string.h>
#include <unistd.h>

#include <md5.h>

//v4l includes
#include <linux/videodev2.h>


#ifndef MAX_PATH
#define MAX_PATH 260
#endif // !MAX_PATH



int  rvc_videocap_get_device_count()
{
	int icount = 0;
	int fd = -1;
	
	for (int index = 0; index < 64; index++)
	{
		char device[MAX_PATH] = { 0 };
		snprintf(device, MAX_PATH, "/dev/video%d", index);
		if (-1 != (fd = open(device, O_RDONLY)) )
		{
			// query device capabilities
			struct v4l2_capability cap = {0};
			if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0){
				close(fd);
				continue;
			}

			if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)){
				continue;
			}

			if (cap.capabilities & V4L2_CAP_STREAMING) {

			}

			if (cap.capabilities & V4L2_CAP_READWRITE) {

			}

			/* 查询支持的格式 */
			struct v4l2_fmtdesc tFmtDesc = {0};
			int iPixelFormat = 0;

			tFmtDesc.index = 0;
			tFmtDesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

			while ((ioctl(fd, VIDIOC_ENUM_FMT, &tFmtDesc)) == 0) {
				if (V4L2_PIX_FMT_YUYV == tFmtDesc.pixelformat || V4L2_PIX_FMT_MJPEG == tFmtDesc.pixelformat)
				{
					iPixelFormat = tFmtDesc.pixelformat;
					icount++;
					break;
				}

				tFmtDesc.index++;
			}
		}
	}
	return icount;
}


int  rvc_videocap_get_device_name(int device_id, char* buf, int len)
{
	int iret = -1;

	char device[MAX_PATH] = { 0 };
	int fd = -1;

	snprintf(device, MAX_PATH, "/dev/video%d", device_id);
	if (-1 != (fd = open(device, O_RDONLY)))
	{
		// query device capabilities
		struct v4l2_capability cap = { 0 };
		if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0){
			close(fd);
			return iret;
		}

		if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)){
			return iret;
		}

		if (cap.capabilities & V4L2_CAP_STREAMING) {

		}

		if (cap.capabilities & V4L2_CAP_READWRITE) {

		}

		/* 查询支持的格式 */
		struct v4l2_fmtdesc tFmtDesc = { 0 };
		int iPixelFormat = 0;

		tFmtDesc.index = 0;
		tFmtDesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

		while ((ioctl(fd, VIDIOC_ENUM_FMT, &tFmtDesc)) == 0) {
			if (V4L2_PIX_FMT_YUYV == tFmtDesc.pixelformat || V4L2_PIX_FMT_MJPEG == tFmtDesc.pixelformat){
				iPixelFormat = tFmtDesc.pixelformat;
				break;
			}
			tFmtDesc.index++;
		}

		if (0 != iPixelFormat)
		{
			snprintf(buf, len, "%s%s%s", cap.card, ";", cap.bus_info);
			iret = 0;
		}
	}
	return iret;
}


int  rvc_videocap_get_device_path(int device_id, char* buf, int len)
{
	return 0;
}


int  rvc_videocap_get_device_info(int device_id, char* namebuf, int namelen, char* pathbuf, int pathlen)
{
	int iret = -1;

	char device[MAX_PATH] = { 0 };
	int fd = -1;

	snprintf(device, MAX_PATH, "/dev/video%d", device_id);
	if (-1 != (fd = open(device, O_RDONLY)))
	{
		// query device capabilities
		struct v4l2_capability cap = { 0 };
		if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0)
		{
			close(fd);
			return iret;
		}

		if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
		{
			return iret;
		}

		if (cap.capabilities & V4L2_CAP_STREAMING) {

		}

		if (cap.capabilities & V4L2_CAP_READWRITE) {

		}

		/* 查询支持的格式 */
		struct v4l2_fmtdesc tFmtDesc = { 0 };
		int iPixelFormat = 0;

		tFmtDesc.index = 0;
		tFmtDesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

		while ((ioctl(fd, VIDIOC_ENUM_FMT, &tFmtDesc)) == 0) {
			if (V4L2_PIX_FMT_YUYV == tFmtDesc.pixelformat || V4L2_PIX_FMT_RGB565 == tFmtDesc.pixelformat)
			{
				iPixelFormat = tFmtDesc.pixelformat;
				break;
			}
			tFmtDesc.index++;
		}

		if (0 != iPixelFormat)
		{
			snprintf(namebuf, namelen, "%s", cap.card);
			snprintf(pathbuf, pathlen, "%s", cap.bus_info);
			iret = 0;
		}
	}
	return iret;
}

static int bin2str(unsigned char* x, int xlen, char* str, int str_size)
{
	static const char* hex2char = "0123456789ABCDEF";
	int i, k = 0;
	if (str_size <= xlen * 2)
		return -1;
	for (i = 0; i < xlen; ++i) {
		int h = x[i] >> 4;
		int l = x[i] & 0xf;
		str[k++] = hex2char[h];
		str[k++] = hex2char[l];
	}
	str[k] = 0;
	return k;
}


int  rvc_videocap_get_device_fullpathname(int device_id, char* fullnamebuf, int fulllen)
{
	int iret = -1;

	char device[MAX_PATH] = { 0 };
	int fd = -1;

	snprintf(device, MAX_PATH, "/dev/video%d", device_id);
	if (-1 != (fd = open(device, O_RDONLY)))
	{
		// query device capabilities
		struct v4l2_capability cap = { 0 };
		if (ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0)
		{
			close(fd);
			return iret;
		}

		if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE))
		{
			return iret;
		}

		if (cap.capabilities & V4L2_CAP_STREAMING) {

		}

		if (cap.capabilities & V4L2_CAP_READWRITE) {

		}

		/* 查询支持的格式 */
		struct v4l2_fmtdesc tFmtDesc = { 0 };
		int iPixelFormat = 0;

		tFmtDesc.index = 0;
		tFmtDesc.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;

		while ((ioctl(fd, VIDIOC_ENUM_FMT, &tFmtDesc)) == 0) {
			if (V4L2_PIX_FMT_YUYV == tFmtDesc.pixelformat || V4L2_PIX_FMT_RGB565 == tFmtDesc.pixelformat)
			{
				iPixelFormat = tFmtDesc.pixelformat;
				break;
			}
			tFmtDesc.index++;
		}

		if (0 != iPixelFormat)
		{
			if (NULL != cap.bus_info && NULL != cap.card)
			{
				char strmd5[MAX_PATH] = { 0 };
				snprintf(strmd5, MAX_PATH, "%s", cap.bus_info);
				unsigned char x[MD5_DIGESTSIZE];
				md5_ctx_t ctx;
				md5_init(&ctx);
				md5(x, strmd5, strlen(strmd5));
				bin2str(x, sizeof(x), strmd5, sizeof(strmd5));

				snprintf(fullnamebuf, fulllen, "%s:%s", cap.card, strmd5);
				iret = 0;
			}
		}
	}
	return iret;
}

int  rvc_videocap_get_video_device_id(const char* dev_name)
{
	int iret = -1;
	if (NULL == dev_name){
		return iret;
	}

	int icount = rvc_videocap_get_device_count();
	int ifound = 0;
	for (int i = 0; i < 64 && ifound < icount; ++i) {
		char strfullname[2*MAX_PATH] = { 0 };
		if (0 == rvc_videocap_get_device_fullpathname(i, strfullname, 2 * MAX_PATH)){
			ifound++;
			printf("camera name is: %s\n", strfullname);
			printf("   dev name is: %s\n", dev_name);
			if (0 == strcasecmp(strfullname, dev_name))
			{
				iret = i;
			}
		}
	}
	return iret;
}