Environment Variables

Name	Type	Default	Range	Description
MDK_BUILD_INFO	int	2	0/1/2	print build info or not. 0: no print. 1: version info only. 2: version and build details
MDK_LOG	int	0	0/1	print log or not
MDK_CLOG	int	0	0/1	output log to defaul std::clog buffer
MDK_LOG_STATUS	int	1	0/1	print playback progress or not
VO_DROP	float	0	[0,1]	frame drop rate on video output
ALSA_DEVICE	int		0/1	alsa device name
CUDA_DEVICE	int		>0	cuda device index
CUDA_STREAM	int	1	0/1	use cuda stream or not
CUDA_PBO	int	0	0/1	use pbo to interop cuda with gl
MMAL_EGLIMAGE_POOL	int	0	>0	use eglimage pool for mmal rendering
MMAL_GL_FORMAT	string		rgba,yuv420p	pixel format of converted eglimage from mmal buffer
VAIMAGE_DERIVE	int	1	0/1	use vaapi derived image if map to host memory
VAIMAGE_FORMAT	string			select a pixel format to get vaapi surface data. derived image is disabled
VDPAU_GL	string	"video" for nv, "output" otherwise	video,output,pixmap	video: map video surface as semi-planar yuv textures output: map output surface as an rgb texture pixmap: use pixmap as rgb texture, supports glx and egl
VAAPI_GL	string	depends on gl context	x11/dri3/drm2/drm	drm2: default for egl + libav2.1.0+ drm: for egl+ legacy libav x11: for glx
VAAPI_VPP	int	0	0/1	1: convert to rgb surface then imported by EGL. usually not required, only for testing, because a surface will be converted automatically if can't be imported(EGL+desktop GL + external only formats)
GL_MAJOR	int		[2,4]	major version of opengl context to create
GL_MINOR	int		[0,6]	minor version of opengl context to create
GL_PROFILE	string		core/compat/no	profile of opengl context to create
GL_ES	int		0/1	create OpenGL Desktop or ES
GL_EGL	int		1/0	prefer EGL or not
EGL_LIB	string			force libEGL path
EGL_ANGLE	string	d3d11		select ANGLE platform implementation to create an EGL context. can be d3d11, d3d11_fl9,d3d9, vulkan, opengl, opengles depends on the angle you use
EGL_SURFACELESS	int	1	1/0	use surfaceless context for an offscreen context and internal shared context
GL_TONE_MAP	int	1	1/0	enable hdr tone map or not. can disable for hdr devices
GL_VAO	int	1	1/0	enable vao or not
GL_VBO	int	1	1/0	enable vbo or not
GL_PBO	int	0	1/0	enable pbo or not
GL_IMMUTABLE_TEX	int	0	1/0	enable immutable textures or not
GL_TEXTURE16_DEPTH	int	16	16/8	texel depth for 16bit images
GL_LEGACY	int	0	1/0	use legacy es2 textures for old devices
DRM_NUM	int	0	>=0	drm device index
DISPMANX_ID	int		>=0	rpi dispmanx id to create a rendering surface
USE_METADATA_PRIMARIES	int	1	0/1	use frame level mastering metadata if available
GPU_TONE_MAP	string	2390	2390/hable	hdr tone map curve
MIN_SEEK_FREQUENCY	int	1	0/1	enable frequently seek optimizations or not
KEY_FRAMES_ONLY	int	0	0/1	decode only key-frames or not
D3D_SYNC	string	fence	fence,map,query,none	d3d11 resource sync
D3D_TRACE	int	0	0/1	trace some d3d11/12 object life time and print logs
D3D11_GL	string		eglstream,eglpbuf,host	rendering d3d11 textures via eglstream, eglpub etc.
D3D11_KMT	int	0	0/1	1: enable sync via kmt, also requires env var D3D11_ZERO_COPY=0
GPU_OPTIMAL_UPLOAD	int	1	0/1	d3d11/12 only. optimize texture upload for UMA. value 2(d3d11 only) always enable optimal path, but result may be not expected