Types and flags used to represent the media graph elements
Media entity typesMEDIA_ENT_F_UNKNOWN and MEDIA_ENT_F_V4L2_SUBDEV_UNKNOWNUnknown entity. That generally indicates that
a driver didn't initialize properly the entity, with is a Kernel bugMEDIA_ENT_F_IO_V4LData streaming input and/or output entity.MEDIA_ENT_F_IO_VBIV4L VBI streaming input or output entityMEDIA_ENT_F_IO_SWRADIOV4L Software Digital Radio (SDR) streaming input or output entityMEDIA_ENT_F_IO_DTVDVB Digital TV streaming input or output entityMEDIA_ENT_F_DTV_DEMODDigital TV demodulator entity.MEDIA_ENT_F_TS_DEMUXMPEG Transport stream demux entity. Could be implemented on hardware or in Kernelspace by the Linux DVB subsystem.MEDIA_ENT_F_DTV_CADigital TV Conditional Access module (CAM) entityMEDIA_ENT_F_DTV_NET_DECAPDigital TV network ULE/MLE desencapsulation entity. Could be implemented on hardware or in KernelspaceMEDIA_ENT_F_CONN_RFConnector for a Radio Frequency (RF) signal.MEDIA_ENT_F_CONN_SVIDEOConnector for a S-Video signal.MEDIA_ENT_F_CONN_COMPOSITEConnector for a RGB composite signal.MEDIA_ENT_F_CAM_SENSORCamera video sensor entity.MEDIA_ENT_F_FLASHFlash controller entity.MEDIA_ENT_F_LENSLens controller entity.MEDIA_ENT_F_ATV_DECODERAnalog video decoder, the basic function of the video decoder
is to accept analogue video from a wide variety of sources such as
broadcast, DVD players, cameras and video cassette recorders, in
either NTSC, PAL, SECAM or HD format, separating the stream
into its component parts, luminance and chrominance, and output
it in some digital video standard, with appropriate timing
signals.MEDIA_ENT_F_TUNERDigital TV, analog TV, radio and/or software radio tuner,
with consists on a PLL tuning stage that converts radio
frequency (RF) signal into an Intermediate Frequency (IF).
Modern tuners have internally IF-PLL decoders for audio
and video, but older models have those stages implemented
on separate entities.
MEDIA_ENT_F_IF_VID_DECODERIF-PLL video decoder. It receives the IF from a PLL
and decodes the analog TV video signal. This is commonly
found on some very old analog tuners, like Philips MK3
designs. They all contain a tda9887 (or some software
compatible similar chip, like tda9885). Those devices
use a different I2C address than the tuner PLL.
MEDIA_ENT_F_IF_AUD_DECODERIF-PLL sound decoder. It receives the IF from a PLL
and decodes the analog TV audio signal. This is commonly
found on some very old analog hardware, like Micronas
msp3400, Philips tda9840, tda985x, etc. Those devices
use a different I2C address than the tuner PLL and
should be controlled together with the IF-PLL video
decoder.
MEDIA_ENT_F_AUDIO_CAPTUREAudio Capture Function Entity.MEDIA_ENT_F_AUDIO_PLAYBACKAudio Playback Function Entity.MEDIA_ENT_F_AUDIO_MIXERAudio Mixer Function Entity.
Media entity flagsMEDIA_ENT_FL_DEFAULTDefault entity for its type. Used to discover the default
audio, VBI and video devices, the default camera sensor, ...MEDIA_ENT_FL_CONNECTORThe entity represents a data conector
Media interface typesMEDIA_INTF_T_DVB_FEDevice node interface for the Digital TV frontendtypically, /dev/dvb/adapter?/frontend?MEDIA_INTF_T_DVB_DEMUXDevice node interface for the Digital TV demuxtypically, /dev/dvb/adapter?/demux?MEDIA_INTF_T_DVB_DVRDevice node interface for the Digital TV DVRtypically, /dev/dvb/adapter?/dvr?MEDIA_INTF_T_DVB_CADevice node interface for the Digital TV Conditional Accesstypically, /dev/dvb/adapter?/ca?MEDIA_INTF_T_DVB_FEDevice node interface for the Digital TV network controltypically, /dev/dvb/adapter?/net?MEDIA_INTF_T_V4L_VIDEODevice node interface for video (V4L)typically, /dev/video?MEDIA_INTF_T_V4L_VBIDevice node interface for VBI (V4L)typically, /dev/vbi?MEDIA_INTF_T_V4L_RADIODevice node interface for radio (V4L)typically, /dev/vbi?MEDIA_INTF_T_V4L_SUBDEVDevice node interface for a V4L subdevicetypically, /dev/v4l-subdev?MEDIA_INTF_T_V4L_SWRADIODevice node interface for Software Defined Radio (V4L)typically, /dev/swradio?MEDIA_INTF_T_ALSA_PCM_CAPTUREDevice node interface for ALSA PCM Capturetypically, /dev/snd/pcmC?D?cMEDIA_INTF_T_ALSA_PCM_PLAYBACKDevice node interface for ALSA PCM Playbacktypically, /dev/snd/pcmC?D?pMEDIA_INTF_T_ALSA_CONTROLDevice node interface for ALSA Controltypically, /dev/snd/controlC?MEDIA_INTF_T_ALSA_COMPRESSDevice node interface for ALSA Compresstypically, /dev/snd/compr?MEDIA_INTF_T_ALSA_RAWMIDIDevice node interface for ALSA Raw MIDItypically, /dev/snd/midi?MEDIA_INTF_T_ALSA_HWDEPDevice node interface for ALSA Hardware Dependenttypically, /dev/snd/hwC?D?MEDIA_INTF_T_ALSA_SEQUENCERDevice node interface for ALSA Sequencertypically, /dev/snd/seqMEDIA_INTF_T_ALSA_TIMERDevice node interface for ALSA Timertypically, /dev/snd/timer
Media pad flagsMEDIA_PAD_FL_SINKInput pad, relative to the entity. Input pads sink data and
are targets of links.MEDIA_PAD_FL_SOURCEOutput pad, relative to the entity. Output pads source data
and are origins of links.MEDIA_PAD_FL_MUST_CONNECTIf this flag is set and the pad is linked to any other
pad, then at least one of those links must be enabled for the
entity to be able to stream. There could be temporary reasons
(e.g. device configuration dependent) for the pad to need
enabled links even when this flag isn't set; the absence of the
flag doesn't imply there is none.
One and only one of MEDIA_PAD_FL_SINK and
MEDIA_PAD_FL_SOURCE must be set for every pad.
Media link flagsMEDIA_LNK_FL_ENABLEDThe link is enabled and can be used to transfer media data.
When two or more links target a sink pad, only one of them can be
enabled at a time.MEDIA_LNK_FL_IMMUTABLEThe link enabled state can't be modified at runtime. An
immutable link is always enabled.MEDIA_LNK_FL_DYNAMICThe link enabled state can be modified during streaming. This
flag is set by drivers and is read-only for applications.MEDIA_LNK_FL_LINK_TYPEThis is a bitmask that defines the type of the link.
Currently, two types of links are supported:MEDIA_LNK_FL_DATA_LINK
if the link is between two padsMEDIA_LNK_FL_INTERFACE_LINK
if the link is between an interface and an entity