6.2. Digital TV Video Device¶
The Digital TV video device controls the MPEG2 video decoder of the Digital TV hardware. It can be accessed through /dev/dvb/adapter0/video0. Data types and ioctl definitions can be accessed by including linux/dvb/video.h in your application.
Note that the Digital TV video device only controls decoding of the MPEG video stream, not its presentation on the TV or computer screen. On PCs this is typically handled by an associated video4linux device, e.g. /dev/video, which allows scaling and defining output windows.
Some Digital TV cards don’t have their own MPEG decoder, which results in the omission of the audio and video device as well as the video4linux device.
The ioctls that deal with SPUs (sub picture units) and navigation packets are only supported on some MPEG decoders made for DVD playback.
These ioctls were also used by V4L2 to control MPEG decoders implemented in V4L2. The use of these ioctls for that purpose has been made obsolete and proper V4L2 ioctls or controls have been created to replace that functionality.