xref: /OK3568_Linux_fs/kernel/Documentation/userspace-api/media/dvb/video.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun.. _dvb_video:
4*4882a593Smuzhiyun
5*4882a593Smuzhiyun#######################
6*4882a593SmuzhiyunDigital TV Video Device
7*4882a593Smuzhiyun#######################
8*4882a593Smuzhiyun
9*4882a593SmuzhiyunThe Digital TV video device controls the MPEG2 video decoder of the Digital
10*4882a593SmuzhiyunTV hardware. It can be accessed through **/dev/dvb/adapter0/video0**. Data
11*4882a593Smuzhiyuntypes and and ioctl definitions can be accessed by including
12*4882a593Smuzhiyun**linux/dvb/video.h** in your application.
13*4882a593Smuzhiyun
14*4882a593SmuzhiyunNote that the Digital TV video device only controls decoding of the MPEG video
15*4882a593Smuzhiyunstream, not its presentation on the TV or computer screen. On PCs this
16*4882a593Smuzhiyunis typically handled by an associated video4linux device, e.g.
17*4882a593Smuzhiyun**/dev/video**, which allows scaling and defining output windows.
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunSome Digital TV cards don’t have their own MPEG decoder, which results in the
20*4882a593Smuzhiyunomission of the audio and video device as well as the video4linux
21*4882a593Smuzhiyundevice.
22*4882a593Smuzhiyun
23*4882a593SmuzhiyunThe ioctls that deal with SPUs (sub picture units) and navigation
24*4882a593Smuzhiyunpackets are only supported on some MPEG decoders made for DVD playback.
25*4882a593Smuzhiyun
26*4882a593SmuzhiyunThese ioctls were also used by V4L2 to control MPEG decoders implemented
27*4882a593Smuzhiyunin V4L2. The use of these ioctls for that purpose has been made obsolete
28*4882a593Smuzhiyunand proper V4L2 ioctls or controls have been created to replace that
29*4882a593Smuzhiyunfunctionality.
30*4882a593Smuzhiyun
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun.. toctree::
33*4882a593Smuzhiyun    :maxdepth: 1
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun    video_types
36*4882a593Smuzhiyun    video_function_calls
37