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author | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-22 19:31:08 -0300 |
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committer | André Fabian Silva Delgado <emulatorman@parabola.nu> | 2016-10-22 19:31:08 -0300 |
commit | 670027c507e99521d416994a18a498def9ef2ea3 (patch) | |
tree | 74b4d761a9e7904a4f8aa4b58b2dc9801f22284d /Documentation/DocBook/media/v4l/dev-codec.xml | |
parent | d0b2f91bede3bd5e3d24dd6803e56eee959c1797 (diff) |
Linux-libre 4.8.3-gnupck-4.8.3-gnu
Diffstat (limited to 'Documentation/DocBook/media/v4l/dev-codec.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/dev-codec.xml | 27 |
1 files changed, 0 insertions, 27 deletions
diff --git a/Documentation/DocBook/media/v4l/dev-codec.xml b/Documentation/DocBook/media/v4l/dev-codec.xml deleted file mode 100644 index ff44c16fc..000000000 --- a/Documentation/DocBook/media/v4l/dev-codec.xml +++ /dev/null @@ -1,27 +0,0 @@ - <title>Codec Interface</title> - - <para>A V4L2 codec can compress, decompress, transform, or otherwise -convert video data from one format into another format, in memory. Typically -such devices are memory-to-memory devices (i.e. devices with the -<constant>V4L2_CAP_VIDEO_M2M</constant> or <constant>V4L2_CAP_VIDEO_M2M_MPLANE</constant> -capability set). -</para> - - <para>A memory-to-memory video node acts just like a normal video node, but it -supports both output (sending frames from memory to the codec hardware) and -capture (receiving the processed frames from the codec hardware into memory) -stream I/O. An application will have to setup the stream -I/O for both sides and finally call &VIDIOC-STREAMON; for both capture and output -to start the codec.</para> - - <para>Video compression codecs use the MPEG controls to setup their codec parameters -(note that the MPEG controls actually support many more codecs than just MPEG). -See <xref linkend="mpeg-controls"></xref>.</para> - - <para>Memory-to-memory devices can often be used as a shared resource: you can -open the video node multiple times, each application setting up their own codec properties -that are local to the file handle, and each can use it independently from the others. -The driver will arbitrate access to the codec and reprogram it whenever another file -handler gets access. This is different from the usual video node behavior where the video properties -are global to the device (i.e. changing something through one file handle is visible -through another file handle).</para> |