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Diffstat (limited to 'Documentation/admin-guide/media/vivid.rst')
| -rw-r--r-- | Documentation/admin-guide/media/vivid.rst | 29 |
1 files changed, 26 insertions, 3 deletions
diff --git a/Documentation/admin-guide/media/vivid.rst b/Documentation/admin-guide/media/vivid.rst index 52e57b773f07..58ac25b2c385 100644 --- a/Documentation/admin-guide/media/vivid.rst +++ b/Documentation/admin-guide/media/vivid.rst @@ -293,6 +293,15 @@ all configurable using the following module options: - 0: vmalloc - 1: dma-contig +- cache_hints: + + specifies if the device should set queues' user-space cache and memory + consistency hint capability (V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS). + The hints are valid only when using MMAP streaming I/O. Default is 0. + + - 0: forbid hints + - 1: allow hints + Taken together, all these module options allow you to precisely customize the driver behavior and test your application with all sorts of permutations. It is also very suitable to emulate hardware that is not yet available, e.g. @@ -383,7 +392,7 @@ Which one is returned depends on the chosen channel, each next valid channel will cycle through the possible audio subchannel combinations. This allows you to test the various combinations by just switching channels.. -Finally, for these inputs the v4l2_timecode struct is filled in in the +Finally, for these inputs the v4l2_timecode struct is filled in the dequeued v4l2_buffer struct. @@ -571,7 +580,7 @@ Metadata Capture ---------------- The Metadata capture generates UVC format metadata. The PTS and SCR are -transmitted based on the values set in vivid contols. +transmitted based on the values set in vivid controls. The Metadata device will only work for the Webcam input, it will give back an error for all other inputs. @@ -705,6 +714,20 @@ The Test Pattern Controls are all specific to video capture. does the same for the EAV (End of Active Video) code. +- Insert Video Guard Band + + adds 4 columns of pixels with the HDMI Video Guard Band code at the + left hand side of the image. This only works with 3 or 4 byte RGB pixel + formats. The RGB pixel value 0xab/0x55/0xab turns out to be equivalent + to the HDMI Video Guard Band code that precedes each active video line + (see section 5.2.2.1 in the HDMI 1.3 Specification). To test if a video + receiver has correct HDMI Video Guard Band processing, enable this + control and then move the image to the left hand side of the screen. + That will result in video lines that start with multiple pixels that + have the same value as the Video Guard Band that precedes them. + Receivers that will just keep skipping Video Guard Band values will + now fail and either loose sync or these video lines will shift. + Capture Feature Selection Controls ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ @@ -1295,7 +1318,7 @@ instance. This setup would require the following commands: $ v4l2-ctl -d2 -i2 $ v4l2-ctl -d2 -c horizontal_movement=4 $ v4l2-ctl -d1 --overlay=1 - $ v4l2-ctl -d1 -c loop_video=1 + $ v4l2-ctl -d0 -c loop_video=1 $ v4l2-ctl -d2 --stream-mmap --overlay=1 And from another console: |