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Diffstat (limited to 'Documentation/userspace-api/media/v4l/control.rst')
| -rw-r--r-- | Documentation/userspace-api/media/v4l/control.rst | 46 |
1 files changed, 29 insertions, 17 deletions
diff --git a/Documentation/userspace-api/media/v4l/control.rst b/Documentation/userspace-api/media/v4l/control.rst index 3e991c1f7a12..19372bb32c4b 100644 --- a/Documentation/userspace-api/media/v4l/control.rst +++ b/Documentation/userspace-api/media/v4l/control.rst @@ -1,11 +1,5 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/userspace-api/media/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L .. _control: @@ -150,9 +144,13 @@ Control IDs recognise the difference between digital and analogue gain use controls ``V4L2_CID_DIGITAL_GAIN`` and ``V4L2_CID_ANALOGUE_GAIN``. +.. _v4l2-cid-hflip: + ``V4L2_CID_HFLIP`` ``(boolean)`` Mirror the picture horizontally. +.. _v4l2-cid-vflip: + ``V4L2_CID_VFLIP`` ``(boolean)`` Mirror the picture vertically. @@ -161,10 +159,13 @@ Control IDs ``V4L2_CID_POWER_LINE_FREQUENCY`` ``(enum)`` Enables a power line frequency filter to avoid flicker. Possible values for ``enum v4l2_power_line_frequency`` are: - ``V4L2_CID_POWER_LINE_FREQUENCY_DISABLED`` (0), - ``V4L2_CID_POWER_LINE_FREQUENCY_50HZ`` (1), - ``V4L2_CID_POWER_LINE_FREQUENCY_60HZ`` (2) and - ``V4L2_CID_POWER_LINE_FREQUENCY_AUTO`` (3). + + ========================================== == + ``V4L2_CID_POWER_LINE_FREQUENCY_DISABLED`` 0 + ``V4L2_CID_POWER_LINE_FREQUENCY_50HZ`` 1 + ``V4L2_CID_POWER_LINE_FREQUENCY_60HZ`` 2 + ``V4L2_CID_POWER_LINE_FREQUENCY_AUTO`` 3 + ========================================== == ``V4L2_CID_HUE_AUTO`` ``(boolean)`` Enables automatic hue control by the device. The effect of setting @@ -204,7 +205,7 @@ Control IDs -.. tabularcolumns:: |p{5.5cm}|p{12cm}| +.. tabularcolumns:: |p{5.7cm}|p{11.8cm}| .. flat-table:: :header-rows: 0 @@ -246,8 +247,17 @@ Control IDs * - ``V4L2_COLORFX_SET_CBCR`` - The Cb and Cr chroma components are replaced by fixed coefficients determined by ``V4L2_CID_COLORFX_CBCR`` control. + * - ``V4L2_COLORFX_SET_RGB`` + - The RGB components are replaced by the fixed RGB components determined + by ``V4L2_CID_COLORFX_RGB`` control. +``V4L2_CID_COLORFX_RGB`` ``(integer)`` + Determines the Red, Green, and Blue coefficients for + ``V4L2_COLORFX_SET_RGB`` color effect. + Bits [7:0] of the supplied 32 bit value are interpreted as Blue component, + bits [15:8] as Green component, bits [23:16] as Red component, and + bits [31:24] must be zero. ``V4L2_CID_COLORFX_CBCR`` ``(integer)`` Determines the Cb and Cr coefficients for ``V4L2_COLORFX_SET_CBCR`` @@ -281,13 +291,15 @@ Control IDs This is a read-only control that can be read by the application and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS. The value is the minimum number of CAPTURE buffers that is - necessary for hardware to work. + necessary for hardware to work. This control is required for stateful + decoders. ``V4L2_CID_MIN_BUFFERS_FOR_OUTPUT`` ``(integer)`` This is a read-only control that can be read by the application and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS. The value is the minimum number of OUTPUT buffers that is - necessary for hardware to work. + necessary for hardware to work. This control is required for stateful + encoders. .. _v4l2-alpha-component: @@ -456,10 +468,10 @@ Example: Changing controls perror("VIDIOC_QUERYCTRL"); exit(EXIT_FAILURE); } else { - printf("V4L2_CID_BRIGHTNESS is not supportedn"); + printf("V4L2_CID_BRIGHTNESS is not supported\n"); } } else if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) { - printf("V4L2_CID_BRIGHTNESS is not supportedn"); + printf("V4L2_CID_BRIGHTNESS is not supported\n"); } else { memset(&control, 0, sizeof (control)); control.id = V4L2_CID_BRIGHTNESS; |