fa92b04d98
Sphinx is really pedantic with respect to the order where table tags and references are created. Putting things at the wrong order causes troubles. The order that seems to work is: .. raw:: latex .. tabularcolumns:: .. _foo_name: .. cssclass: longtable .. flat-table:: Reorder the tags to the above order, to avoid troubles, and fix remaining warnings introduced by media recent patches. Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
188 lines
3.3 KiB
ReStructuredText
188 lines
3.3 KiB
ReStructuredText
.. -*- coding: utf-8; mode: rst -*-
|
|
|
|
.. _VIDIOC_G_JPEGCOMP:
|
|
|
|
******************************************
|
|
ioctl VIDIOC_G_JPEGCOMP, VIDIOC_S_JPEGCOMP
|
|
******************************************
|
|
|
|
Name
|
|
====
|
|
|
|
VIDIOC_G_JPEGCOMP - VIDIOC_S_JPEGCOMP
|
|
|
|
|
|
Synopsis
|
|
========
|
|
|
|
.. cpp:function:: int ioctl( int fd, int request, v4l2_jpegcompression *argp )
|
|
|
|
.. cpp:function:: int ioctl( int fd, int request, const v4l2_jpegcompression *argp )
|
|
|
|
|
|
Arguments
|
|
=========
|
|
|
|
``fd``
|
|
File descriptor returned by :ref:`open() <func-open>`.
|
|
|
|
``request``
|
|
VIDIOC_G_JPEGCOMP, VIDIOC_S_JPEGCOMP
|
|
|
|
``argp``
|
|
|
|
|
|
Description
|
|
===========
|
|
|
|
These ioctls are **deprecated**. New drivers and applications should use
|
|
:ref:`JPEG class controls <jpeg-controls>` for image quality and JPEG
|
|
markers control.
|
|
|
|
[to do]
|
|
|
|
Ronald Bultje elaborates:
|
|
|
|
APP is some application-specific information. The application can set it
|
|
itself, and it'll be stored in the JPEG-encoded fields (eg; interlacing
|
|
information for in an AVI or so). COM is the same, but it's comments,
|
|
like 'encoded by me' or so.
|
|
|
|
jpeg_markers describes whether the huffman tables, quantization tables
|
|
and the restart interval information (all JPEG-specific stuff) should be
|
|
stored in the JPEG-encoded fields. These define how the JPEG field is
|
|
encoded. If you omit them, applications assume you've used standard
|
|
encoding. You usually do want to add them.
|
|
|
|
|
|
.. tabularcolumns:: |p{1.2cm}|p{3.0cm}|p{13.3cm}|
|
|
|
|
.. _v4l2-jpegcompression:
|
|
|
|
.. flat-table:: struct v4l2_jpegcompression
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 1 1 2
|
|
|
|
|
|
- .. row 1
|
|
|
|
- int
|
|
|
|
- ``quality``
|
|
|
|
- Deprecated. If
|
|
:ref:`V4L2_CID_JPEG_COMPRESSION_QUALITY <jpeg-quality-control>`
|
|
control is exposed by a driver applications should use it instead
|
|
and ignore this field.
|
|
|
|
- .. row 2
|
|
|
|
- int
|
|
|
|
- ``APPn``
|
|
|
|
-
|
|
|
|
- .. row 3
|
|
|
|
- int
|
|
|
|
- ``APP_len``
|
|
|
|
-
|
|
|
|
- .. row 4
|
|
|
|
- char
|
|
|
|
- ``APP_data``\ [60]
|
|
|
|
-
|
|
|
|
- .. row 5
|
|
|
|
- int
|
|
|
|
- ``COM_len``
|
|
|
|
-
|
|
|
|
- .. row 6
|
|
|
|
- char
|
|
|
|
- ``COM_data``\ [60]
|
|
|
|
-
|
|
|
|
- .. row 7
|
|
|
|
- __u32
|
|
|
|
- ``jpeg_markers``
|
|
|
|
- See :ref:`jpeg-markers`. Deprecated. If
|
|
:ref:`V4L2_CID_JPEG_ACTIVE_MARKER <jpeg-active-marker-control>`
|
|
control is exposed by a driver applications should use it instead
|
|
and ignore this field.
|
|
|
|
|
|
.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
|
|
|
|
.. _jpeg-markers:
|
|
|
|
.. flat-table:: JPEG Markers Flags
|
|
:header-rows: 0
|
|
:stub-columns: 0
|
|
:widths: 3 1 4
|
|
|
|
|
|
- .. row 1
|
|
|
|
- ``V4L2_JPEG_MARKER_DHT``
|
|
|
|
- (1<<3)
|
|
|
|
- Define Huffman Tables
|
|
|
|
- .. row 2
|
|
|
|
- ``V4L2_JPEG_MARKER_DQT``
|
|
|
|
- (1<<4)
|
|
|
|
- Define Quantization Tables
|
|
|
|
- .. row 3
|
|
|
|
- ``V4L2_JPEG_MARKER_DRI``
|
|
|
|
- (1<<5)
|
|
|
|
- Define Restart Interval
|
|
|
|
- .. row 4
|
|
|
|
- ``V4L2_JPEG_MARKER_COM``
|
|
|
|
- (1<<6)
|
|
|
|
- Comment segment
|
|
|
|
- .. row 5
|
|
|
|
- ``V4L2_JPEG_MARKER_APP``
|
|
|
|
- (1<<7)
|
|
|
|
- App segment, driver will always use APP0
|
|
|
|
|
|
Return Value
|
|
============
|
|
|
|
On success 0 is returned, on error -1 and the ``errno`` variable is set
|
|
appropriately. The generic error codes are described at the
|
|
:ref:`Generic Error Codes <gen-errors>` chapter.
|