^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) .. c:namespace:: V4L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) .. _VIDIOC_G_JPEGCOMP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) ******************************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) ioctl VIDIOC_G_JPEGCOMP, VIDIOC_S_JPEGCOMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) ******************************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) ====
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) VIDIOC_G_JPEGCOMP - VIDIOC_S_JPEGCOMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Synopsis
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) ========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) .. c:macro:: VIDIOC_G_JPEGCOMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) ``int ioctl(int fd, VIDIOC_G_JPEGCOMP, v4l2_jpegcompression *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) .. c:macro:: VIDIOC_S_JPEGCOMP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) ``int ioctl(int fd, VIDIOC_S_JPEGCOMP, const v4l2_jpegcompression *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) Arguments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) =========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) ``fd``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) File descriptor returned by :c:func:`open()`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) ``argp``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) Pointer to struct :c:type:`v4l2_jpegcompression`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) ===========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) These ioctls are **deprecated**. New drivers and applications should use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) :ref:`JPEG class controls <jpeg-controls>` for image quality and JPEG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) markers control.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) [to do]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) Ronald Bultje elaborates:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) APP is some application-specific information. The application can set it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) itself, and it'll be stored in the JPEG-encoded fields (eg; interlacing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) information for in an AVI or so). COM is the same, but it's comments,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) like 'encoded by me' or so.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) jpeg_markers describes whether the huffman tables, quantization tables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) and the restart interval information (all JPEG-specific stuff) should be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) stored in the JPEG-encoded fields. These define how the JPEG field is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) encoded. If you omit them, applications assume you've used standard
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) encoding. You usually do want to add them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) .. tabularcolumns:: |p{1.2cm}|p{3.0cm}|p{13.3cm}|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) .. c:type:: v4l2_jpegcompression
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) .. flat-table:: struct v4l2_jpegcompression
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) :header-rows: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) :stub-columns: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) :widths: 1 1 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) * - int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) - ``quality``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) - Deprecated. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) :ref:`V4L2_CID_JPEG_COMPRESSION_QUALITY <jpeg-quality-control>`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) control is exposed by a driver applications should use it instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) and ignore this field.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * - int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) - ``APPn``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) * - int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) - ``APP_len``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * - char
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) - ``APP_data``\ [60]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * - int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) - ``COM_len``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * - char
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) - ``COM_data``\ [60]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) - ``jpeg_markers``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) - See :ref:`jpeg-markers`. Deprecated. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) :ref:`V4L2_CID_JPEG_ACTIVE_MARKER <jpeg-active-marker-control>`
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) control is exposed by a driver applications should use it instead
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) and ignore this field.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) .. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) .. _jpeg-markers:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) .. flat-table:: JPEG Markers Flags
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) :header-rows: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) :stub-columns: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) :widths: 3 1 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * - ``V4L2_JPEG_MARKER_DHT``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) - (1<<3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) - Define Huffman Tables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * - ``V4L2_JPEG_MARKER_DQT``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) - (1<<4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) - Define Quantization Tables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) * - ``V4L2_JPEG_MARKER_DRI``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) - (1<<5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) - Define Restart Interval
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * - ``V4L2_JPEG_MARKER_COM``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) - (1<<6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) - Comment segment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * - ``V4L2_JPEG_MARKER_APP``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) - (1<<7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) - App segment, driver will always use APP0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) Return Value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) ============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) On success 0 is returned, on error -1 and the ``errno`` variable is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) appropriately. The generic error codes are described at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) :ref:`Generic Error Codes <gen-errors>` chapter.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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