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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _packed-yuv:
+
+******************
+Packed YUV formats
+******************
+
+Similarly to the packed RGB formats, the packed YUV formats store the Y, Cb and
+Cr components consecutively in memory. They may apply subsampling to the chroma
+components and thus differ in how they interlave the three components.
+
+.. note::
+
+ - In all the tables that follow, bit 7 is the most significant bit in a byte.
+ - 'Y', 'Cb' and 'Cr' denote bits of the luma, blue chroma (also known as
+ 'U') and red chroma (also known as 'V') components respectively. 'A'
+ denotes bits of the alpha component (if supported by the format), and 'X'
+ denotes padding bits.
+
+
+4:4:4 Subsampling
+=================
+
+These formats do not subsample the chroma components and store each pixels as a
+full triplet of Y, Cb and Cr values.
+
+The next table lists the packed YUV 4:4:4 formats with less than 8 bits per
+component. They are named based on the order of the Y, Cb and Cr components as
+seen in a 16-bit word, which is then stored in memory in little endian byte
+order, and on the number of bits for each component. For instance the YUV565
+format stores a pixel in a 16-bit word [15:0] laid out at as [Y'\ :sub:`4-0`
+Cb\ :sub:`5-0` Cr\ :sub:`4-0`], and stored in memory in two bytes,
+[Cb\ :sub:`2-0` Cr\ :sub:`4-0`] followed by [Y'\ :sub:`4-0` Cb\ :sub:`5-3`].
+
+.. raw:: latex
+
+ \begingroup
+ \scriptsize
+ \setlength{\tabcolsep}{2pt}
+
+.. tabularcolumns:: |p{3.5cm}|p{0.96cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|p{0.52cm}|
+
+.. flat-table:: Packed YUV 4:4:4 Image Formats (less than 8bpc)
+ :header-rows: 2
+ :stub-columns: 0
+
+ * - Identifier
+ - Code
+
+ - :cspan:`7` Byte 0 in memory
+
+ - :cspan:`7` Byte 1
+
+ * -
+ -
+ - 7
+ - 6
+ - 5
+ - 4
+ - 3
+ - 2
+ - 1
+ - 0
+
+ - 7
+ - 6
+ - 5
+ - 4
+ - 3
+ - 2
+ - 1
+ - 0
+
+ * .. _V4L2-PIX-FMT-YUV444:
+
+ - ``V4L2_PIX_FMT_YUV444``
+ - 'Y444'
+
+ - Cb\ :sub:`3`
+ - Cb\ :sub:`2`
+ - Cb\ :sub:`1`
+ - Cb\ :sub:`0`
+ - Cr\ :sub:`3`
+ - Cr\ :sub:`2`
+ - Cr\ :sub:`1`
+ - Cr\ :sub:`0`
+
+ - a\ :sub:`3`
+ - a\ :sub:`2`
+ - a\ :sub:`1`
+ - a\ :sub:`0`
+ - Y'\ :sub:`3`
+ - Y'\ :sub:`2`
+ - Y'\ :sub:`1`
+ - Y'\ :sub:`0`
+
+ * .. _V4L2-PIX-FMT-YUV555:
+
+ - ``V4L2_PIX_FMT_YUV555``
+ - 'YUVO'
+
+ - Cb\ :sub:`2`
+ - Cb\ :sub:`1`
+ - Cb\ :sub:`0`
+ - Cr\ :sub:`4`
+ - Cr\ :sub:`3`
+ - Cr\ :sub:`2`
+ - Cr\ :sub:`1`
+ - Cr\ :sub:`0`
+
+ - a
+ - Y'\ :sub:`4`
+ - Y'\ :sub:`3`
+ - Y'\ :sub:`2`
+ - Y'\ :sub:`1`
+ - Y'\ :sub:`0`
+ - Cb\ :sub:`4`
+ - Cb\ :sub:`3`
+
+ * .. _V4L2-PIX-FMT-YUV565:
+
+ - ``V4L2_PIX_FMT_YUV565``
+ - 'YUVP'
+
+ - Cb\ :sub:`2`
+ - Cb\ :sub:`1`
+ - Cb\ :sub:`0`
+ - Cr\ :sub:`4`
+ - Cr\ :sub:`3`
+ - Cr\ :sub:`2`
+ - Cr\ :sub:`1`
+ - Cr\ :sub:`0`
+
+ - Y'\ :sub:`4`
+ - Y'\ :sub:`3`
+ - Y'\ :sub:`2`
+ - Y'\ :sub:`1`
+ - Y'\ :sub:`0`
+ - Cb\ :sub:`5`
+ - Cb\ :sub:`4`
+ - Cb\ :sub:`3`
+
+.. raw:: latex
+
+ \endgroup
+
+.. note::
+
+ For the YUV444 and YUV555 formats, the value of alpha bits is undefined
+ when reading from the driver, ignored when writing to the driver, except
+ when alpha blending has been negotiated for a :ref:`Video Overlay
+ <overlay>` or :ref:`Video Output Overlay <osd>`.
+
+
+The next table lists the packed YUV 4:4:4 formats with 8 bits per component.
+They are named based on the order of the Y, Cb and Cr components as stored in
+memory, and on the total number of bits per pixel. For instance, the VUYX32
+format stores a pixel with Cr\ :sub:`7-0` in the first byte, Cb\ :sub:`7-0` in
+the second byte and Y'\ :sub:`7-0` in the third byte.
+
+.. flat-table:: Packed YUV Image Formats (8bpc)
+ :header-rows: 1
+ :stub-columns: 0
+
+ * - Identifier
+ - Code
+ - Byte 0
+ - Byte 1
+ - Byte 2
+ - Byte 3
+
+ * .. _V4L2-PIX-FMT-YUV32:
+
+ - ``V4L2_PIX_FMT_YUV32``
+ - 'YUV4'
+
+ - A\ :sub:`7-0`
+ - Y'\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Cr\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-AYUV32:
+
+ - ``V4L2_PIX_FMT_AYUV32``
+ - 'AYUV'
+
+ - A\ :sub:`7-0`
+ - Y'\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Cr\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-XYUV32:
+
+ - ``V4L2_PIX_FMT_XYUV32``
+ - 'XYUV'
+
+ - X\ :sub:`7-0`
+ - Y'\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Cr\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-VUYA32:
+
+ - ``V4L2_PIX_FMT_VUYA32``
+ - 'VUYA'
+
+ - Cr\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Y'\ :sub:`7-0`
+ - A\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-VUYX32:
+
+ - ``V4L2_PIX_FMT_VUYX32``
+ - 'VUYX'
+
+ - Cr\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Y'\ :sub:`7-0`
+ - X\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-YUVA32:
+
+ - ``V4L2_PIX_FMT_YUVA32``
+ - 'YUVA'
+
+ - Y'\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Cr\ :sub:`7-0`
+ - A\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-YUVX32:
+
+ - ``V4L2_PIX_FMT_YUVX32``
+ - 'YUVX'
+
+ - Y'\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Cr\ :sub:`7-0`
+ - X\ :sub:`7-0`
+
+ * .. _V4L2-PIX-FMT-YUV24:
+
+ - ``V4L2_PIX_FMT_YUV24``
+ - 'YUV3'
+
+ - Y'\ :sub:`7-0`
+ - Cb\ :sub:`7-0`
+ - Cr\ :sub:`7-0`
+ - -\
+
+.. note::
+
+ - The alpha component is expected to contain a meaningful value that can be
+ used by drivers and applications.
+ - The padding bits contain undefined values that must be ignored by all
+ applications and drivers.
+
+
+4:2:2 Subsampling
+=================
+
+These formats, commonly referred to as YUYV or YUY2, subsample the chroma
+components horizontally by 2, storing 2 pixels in 4 bytes.
+
+.. raw:: latex
+
+ \footnotesize
+
+.. tabularcolumns:: |p{3.4cm}|p{1.2cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|p{0.8cm}|
+
+.. flat-table:: Packed YUV 4:2:2 Formats
+ :header-rows: 1
+ :stub-columns: 0
+
+ * - Identifier
+ - Code
+ - Byte 0
+ - Byte 1
+ - Byte 2
+ - Byte 3
+ - Byte 4
+ - Byte 5
+ - Byte 6
+ - Byte 7
+ * .. _V4L2-PIX-FMT-UYVY:
+
+ - ``V4L2_PIX_FMT_UYVY``
+ - 'UYVY'
+
+ - Cb\ :sub:`0`
+ - Y'\ :sub:`0`
+ - Cr\ :sub:`0`
+ - Y'\ :sub:`1`
+ - Cb\ :sub:`2`
+ - Y'\ :sub:`2`
+ - Cr\ :sub:`2`
+ - Y'\ :sub:`3`
+ * .. _V4L2-PIX-FMT-VYUY:
+
+ - ``V4L2_PIX_FMT_VYUY``
+ - 'VYUY'
+
+ - Cr\ :sub:`0`
+ - Y'\ :sub:`0`
+ - Cb\ :sub:`0`
+ - Y'\ :sub:`1`
+ - Cr\ :sub:`2`
+ - Y'\ :sub:`2`
+ - Cb\ :sub:`2`
+ - Y'\ :sub:`3`
+ * .. _V4L2-PIX-FMT-YUYV:
+
+ - ``V4L2_PIX_FMT_YUYV``
+ - 'YUYV'
+
+ - Y'\ :sub:`0`
+ - Cb\ :sub:`0`
+ - Y'\ :sub:`1`
+ - Cr\ :sub:`0`
+ - Y'\ :sub:`2`
+ - Cb\ :sub:`2`
+ - Y'\ :sub:`3`
+ - Cr\ :sub:`2`
+ * .. _V4L2-PIX-FMT-YVYU:
+
+ - ``V4L2_PIX_FMT_YVYU``
+ - 'YVYU'
+
+ - Y'\ :sub:`0`
+ - Cr\ :sub:`0`
+ - Y'\ :sub:`1`
+ - Cb\ :sub:`0`
+ - Y'\ :sub:`2`
+ - Cr\ :sub:`2`
+ - Y'\ :sub:`3`
+ - Cb\ :sub:`2`
+
+.. raw:: latex
+
+ \normalsize
+
+**Color Sample Location:**
+Chroma samples are :ref:`interstitially sited<yuv-chroma-centered>`
+horizontally.
+
+
+4:1:1 Subsampling
+=================
+
+This format subsamples the chroma components horizontally by 4, storing 8
+pixels in 12 bytes.
+
+.. raw:: latex
+
+ \scriptsize
+
+.. tabularcolumns:: |p{2.9cm}|p{0.8cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|p{0.5cm}|
+
+.. flat-table:: Packed YUV 4:1:1 Formats
+ :header-rows: 1
+ :stub-columns: 0
+
+ * - Identifier
+ - Code
+ - Byte 0
+ - Byte 1
+ - Byte 2
+ - Byte 3
+ - Byte 4
+ - Byte 5
+ - Byte 6
+ - Byte 7
+ - Byte 8
+ - Byte 9
+ - Byte 10
+ - Byte 11
+ * .. _V4L2-PIX-FMT-Y41P:
+
+ - ``V4L2_PIX_FMT_Y41P``
+ - 'Y41P'
+
+ - Cb\ :sub:`0`
+ - Y'\ :sub:`0`
+ - Cr\ :sub:`0`
+ - Y'\ :sub:`1`
+ - Cb\ :sub:`4`
+ - Y'\ :sub:`2`
+ - Cr\ :sub:`4`
+ - Y'\ :sub:`3`
+ - Y'\ :sub:`4`
+ - Y'\ :sub:`5`
+ - Y'\ :sub:`6`
+ - Y'\ :sub:`7`
+
+.. raw:: latex
+
+ \normalsize
+
+.. note::
+
+ Do not confuse ``V4L2_PIX_FMT_Y41P`` with
+ :ref:`V4L2_PIX_FMT_YUV411P <V4L2-PIX-FMT-YUV411P>`. Y41P is derived from
+ "YUV 4:1:1 **packed**", while YUV411P stands for "YUV 4:1:1 **planar**".
+
+**Color Sample Location:**
+Chroma samples are :ref:`interstitially sited<yuv-chroma-centered>`
+horizontally.
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-31 22:31:20 +0000