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diff --git a/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst b/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst new file mode 100644 index 0000000000..9f111ed594 --- /dev/null +++ b/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst @@ -0,0 +1,482 @@ +.. 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. + +The next table lists the packed YUV 4:4:4 formats with 12 bits per component. +Expand the bits per component to 16 bits, data in the high bits, zeros in the low bits, +arranged in little endian order, storing 1 pixel in 6 bytes. + +.. flat-table:: Packed YUV 4:4:4 Image Formats (12bpc) + :header-rows: 1 + :stub-columns: 0 + + * - Identifier + - Code + - Byte 1-0 + - Byte 3-2 + - Byte 5-4 + - Byte 7-6 + - Byte 9-8 + - Byte 11-10 + + * .. _V4L2-PIX-FMT-YUV48-12: + + - ``V4L2_PIX_FMT_YUV48_12`` + - 'Y312' + + - Y'\ :sub:`0` + - Cb\ :sub:`0` + - Cr\ :sub:`0` + - Y'\ :sub:`1` + - Cb\ :sub:`1` + - Cr\ :sub:`1` + +4:2:2 Subsampling +================= + +These formats, commonly referred to as YUYV or YUY2, subsample the chroma +components horizontally by 2, storing 2 pixels in a container. The container +is 32-bits for 8-bit formats, and 64-bits for 10+-bit formats. + +The packed YUYV formats with more than 8 bits per component are stored as four +16-bit little-endian words. Each word's most significant bits contain one +component, and the least significant bits are zero padding. + +.. 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 in 32-bit container + :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` + +.. 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 in 64-bit container + :header-rows: 1 + :stub-columns: 0 + + * - Identifier + - Code + - Word 0 + - Word 1 + - Word 2 + - Word 3 + * .. _V4L2-PIX-FMT-Y210: + + - ``V4L2_PIX_FMT_Y210`` + - 'Y210' + + - Y'\ :sub:`0` (bits 15-6) + - Cb\ :sub:`0` (bits 15-6) + - Y'\ :sub:`1` (bits 15-6) + - Cr\ :sub:`0` (bits 15-6) + * .. _V4L2-PIX-FMT-Y212: + + - ``V4L2_PIX_FMT_Y212`` + - 'Y212' + + - Y'\ :sub:`0` (bits 15-4) + - Cb\ :sub:`0` (bits 15-4) + - Y'\ :sub:`1` (bits 15-4) + - Cr\ :sub:`0` (bits 15-4) + * .. _V4L2-PIX-FMT-Y216: + + - ``V4L2_PIX_FMT_Y216`` + - 'Y216' + + - Y'\ :sub:`0` (bits 15-0) + - Cb\ :sub:`0` (bits 15-0) + - Y'\ :sub:`1` (bits 15-0) + - Cr\ :sub:`0` (bits 15-0) + +.. 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. |