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diff --git a/Documentation/media/uapi/v4l/pixfmt-intro.rst b/Documentation/media/uapi/v4l/pixfmt-intro.rst deleted file mode 100644 index ca0a6e0d8959..000000000000 --- a/Documentation/media/uapi/v4l/pixfmt-intro.rst +++ /dev/null @@ -1,58 +0,0 @@ -.. 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/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -********************** -Standard Image Formats -********************** - -In order to exchange images between drivers and applications, it is -necessary to have standard image data formats which both sides will -interpret the same way. V4L2 includes several such formats, and this -section is intended to be an unambiguous specification of the standard -image data formats in V4L2. - -V4L2 drivers are not limited to these formats, however. Driver-specific -formats are possible. In that case the application may depend on a codec -to convert images to one of the standard formats when needed. But the -data can still be stored and retrieved in the proprietary format. For -example, a device may support a proprietary compressed format. -Applications can still capture and save the data in the compressed -format, saving much disk space, and later use a codec to convert the -images to the X Windows screen format when the video is to be displayed. - -Even so, ultimately, some standard formats are needed, so the V4L2 -specification would not be complete without well-defined standard -formats. - -The V4L2 standard formats are mainly uncompressed formats. The pixels -are always arranged in memory from left to right, and from top to -bottom. The first byte of data in the image buffer is always for the -leftmost pixel of the topmost row. Following that is the pixel -immediately to its right, and so on until the end of the top row of -pixels. Following the rightmost pixel of the row there may be zero or -more bytes of padding to guarantee that each row of pixel data has a -certain alignment. Following the pad bytes, if any, is data for the -leftmost pixel of the second row from the top, and so on. The last row -has just as many pad bytes after it as the other rows. - -In V4L2 each format has an identifier which looks like ``PIX_FMT_XXX``, -defined in the :ref:`videodev2.h <videodev>` header file. These -identifiers represent -:ref:`four character (FourCC) codes <v4l2-fourcc>` which are also -listed below, however they are not the same as those used in the Windows -world. - -For some formats, data is stored in separate, discontiguous memory -buffers. Those formats are identified by a separate set of FourCC codes -and are referred to as "multi-planar formats". For example, a -:ref:`YUV422 <V4L2-PIX-FMT-YUV422M>` frame is normally stored in one -memory buffer, but it can also be placed in two or three separate -buffers, with Y component in one buffer and CbCr components in another -in the 2-planar version or with each component in its own buffer in the -3-planar case. Those sub-buffers are referred to as "*planes*". |