8 BIT PHOTO CONVERTER CODE
A FOURCC code is a 32-bit unsigned integer that is created by concatenating four ASCII characters.Ī single 4:4:4 format is recommended, with the FOURCC code AYUV. In a planar format, the Y, U, and V components are stored as three separate planes.Įach of the YUV formats described in this article has an assigned FOURCC code. Pixels are organized into groups of macropixels, whose layout depends on the format. In a packed format, the Y, U, and V components are stored in a single array. YUV formats are divided into packed formats and planar formats. The alignment can be larger than 32 bits, however, depending on the needs of the hardware. The surface must always be DWORD aligned that is, individual lines within the surface are guaranteed to originate on a 32-bit (DWORD) boundary. The alignment of a surface is at the discretion of the graphics display driver. Given a surface origin at the top left corner, the stride is always positive. The stride of a surface, sometimes called the pitch, is the width of the surface in bytes. For the YUV formats described in this article, the origin (0,0) is always the top left corner of the surface.
These fall into several categories:įirst, you should be aware of the following concepts in order to understand what follows: This section describes the 8-bit YUV formats that are recommended for video rendering. For this reason, the MPEG-2 scheme is preferred in Windows, and should be considered the default interpretation of 4:2:0 formats. One of these is used in MPEG-2 video, and the other is used in MPEG-1 and in ITU-T Recommendations H.261 and H.263.Ĭompared with the MPEG-1 scheme, it is simpler to convert between the MPEG-2 scheme and the sampling grids defined for 4:2:2 and 4:4:4 formats. There are two common variants of 4:2:0 sampling. The dominant form of 4:2:2 sampling is defined in ITU-R Recommendation BT.601. Luma samples are represented by a cross, and chroma samples are represented by a circle. The following diagrams shows how chroma is sampled for each of the downsampling rates. 4:1:1 sampling is less common than other formats, and is not discussed in detail in this article. Every scan line contains four Y samples for each U and V sample.
8 BIT PHOTO CONVERTER HOW TO
Explains how to describe YUV format types in Media Foundation.Ĭhroma channels can have a lower sampling rate than the luma channel, without any dramatic loss of perceptual quality. Identifying YUV Formats in Media Foundation.Provides some guidelines for converting between YUV and RGB formats and for converting between different YUV formats. Color Space and Chroma Sampling Rate Conversions.Describes the most common YUV sampling techniques. This article covers the following topics: This article does not cover YUV formats with 10-bit or higher Y channels.įor the purposes of this article, the term U is equivalent to Cb, and the term V is equivalent to Cr. However, most YUV formats use fewer than 24 bits per pixel on average, because they contain fewer samples of U and V than of Y. The formats described in this article all use 8 bits per pixel location to encode the Y channel (also called the luma channel), and use 8 bits per sample to encode each U or V chroma sample. This article does not address other uses of YUV color, such as still photography. Decoder vendors and display vendors are encouraged to support the formats described in this article.
This article identifies the 8-bit YUV formats that are recommended for video rendering in Windows. Numerous YUV formats are defined throughout the video industry. This article is intended for anyone working with YUV video decoding or rendering in Windows. This article presents techniques for converting between YUV and RGB formats, and also provides techniques for upsampling YUV formats.
8 BIT PHOTO CONVERTER WINDOWS
This topic describes the 8-bit YUV color formats that are recommended for video rendering in the Windows operating system.
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