Documentation/userspace-api/media/v4l/pixfmt-m420.rst
Source file repositories/reference/linux-study-clean/Documentation/userspace-api/media/v4l/pixfmt-m420.rst
File Facts
- System
- Linux kernel
- Corpus path
Documentation/userspace-api/media/v4l/pixfmt-m420.rst- Extension
.rst- Size
- 1804 bytes
- Lines
- 73
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: V4L
.. _V4L2-PIX-FMT-M420:
**************************
V4L2_PIX_FMT_M420 ('M420')
**************************
Format with ½ horizontal and vertical chroma resolution, also known as
YUV 4:2:0. Hybrid plane line-interleaved layout.
Description
===========
M420 is a YUV format with ½ horizontal and vertical chroma subsampling
(YUV 4:2:0). Pixels are organized as interleaved luma and chroma planes.
Two lines of luma data are followed by one line of chroma data.
The luma plane has one byte per pixel. The chroma plane contains
interleaved CbCr pixels subsampled by ½ in the horizontal and vertical
directions. Each CbCr pair belongs to four pixels. For example,
Cb\ :sub:`0`/Cr\ :sub:`0` belongs to Y'\ :sub:`00`, Y'\ :sub:`01`,
Y'\ :sub:`10`, Y'\ :sub:`11`.
All line lengths are identical: if the Y lines include pad bytes so do
the CbCr lines.
**Byte Order.**
Each cell is one byte.
.. flat-table::
:header-rows: 0
:stub-columns: 0
* - start + 0:
- Y'\ :sub:`00`
- Y'\ :sub:`01`
- Y'\ :sub:`02`
- Y'\ :sub:`03`
* - start + 4:
- Y'\ :sub:`10`
- Y'\ :sub:`11`
- Y'\ :sub:`12`
- Y'\ :sub:`13`
* - start + 8:
- Cb\ :sub:`00`
- Cr\ :sub:`00`
- Cb\ :sub:`01`
- Cr\ :sub:`01`
* - start + 16:
- Y'\ :sub:`20`
- Y'\ :sub:`21`
- Y'\ :sub:`22`
- Y'\ :sub:`23`
* - start + 20:
- Y'\ :sub:`30`
- Y'\ :sub:`31`
- Y'\ :sub:`32`
- Y'\ :sub:`33`
* - start + 24:
- Cb\ :sub:`10`
- Cr\ :sub:`10`
- Cb\ :sub:`11`
- Cr\ :sub:`11`
**Color Sample Location:**
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.