tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: V4L
3
4.. _V4L2-SDR-FMT-PCU18BE:
5
6******************************
7V4L2_SDR_FMT_PCU18BE ('PC18')
8******************************
9
10Planar complex unsigned 18-bit big endian IQ sample
11
12Description
13===========
14
15This format contains a sequence of complex number samples. Each complex
16number consist of two parts called In-phase and Quadrature (IQ). Both I
17and Q are represented as a 18 bit unsigned big endian number stored in
1832 bit space. The remaining unused bits within the 32 bit space will be
19padded with 0. I value starts first and Q value starts at an offset
20equalling half of the buffer size (i.e.) offset = buffersize/2. Out of
21the 18 bits, bit 17:2 (16 bit) is data and bit 1:0 (2 bit) can be any
22value.
23
24**Byte Order.**
25Each cell is one byte.
26
27.. flat-table::
28 :header-rows: 1
29 :stub-columns: 0
30
31 * - Offset:
32 - Byte B0
33 - Byte B1
34 - Byte B2
35 - Byte B3
36 * - start + 0:
37 - I'\ :sub:`0[17:10]`
38 - I'\ :sub:`0[9:2]`
39 - I'\ :sub:`0[1:0]; B2[5:0]=pad`
40 - pad
41 * - start + 4:
42 - I'\ :sub:`1[17:10]`
43 - I'\ :sub:`1[9:2]`
44 - I'\ :sub:`1[1:0]; B2[5:0]=pad`
45 - pad
46 * - ...
47 * - start + offset:
48 - Q'\ :sub:`0[17:10]`
49 - Q'\ :sub:`0[9:2]`
50 - Q'\ :sub:`0[1:0]; B2[5:0]=pad`
51 - pad
52 * - start + offset + 4:
53 - Q'\ :sub:`1[17:10]`
54 - Q'\ :sub:`1[9:2]`
55 - Q'\ :sub:`1[1:0]; B2[5:0]=pad`
56 - pad