xref: /linux/Documentation/userspace-api/media/v4l/pixfmt-packed-yuv.rst (revision 778b8ebe5192e7a7f00563a7456517dfa63e1d90) 
1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: V4L
3
4.. _packed-yuv:
5
6******************
7Packed YUV formats
8******************
9
10Similarly to the packed RGB formats, the packed YUV formats store the Y, Cb and
11Cr components consecutively in memory. They may apply subsampling to the chroma
12components and thus differ in how they interlave the three components.
13
14.. note::
15
16   - In all the tables that follow, bit 7 is the most significant bit in a byte.
17   - 'Y', 'Cb' and 'Cr' denote bits of the luma, blue chroma (also known as
18     'U') and red chroma (also known as 'V') components respectively. 'A'
19     denotes bits of the alpha component (if supported by the format), and 'X'
20     denotes padding bits.
21
22
234:4:4 Subsampling
24=================
25
26These formats do not subsample the chroma components and store each pixels as a
27full triplet of Y, Cb and Cr values.
28
29The next table lists the packed YUV 4:4:4 formats with less than 8 bits per
30component. They are named based on the order of the Y, Cb and Cr components as
31seen in a 16-bit word, which is then stored in memory in little endian byte
32order, and on the number of bits for each component. For instance the YUV565
33format stores a pixel in a 16-bit word [15:0] laid out at as [Y'\ :sub:`4-0`
34Cb\ :sub:`5-0` Cr\ :sub:`4-0`], and stored in memory in two bytes,
35[Cb\ :sub:`2-0` Cr\ :sub:`4-0`] followed by [Y'\ :sub:`4-0` Cb\ :sub:`5-3`].
36
37.. raw:: latex
38
39    \begingroup
40    \scriptsize
41    \setlength{\tabcolsep}{2pt}
42
43.. 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}|
44
45.. flat-table:: Packed YUV 4:4:4 Image Formats (less than 8bpc)
46    :header-rows:  2
47    :stub-columns: 0
48
49    * - Identifier
50      - Code
51
52      - :cspan:`7` Byte 0 in memory
53
54      - :cspan:`7` Byte 1
55
56    * -
57      -
58      - 7
59      - 6
60      - 5
61      - 4
62      - 3
63      - 2
64      - 1
65      - 0
66
67      - 7
68      - 6
69      - 5
70      - 4
71      - 3
72      - 2
73      - 1
74      - 0
75
76    * .. _V4L2-PIX-FMT-YUV444:
77
78      - ``V4L2_PIX_FMT_YUV444``
79      - 'Y444'
80
81      - Cb\ :sub:`3`
82      - Cb\ :sub:`2`
83      - Cb\ :sub:`1`
84      - Cb\ :sub:`0`
85      - Cr\ :sub:`3`
86      - Cr\ :sub:`2`
87      - Cr\ :sub:`1`
88      - Cr\ :sub:`0`
89
90      - a\ :sub:`3`
91      - a\ :sub:`2`
92      - a\ :sub:`1`
93      - a\ :sub:`0`
94      - Y'\ :sub:`3`
95      - Y'\ :sub:`2`
96      - Y'\ :sub:`1`
97      - Y'\ :sub:`0`
98
99    * .. _V4L2-PIX-FMT-YUV555:
100
101      - ``V4L2_PIX_FMT_YUV555``
102      - 'YUVO'
103
104      - Cb\ :sub:`2`
105      - Cb\ :sub:`1`
106      - Cb\ :sub:`0`
107      - Cr\ :sub:`4`
108      - Cr\ :sub:`3`
109      - Cr\ :sub:`2`
110      - Cr\ :sub:`1`
111      - Cr\ :sub:`0`
112
113      - a
114      - Y'\ :sub:`4`
115      - Y'\ :sub:`3`
116      - Y'\ :sub:`2`
117      - Y'\ :sub:`1`
118      - Y'\ :sub:`0`
119      - Cb\ :sub:`4`
120      - Cb\ :sub:`3`
121
122    * .. _V4L2-PIX-FMT-YUV565:
123
124      - ``V4L2_PIX_FMT_YUV565``
125      - 'YUVP'
126
127      - Cb\ :sub:`2`
128      - Cb\ :sub:`1`
129      - Cb\ :sub:`0`
130      - Cr\ :sub:`4`
131      - Cr\ :sub:`3`
132      - Cr\ :sub:`2`
133      - Cr\ :sub:`1`
134      - Cr\ :sub:`0`
135
136      - Y'\ :sub:`4`
137      - Y'\ :sub:`3`
138      - Y'\ :sub:`2`
139      - Y'\ :sub:`1`
140      - Y'\ :sub:`0`
141      - Cb\ :sub:`5`
142      - Cb\ :sub:`4`
143      - Cb\ :sub:`3`
144
145.. raw:: latex
146
147    \endgroup
148
149.. note::
150
151    For the YUV444 and YUV555 formats, the value of alpha bits is undefined
152    when reading from the driver, ignored when writing to the driver, except
153    when alpha blending has been negotiated for a :ref:`Video Overlay
154    <overlay>` or :ref:`Video Output Overlay <osd>`.
155
156
157The next table lists the packed YUV 4:4:4 formats with 8 bits per component.
158They are named based on the order of the Y, Cb and Cr components as stored in
159memory, and on the total number of bits per pixel. For instance, the VUYX32
160format stores a pixel with Cr\ :sub:`7-0` in the first byte, Cb\ :sub:`7-0` in
161the second byte and Y'\ :sub:`7-0` in the third byte.
162
163.. flat-table:: Packed YUV Image Formats (8bpc)
164    :header-rows: 1
165    :stub-columns: 0
166
167    * - Identifier
168      - Code
169      - Byte 0
170      - Byte 1
171      - Byte 2
172      - Byte 3
173
174    * .. _V4L2-PIX-FMT-YUV32:
175
176      - ``V4L2_PIX_FMT_YUV32``
177      - 'YUV4'
178
179      - A\ :sub:`7-0`
180      - Y'\ :sub:`7-0`
181      - Cb\ :sub:`7-0`
182      - Cr\ :sub:`7-0`
183
184    * .. _V4L2-PIX-FMT-AYUV32:
185
186      - ``V4L2_PIX_FMT_AYUV32``
187      - 'AYUV'
188
189      - A\ :sub:`7-0`
190      - Y'\ :sub:`7-0`
191      - Cb\ :sub:`7-0`
192      - Cr\ :sub:`7-0`
193
194    * .. _V4L2-PIX-FMT-XYUV32:
195
196      - ``V4L2_PIX_FMT_XYUV32``
197      - 'XYUV'
198
199      - X\ :sub:`7-0`
200      - Y'\ :sub:`7-0`
201      - Cb\ :sub:`7-0`
202      - Cr\ :sub:`7-0`
203
204    * .. _V4L2-PIX-FMT-VUYA32:
205
206      - ``V4L2_PIX_FMT_VUYA32``
207      - 'VUYA'
208
209      - Cr\ :sub:`7-0`
210      - Cb\ :sub:`7-0`
211      - Y'\ :sub:`7-0`
212      - A\ :sub:`7-0`
213
214    * .. _V4L2-PIX-FMT-VUYX32:
215
216      - ``V4L2_PIX_FMT_VUYX32``
217      - 'VUYX'
218
219      - Cr\ :sub:`7-0`
220      - Cb\ :sub:`7-0`
221      - Y'\ :sub:`7-0`
222      - X\ :sub:`7-0`
223
224    * .. _V4L2-PIX-FMT-YUVA32:
225
226      - ``V4L2_PIX_FMT_YUVA32``
227      - 'YUVA'
228
229      - Y'\ :sub:`7-0`
230      - Cb\ :sub:`7-0`
231      - Cr\ :sub:`7-0`
232      - A\ :sub:`7-0`
233
234    * .. _V4L2-PIX-FMT-YUVX32:
235
236      - ``V4L2_PIX_FMT_YUVX32``
237      - 'YUVX'
238
239      - Y'\ :sub:`7-0`
240      - Cb\ :sub:`7-0`
241      - Cr\ :sub:`7-0`
242      - X\ :sub:`7-0`
243
244    * .. _V4L2-PIX-FMT-YUV24:
245
246      - ``V4L2_PIX_FMT_YUV24``
247      - 'YUV3'
248
249      - Y'\ :sub:`7-0`
250      - Cb\ :sub:`7-0`
251      - Cr\ :sub:`7-0`
252      - -\
253
254.. note::
255
256    - The alpha component is expected to contain a meaningful value that can be
257      used by drivers and applications.
258    - The padding bits contain undefined values that must be ignored by all
259      applications and drivers.
260
261The next table lists the packed YUV 4:4:4 formats with 12 bits per component.
262Expand the bits per component to 16 bits, data in the high bits, zeros in the low bits,
263arranged in little endian order, storing 1 pixel in 6 bytes.
264
265.. flat-table:: Packed YUV 4:4:4 Image Formats (12bpc)
266    :header-rows: 1
267    :stub-columns: 0
268
269    * - Identifier
270      - Code
271      - Byte 1-0
272      - Byte 3-2
273      - Byte 5-4
274      - Byte 7-6
275      - Byte 9-8
276      - Byte 11-10
277
278    * .. _V4L2-PIX-FMT-YUV48-12:
279
280      - ``V4L2_PIX_FMT_YUV48_12``
281      - 'Y312'
282
283      - Y'\ :sub:`0`
284      - Cb\ :sub:`0`
285      - Cr\ :sub:`0`
286      - Y'\ :sub:`1`
287      - Cb\ :sub:`1`
288      - Cr\ :sub:`1`
289
2904:2:2 Subsampling
291=================
292
293These formats, commonly referred to as YUYV or YUY2, subsample the chroma
294components horizontally by 2, storing 2 pixels in a container. The container
295is 32-bits for 8-bit formats, and 64-bits for 10+-bit formats.
296
297The packed YUYV formats with more than 8 bits per component are stored as four
29816-bit little-endian words. Each word's most significant bits contain one
299component, and the least significant bits are zero padding.
300
301.. raw:: latex
302
303    \footnotesize
304
305.. 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}|
306
307.. flat-table:: Packed YUV 4:2:2 Formats in 32-bit container
308    :header-rows: 1
309    :stub-columns: 0
310
311    * - Identifier
312      - Code
313      - Byte 0
314      - Byte 1
315      - Byte 2
316      - Byte 3
317      - Byte 4
318      - Byte 5
319      - Byte 6
320      - Byte 7
321    * .. _V4L2-PIX-FMT-UYVY:
322
323      - ``V4L2_PIX_FMT_UYVY``
324      - 'UYVY'
325
326      - Cb\ :sub:`0`
327      - Y'\ :sub:`0`
328      - Cr\ :sub:`0`
329      - Y'\ :sub:`1`
330      - Cb\ :sub:`2`
331      - Y'\ :sub:`2`
332      - Cr\ :sub:`2`
333      - Y'\ :sub:`3`
334    * .. _V4L2-PIX-FMT-VYUY:
335
336      - ``V4L2_PIX_FMT_VYUY``
337      - 'VYUY'
338
339      - Cr\ :sub:`0`
340      - Y'\ :sub:`0`
341      - Cb\ :sub:`0`
342      - Y'\ :sub:`1`
343      - Cr\ :sub:`2`
344      - Y'\ :sub:`2`
345      - Cb\ :sub:`2`
346      - Y'\ :sub:`3`
347    * .. _V4L2-PIX-FMT-YUYV:
348
349      - ``V4L2_PIX_FMT_YUYV``
350      - 'YUYV'
351
352      - Y'\ :sub:`0`
353      - Cb\ :sub:`0`
354      - Y'\ :sub:`1`
355      - Cr\ :sub:`0`
356      - Y'\ :sub:`2`
357      - Cb\ :sub:`2`
358      - Y'\ :sub:`3`
359      - Cr\ :sub:`2`
360    * .. _V4L2-PIX-FMT-YVYU:
361
362      - ``V4L2_PIX_FMT_YVYU``
363      - 'YVYU'
364
365      - Y'\ :sub:`0`
366      - Cr\ :sub:`0`
367      - Y'\ :sub:`1`
368      - Cb\ :sub:`0`
369      - Y'\ :sub:`2`
370      - Cr\ :sub:`2`
371      - Y'\ :sub:`3`
372      - Cb\ :sub:`2`
373
374.. 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}|
375
376.. flat-table:: Packed YUV 4:2:2 Formats in 64-bit container
377    :header-rows: 1
378    :stub-columns: 0
379
380    * - Identifier
381      - Code
382      - Word 0
383      - Word 1
384      - Word 2
385      - Word 3
386    * .. _V4L2-PIX-FMT-Y210:
387
388      - ``V4L2_PIX_FMT_Y210``
389      - 'Y210'
390
391      - Y'\ :sub:`0` (bits 15-6)
392      - Cb\ :sub:`0` (bits 15-6)
393      - Y'\ :sub:`1` (bits 15-6)
394      - Cr\ :sub:`0` (bits 15-6)
395    * .. _V4L2-PIX-FMT-Y212:
396
397      - ``V4L2_PIX_FMT_Y212``
398      - 'Y212'
399
400      - Y'\ :sub:`0` (bits 15-4)
401      - Cb\ :sub:`0` (bits 15-4)
402      - Y'\ :sub:`1` (bits 15-4)
403      - Cr\ :sub:`0` (bits 15-4)
404    * .. _V4L2-PIX-FMT-Y216:
405
406      - ``V4L2_PIX_FMT_Y216``
407      - 'Y216'
408
409      - Y'\ :sub:`0` (bits 15-0)
410      - Cb\ :sub:`0` (bits 15-0)
411      - Y'\ :sub:`1` (bits 15-0)
412      - Cr\ :sub:`0` (bits 15-0)
413
414.. raw:: latex
415
416    \normalsize
417
418**Color Sample Location:**
419Chroma samples are :ref:`interstitially sited<yuv-chroma-centered>`
420horizontally.
421
422
4234:1:1 Subsampling
424=================
425
426This format subsamples the chroma components horizontally by 4, storing 8
427pixels in 12 bytes.
428
429.. raw:: latex
430
431    \scriptsize
432
433.. 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}|
434
435.. flat-table:: Packed YUV 4:1:1 Formats
436    :header-rows: 1
437    :stub-columns: 0
438
439    * - Identifier
440      - Code
441      - Byte 0
442      - Byte 1
443      - Byte 2
444      - Byte 3
445      - Byte 4
446      - Byte 5
447      - Byte 6
448      - Byte 7
449      - Byte 8
450      - Byte 9
451      - Byte 10
452      - Byte 11
453    * .. _V4L2-PIX-FMT-Y41P:
454
455      - ``V4L2_PIX_FMT_Y41P``
456      - 'Y41P'
457
458      - Cb\ :sub:`0`
459      - Y'\ :sub:`0`
460      - Cr\ :sub:`0`
461      - Y'\ :sub:`1`
462      - Cb\ :sub:`4`
463      - Y'\ :sub:`2`
464      - Cr\ :sub:`4`
465      - Y'\ :sub:`3`
466      - Y'\ :sub:`4`
467      - Y'\ :sub:`5`
468      - Y'\ :sub:`6`
469      - Y'\ :sub:`7`
470
471.. raw:: latex
472
473    \normalsize
474
475.. note::
476
477    Do not confuse ``V4L2_PIX_FMT_Y41P`` with
478    :ref:`V4L2_PIX_FMT_YUV411P <V4L2-PIX-FMT-YUV411P>`. Y41P is derived from
479    "YUV 4:1:1 **packed**", while YUV411P stands for "YUV 4:1:1 **planar**".
480
481**Color Sample Location:**
482Chroma samples are :ref:`interstitially sited<yuv-chroma-centered>`
483horizontally.
484