1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2
3.. _codec-stateless-controls:
4
5*********************************
6Stateless Codec Control Reference
7*********************************
8
9The Stateless Codec control class is intended to support
10stateless decoder and encoders (i.e. hardware accelerators).
11
12These drivers are typically supported by the :ref:`stateless_decoder`,
13and deal with parsed pixel formats such as V4L2_PIX_FMT_H264_SLICE.
14
15Stateless Codec Control ID
16==========================
17
18.. _codec-stateless-control-id:
19
20``V4L2_CID_CODEC_STATELESS_CLASS (class)``
21    The Stateless Codec class descriptor.
22
23.. _v4l2-codec-stateless-h264:
24
25``V4L2_CID_STATELESS_H264_SPS (struct)``
26    Specifies the sequence parameter set (as extracted from the
27    bitstream) for the associated H264 slice data. This includes the
28    necessary parameters for configuring a stateless hardware decoding
29    pipeline for H264. The bitstream parameters are defined according
30    to :ref:`h264`, section 7.4.2.1.1 "Sequence Parameter Set Data
31    Semantics". For further documentation, refer to the above
32    specification, unless there is an explicit comment stating
33    otherwise.
34
35.. c:type:: v4l2_ctrl_h264_sps
36
37.. raw:: latex
38
39    \small
40
41.. tabularcolumns:: |p{1.2cm}|p{8.6cm}|p{7.5cm}|
42
43.. flat-table:: struct v4l2_ctrl_h264_sps
44    :header-rows:  0
45    :stub-columns: 0
46    :widths:       1 1 2
47
48    * - __u8
49      - ``profile_idc``
50      -
51    * - __u8
52      - ``constraint_set_flags``
53      - See :ref:`Sequence Parameter Set Constraints Set Flags <h264_sps_constraints_set_flags>`
54    * - __u8
55      - ``level_idc``
56      -
57    * - __u8
58      - ``seq_parameter_set_id``
59      -
60    * - __u8
61      - ``chroma_format_idc``
62      -
63    * - __u8
64      - ``bit_depth_luma_minus8``
65      -
66    * - __u8
67      - ``bit_depth_chroma_minus8``
68      -
69    * - __u8
70      - ``log2_max_frame_num_minus4``
71      -
72    * - __u8
73      - ``pic_order_cnt_type``
74      -
75    * - __u8
76      - ``log2_max_pic_order_cnt_lsb_minus4``
77      -
78    * - __u8
79      - ``max_num_ref_frames``
80      -
81    * - __u8
82      - ``num_ref_frames_in_pic_order_cnt_cycle``
83      -
84    * - __s32
85      - ``offset_for_ref_frame[255]``
86      -
87    * - __s32
88      - ``offset_for_non_ref_pic``
89      -
90    * - __s32
91      - ``offset_for_top_to_bottom_field``
92      -
93    * - __u16
94      - ``pic_width_in_mbs_minus1``
95      -
96    * - __u16
97      - ``pic_height_in_map_units_minus1``
98      -
99    * - __u32
100      - ``flags``
101      - See :ref:`Sequence Parameter Set Flags <h264_sps_flags>`
102
103.. raw:: latex
104
105    \normalsize
106
107.. _h264_sps_constraints_set_flags:
108
109``Sequence Parameter Set Constraints Set Flags``
110
111.. cssclass:: longtable
112
113.. flat-table::
114    :header-rows:  0
115    :stub-columns: 0
116    :widths:       1 1 2
117
118    * - ``V4L2_H264_SPS_CONSTRAINT_SET0_FLAG``
119      - 0x00000001
120      -
121    * - ``V4L2_H264_SPS_CONSTRAINT_SET1_FLAG``
122      - 0x00000002
123      -
124    * - ``V4L2_H264_SPS_CONSTRAINT_SET2_FLAG``
125      - 0x00000004
126      -
127    * - ``V4L2_H264_SPS_CONSTRAINT_SET3_FLAG``
128      - 0x00000008
129      -
130    * - ``V4L2_H264_SPS_CONSTRAINT_SET4_FLAG``
131      - 0x00000010
132      -
133    * - ``V4L2_H264_SPS_CONSTRAINT_SET5_FLAG``
134      - 0x00000020
135      -
136
137.. _h264_sps_flags:
138
139``Sequence Parameter Set Flags``
140
141.. cssclass:: longtable
142
143.. flat-table::
144    :header-rows:  0
145    :stub-columns: 0
146    :widths:       1 1 2
147
148    * - ``V4L2_H264_SPS_FLAG_SEPARATE_COLOUR_PLANE``
149      - 0x00000001
150      -
151    * - ``V4L2_H264_SPS_FLAG_QPPRIME_Y_ZERO_TRANSFORM_BYPASS``
152      - 0x00000002
153      -
154    * - ``V4L2_H264_SPS_FLAG_DELTA_PIC_ORDER_ALWAYS_ZERO``
155      - 0x00000004
156      -
157    * - ``V4L2_H264_SPS_FLAG_GAPS_IN_FRAME_NUM_VALUE_ALLOWED``
158      - 0x00000008
159      -
160    * - ``V4L2_H264_SPS_FLAG_FRAME_MBS_ONLY``
161      - 0x00000010
162      -
163    * - ``V4L2_H264_SPS_FLAG_MB_ADAPTIVE_FRAME_FIELD``
164      - 0x00000020
165      -
166    * - ``V4L2_H264_SPS_FLAG_DIRECT_8X8_INFERENCE``
167      - 0x00000040
168      -
169
170``V4L2_CID_STATELESS_H264_PPS (struct)``
171    Specifies the picture parameter set (as extracted from the
172    bitstream) for the associated H264 slice data. This includes the
173    necessary parameters for configuring a stateless hardware decoding
174    pipeline for H264.  The bitstream parameters are defined according
175    to :ref:`h264`, section 7.4.2.2 "Picture Parameter Set RBSP
176    Semantics". For further documentation, refer to the above
177    specification, unless there is an explicit comment stating
178    otherwise.
179
180.. c:type:: v4l2_ctrl_h264_pps
181
182.. raw:: latex
183
184    \small
185
186.. flat-table:: struct v4l2_ctrl_h264_pps
187    :header-rows:  0
188    :stub-columns: 0
189    :widths:       1 1 2
190
191    * - __u8
192      - ``pic_parameter_set_id``
193      -
194    * - __u8
195      - ``seq_parameter_set_id``
196      -
197    * - __u8
198      - ``num_slice_groups_minus1``
199      -
200    * - __u8
201      - ``num_ref_idx_l0_default_active_minus1``
202      -
203    * - __u8
204      - ``num_ref_idx_l1_default_active_minus1``
205      -
206    * - __u8
207      - ``weighted_bipred_idc``
208      -
209    * - __s8
210      - ``pic_init_qp_minus26``
211      -
212    * - __s8
213      - ``pic_init_qs_minus26``
214      -
215    * - __s8
216      - ``chroma_qp_index_offset``
217      -
218    * - __s8
219      - ``second_chroma_qp_index_offset``
220      -
221    * - __u16
222      - ``flags``
223      - See :ref:`Picture Parameter Set Flags <h264_pps_flags>`
224
225.. raw:: latex
226
227    \normalsize
228
229.. _h264_pps_flags:
230
231``Picture Parameter Set Flags``
232
233.. raw:: latex
234
235    \begingroup
236    \scriptsize
237    \setlength{\tabcolsep}{2pt}
238
239.. tabularcolumns:: |p{9.8cm}|p{1.0cm}|p{6.5cm}|
240
241.. flat-table::
242    :header-rows:  0
243    :stub-columns: 0
244    :widths:       10 1 4
245
246    * - ``V4L2_H264_PPS_FLAG_ENTROPY_CODING_MODE``
247      - 0x0001
248      -
249    * - ``V4L2_H264_PPS_FLAG_BOTTOM_FIELD_PIC_ORDER_IN_FRAME_PRESENT``
250      - 0x0002
251      -
252    * - ``V4L2_H264_PPS_FLAG_WEIGHTED_PRED``
253      - 0x0004
254      -
255    * - ``V4L2_H264_PPS_FLAG_DEBLOCKING_FILTER_CONTROL_PRESENT``
256      - 0x0008
257      -
258    * - ``V4L2_H264_PPS_FLAG_CONSTRAINED_INTRA_PRED``
259      - 0x0010
260      -
261    * - ``V4L2_H264_PPS_FLAG_REDUNDANT_PIC_CNT_PRESENT``
262      - 0x0020
263      -
264    * - ``V4L2_H264_PPS_FLAG_TRANSFORM_8X8_MODE``
265      - 0x0040
266      -
267    * - ``V4L2_H264_PPS_FLAG_SCALING_MATRIX_PRESENT``
268      - 0x0080
269      - ``V4L2_CID_STATELESS_H264_SCALING_MATRIX``
270        must be used for this picture.
271
272.. raw:: latex
273
274    \endgroup
275
276``V4L2_CID_STATELESS_H264_SCALING_MATRIX (struct)``
277    Specifies the scaling matrix (as extracted from the bitstream) for
278    the associated H264 slice data. The bitstream parameters are
279    defined according to :ref:`h264`, section 7.4.2.1.1.1 "Scaling
280    List Semantics". For further documentation, refer to the above
281    specification, unless there is an explicit comment stating
282    otherwise.
283
284.. c:type:: v4l2_ctrl_h264_scaling_matrix
285
286.. raw:: latex
287
288    \small
289
290.. tabularcolumns:: |p{0.6cm}|p{4.8cm}|p{11.9cm}|
291
292.. flat-table:: struct v4l2_ctrl_h264_scaling_matrix
293    :header-rows:  0
294    :stub-columns: 0
295    :widths:       1 1 2
296
297    * - __u8
298      - ``scaling_list_4x4[6][16]``
299      - Scaling matrix after applying the inverse scanning process.
300        Expected list order is Intra Y, Intra Cb, Intra Cr, Inter Y,
301        Inter Cb, Inter Cr. The values on each scaling list are
302        expected in raster scan order.
303    * - __u8
304      - ``scaling_list_8x8[6][64]``
305      - Scaling matrix after applying the inverse scanning process.
306        Expected list order is Intra Y, Inter Y, Intra Cb, Inter Cb,
307        Intra Cr, Inter Cr. The values on each scaling list are
308        expected in raster scan order.
309
310``V4L2_CID_STATELESS_H264_SLICE_PARAMS (struct)``
311    Specifies the slice parameters (as extracted from the bitstream)
312    for the associated H264 slice data. This includes the necessary
313    parameters for configuring a stateless hardware decoding pipeline
314    for H264.  The bitstream parameters are defined according to
315    :ref:`h264`, section 7.4.3 "Slice Header Semantics". For further
316    documentation, refer to the above specification, unless there is
317    an explicit comment stating otherwise.
318
319.. c:type:: v4l2_ctrl_h264_slice_params
320
321.. raw:: latex
322
323    \small
324
325.. tabularcolumns:: |p{4.0cm}|p{5.9cm}|p{7.4cm}|
326
327.. flat-table:: struct v4l2_ctrl_h264_slice_params
328    :header-rows:  0
329    :stub-columns: 0
330    :widths:       1 1 2
331
332    * - __u32
333      - ``header_bit_size``
334      - Offset in bits to slice_data() from the beginning of this slice.
335    * - __u32
336      - ``first_mb_in_slice``
337      -
338    * - __u8
339      - ``slice_type``
340      -
341    * - __u8
342      - ``colour_plane_id``
343      -
344    * - __u8
345      - ``redundant_pic_cnt``
346      -
347    * - __u8
348      - ``cabac_init_idc``
349      -
350    * - __s8
351      - ``slice_qp_delta``
352      -
353    * - __s8
354      - ``slice_qs_delta``
355      -
356    * - __u8
357      - ``disable_deblocking_filter_idc``
358      -
359    * - __s8
360      - ``slice_alpha_c0_offset_div2``
361      -
362    * - __s8
363      - ``slice_beta_offset_div2``
364      -
365    * - __u8
366      - ``num_ref_idx_l0_active_minus1``
367      - If num_ref_idx_active_override_flag is not set, this field must be
368        set to the value of num_ref_idx_l0_default_active_minus1
369    * - __u8
370      - ``num_ref_idx_l1_active_minus1``
371      - If num_ref_idx_active_override_flag is not set, this field must be
372        set to the value of num_ref_idx_l1_default_active_minus1
373    * - __u8
374      - ``reserved``
375      - Applications and drivers must set this to zero.
376    * - struct :c:type:`v4l2_h264_reference`
377      - ``ref_pic_list0[32]``
378      - Reference picture list after applying the per-slice modifications
379    * - struct :c:type:`v4l2_h264_reference`
380      - ``ref_pic_list1[32]``
381      - Reference picture list after applying the per-slice modifications
382    * - __u32
383      - ``flags``
384      - See :ref:`Slice Parameter Flags <h264_slice_flags>`
385
386.. raw:: latex
387
388    \normalsize
389
390.. _h264_slice_flags:
391
392``Slice Parameter Set Flags``
393
394.. cssclass:: longtable
395
396.. flat-table::
397    :header-rows:  0
398    :stub-columns: 0
399    :widths:       1 1 2
400
401    * - ``V4L2_H264_SLICE_FLAG_DIRECT_SPATIAL_MV_PRED``
402      - 0x00000001
403      -
404    * - ``V4L2_H264_SLICE_FLAG_SP_FOR_SWITCH``
405      - 0x00000002
406      -
407
408``V4L2_CID_STATELESS_H264_PRED_WEIGHTS (struct)``
409    Prediction weight table defined according to :ref:`h264`,
410    section 7.4.3.2 "Prediction Weight Table Semantics".
411    The prediction weight table must be passed by applications
412    under the conditions explained in section 7.3.3 "Slice header
413    syntax".
414
415.. c:type:: v4l2_ctrl_h264_pred_weights
416
417.. raw:: latex
418
419    \small
420
421.. tabularcolumns:: |p{4.9cm}|p{4.9cm}|p{7.5cm}|
422
423.. flat-table:: struct v4l2_ctrl_h264_pred_weights
424    :header-rows:  0
425    :stub-columns: 0
426    :widths:       1 1 2
427
428    * - __u16
429      - ``luma_log2_weight_denom``
430      -
431    * - __u16
432      - ``chroma_log2_weight_denom``
433      -
434    * - struct :c:type:`v4l2_h264_weight_factors`
435      - ``weight_factors[2]``
436      - The weight factors at index 0 are the weight factors for the reference
437        list 0, the one at index 1 for the reference list 1.
438
439.. raw:: latex
440
441    \normalsize
442
443.. c:type:: v4l2_h264_weight_factors
444
445.. raw:: latex
446
447    \small
448
449.. tabularcolumns:: |p{1.0cm}|p{4.5cm}|p{11.8cm}|
450
451.. flat-table:: struct v4l2_h264_weight_factors
452    :header-rows:  0
453    :stub-columns: 0
454    :widths:       1 1 2
455
456    * - __s16
457      - ``luma_weight[32]``
458      -
459    * - __s16
460      - ``luma_offset[32]``
461      -
462    * - __s16
463      - ``chroma_weight[32][2]``
464      -
465    * - __s16
466      - ``chroma_offset[32][2]``
467      -
468
469.. raw:: latex
470
471    \normalsize
472
473``Picture Reference``
474
475.. c:type:: v4l2_h264_reference
476
477.. cssclass:: longtable
478
479.. flat-table:: struct v4l2_h264_reference
480    :header-rows:  0
481    :stub-columns: 0
482    :widths:       1 1 2
483
484    * - __u8
485      - ``fields``
486      - Specifies how the picture is referenced. See :ref:`Reference Fields <h264_ref_fields>`
487    * - __u8
488      - ``index``
489      - Index into the :c:type:`v4l2_ctrl_h264_decode_params`.dpb array.
490
491.. _h264_ref_fields:
492
493``Reference Fields``
494
495.. raw:: latex
496
497    \small
498
499.. tabularcolumns:: |p{5.4cm}|p{0.8cm}|p{11.1cm}|
500
501.. flat-table::
502    :header-rows:  0
503    :stub-columns: 0
504    :widths:       1 1 2
505
506    * - ``V4L2_H264_TOP_FIELD_REF``
507      - 0x1
508      - The top field in field pair is used for short-term reference.
509    * - ``V4L2_H264_BOTTOM_FIELD_REF``
510      - 0x2
511      - The bottom field in field pair is used for short-term reference.
512    * - ``V4L2_H264_FRAME_REF``
513      - 0x3
514      - The frame (or the top/bottom fields, if it's a field pair)
515        is used for short-term reference.
516
517.. raw:: latex
518
519    \normalsize
520
521``V4L2_CID_STATELESS_H264_DECODE_PARAMS (struct)``
522    Specifies the decode parameters (as extracted from the bitstream)
523    for the associated H264 slice data. This includes the necessary
524    parameters for configuring a stateless hardware decoding pipeline
525    for H264. The bitstream parameters are defined according to
526    :ref:`h264`. For further documentation, refer to the above
527    specification, unless there is an explicit comment stating
528    otherwise.
529
530.. c:type:: v4l2_ctrl_h264_decode_params
531
532.. raw:: latex
533
534    \small
535
536.. tabularcolumns:: |p{4.0cm}|p{5.9cm}|p{7.4cm}|
537
538.. flat-table:: struct v4l2_ctrl_h264_decode_params
539    :header-rows:  0
540    :stub-columns: 0
541    :widths:       1 1 2
542
543    * - struct :c:type:`v4l2_h264_dpb_entry`
544      - ``dpb[16]``
545      -
546    * - __u16
547      - ``nal_ref_idc``
548      - NAL reference ID value coming from the NAL Unit header
549    * - __u16
550      - ``frame_num``
551      -
552    * - __s32
553      - ``top_field_order_cnt``
554      - Picture Order Count for the coded top field
555    * - __s32
556      - ``bottom_field_order_cnt``
557      - Picture Order Count for the coded bottom field
558    * - __u16
559      - ``idr_pic_id``
560      -
561    * - __u16
562      - ``pic_order_cnt_lsb``
563      -
564    * - __s32
565      - ``delta_pic_order_cnt_bottom``
566      -
567    * - __s32
568      - ``delta_pic_order_cnt0``
569      -
570    * - __s32
571      - ``delta_pic_order_cnt1``
572      -
573    * - __u32
574      - ``dec_ref_pic_marking_bit_size``
575      - Size in bits of the dec_ref_pic_marking() syntax element.
576    * - __u32
577      - ``pic_order_cnt_bit_size``
578      - Combined size in bits of the picture order count related syntax
579        elements: pic_order_cnt_lsb, delta_pic_order_cnt_bottom,
580        delta_pic_order_cnt0, and delta_pic_order_cnt1.
581    * - __u32
582      - ``slice_group_change_cycle``
583      -
584    * - __u32
585      - ``reserved``
586      - Applications and drivers must set this to zero.
587    * - __u32
588      - ``flags``
589      - See :ref:`Decode Parameters Flags <h264_decode_params_flags>`
590
591.. raw:: latex
592
593    \normalsize
594
595.. _h264_decode_params_flags:
596
597``Decode Parameters Flags``
598
599.. raw:: latex
600
601    \small
602
603.. tabularcolumns:: |p{8.3cm}|p{2.1cm}|p{6.9cm}|
604
605.. flat-table::
606    :header-rows:  0
607    :stub-columns: 0
608    :widths:       1 1 2
609
610    * - ``V4L2_H264_DECODE_PARAM_FLAG_IDR_PIC``
611      - 0x00000001
612      - That picture is an IDR picture
613    * - ``V4L2_H264_DECODE_PARAM_FLAG_FIELD_PIC``
614      - 0x00000002
615      -
616    * - ``V4L2_H264_DECODE_PARAM_FLAG_BOTTOM_FIELD``
617      - 0x00000004
618      -
619    * - ``V4L2_H264_DECODE_PARAM_FLAG_PFRAME``
620      - 0x00000008
621      -
622    * - ``V4L2_H264_DECODE_PARAM_FLAG_BFRAME``
623      - 0x00000010
624      -
625
626.. raw:: latex
627
628    \normalsize
629
630.. c:type:: v4l2_h264_dpb_entry
631
632.. raw:: latex
633
634    \small
635
636.. tabularcolumns:: |p{1.0cm}|p{4.9cm}|p{11.4cm}|
637
638.. flat-table:: struct v4l2_h264_dpb_entry
639    :header-rows:  0
640    :stub-columns: 0
641    :widths:       1 1 2
642
643    * - __u64
644      - ``reference_ts``
645      - Timestamp of the V4L2 capture buffer to use as reference, used
646        with B-coded and P-coded frames. The timestamp refers to the
647        ``timestamp`` field in struct :c:type:`v4l2_buffer`. Use the
648        :c:func:`v4l2_timeval_to_ns()` function to convert the struct
649        :c:type:`timeval` in struct :c:type:`v4l2_buffer` to a __u64.
650    * - __u32
651      - ``pic_num``
652      - For short term references, this must match the derived value PicNum
653	(8-28) and for long term references it must match the derived value
654	LongTermPicNum (8-29). When decoding frames (as opposed to fields)
655	pic_num is the same as FrameNumWrap.
656    * - __u16
657      - ``frame_num``
658      - For short term references, this must match the frame_num value from
659	the slice header syntax (the driver will wrap the value if needed). For
660	long term references, this must be set to the value of
661	long_term_frame_idx described in the dec_ref_pic_marking() syntax.
662    * - __u8
663      - ``fields``
664      - Specifies how the DPB entry is referenced. See :ref:`Reference Fields <h264_ref_fields>`
665    * - __u8
666      - ``reserved[5]``
667      - Applications and drivers must set this to zero.
668    * - __s32
669      - ``top_field_order_cnt``
670      -
671    * - __s32
672      - ``bottom_field_order_cnt``
673      -
674    * - __u32
675      - ``flags``
676      - See :ref:`DPB Entry Flags <h264_dpb_flags>`
677
678.. raw:: latex
679
680    \normalsize
681
682.. _h264_dpb_flags:
683
684``DPB Entries Flags``
685
686.. raw:: latex
687
688    \small
689
690.. tabularcolumns:: |p{7.7cm}|p{2.1cm}|p{7.5cm}|
691
692.. flat-table::
693    :header-rows:  0
694    :stub-columns: 0
695    :widths:       1 1 2
696
697    * - ``V4L2_H264_DPB_ENTRY_FLAG_VALID``
698      - 0x00000001
699      - The DPB entry is valid (non-empty) and should be considered.
700    * - ``V4L2_H264_DPB_ENTRY_FLAG_ACTIVE``
701      - 0x00000002
702      - The DPB entry is used for reference.
703    * - ``V4L2_H264_DPB_ENTRY_FLAG_LONG_TERM``
704      - 0x00000004
705      - The DPB entry is used for long-term reference.
706    * - ``V4L2_H264_DPB_ENTRY_FLAG_FIELD``
707      - 0x00000008
708      - The DPB entry is a single field or a complementary field pair.
709
710.. raw:: latex
711
712    \normalsize
713
714``V4L2_CID_STATELESS_H264_DECODE_MODE (enum)``
715    Specifies the decoding mode to use. Currently exposes slice-based and
716    frame-based decoding but new modes might be added later on.
717    This control is used as a modifier for V4L2_PIX_FMT_H264_SLICE
718    pixel format. Applications that support V4L2_PIX_FMT_H264_SLICE
719    are required to set this control in order to specify the decoding mode
720    that is expected for the buffer.
721    Drivers may expose a single or multiple decoding modes, depending
722    on what they can support.
723
724.. c:type:: v4l2_stateless_h264_decode_mode
725
726.. raw:: latex
727
728    \scriptsize
729
730.. tabularcolumns:: |p{7.4cm}|p{0.3cm}|p{9.6cm}|
731
732.. flat-table::
733    :header-rows:  0
734    :stub-columns: 0
735    :widths:       1 1 2
736
737    * - ``V4L2_STATELESS_H264_DECODE_MODE_SLICE_BASED``
738      - 0
739      - Decoding is done at the slice granularity.
740        The OUTPUT buffer must contain a single slice.
741        When this mode is selected, the ``V4L2_CID_STATELESS_H264_SLICE_PARAMS``
742        control shall be set. When multiple slices compose a frame,
743        use of ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` flag
744        is required.
745    * - ``V4L2_STATELESS_H264_DECODE_MODE_FRAME_BASED``
746      - 1
747      - Decoding is done at the frame granularity,
748        The OUTPUT buffer must contain all slices needed to decode the
749        frame. The OUTPUT buffer must also contain both fields.
750        This mode will be supported by devices that
751        parse the slice(s) header(s) in hardware. When this mode is
752        selected, the ``V4L2_CID_STATELESS_H264_SLICE_PARAMS``
753        control shall not be set.
754
755.. raw:: latex
756
757    \normalsize
758
759``V4L2_CID_STATELESS_H264_START_CODE (enum)``
760    Specifies the H264 slice start code expected for each slice.
761    This control is used as a modifier for V4L2_PIX_FMT_H264_SLICE
762    pixel format. Applications that support V4L2_PIX_FMT_H264_SLICE
763    are required to set this control in order to specify the start code
764    that is expected for the buffer.
765    Drivers may expose a single or multiple start codes, depending
766    on what they can support.
767
768.. c:type:: v4l2_stateless_h264_start_code
769
770.. raw:: latex
771
772    \small
773
774.. tabularcolumns:: |p{7.9cm}|p{0.4cm}|p{9.0cm}|
775
776.. flat-table::
777    :header-rows:  0
778    :stub-columns: 0
779    :widths:       4 1 4
780
781    * - ``V4L2_STATELESS_H264_START_CODE_NONE``
782      - 0
783      - Selecting this value specifies that H264 slices are passed
784        to the driver without any start code. The bitstream data should be
785        according to :ref:`h264` 7.3.1 NAL unit syntax, hence contains
786        emulation prevention bytes when required.
787    * - ``V4L2_STATELESS_H264_START_CODE_ANNEX_B``
788      - 1
789      - Selecting this value specifies that H264 slices are expected
790        to be prefixed by Annex B start codes. According to :ref:`h264`
791        valid start codes can be 3-bytes 0x000001 or 4-bytes 0x00000001.
792
793.. raw:: latex
794
795    \normalsize
796
797.. _codec-stateless-fwht:
798
799``V4L2_CID_STATELESS_FWHT_PARAMS (struct)``
800    Specifies the FWHT (Fast Walsh Hadamard Transform) parameters (as extracted
801    from the bitstream) for the associated FWHT data. This includes the necessary
802    parameters for configuring a stateless hardware decoding pipeline for FWHT.
803    This codec is specific to the vicodec test driver.
804
805.. c:type:: v4l2_ctrl_fwht_params
806
807.. raw:: latex
808
809    \small
810
811.. tabularcolumns:: |p{1.4cm}|p{3.9cm}|p{12.0cm}|
812
813.. flat-table:: struct v4l2_ctrl_fwht_params
814    :header-rows:  0
815    :stub-columns: 0
816    :widths:       1 1 2
817
818    * - __u64
819      - ``backward_ref_ts``
820      - Timestamp of the V4L2 capture buffer to use as backward reference, used
821        with P-coded frames. The timestamp refers to the
822	``timestamp`` field in struct :c:type:`v4l2_buffer`. Use the
823	:c:func:`v4l2_timeval_to_ns()` function to convert the struct
824	:c:type:`timeval` in struct :c:type:`v4l2_buffer` to a __u64.
825    * - __u32
826      - ``version``
827      - The version of the codec. Set to ``V4L2_FWHT_VERSION``.
828    * - __u32
829      - ``width``
830      - The width of the frame.
831    * - __u32
832      - ``height``
833      - The height of the frame.
834    * - __u32
835      - ``flags``
836      - The flags of the frame, see :ref:`fwht-flags`.
837    * - __u32
838      - ``colorspace``
839      - The colorspace of the frame, from enum :c:type:`v4l2_colorspace`.
840    * - __u32
841      - ``xfer_func``
842      - The transfer function, from enum :c:type:`v4l2_xfer_func`.
843    * - __u32
844      - ``ycbcr_enc``
845      - The Y'CbCr encoding, from enum :c:type:`v4l2_ycbcr_encoding`.
846    * - __u32
847      - ``quantization``
848      - The quantization range, from enum :c:type:`v4l2_quantization`.
849
850.. raw:: latex
851
852    \normalsize
853
854.. _fwht-flags:
855
856FWHT Flags
857==========
858
859.. raw:: latex
860
861    \small
862
863.. tabularcolumns:: |p{7.0cm}|p{2.3cm}|p{8.0cm}|
864
865.. flat-table::
866    :header-rows:  0
867    :stub-columns: 0
868    :widths:       3 1 4
869
870    * - ``V4L2_FWHT_FL_IS_INTERLACED``
871      - 0x00000001
872      - Set if this is an interlaced format.
873    * - ``V4L2_FWHT_FL_IS_BOTTOM_FIRST``
874      - 0x00000002
875      - Set if this is a bottom-first (NTSC) interlaced format.
876    * - ``V4L2_FWHT_FL_IS_ALTERNATE``
877      - 0x00000004
878      - Set if each 'frame' contains just one field.
879    * - ``V4L2_FWHT_FL_IS_BOTTOM_FIELD``
880      - 0x00000008
881      - If V4L2_FWHT_FL_IS_ALTERNATE was set, then this is set if this 'frame' is the
882	bottom field, else it is the top field.
883    * - ``V4L2_FWHT_FL_LUMA_IS_UNCOMPRESSED``
884      - 0x00000010
885      - Set if the Y' (luma) plane is uncompressed.
886    * - ``V4L2_FWHT_FL_CB_IS_UNCOMPRESSED``
887      - 0x00000020
888      - Set if the Cb plane is uncompressed.
889    * - ``V4L2_FWHT_FL_CR_IS_UNCOMPRESSED``
890      - 0x00000040
891      - Set if the Cr plane is uncompressed.
892    * - ``V4L2_FWHT_FL_CHROMA_FULL_HEIGHT``
893      - 0x00000080
894      - Set if the chroma plane has the same height as the luma plane,
895	else the chroma plane is half the height of the luma plane.
896    * - ``V4L2_FWHT_FL_CHROMA_FULL_WIDTH``
897      - 0x00000100
898      - Set if the chroma plane has the same width as the luma plane,
899	else the chroma plane is half the width of the luma plane.
900    * - ``V4L2_FWHT_FL_ALPHA_IS_UNCOMPRESSED``
901      - 0x00000200
902      - Set if the alpha plane is uncompressed.
903    * - ``V4L2_FWHT_FL_I_FRAME``
904      - 0x00000400
905      - Set if this is an I-frame.
906    * - ``V4L2_FWHT_FL_COMPONENTS_NUM_MSK``
907      - 0x00070000
908      - The number of color components minus one.
909    * - ``V4L2_FWHT_FL_PIXENC_MSK``
910      - 0x00180000
911      - The mask for the pixel encoding.
912    * - ``V4L2_FWHT_FL_PIXENC_YUV``
913      - 0x00080000
914      - Set if the pixel encoding is YUV.
915    * - ``V4L2_FWHT_FL_PIXENC_RGB``
916      - 0x00100000
917      - Set if the pixel encoding is RGB.
918    * - ``V4L2_FWHT_FL_PIXENC_HSV``
919      - 0x00180000
920      - Set if the pixel encoding is HSV.
921
922.. raw:: latex
923
924    \normalsize
925
926.. _v4l2-codec-stateless-vp8:
927
928``V4L2_CID_STATELESS_VP8_FRAME (struct)``
929    Specifies the frame parameters for the associated VP8 parsed frame data.
930    This includes the necessary parameters for
931    configuring a stateless hardware decoding pipeline for VP8.
932    The bitstream parameters are defined according to :ref:`vp8`.
933
934.. c:type:: v4l2_ctrl_vp8_frame
935
936.. raw:: latex
937
938    \small
939
940.. tabularcolumns:: |p{7.0cm}|p{4.6cm}|p{5.7cm}|
941
942.. cssclass:: longtable
943
944.. flat-table:: struct v4l2_ctrl_vp8_frame
945    :header-rows:  0
946    :stub-columns: 0
947    :widths:       1 1 2
948
949    * - struct :c:type:`v4l2_vp8_segment`
950      - ``segment``
951      - Structure with segment-based adjustments metadata.
952    * - struct :c:type:`v4l2_vp8_loop_filter`
953      - ``lf``
954      - Structure with loop filter level adjustments metadata.
955    * - struct :c:type:`v4l2_vp8_quantization`
956      - ``quant``
957      - Structure with VP8 dequantization indices metadata.
958    * - struct :c:type:`v4l2_vp8_entropy`
959      - ``entropy``
960      - Structure with VP8 entropy coder probabilities metadata.
961    * - struct :c:type:`v4l2_vp8_entropy_coder_state`
962      - ``coder_state``
963      - Structure with VP8 entropy coder state.
964    * - __u16
965      - ``width``
966      - The width of the frame. Must be set for all frames.
967    * - __u16
968      - ``height``
969      - The height of the frame. Must be set for all frames.
970    * - __u8
971      - ``horizontal_scale``
972      - Horizontal scaling factor.
973    * - __u8
974      - ``vertical_scaling factor``
975      - Vertical scale.
976    * - __u8
977      - ``version``
978      - Bitstream version.
979    * - __u8
980      - ``prob_skip_false``
981      - Indicates the probability that the macroblock is not skipped.
982    * - __u8
983      - ``prob_intra``
984      - Indicates the probability that a macroblock is intra-predicted.
985    * - __u8
986      - ``prob_last``
987      - Indicates the probability that the last reference frame is used
988        for inter-prediction
989    * - __u8
990      - ``prob_gf``
991      - Indicates the probability that the golden reference frame is used
992        for inter-prediction
993    * - __u8
994      - ``num_dct_parts``
995      - Number of DCT coefficients partitions. Must be one of: 1, 2, 4, or 8.
996    * - __u32
997      - ``first_part_size``
998      - Size of the first partition, i.e. the control partition.
999    * - __u32
1000      - ``first_part_header_bits``
1001      - Size in bits of the first partition header portion.
1002    * - __u32
1003      - ``dct_part_sizes[8]``
1004      - DCT coefficients sizes.
1005    * - __u64
1006      - ``last_frame_ts``
1007      - Timestamp for the V4L2 capture buffer to use as last reference frame, used
1008        with inter-coded frames. The timestamp refers to the ``timestamp`` field in
1009	struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1010	function to convert the struct :c:type:`timeval` in struct
1011	:c:type:`v4l2_buffer` to a __u64.
1012    * - __u64
1013      - ``golden_frame_ts``
1014      - Timestamp for the V4L2 capture buffer to use as last reference frame, used
1015        with inter-coded frames. The timestamp refers to the ``timestamp`` field in
1016	struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1017	function to convert the struct :c:type:`timeval` in struct
1018	:c:type:`v4l2_buffer` to a __u64.
1019    * - __u64
1020      - ``alt_frame_ts``
1021      - Timestamp for the V4L2 capture buffer to use as alternate reference frame, used
1022        with inter-coded frames. The timestamp refers to the ``timestamp`` field in
1023	struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1024	function to convert the struct :c:type:`timeval` in struct
1025	:c:type:`v4l2_buffer` to a __u64.
1026    * - __u64
1027      - ``flags``
1028      - See :ref:`Frame Flags <vp8_frame_flags>`
1029
1030.. raw:: latex
1031
1032    \normalsize
1033
1034.. _vp8_frame_flags:
1035
1036``Frame Flags``
1037
1038.. tabularcolumns:: |p{9.8cm}|p{0.8cm}|p{6.7cm}|
1039
1040.. cssclass:: longtable
1041
1042.. flat-table::
1043    :header-rows:  0
1044    :stub-columns: 0
1045    :widths:       1 1 2
1046
1047    * - ``V4L2_VP8_FRAME_FLAG_KEY_FRAME``
1048      - 0x01
1049      - Indicates if the frame is a key frame.
1050    * - ``V4L2_VP8_FRAME_FLAG_EXPERIMENTAL``
1051      - 0x02
1052      - Experimental bitstream.
1053    * - ``V4L2_VP8_FRAME_FLAG_SHOW_FRAME``
1054      - 0x04
1055      - Show frame flag, indicates if the frame is for display.
1056    * - ``V4L2_VP8_FRAME_FLAG_MB_NO_SKIP_COEFF``
1057      - 0x08
1058      - Enable/disable skipping of macroblocks with no non-zero coefficients.
1059    * - ``V4L2_VP8_FRAME_FLAG_SIGN_BIAS_GOLDEN``
1060      - 0x10
1061      - Sign of motion vectors when the golden frame is referenced.
1062    * - ``V4L2_VP8_FRAME_FLAG_SIGN_BIAS_ALT``
1063      - 0x20
1064      - Sign of motion vectors when the alt frame is referenced.
1065
1066.. c:type:: v4l2_vp8_entropy_coder_state
1067
1068.. cssclass:: longtable
1069
1070.. tabularcolumns:: |p{1.0cm}|p{2.0cm}|p{14.3cm}|
1071
1072.. flat-table:: struct v4l2_vp8_entropy_coder_state
1073    :header-rows:  0
1074    :stub-columns: 0
1075    :widths:       1 1 2
1076
1077    * - __u8
1078      - ``range``
1079      - coder state value for "Range"
1080    * - __u8
1081      - ``value``
1082      - coder state value for "Value"-
1083    * - __u8
1084      - ``bit_count``
1085      - number of bits left.
1086    * - __u8
1087      - ``padding``
1088      - Applications and drivers must set this to zero.
1089
1090.. c:type:: v4l2_vp8_segment
1091
1092.. cssclass:: longtable
1093
1094.. tabularcolumns:: |p{1.2cm}|p{4.0cm}|p{12.1cm}|
1095
1096.. flat-table:: struct v4l2_vp8_segment
1097    :header-rows:  0
1098    :stub-columns: 0
1099    :widths:       1 1 2
1100
1101    * - __s8
1102      - ``quant_update[4]``
1103      - Signed quantizer value update.
1104    * - __s8
1105      - ``lf_update[4]``
1106      - Signed loop filter level value update.
1107    * - __u8
1108      - ``segment_probs[3]``
1109      - Segment probabilities.
1110    * - __u8
1111      - ``padding``
1112      - Applications and drivers must set this to zero.
1113    * - __u32
1114      - ``flags``
1115      - See :ref:`Segment Flags <vp8_segment_flags>`
1116
1117.. _vp8_segment_flags:
1118
1119``Segment Flags``
1120
1121.. raw:: latex
1122
1123    \small
1124
1125.. tabularcolumns:: |p{10cm}|p{1.0cm}|p{6.3cm}|
1126
1127.. flat-table::
1128    :header-rows:  0
1129    :stub-columns: 0
1130    :widths:       1 1 2
1131
1132    * - ``V4L2_VP8_SEGMENT_FLAG_ENABLED``
1133      - 0x01
1134      - Enable/disable segment-based adjustments.
1135    * - ``V4L2_VP8_SEGMENT_FLAG_UPDATE_MAP``
1136      - 0x02
1137      - Indicates if the macroblock segmentation map is updated in this frame.
1138    * - ``V4L2_VP8_SEGMENT_FLAG_UPDATE_FEATURE_DATA``
1139      - 0x04
1140      - Indicates if the segment feature data is updated in this frame.
1141    * - ``V4L2_VP8_SEGMENT_FLAG_DELTA_VALUE_MODE``
1142      - 0x08
1143      - If is set, the segment feature data mode is delta-value.
1144        If cleared, it's absolute-value.
1145
1146.. raw:: latex
1147
1148    \normalsize
1149
1150.. c:type:: v4l2_vp8_loop_filter
1151
1152.. cssclass:: longtable
1153
1154.. tabularcolumns:: |p{1.5cm}|p{3.9cm}|p{11.9cm}|
1155
1156.. flat-table:: struct v4l2_vp8_loop_filter
1157    :header-rows:  0
1158    :stub-columns: 0
1159    :widths:       1 1 2
1160
1161    * - __s8
1162      - ``ref_frm_delta[4]``
1163      - Reference adjustment (signed) delta value.
1164    * - __s8
1165      - ``mb_mode_delta[4]``
1166      - Macroblock prediction mode adjustment (signed) delta value.
1167    * - __u8
1168      - ``sharpness_level``
1169      - Sharpness level
1170    * - __u8
1171      - ``level``
1172      - Filter level
1173    * - __u16
1174      - ``padding``
1175      - Applications and drivers must set this to zero.
1176    * - __u32
1177      - ``flags``
1178      - See :ref:`Loop Filter Flags <vp8_loop_filter_flags>`
1179
1180.. _vp8_loop_filter_flags:
1181
1182``Loop Filter Flags``
1183
1184.. tabularcolumns:: |p{7.0cm}|p{1.2cm}|p{9.1cm}|
1185
1186.. flat-table::
1187    :header-rows:  0
1188    :stub-columns: 0
1189    :widths:       1 1 2
1190
1191    * - ``V4L2_VP8_LF_ADJ_ENABLE``
1192      - 0x01
1193      - Enable/disable macroblock-level loop filter adjustment.
1194    * - ``V4L2_VP8_LF_DELTA_UPDATE``
1195      - 0x02
1196      - Indicates if the delta values used in an adjustment are updated.
1197    * - ``V4L2_VP8_LF_FILTER_TYPE_SIMPLE``
1198      - 0x04
1199      - If set, indicates the filter type is simple.
1200        If cleared, the filter type is normal.
1201
1202.. c:type:: v4l2_vp8_quantization
1203
1204.. tabularcolumns:: |p{1.5cm}|p{3.5cm}|p{12.3cm}|
1205
1206.. flat-table:: struct v4l2_vp8_quantization
1207    :header-rows:  0
1208    :stub-columns: 0
1209    :widths:       1 1 2
1210
1211    * - __u8
1212      - ``y_ac_qi``
1213      - Luma AC coefficient table index.
1214    * - __s8
1215      - ``y_dc_delta``
1216      - Luma DC delta vaue.
1217    * - __s8
1218      - ``y2_dc_delta``
1219      - Y2 block DC delta value.
1220    * - __s8
1221      - ``y2_ac_delta``
1222      - Y2 block AC delta value.
1223    * - __s8
1224      - ``uv_dc_delta``
1225      - Chroma DC delta value.
1226    * - __s8
1227      - ``uv_ac_delta``
1228      - Chroma AC delta value.
1229    * - __u16
1230      - ``padding``
1231      - Applications and drivers must set this to zero.
1232
1233.. c:type:: v4l2_vp8_entropy
1234
1235.. cssclass:: longtable
1236
1237.. tabularcolumns:: |p{1.5cm}|p{5.8cm}|p{10.0cm}|
1238
1239.. flat-table:: struct v4l2_vp8_entropy
1240    :header-rows:  0
1241    :stub-columns: 0
1242    :widths:       1 1 2
1243
1244    * - __u8
1245      - ``coeff_probs[4][8][3][11]``
1246      - Coefficient update probabilities.
1247    * - __u8
1248      - ``y_mode_probs[4]``
1249      - Luma mode update probabilities.
1250    * - __u8
1251      - ``uv_mode_probs[3]``
1252      - Chroma mode update probabilities.
1253    * - __u8
1254      - ``mv_probs[2][19]``
1255      - MV decoding update probabilities.
1256    * - __u8
1257      - ``padding[3]``
1258      - Applications and drivers must set this to zero.
1259
1260.. _v4l2-codec-stateless-mpeg2:
1261
1262``V4L2_CID_STATELESS_MPEG2_SEQUENCE (struct)``
1263    Specifies the sequence parameters (as extracted from the bitstream) for the
1264    associated MPEG-2 slice data. This includes fields matching the syntax
1265    elements from the sequence header and sequence extension parts of the
1266    bitstream as specified by :ref:`mpeg2part2`.
1267
1268.. c:type:: v4l2_ctrl_mpeg2_sequence
1269
1270.. raw:: latex
1271
1272    \small
1273
1274.. cssclass:: longtable
1275
1276.. tabularcolumns:: |p{1.4cm}|p{6.5cm}|p{9.4cm}|
1277
1278.. flat-table:: struct v4l2_ctrl_mpeg2_sequence
1279    :header-rows:  0
1280    :stub-columns: 0
1281    :widths:       1 1 2
1282
1283    * - __u16
1284      - ``horizontal_size``
1285      - The width of the displayable part of the frame's luminance component.
1286    * - __u16
1287      - ``vertical_size``
1288      - The height of the displayable part of the frame's luminance component.
1289    * - __u32
1290      - ``vbv_buffer_size``
1291      - Used to calculate the required size of the video buffering verifier,
1292	defined (in bits) as: 16 * 1024 * vbv_buffer_size.
1293    * - __u16
1294      - ``profile_and_level_indication``
1295      - The current profile and level indication as extracted from the
1296	bitstream.
1297    * - __u8
1298      - ``chroma_format``
1299      - The chrominance sub-sampling format (1: 4:2:0, 2: 4:2:2, 3: 4:4:4).
1300    * - __u8
1301      - ``flags``
1302      - See :ref:`MPEG-2 Sequence Flags <mpeg2_sequence_flags>`.
1303
1304.. _mpeg2_sequence_flags:
1305
1306``MPEG-2 Sequence Flags``
1307
1308.. cssclass:: longtable
1309
1310.. flat-table::
1311    :header-rows:  0
1312    :stub-columns: 0
1313    :widths:       1 1 2
1314
1315    * - ``V4L2_MPEG2_SEQ_FLAG_PROGRESSIVE``
1316      - 0x01
1317      - Indication that all the frames for the sequence are progressive instead
1318	of interlaced.
1319
1320.. raw:: latex
1321
1322    \normalsize
1323
1324``V4L2_CID_STATELESS_MPEG2_PICTURE (struct)``
1325    Specifies the picture parameters (as extracted from the bitstream) for the
1326    associated MPEG-2 slice data. This includes fields matching the syntax
1327    elements from the picture header and picture coding extension parts of the
1328    bitstream as specified by :ref:`mpeg2part2`.
1329
1330.. c:type:: v4l2_ctrl_mpeg2_picture
1331
1332.. raw:: latex
1333
1334    \small
1335
1336.. cssclass:: longtable
1337
1338.. tabularcolumns:: |p{1.0cm}|p{5.6cm}|p{10.7cm}|
1339
1340.. flat-table:: struct v4l2_ctrl_mpeg2_picture
1341    :header-rows:  0
1342    :stub-columns: 0
1343    :widths:       1 1 2
1344
1345    * - __u64
1346      - ``backward_ref_ts``
1347      - Timestamp of the V4L2 capture buffer to use as backward reference, used
1348        with B-coded and P-coded frames. The timestamp refers to the
1349	``timestamp`` field in struct :c:type:`v4l2_buffer`. Use the
1350	:c:func:`v4l2_timeval_to_ns()` function to convert the struct
1351	:c:type:`timeval` in struct :c:type:`v4l2_buffer` to a __u64.
1352    * - __u64
1353      - ``forward_ref_ts``
1354      - Timestamp for the V4L2 capture buffer to use as forward reference, used
1355        with B-coded frames. The timestamp refers to the ``timestamp`` field in
1356	struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1357	function to convert the struct :c:type:`timeval` in struct
1358	:c:type:`v4l2_buffer` to a __u64.
1359    * - __u32
1360      - ``flags``
1361      - See :ref:`MPEG-2 Picture Flags <mpeg2_picture_flags>`.
1362    * - __u8
1363      - ``f_code[2][2]``
1364      - Motion vector codes.
1365    * - __u8
1366      - ``picture_coding_type``
1367      - Picture coding type for the frame covered by the current slice
1368	(V4L2_MPEG2_PIC_CODING_TYPE_I, V4L2_MPEG2_PIC_CODING_TYPE_P or
1369	V4L2_MPEG2_PIC_CODING_TYPE_B).
1370    * - __u8
1371      - ``picture_structure``
1372      - Picture structure (1: interlaced top field, 2: interlaced bottom field,
1373	3: progressive frame).
1374    * - __u8
1375      - ``intra_dc_precision``
1376      - Precision of Discrete Cosine transform (0: 8 bits precision,
1377	1: 9 bits precision, 2: 10 bits precision, 3: 11 bits precision).
1378    * - __u8
1379      - ``reserved[5]``
1380      - Applications and drivers must set this to zero.
1381
1382.. _mpeg2_picture_flags:
1383
1384``MPEG-2 Picture Flags``
1385
1386.. cssclass:: longtable
1387
1388.. flat-table::
1389    :header-rows:  0
1390    :stub-columns: 0
1391    :widths:       1 1 2
1392
1393    * - ``V4L2_MPEG2_PIC_FLAG_TOP_FIELD_FIRST``
1394      - 0x00000001
1395      - If set and it's an interlaced stream, top field is output first.
1396    * - ``V4L2_MPEG2_PIC_FLAG_FRAME_PRED_DCT``
1397      - 0x00000002
1398      - If set only frame-DCT and frame prediction are used.
1399    * - ``V4L2_MPEG2_PIC_FLAG_CONCEALMENT_MV``
1400      - 0x00000004
1401      -  If set motion vectors are coded for intra macroblocks.
1402    * - ``V4L2_MPEG2_PIC_FLAG_Q_SCALE_TYPE``
1403      - 0x00000008
1404      - This flag affects the inverse quantization process.
1405    * - ``V4L2_MPEG2_PIC_FLAG_INTRA_VLC``
1406      - 0x00000010
1407      - This flag affects the decoding of transform coefficient data.
1408    * - ``V4L2_MPEG2_PIC_FLAG_ALT_SCAN``
1409      - 0x00000020
1410      - This flag affects the decoding of transform coefficient data.
1411    * - ``V4L2_MPEG2_PIC_FLAG_REPEAT_FIRST``
1412      - 0x00000040
1413      - This flag affects the decoding process of progressive frames.
1414    * - ``V4L2_MPEG2_PIC_FLAG_PROGRESSIVE``
1415      - 0x00000080
1416      - Indicates whether the current frame is progressive.
1417
1418.. raw:: latex
1419
1420    \normalsize
1421
1422``V4L2_CID_STATELESS_MPEG2_QUANTISATION (struct)``
1423    Specifies quantisation matrices, in zigzag scanning order, for the
1424    associated MPEG-2 slice data. This control is initialized by the kernel
1425    to the matrices default values. If a bitstream transmits a user-defined
1426    quantisation matrices load, applications are expected to use this control.
1427    Applications are also expected to set the control loading the default
1428    values, if the quantisation matrices need to be reset, for instance on a
1429    sequence header. This process is specified by section 6.3.7.
1430    "Quant matrix extension" of the specification.
1431
1432.. c:type:: v4l2_ctrl_mpeg2_quantisation
1433
1434.. tabularcolumns:: |p{0.8cm}|p{8.0cm}|p{8.5cm}|
1435
1436.. cssclass:: longtable
1437
1438.. raw:: latex
1439
1440    \small
1441
1442.. flat-table:: struct v4l2_ctrl_mpeg2_quantisation
1443    :header-rows:  0
1444    :stub-columns: 0
1445    :widths:       1 1 2
1446
1447    * - __u8
1448      - ``intra_quantiser_matrix[64]``
1449      - The quantisation matrix coefficients for intra-coded frames, in zigzag
1450	scanning order. It is relevant for both luma and chroma components,
1451	although it can be superseded by the chroma-specific matrix for
1452	non-4:2:0 YUV formats.
1453    * - __u8
1454      - ``non_intra_quantiser_matrix[64]``
1455      - The quantisation matrix coefficients for non-intra-coded frames, in
1456	zigzag scanning order. It is relevant for both luma and chroma
1457	components, although it can be superseded by the chroma-specific matrix
1458	for non-4:2:0 YUV formats.
1459    * - __u8
1460      - ``chroma_intra_quantiser_matrix[64]``
1461      - The quantisation matrix coefficients for the chominance component of
1462	intra-coded frames, in zigzag scanning order. Only relevant for
1463	non-4:2:0 YUV formats.
1464    * - __u8
1465      - ``chroma_non_intra_quantiser_matrix[64]``
1466      - The quantisation matrix coefficients for the chrominance component of
1467	non-intra-coded frames, in zigzag scanning order. Only relevant for
1468	non-4:2:0 YUV formats.
1469
1470.. raw:: latex
1471
1472    \normalsize
1473
1474.. _v4l2-codec-stateless-vp9:
1475
1476``V4L2_CID_STATELESS_VP9_COMPRESSED_HDR (struct)``
1477    Stores VP9 probabilities updates as parsed from the current compressed frame
1478    header. A value of zero in an array element means no update of the relevant
1479    probability. Motion vector-related updates contain a new value or zero. All
1480    other updates contain values translated with inv_map_table[] (see 6.3.5 in
1481    :ref:`vp9`).
1482
1483.. c:type:: v4l2_ctrl_vp9_compressed_hdr
1484
1485.. tabularcolumns:: |p{1cm}|p{4.8cm}|p{11.4cm}|
1486
1487.. cssclass:: longtable
1488
1489.. flat-table:: struct v4l2_ctrl_vp9_compressed_hdr
1490    :header-rows:  0
1491    :stub-columns: 0
1492    :widths:       1 1 2
1493
1494    * - __u8
1495      - ``tx_mode``
1496      - Specifies the TX mode. See :ref:`TX Mode <vp9_tx_mode>` for more details.
1497    * - __u8
1498      - ``tx8[2][1]``
1499      - TX 8x8 probabilities delta.
1500    * - __u8
1501      - ``tx16[2][2]``
1502      - TX 16x16 probabilities delta.
1503    * - __u8
1504      - ``tx32[2][3]``
1505      - TX 32x32 probabilities delta.
1506    * - __u8
1507      - ``coef[4][2][2][6][6][3]``
1508      - Coefficient probabilities delta.
1509    * - __u8
1510      - ``skip[3]``
1511      - Skip probabilities delta.
1512    * - __u8
1513      - ``inter_mode[7][3]``
1514      - Inter prediction mode probabilities delta.
1515    * - __u8
1516      - ``interp_filter[4][2]``
1517      - Interpolation filter probabilities delta.
1518    * - __u8
1519      - ``is_inter[4]``
1520      - Is inter-block probabilities delta.
1521    * - __u8
1522      - ``comp_mode[5]``
1523      - Compound prediction mode probabilities delta.
1524    * - __u8
1525      - ``single_ref[5][2]``
1526      - Single reference probabilities delta.
1527    * - __u8
1528      - ``comp_ref[5]``
1529      - Compound reference probabilities delta.
1530    * - __u8
1531      - ``y_mode[4][9]``
1532      - Y prediction mode probabilities delta.
1533    * - __u8
1534      - ``uv_mode[10][9]``
1535      - UV prediction mode probabilities delta.
1536    * - __u8
1537      - ``partition[16][3]``
1538      - Partition probabilities delta.
1539    * - __u8
1540      - ``mv.joint[3]``
1541      - Motion vector joint probabilities delta.
1542    * - __u8
1543      - ``mv.sign[2]``
1544      - Motion vector sign probabilities delta.
1545    * - __u8
1546      - ``mv.classes[2][10]``
1547      - Motion vector class probabilities delta.
1548    * - __u8
1549      - ``mv.class0_bit[2]``
1550      - Motion vector class0 bit probabilities delta.
1551    * - __u8
1552      - ``mv.bits[2][10]``
1553      - Motion vector bits probabilities delta.
1554    * - __u8
1555      - ``mv.class0_fr[2][2][3]``
1556      - Motion vector class0 fractional bit probabilities delta.
1557    * - __u8
1558      - ``mv.fr[2][3]``
1559      - Motion vector fractional bit probabilities delta.
1560    * - __u8
1561      - ``mv.class0_hp[2]``
1562      - Motion vector class0 high precision fractional bit probabilities delta.
1563    * - __u8
1564      - ``mv.hp[2]``
1565      - Motion vector high precision fractional bit probabilities delta.
1566
1567.. _vp9_tx_mode:
1568
1569``TX Mode``
1570
1571.. tabularcolumns:: |p{6.5cm}|p{0.5cm}|p{10.3cm}|
1572
1573.. flat-table::
1574    :header-rows:  0
1575    :stub-columns: 0
1576    :widths:       1 1 2
1577
1578    * - ``V4L2_VP9_TX_MODE_ONLY_4X4``
1579      - 0
1580      - Transform size is 4x4.
1581    * - ``V4L2_VP9_TX_MODE_ALLOW_8X8``
1582      - 1
1583      - Transform size can be up to 8x8.
1584    * - ``V4L2_VP9_TX_MODE_ALLOW_16X16``
1585      - 2
1586      - Transform size can be up to 16x16.
1587    * - ``V4L2_VP9_TX_MODE_ALLOW_32X32``
1588      - 3
1589      - transform size can be up to 32x32.
1590    * - ``V4L2_VP9_TX_MODE_SELECT``
1591      - 4
1592      - Bitstream contains the transform size for each block.
1593
1594See section '7.3.1 Tx mode semantics' of the :ref:`vp9` specification for more details.
1595
1596``V4L2_CID_STATELESS_VP9_FRAME (struct)``
1597    Specifies the frame parameters for the associated VP9 frame decode request.
1598    This includes the necessary parameters for configuring a stateless hardware
1599    decoding pipeline for VP9. The bitstream parameters are defined according
1600    to :ref:`vp9`.
1601
1602.. c:type:: v4l2_ctrl_vp9_frame
1603
1604.. raw:: latex
1605
1606    \small
1607
1608.. tabularcolumns:: |p{4.7cm}|p{5.5cm}|p{7.1cm}|
1609
1610.. cssclass:: longtable
1611
1612.. flat-table:: struct v4l2_ctrl_vp9_frame
1613    :header-rows:  0
1614    :stub-columns: 0
1615    :widths:       1 1 2
1616
1617    * - struct :c:type:`v4l2_vp9_loop_filter`
1618      - ``lf``
1619      - Loop filter parameters. See struct :c:type:`v4l2_vp9_loop_filter` for more details.
1620    * - struct :c:type:`v4l2_vp9_quantization`
1621      - ``quant``
1622      - Quantization parameters. See :c:type:`v4l2_vp9_quantization` for more details.
1623    * - struct :c:type:`v4l2_vp9_segmentation`
1624      - ``seg``
1625      - Segmentation parameters. See :c:type:`v4l2_vp9_segmentation` for more details.
1626    * - __u32
1627      - ``flags``
1628      - Combination of V4L2_VP9_FRAME_FLAG_* flags. See :ref:`Frame Flags<vp9_frame_flags>`.
1629    * - __u16
1630      - ``compressed_header_size``
1631      - Compressed header size in bytes.
1632    * - __u16
1633      - ``uncompressed_header_size``
1634      - Uncompressed header size in bytes.
1635    * - __u16
1636      - ``frame_width_minus_1``
1637      - Add 1 to get the frame width expressed in pixels. See section 7.2.3 in :ref:`vp9`.
1638    * - __u16
1639      - ``frame_height_minus_1``
1640      - Add 1 to get the frame height expressed in pixels. See section 7.2.3 in :ref:`vp9`.
1641    * - __u16
1642      - ``render_width_minus_1``
1643      - Add 1 to get the expected render width expressed in pixels. This is
1644        not used during the decoding process but might be used by HW scalers to
1645        prepare a frame that's ready for scanout. See section 7.2.4 in :ref:`vp9`.
1646    * - __u16
1647      - render_height_minus_1
1648      - Add 1 to get the expected render height expressed in pixels. This is
1649        not used during the decoding process but might be used by HW scalers to
1650        prepare a frame that's ready for scanout. See section 7.2.4 in :ref:`vp9`.
1651    * - __u64
1652      - ``last_frame_ts``
1653      - "last" reference buffer timestamp.
1654	The timestamp refers to the ``timestamp`` field in
1655        struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1656        function to convert the struct :c:type:`timeval` in struct
1657        :c:type:`v4l2_buffer` to a __u64.
1658    * - __u64
1659      - ``golden_frame_ts``
1660      - "golden" reference buffer timestamp.
1661	The timestamp refers to the ``timestamp`` field in
1662        struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1663        function to convert the struct :c:type:`timeval` in struct
1664        :c:type:`v4l2_buffer` to a __u64.
1665    * - __u64
1666      - ``alt_frame_ts``
1667      - "alt" reference buffer timestamp.
1668	The timestamp refers to the ``timestamp`` field in
1669        struct :c:type:`v4l2_buffer`. Use the :c:func:`v4l2_timeval_to_ns()`
1670        function to convert the struct :c:type:`timeval` in struct
1671        :c:type:`v4l2_buffer` to a __u64.
1672    * - __u8
1673      - ``ref_frame_sign_bias``
1674      - a bitfield specifying whether the sign bias is set for a given
1675        reference frame. See :ref:`Reference Frame Sign Bias<vp9_ref_frame_sign_bias>`
1676        for more details.
1677    * - __u8
1678      - ``reset_frame_context``
1679      - specifies whether the frame context should be reset to default values. See
1680        :ref:`Reset Frame Context<vp9_reset_frame_context>` for more details.
1681    * - __u8
1682      - ``frame_context_idx``
1683      - Frame context that should be used/updated.
1684    * - __u8
1685      - ``profile``
1686      - VP9 profile. Can be 0, 1, 2 or 3.
1687    * - __u8
1688      - ``bit_depth``
1689      - Component depth in bits. Can be 8, 10 or 12. Note that not all profiles
1690        support 10 and/or 12 bits depths.
1691    * - __u8
1692      - ``interpolation_filter``
1693      - Specifies the filter selection used for performing inter prediction. See
1694        :ref:`Interpolation Filter<vp9_interpolation_filter>` for more details.
1695    * - __u8
1696      - ``tile_cols_log2``
1697      - Specifies the base 2 logarithm of the width of each tile (where the
1698        width is measured in units of 8x8 blocks). Shall be less than or equal
1699        to 6.
1700    * - __u8
1701      - ``tile_rows_log2``
1702      - Specifies the base 2 logarithm of the height of each tile (where the
1703        height is measured in units of 8x8 blocks).
1704    * - __u8
1705      - ``reference_mode``
1706      - Specifies the type of inter prediction to be used. See
1707        :ref:`Reference Mode<vp9_reference_mode>` for more details. Note that
1708	this is derived as part of the compressed header parsing process and
1709	for this reason should have been part of
1710	:c:type: `v4l2_ctrl_vp9_compressed_hdr` optional control. It is safe to
1711	set this value to zero if the driver does not require compressed
1712	headers.
1713    * - __u8
1714      - ``reserved[7]``
1715      - Applications and drivers must set this to zero.
1716
1717.. raw:: latex
1718
1719    \normalsize
1720
1721.. _vp9_frame_flags:
1722
1723``Frame Flags``
1724
1725.. tabularcolumns:: |p{10.0cm}|p{1.2cm}|p{6.1cm}|
1726
1727.. flat-table::
1728    :header-rows:  0
1729    :stub-columns: 0
1730    :widths:       1 1 2
1731
1732    * - ``V4L2_VP9_FRAME_FLAG_KEY_FRAME``
1733      - 0x001
1734      - The frame is a key frame.
1735    * - ``V4L2_VP9_FRAME_FLAG_SHOW_FRAME``
1736      - 0x002
1737      - The frame should be displayed.
1738    * - ``V4L2_VP9_FRAME_FLAG_ERROR_RESILIENT``
1739      - 0x004
1740      - The decoding should be error resilient.
1741    * - ``V4L2_VP9_FRAME_FLAG_INTRA_ONLY``
1742      - 0x008
1743      - The frame does not reference other frames.
1744    * - ``V4L2_VP9_FRAME_FLAG_ALLOW_HIGH_PREC_MV``
1745      - 0x010
1746      - The frame can use high precision motion vectors.
1747    * - ``V4L2_VP9_FRAME_FLAG_REFRESH_FRAME_CTX``
1748      - 0x020
1749      - Frame context should be updated after decoding.
1750    * - ``V4L2_VP9_FRAME_FLAG_PARALLEL_DEC_MODE``
1751      - 0x040
1752      - Parallel decoding is used.
1753    * - ``V4L2_VP9_FRAME_FLAG_X_SUBSAMPLING``
1754      - 0x080
1755      - Vertical subsampling is enabled.
1756    * - ``V4L2_VP9_FRAME_FLAG_Y_SUBSAMPLING``
1757      - 0x100
1758      - Horizontal subsampling is enabled.
1759    * - ``V4L2_VP9_FRAME_FLAG_COLOR_RANGE_FULL_SWING``
1760      - 0x200
1761      - The full UV range is used.
1762
1763.. _vp9_ref_frame_sign_bias:
1764
1765``Reference Frame Sign Bias``
1766
1767.. tabularcolumns:: |p{7.0cm}|p{1.2cm}|p{9.1cm}|
1768
1769.. flat-table::
1770    :header-rows:  0
1771    :stub-columns: 0
1772    :widths:       1 1 2
1773
1774    * - ``V4L2_VP9_SIGN_BIAS_LAST``
1775      - 0x1
1776      - Sign bias is set for the last reference frame.
1777    * - ``V4L2_VP9_SIGN_BIAS_GOLDEN``
1778      - 0x2
1779      - Sign bias is set for the golden reference frame.
1780    * - ``V4L2_VP9_SIGN_BIAS_ALT``
1781      - 0x2
1782      - Sign bias is set for the alt reference frame.
1783
1784.. _vp9_reset_frame_context:
1785
1786``Reset Frame Context``
1787
1788.. tabularcolumns:: |p{7.0cm}|p{1.2cm}|p{9.1cm}|
1789
1790.. flat-table::
1791    :header-rows:  0
1792    :stub-columns: 0
1793    :widths:       1 1 2
1794
1795    * - ``V4L2_VP9_RESET_FRAME_CTX_NONE``
1796      - 0
1797      - Do not reset any frame context.
1798    * - ``V4L2_VP9_RESET_FRAME_CTX_SPEC``
1799      - 1
1800      - Reset the frame context pointed to by
1801        :c:type:`v4l2_ctrl_vp9_frame`.frame_context_idx.
1802    * - ``V4L2_VP9_RESET_FRAME_CTX_ALL``
1803      - 2
1804      - Reset all frame contexts.
1805
1806See section '7.2 Uncompressed header semantics' of the :ref:`vp9` specification
1807for more details.
1808
1809.. _vp9_interpolation_filter:
1810
1811``Interpolation Filter``
1812
1813.. tabularcolumns:: |p{9.0cm}|p{1.2cm}|p{7.1cm}|
1814
1815.. flat-table::
1816    :header-rows:  0
1817    :stub-columns: 0
1818    :widths:       1 1 2
1819
1820    * - ``V4L2_VP9_INTERP_FILTER_EIGHTTAP``
1821      - 0
1822      - Eight tap filter.
1823    * - ``V4L2_VP9_INTERP_FILTER_EIGHTTAP_SMOOTH``
1824      - 1
1825      - Eight tap smooth filter.
1826    * - ``V4L2_VP9_INTERP_FILTER_EIGHTTAP_SHARP``
1827      - 2
1828      - Eeight tap sharp filter.
1829    * - ``V4L2_VP9_INTERP_FILTER_BILINEAR``
1830      - 3
1831      - Bilinear filter.
1832    * - ``V4L2_VP9_INTERP_FILTER_SWITCHABLE``
1833      - 4
1834      - Filter selection is signaled at the block level.
1835
1836See section '7.2.7 Interpolation filter semantics' of the :ref:`vp9` specification
1837for more details.
1838
1839.. _vp9_reference_mode:
1840
1841``Reference Mode``
1842
1843.. tabularcolumns:: |p{9.6cm}|p{0.5cm}|p{7.2cm}|
1844
1845.. flat-table::
1846    :header-rows:  0
1847    :stub-columns: 0
1848    :widths:       1 1 2
1849
1850    * - ``V4L2_VP9_REFERENCE_MODE_SINGLE_REFERENCE``
1851      - 0
1852      - Indicates that all the inter blocks use only a single reference frame
1853        to generate motion compensated prediction.
1854    * - ``V4L2_VP9_REFERENCE_MODE_COMPOUND_REFERENCE``
1855      - 1
1856      - Requires all the inter blocks to use compound mode. Single reference
1857        frame prediction is not allowed.
1858    * - ``V4L2_VP9_REFERENCE_MODE_SELECT``
1859      - 2
1860      - Allows each individual inter block to select between single and
1861        compound prediction modes.
1862
1863See section '7.3.6 Frame reference mode semantics' of the :ref:`vp9` specification for more details.
1864
1865.. c:type:: v4l2_vp9_segmentation
1866
1867Encodes the quantization parameters. See section '7.2.10 Segmentation
1868params syntax' of the :ref:`vp9` specification for more details.
1869
1870.. tabularcolumns:: |p{0.8cm}|p{5cm}|p{11.4cm}|
1871
1872.. cssclass:: longtable
1873
1874.. flat-table:: struct v4l2_vp9_segmentation
1875    :header-rows:  0
1876    :stub-columns: 0
1877    :widths:       1 1 2
1878
1879    * - __u8
1880      - ``feature_data[8][4]``
1881      - Data attached to each feature. Data entry is only valid if the feature
1882        is enabled. The array shall be indexed with segment number as the first dimension
1883        (0..7) and one of V4L2_VP9_SEG_* as the second dimension.
1884        See :ref:`Segment Feature IDs<vp9_segment_feature>`.
1885    * - __u8
1886      - ``feature_enabled[8]``
1887      - Bitmask defining which features are enabled in each segment. The value for each
1888        segment is a combination of V4L2_VP9_SEGMENT_FEATURE_ENABLED(id) values where id is
1889        one of V4L2_VP9_SEG_*. See :ref:`Segment Feature IDs<vp9_segment_feature>`.
1890    * - __u8
1891      - ``tree_probs[7]``
1892      - Specifies the probability values to be used when decoding a Segment-ID.
1893        See '5.15. Segmentation map' section of :ref:`vp9` for more details.
1894    * - __u8
1895      - ``pred_probs[3]``
1896      - Specifies the probability values to be used when decoding a
1897        Predicted-Segment-ID. See '6.4.14. Get segment id syntax'
1898        section of :ref:`vp9` for more details.
1899    * - __u8
1900      - ``flags``
1901      - Combination of V4L2_VP9_SEGMENTATION_FLAG_* flags. See
1902        :ref:`Segmentation Flags<vp9_segmentation_flags>`.
1903    * - __u8
1904      - ``reserved[5]``
1905      - Applications and drivers must set this to zero.
1906
1907.. _vp9_segment_feature:
1908
1909``Segment feature IDs``
1910
1911.. tabularcolumns:: |p{6.0cm}|p{1cm}|p{10.3cm}|
1912
1913.. flat-table::
1914    :header-rows:  0
1915    :stub-columns: 0
1916    :widths:       1 1 2
1917
1918    * - ``V4L2_VP9_SEG_LVL_ALT_Q``
1919      - 0
1920      - Quantizer segment feature.
1921    * - ``V4L2_VP9_SEG_LVL_ALT_L``
1922      - 1
1923      - Loop filter segment feature.
1924    * - ``V4L2_VP9_SEG_LVL_REF_FRAME``
1925      - 2
1926      - Reference frame segment feature.
1927    * - ``V4L2_VP9_SEG_LVL_SKIP``
1928      - 3
1929      - Skip segment feature.
1930    * - ``V4L2_VP9_SEG_LVL_MAX``
1931      - 4
1932      - Number of segment features.
1933
1934.. _vp9_segmentation_flags:
1935
1936``Segmentation Flags``
1937
1938.. tabularcolumns:: |p{10.6cm}|p{0.8cm}|p{5.9cm}|
1939
1940.. flat-table::
1941    :header-rows:  0
1942    :stub-columns: 0
1943    :widths:       1 1 2
1944
1945    * - ``V4L2_VP9_SEGMENTATION_FLAG_ENABLED``
1946      - 0x01
1947      - Indicates that this frame makes use of the segmentation tool.
1948    * - ``V4L2_VP9_SEGMENTATION_FLAG_UPDATE_MAP``
1949      - 0x02
1950      - Indicates that the segmentation map should be updated during the
1951        decoding of this frame.
1952    * - ``V4L2_VP9_SEGMENTATION_FLAG_TEMPORAL_UPDATE``
1953      - 0x04
1954      - Indicates that the updates to the segmentation map are coded
1955        relative to the existing segmentation map.
1956    * - ``V4L2_VP9_SEGMENTATION_FLAG_UPDATE_DATA``
1957      - 0x08
1958      - Indicates that new parameters are about to be specified for each
1959        segment.
1960    * - ``V4L2_VP9_SEGMENTATION_FLAG_ABS_OR_DELTA_UPDATE``
1961      - 0x10
1962      - Indicates that the segmentation parameters represent the actual values
1963        to be used.
1964
1965.. c:type:: v4l2_vp9_quantization
1966
1967Encodes the quantization parameters. See section '7.2.9 Quantization params
1968syntax' of the VP9 specification for more details.
1969
1970.. tabularcolumns:: |p{0.8cm}|p{4cm}|p{12.4cm}|
1971
1972.. cssclass:: longtable
1973
1974.. flat-table:: struct v4l2_vp9_quantization
1975    :header-rows:  0
1976    :stub-columns: 0
1977    :widths:       1 1 2
1978
1979    * - __u8
1980      - ``base_q_idx``
1981      - Indicates the base frame qindex.
1982    * - __s8
1983      - ``delta_q_y_dc``
1984      - Indicates the Y DC quantizer relative to base_q_idx.
1985    * - __s8
1986      - ``delta_q_uv_dc``
1987      - Indicates the UV DC quantizer relative to base_q_idx.
1988    * - __s8
1989      - ``delta_q_uv_ac``
1990      - Indicates the UV AC quantizer relative to base_q_idx.
1991    * - __u8
1992      - ``reserved[4]``
1993      - Applications and drivers must set this to zero.
1994
1995.. c:type:: v4l2_vp9_loop_filter
1996
1997This structure contains all loop filter related parameters. See sections
1998'7.2.8 Loop filter semantics' of the :ref:`vp9` specification for more details.
1999
2000.. tabularcolumns:: |p{0.8cm}|p{4cm}|p{12.4cm}|
2001
2002.. cssclass:: longtable
2003
2004.. flat-table:: struct v4l2_vp9_loop_filter
2005    :header-rows:  0
2006    :stub-columns: 0
2007    :widths:       1 1 2
2008
2009    * - __s8
2010      - ``ref_deltas[4]``
2011      - Contains the adjustment needed for the filter level based on the chosen
2012        reference frame.
2013    * - __s8
2014      - ``mode_deltas[2]``
2015      - Contains the adjustment needed for the filter level based on the chosen
2016        mode.
2017    * - __u8
2018      - ``level``
2019      - Indicates the loop filter strength.
2020    * - __u8
2021      - ``sharpness``
2022      - Indicates the sharpness level.
2023    * - __u8
2024      - ``flags``
2025      - Combination of V4L2_VP9_LOOP_FILTER_FLAG_* flags.
2026        See :ref:`Loop Filter Flags <vp9_loop_filter_flags>`.
2027    * - __u8
2028      - ``reserved[7]``
2029      - Applications and drivers must set this to zero.
2030
2031
2032.. _vp9_loop_filter_flags:
2033
2034``Loop Filter Flags``
2035
2036.. tabularcolumns:: |p{9.6cm}|p{0.5cm}|p{7.2cm}|
2037
2038.. flat-table::
2039    :header-rows:  0
2040    :stub-columns: 0
2041    :widths:       1 1 2
2042
2043    * - ``V4L2_VP9_LOOP_FILTER_FLAG_DELTA_ENABLED``
2044      - 0x1
2045      - When set, the filter level depends on the mode and reference frame used
2046        to predict a block.
2047    * - ``V4L2_VP9_LOOP_FILTER_FLAG_DELTA_UPDATE``
2048      - 0x2
2049      - When set, the bitstream contains additional syntax elements that
2050        specify which mode and reference frame deltas are to be updated.
2051