[PATCH RFC 01/10] media: hevc: Add H.265 syntax definitions

[Arun Iyengar <aiyengar1990@gmail.com>]

Add the ITU-T Rec. H.265 constants that a stateless HEVC encoder needs
to produce a bitstream: NAL unit type codes (Table 7-1), profile IDCs
(Annex A), access unit delimiter picture types (Table 7-2) and the VUI
colour description code points (Tables E.3 to E.5, shared with ITU-T
H.273).

Also add small helpers that classify NAL unit types (IRAP, IDR, BLA,
leading and sub-layer non-reference pictures), since the reference
picture set and picture order count rules depend on them.

These are kernel-internal definitions: the uAPI carries nal_unit_type as
the raw H.265 value, like the HEVC decoding controls already do.

Signed-off-by: Arun Iyengar <aiyengar1990@gmail.com>
---
 include/media/v4l2-hevc.h | 132 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 131 insertions(+), 1 deletion(-)

diff --git a/include/media/v4l2-hevc.h b/include/media/v4l2-hevc.h
index 973c96be16be..cc649b212a6d 100644
--- a/include/media/v4l2-hevc.h
+++ b/include/media/v4l2-hevc.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
- * Helper functions for HEVC stateless codecs.
+ * Helper functions and ITU-T Rec. H.265 syntax definitions for HEVC stateless
+ * codecs.
  */
 
 #ifndef _MEDIA_V4L2_HEVC_H
@@ -38,4 +39,133 @@ v4l2_hevc_pps_num_tile_rows(const struct v4l2_ctrl_hevc_pps *pps)
 		     ARRAY_SIZE(pps->row_height_minus1));
 }
 
+/* ITU-T Rec. H.265 Table 7-1: NAL unit type codes */
+#define V4L2_HEVC_NAL_TRAIL_N		0
+#define V4L2_HEVC_NAL_TRAIL_R		1
+#define V4L2_HEVC_NAL_TSA_N		2
+#define V4L2_HEVC_NAL_TSA_R		3
+#define V4L2_HEVC_NAL_STSA_N		4
+#define V4L2_HEVC_NAL_STSA_R		5
+#define V4L2_HEVC_NAL_RADL_N		6
+#define V4L2_HEVC_NAL_RADL_R		7
+#define V4L2_HEVC_NAL_RASL_N		8
+#define V4L2_HEVC_NAL_RASL_R		9
+#define V4L2_HEVC_NAL_RSV_VCL_N14	14
+#define V4L2_HEVC_NAL_BLA_W_LP		16
+#define V4L2_HEVC_NAL_BLA_W_RADL	17
+#define V4L2_HEVC_NAL_BLA_N_LP		18
+#define V4L2_HEVC_NAL_IDR_W_RADL	19
+#define V4L2_HEVC_NAL_IDR_N_LP		20
+#define V4L2_HEVC_NAL_CRA_NUT		21
+#define V4L2_HEVC_NAL_RSV_IRAP_VCL23	23
+#define V4L2_HEVC_NAL_VPS		32
+#define V4L2_HEVC_NAL_SPS		33
+#define V4L2_HEVC_NAL_PPS		34
+#define V4L2_HEVC_NAL_AUD		35
+#define V4L2_HEVC_NAL_EOS		36
+#define V4L2_HEVC_NAL_EOB		37
+#define V4L2_HEVC_NAL_FD		38
+#define V4L2_HEVC_NAL_PREFIX_SEI	39
+#define V4L2_HEVC_NAL_SUFFIX_SEI	40
+
+/* ITU-T Rec. H.265 Annex A: general_profile_idc */
+#define V4L2_HEVC_PROFILE_IDC_MAIN		1
+#define V4L2_HEVC_PROFILE_IDC_MAIN_10		2
+#define V4L2_HEVC_PROFILE_IDC_MAIN_STILL_PICTURE	3
+#define V4L2_HEVC_PROFILE_IDC_RANGE_EXTENSIONS	4
+
+/* ITU-T Rec. H.265 Table 7-2: pic_type in access unit delimiters */
+#define V4L2_HEVC_AUD_PIC_TYPE_I	0
+#define V4L2_HEVC_AUD_PIC_TYPE_PI	1
+#define V4L2_HEVC_AUD_PIC_TYPE_BPI	2
+
+/* ITU-T Rec. H.265 Table E.1: aspect_ratio_idc */
+#define V4L2_HEVC_VUI_ASPECT_RATIO_IDC_EXTENDED	255
+
+/* ITU-T Rec. H.265 Table E.2: video_format */
+#define V4L2_HEVC_VUI_VIDEO_FORMAT_UNSPECIFIED	5
+
+/* ITU-T Rec. H.265 Tables E.3 to E.5 (ITU-T H.273 code points) */
+#define V4L2_HEVC_VUI_COLOUR_BT709		1
+#define V4L2_HEVC_VUI_COLOUR_UNSPECIFIED	2
+#define V4L2_HEVC_VUI_COLOUR_BT470_SYSTEM_M	4
+#define V4L2_HEVC_VUI_COLOUR_BT470_SYSTEM_BG	5
+#define V4L2_HEVC_VUI_COLOUR_SMPTE170M		6
+#define V4L2_HEVC_VUI_COLOUR_SMPTE240M		7
+#define V4L2_HEVC_VUI_COLOUR_BT2020		9
+#define V4L2_HEVC_VUI_COLOUR_SMPTE431		11
+
+#define V4L2_HEVC_VUI_TRANSFER_BT709		1
+#define V4L2_HEVC_VUI_TRANSFER_UNSPECIFIED	2
+#define V4L2_HEVC_VUI_TRANSFER_SMPTE170M	6
+#define V4L2_HEVC_VUI_TRANSFER_SMPTE240M	7
+#define V4L2_HEVC_VUI_TRANSFER_LINEAR		8
+#define V4L2_HEVC_VUI_TRANSFER_SRGB		13
+#define V4L2_HEVC_VUI_TRANSFER_SMPTE2084	16
+
+#define V4L2_HEVC_VUI_MATRIX_BT709		1
+#define V4L2_HEVC_VUI_MATRIX_UNSPECIFIED	2
+#define V4L2_HEVC_VUI_MATRIX_BT470_SYSTEM_BG	5
+#define V4L2_HEVC_VUI_MATRIX_SMPTE170M		6
+#define V4L2_HEVC_VUI_MATRIX_SMPTE240M		7
+#define V4L2_HEVC_VUI_MATRIX_BT2020_NCL		9
+#define V4L2_HEVC_VUI_MATRIX_BT2020_CL		10
+
+/* Maximum number of temporal sub-layers (sps_max_sub_layers_minus1 + 1) */
+#define V4L2_HEVC_MAX_SUB_LAYERS	7
+
+/* Maximum number of pictures in a short-term RPS (7.4.8) */
+#define V4L2_HEVC_MAX_ST_RPS_PICS	16
+
+/* Maximum number of long-term pictures signalled in a slice header */
+#define V4L2_HEVC_MAX_LT_PICS		16
+
+static inline bool v4l2_hevc_nal_is_irap(unsigned int nal_unit_type)
+{
+	return nal_unit_type >= V4L2_HEVC_NAL_BLA_W_LP &&
+	       nal_unit_type <= V4L2_HEVC_NAL_RSV_IRAP_VCL23;
+}
+
+static inline bool v4l2_hevc_nal_is_idr(unsigned int nal_unit_type)
+{
+	return nal_unit_type == V4L2_HEVC_NAL_IDR_W_RADL ||
+	       nal_unit_type == V4L2_HEVC_NAL_IDR_N_LP;
+}
+
+static inline bool v4l2_hevc_nal_is_bla(unsigned int nal_unit_type)
+{
+	return nal_unit_type >= V4L2_HEVC_NAL_BLA_W_LP &&
+	       nal_unit_type <= V4L2_HEVC_NAL_BLA_N_LP;
+}
+
+/*
+ * Sub-layer non-reference picture (3.132): even nal_unit_type values in the
+ * VCL range below RSV_VCL_N14.
+ */
+static inline bool v4l2_hevc_nal_is_sub_layer_non_ref(unsigned int nal_unit_type)
+{
+	return nal_unit_type <= V4L2_HEVC_NAL_RSV_VCL_N14 &&
+	       !(nal_unit_type & 1);
+}
+
+static inline bool v4l2_hevc_nal_is_leading(unsigned int nal_unit_type)
+{
+	return nal_unit_type >= V4L2_HEVC_NAL_RADL_N &&
+	       nal_unit_type <= V4L2_HEVC_NAL_RASL_R;
+}
+
+static inline char v4l2_hevc_slice_type_char(unsigned char slice_type)
+{
+	switch (slice_type) {
+	case V4L2_HEVC_SLICE_TYPE_B:
+		return 'B';
+	case V4L2_HEVC_SLICE_TYPE_P:
+		return 'P';
+	case V4L2_HEVC_SLICE_TYPE_I:
+		return 'I';
+	default:
+		return 'X';
+	}
+}
+
 #endif /* _MEDIA_V4L2_HEVC_H */

-- 
2.55.0