1 /*
2 * Copyright 2021 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #pragma once
18
19 #include <ui/GraphicTypes.h>
20
21 namespace android {
22
23 enum class HdrRenderType {
24 SDR, // just render to SDR
25 DISPLAY_HDR, // HDR by extended brightness
26 GENERIC_HDR // tonemapped HDR
27 };
28
29 /***
30 * A helper function to classify how we treat the result based on params.
31 *
32 * @param dataspace the dataspace
33 * @param pixelFormat optional, in case there is no source buffer.
34 * @param hdrSdrRatio default is 1.f, render engine side doesn't take care of it.
35 * @return HdrRenderType
36 */
37 inline HdrRenderType getHdrRenderType(ui::Dataspace dataspace,
38 std::optional<ui::PixelFormat> pixelFormat,
39 float hdrSdrRatio = 1.f, bool hasHdrMetadata = false) {
40 const auto transfer = dataspace & HAL_DATASPACE_TRANSFER_MASK;
41 const auto range = dataspace & HAL_DATASPACE_RANGE_MASK;
42
43 if (transfer == HAL_DATASPACE_TRANSFER_ST2084 || transfer == HAL_DATASPACE_TRANSFER_HLG) {
44 return HdrRenderType::GENERIC_HDR;
45 }
46
47 static const auto BT2020_LINEAR_EXT = static_cast<ui::Dataspace>(HAL_DATASPACE_STANDARD_BT2020 |
48 HAL_DATASPACE_TRANSFER_LINEAR |
49 HAL_DATASPACE_RANGE_EXTENDED);
50
51 if ((dataspace == BT2020_LINEAR_EXT || dataspace == ui::Dataspace::V0_SCRGB) &&
52 pixelFormat.has_value() && pixelFormat.value() == ui::PixelFormat::RGBA_FP16 &&
53 hasHdrMetadata) {
54 return HdrRenderType::GENERIC_HDR;
55 }
56
57 // Extended range layer with an hdr/sdr ratio of > 1.01f can "self-promote" to HDR.
58 if (range == HAL_DATASPACE_RANGE_EXTENDED && hdrSdrRatio > 1.01f) {
59 return HdrRenderType::DISPLAY_HDR;
60 }
61
62 return HdrRenderType::SDR;
63 }
64
65 /**
66 * Returns the maximum headroom allowed for this content under "idealized"
67 * display conditions (low surround luminance, high-enough display brightness).
68 *
69 * TODO: take into account hdr metadata, but square it with the fact that some
70 * HLG content has CTA.861-3 metadata
71 */
getIdealizedMaxHeadroom(ui::Dataspace dataspace)72 inline float getIdealizedMaxHeadroom(ui::Dataspace dataspace) {
73 const auto transfer = dataspace & HAL_DATASPACE_TRANSFER_MASK;
74
75 switch (transfer) {
76 case HAL_DATASPACE_TRANSFER_ST2084:
77 return 10000.0f / 203.0f;
78 case HAL_DATASPACE_TRANSFER_HLG:
79 return 1000.0f / 203.0f;
80 default:
81 return 1.0f;
82 }
83 }
84
85 } // namespace android
86