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/*
* Copyright (c) 2023 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "api/video_codecs/h265_profile_tier_level.h"
#include <string>
#include "absl/types/optional.h"
#include "api/rtp_parameters.h"
#include "api/video/resolution.h"
#include "rtc_base/arraysize.h"
#include "rtc_base/string_to_number.h"
namespace webrtc {
namespace {
const char kH265FmtpProfile[] = "profile-id";
const char kH265FmtpTier[] = "tier-flag";
const char kH265FmtpLevel[] = "level-id";
// Used to align frame width and height for luma picture size calculation.
// Use the maximum value allowed by spec to get upper bound of luma picture
// size for given resolution.
static constexpr int kMinCbSizeYMax = 64;
struct LevelConstraint {
const int max_luma_picture_size;
const double max_luma_sample_rate;
const int max_pic_width_or_height_in_pixels;
const H265Level level;
};
// This is from ITU-T H.265 (09/2023) Table A.8, A.9 & A.11 – Level limits.
// The max_pic_width_or_height_in_luma_samples is pre-calculated following
// ITU-T H.265 section A.4.1, that is, find the largest integer value that
// is multiple of minimal MinCbSizeY(8 according to equation 7-10 and 7-12), is
// less than sqrt(max_luma_picture_size * 8). For example, at level 1,
// max_luma_picture_size is 36864, so pic_width_in_luma_samples <= sqrt(36864 *
// 8) = 543.06. The largest integer that is multiple of 8 and less than 543.06
// is 536.
static constexpr LevelConstraint kLevelConstraints[] = {
{36864, 552960, 536, H265Level::kLevel1},
{122880, 3686400, 984, H265Level::kLevel2},
{245760, 7372800, 1400, H265Level::kLevel2_1},
{552960, 16588800, 2096, H265Level::kLevel3},
{983040, 33177600, 2800, H265Level::kLevel3_1},
{2228224, 66846720, 4216, H265Level::kLevel4},
{2228224, 133693400, 4216, H265Level::kLevel4_1},
{8912896, 267386880, 8440, H265Level::kLevel5},
{8912896, 534773760, 8440, H265Level::kLevel5_1},
{8912896, 1069547520, 8440, H265Level::kLevel5_2},
{35651584, 1069547520, 16888, H265Level::kLevel6},
{35651584, 2139095040, 16888, H265Level::kLevel6_1},
{35651584, 4278190080, 16888, H265Level::kLevel6_2},
};
} // anonymous namespace
absl::optional<H265Profile> StringToH265Profile(const std::string& profile) {
absl::optional<int> i = rtc::StringToNumber<int>(profile);
if (!i.has_value()) {
return absl::nullopt;
}
switch (i.value()) {
case 1:
return H265Profile::kProfileMain;
case 2:
return H265Profile::kProfileMain10;
case 3:
return H265Profile::kProfileMainStill;
case 4:
return H265Profile::kProfileRangeExtensions;
case 5:
return H265Profile::kProfileHighThroughput;
case 6:
return H265Profile::kProfileMultiviewMain;
case 7:
return H265Profile::kProfileScalableMain;
case 8:
return H265Profile::kProfile3dMain;
case 9:
return H265Profile::kProfileScreenContentCoding;
case 10:
return H265Profile::kProfileScalableRangeExtensions;
case 11:
return H265Profile::kProfileHighThroughputScreenContentCoding;
default:
return absl::nullopt;
}
}
// tiers and levels.
absl::optional<H265Tier> StringToH265Tier(const std::string& tier) {
absl::optional<int> i = rtc::StringToNumber<int>(tier);
if (!i.has_value()) {
return absl::nullopt;
}
switch (i.value()) {
case 0:
return H265Tier::kTier0;
case 1:
return H265Tier::kTier1;
default:
return absl::nullopt;
}
}
absl::optional<H265Level> StringToH265Level(const std::string& level) {
const absl::optional<int> i = rtc::StringToNumber<int>(level);
if (!i.has_value())
return absl::nullopt;
switch (i.value()) {
case 30:
return H265Level::kLevel1;
case 60:
return H265Level::kLevel2;
case 63:
return H265Level::kLevel2_1;
case 90:
return H265Level::kLevel3;
case 93:
return H265Level::kLevel3_1;
case 120:
return H265Level::kLevel4;
case 123:
return H265Level::kLevel4_1;
case 150:
return H265Level::kLevel5;
case 153:
return H265Level::kLevel5_1;
case 156:
return H265Level::kLevel5_2;
case 180:
return H265Level::kLevel6;
case 183:
return H265Level::kLevel6_1;
case 186:
return H265Level::kLevel6_2;
default:
return absl::nullopt;
}
}
std::string H265ProfileToString(H265Profile profile) {
switch (profile) {
case H265Profile::kProfileMain:
return "1";
case H265Profile::kProfileMain10:
return "2";
case H265Profile::kProfileMainStill:
return "3";
case H265Profile::kProfileRangeExtensions:
return "4";
case H265Profile::kProfileHighThroughput:
return "5";
case H265Profile::kProfileMultiviewMain:
return "6";
case H265Profile::kProfileScalableMain:
return "7";
case H265Profile::kProfile3dMain:
return "8";
case H265Profile::kProfileScreenContentCoding:
return "9";
case H265Profile::kProfileScalableRangeExtensions:
return "10";
case H265Profile::kProfileHighThroughputScreenContentCoding:
return "11";
}
}
std::string H265TierToString(H265Tier tier) {
switch (tier) {
case H265Tier::kTier0:
return "0";
case H265Tier::kTier1:
return "1";
}
}
std::string H265LevelToString(H265Level level) {
switch (level) {
case H265Level::kLevel1:
return "30";
case H265Level::kLevel2:
return "60";
case H265Level::kLevel2_1:
return "63";
case H265Level::kLevel3:
return "90";
case H265Level::kLevel3_1:
return "93";
case H265Level::kLevel4:
return "120";
case H265Level::kLevel4_1:
return "123";
case H265Level::kLevel5:
return "150";
case H265Level::kLevel5_1:
return "153";
case H265Level::kLevel5_2:
return "156";
case H265Level::kLevel6:
return "180";
case H265Level::kLevel6_1:
return "183";
case H265Level::kLevel6_2:
return "186";
}
}
absl::optional<H265ProfileTierLevel> ParseSdpForH265ProfileTierLevel(
const CodecParameterMap& params) {
static const H265ProfileTierLevel kDefaultProfileTierLevel(
H265Profile::kProfileMain, H265Tier::kTier0, H265Level::kLevel3_1);
bool profile_tier_level_specified = false;
absl::optional<H265Profile> profile;
const auto profile_it = params.find(kH265FmtpProfile);
if (profile_it != params.end()) {
profile_tier_level_specified = true;
const std::string& profile_str = profile_it->second;
profile = StringToH265Profile(profile_str);
if (!profile) {
return absl::nullopt;
}
} else {
profile = H265Profile::kProfileMain;
}
absl::optional<H265Tier> tier;
const auto tier_it = params.find(kH265FmtpTier);
if (tier_it != params.end()) {
profile_tier_level_specified = true;
const std::string& tier_str = tier_it->second;
tier = StringToH265Tier(tier_str);
if (!tier) {
return absl::nullopt;
}
} else {
tier = H265Tier::kTier0;
}
absl::optional<H265Level> level;
const auto level_it = params.find(kH265FmtpLevel);
if (level_it != params.end()) {
profile_tier_level_specified = true;
const std::string& level_str = level_it->second;
level = StringToH265Level(level_str);
if (!level) {
return absl::nullopt;
}
} else {
level = H265Level::kLevel3_1;
}
// Spec Table A.9, level 1 to level 3.1 does not allow high tiers.
if (level <= H265Level::kLevel3_1 && tier == H265Tier::kTier1) {
return absl::nullopt;
}
return !profile_tier_level_specified
? kDefaultProfileTierLevel
: H265ProfileTierLevel(profile.value(), tier.value(),
level.value());
}
bool H265IsSameProfileTierLevel(const CodecParameterMap& params1,
const CodecParameterMap& params2) {
const absl::optional<H265ProfileTierLevel> ptl1 =
ParseSdpForH265ProfileTierLevel(params1);
const absl::optional<H265ProfileTierLevel> ptl2 =
ParseSdpForH265ProfileTierLevel(params2);
return ptl1 && ptl2 && ptl1->profile == ptl2->profile &&
ptl1->tier == ptl2->tier && ptl1->level == ptl2->level;
}
absl::optional<H265Level> GetSupportedH265Level(const Resolution& resolution,
float max_fps) {
int aligned_width =
(resolution.width + kMinCbSizeYMax - 1) & ~(kMinCbSizeYMax - 1);
int aligned_height =
(resolution.height + kMinCbSizeYMax - 1) & ~(kMinCbSizeYMax - 1);
for (int i = arraysize(kLevelConstraints) - 1; i >= 0; --i) {
const LevelConstraint& level_constraint = kLevelConstraints[i];
if (level_constraint.max_luma_picture_size <=
aligned_width * aligned_height &&
level_constraint.max_luma_sample_rate <=
aligned_width * aligned_height * max_fps &&
level_constraint.max_pic_width_or_height_in_pixels >= aligned_width &&
level_constraint.max_pic_width_or_height_in_pixels >= aligned_height) {
return level_constraint.level;
}
}
return absl::nullopt;
}
} // namespace webrtc