312 lines
11 KiB
C++
312 lines
11 KiB
C++
|
/*
|
|||
|
|
* Copyright (c) 2017 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 "media/base/h264_profile_level_id.h"
|
|||
|
|
|
|||
|
|
#include <cstdio>
|
|||
|
|
#include <cstdlib>
|
|||
|
|
#include <cstring>
|
|||
|
|
|
|||
|
|
#include "rtc_base/arraysize.h"
|
|||
|
|
#include "rtc_base/checks.h"
|
|||
|
|
|
|||
|
|
namespace webrtc {
|
|||
|
|
namespace H264 {
|
|||
|
|
|
|||
|
|
namespace {
|
|||
|
|
|
|||
|
|
const char kProfileLevelId[] = "profile-level-id";
|
|||
|
|
const char kLevelAsymmetryAllowed[] = "level-asymmetry-allowed";
|
|||
|
|
|
|||
|
|
// For level_idc=11 and profile_idc=0x42, 0x4D, or 0x58, the constraint set3
|
|||
|
|
// flag specifies if level 1b or level 1.1 is used.
|
|||
|
|
const uint8_t kConstraintSet3Flag = 0x10;
|
|||
|
|
|
|||
|
|
// Convert a string of 8 characters into a byte where the positions containing
|
|||
|
|
// character c will have their bit set. For example, c = 'x', str = "x1xx0000"
|
|||
|
|
// will return 0b10110000. constexpr is used so that the pattern table in
|
|||
|
|
// kProfilePatterns is statically initialized.
|
|||
|
|
constexpr uint8_t ByteMaskString(char c, const char (&str)[9]) {
|
|||
|
|
return (str[0] == c) << 7 | (str[1] == c) << 6 | (str[2] == c) << 5 |
|
|||
|
|
(str[3] == c) << 4 | (str[4] == c) << 3 | (str[5] == c) << 2 |
|
|||
|
|
(str[6] == c) << 1 | (str[7] == c) << 0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Class for matching bit patterns such as "x1xx0000" where 'x' is allowed to be
|
|||
|
|
// either 0 or 1.
|
|||
|
|
class BitPattern {
|
|||
|
|
public:
|
|||
|
|
explicit constexpr BitPattern(const char (&str)[9])
|
|||
|
|
: mask_(~ByteMaskString('x', str)),
|
|||
|
|
masked_value_(ByteMaskString('1', str)) {}
|
|||
|
|
|
|||
|
|
bool IsMatch(uint8_t value) const { return masked_value_ == (value & mask_); }
|
|||
|
|
|
|||
|
|
private:
|
|||
|
|
const uint8_t mask_;
|
|||
|
|
const uint8_t masked_value_;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
// Table for converting between profile_idc/profile_iop to H264::Profile.
|
|||
|
|
struct ProfilePattern {
|
|||
|
|
const uint8_t profile_idc;
|
|||
|
|
const BitPattern profile_iop;
|
|||
|
|
const Profile profile;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
// This is from https://tools.ietf.org/html/rfc6184#section-8.1.
|
|||
|
|
constexpr ProfilePattern kProfilePatterns[] = {
|
|||
|
|
{0x42, BitPattern("x1xx0000"), kProfileConstrainedBaseline},
|
|||
|
|
{0x4D, BitPattern("1xxx0000"), kProfileConstrainedBaseline},
|
|||
|
|
{0x58, BitPattern("11xx0000"), kProfileConstrainedBaseline},
|
|||
|
|
{0x42, BitPattern("x0xx0000"), kProfileBaseline},
|
|||
|
|
{0x58, BitPattern("10xx0000"), kProfileBaseline},
|
|||
|
|
{0x4D, BitPattern("0x0x0000"), kProfileMain},
|
|||
|
|
{0x64, BitPattern("00000000"), kProfileHigh},
|
|||
|
|
{0x64, BitPattern("00001100"), kProfileConstrainedHigh}};
|
|||
|
|
|
|||
|
|
// Compare H264 levels and handle the level 1b case.
|
|||
|
|
bool IsLess(Level a, Level b) {
|
|||
|
|
if (a == kLevel1_b)
|
|||
|
|
return b != kLevel1 && b != kLevel1_b;
|
|||
|
|
if (b == kLevel1_b)
|
|||
|
|
return a == kLevel1;
|
|||
|
|
return a < b;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
Level Min(Level a, Level b) {
|
|||
|
|
return IsLess(a, b) ? a : b;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
bool IsLevelAsymmetryAllowed(const CodecParameterMap& params) {
|
|||
|
|
const auto it = params.find(kLevelAsymmetryAllowed);
|
|||
|
|
return it != params.end() && strcmp(it->second.c_str(), "1") == 0;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
struct LevelConstraint {
|
|||
|
|
const int max_macroblocks_per_second;
|
|||
|
|
const int max_macroblock_frame_size;
|
|||
|
|
const webrtc::H264::Level level;
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
// This is from ITU-T H.264 (02/2016) Table A-1 – Level limits.
|
|||
|
|
static constexpr LevelConstraint kLevelConstraints[] = {
|
|||
|
|
{1485, 99, webrtc::H264::kLevel1},
|
|||
|
|
{1485, 99, webrtc::H264::kLevel1_b},
|
|||
|
|
{3000, 396, webrtc::H264::kLevel1_1},
|
|||
|
|
{6000, 396, webrtc::H264::kLevel1_2},
|
|||
|
|
{11880, 396, webrtc::H264::kLevel1_3},
|
|||
|
|
{11880, 396, webrtc::H264::kLevel2},
|
|||
|
|
{19800, 792, webrtc::H264::kLevel2_1},
|
|||
|
|
{20250, 1620, webrtc::H264::kLevel2_2},
|
|||
|
|
{40500, 1620, webrtc::H264::kLevel3},
|
|||
|
|
{108000, 3600, webrtc::H264::kLevel3_1},
|
|||
|
|
{216000, 5120, webrtc::H264::kLevel3_2},
|
|||
|
|
{245760, 8192, webrtc::H264::kLevel4},
|
|||
|
|
{245760, 8192, webrtc::H264::kLevel4_1},
|
|||
|
|
{522240, 8704, webrtc::H264::kLevel4_2},
|
|||
|
|
{589824, 22080, webrtc::H264::kLevel5},
|
|||
|
|
{983040, 36864, webrtc::H264::kLevel5_1},
|
|||
|
|
{2073600, 36864, webrtc::H264::kLevel5_2},
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
} // anonymous namespace
|
|||
|
|
|
|||
|
|
absl::optional<ProfileLevelId> ParseProfileLevelId(const char* str) {
|
|||
|
|
// The string should consist of 3 bytes in hexadecimal format.
|
|||
|
|
if (strlen(str) != 6u)
|
|||
|
|
return absl::nullopt;
|
|||
|
|
const uint32_t profile_level_id_numeric = strtol(str, nullptr, 16);
|
|||
|
|
if (profile_level_id_numeric == 0)
|
|||
|
|
return absl::nullopt;
|
|||
|
|
|
|||
|
|
// Separate into three bytes.
|
|||
|
|
const uint8_t level_idc =
|
|||
|
|
static_cast<uint8_t>(profile_level_id_numeric & 0xFF);
|
|||
|
|
const uint8_t profile_iop =
|
|||
|
|
static_cast<uint8_t>((profile_level_id_numeric >> 8) & 0xFF);
|
|||
|
|
const uint8_t profile_idc =
|
|||
|
|
static_cast<uint8_t>((profile_level_id_numeric >> 16) & 0xFF);
|
|||
|
|
|
|||
|
|
// Parse level based on level_idc and constraint set 3 flag.
|
|||
|
|
Level level;
|
|||
|
|
switch (level_idc) {
|
|||
|
|
case kLevel1_1:
|
|||
|
|
level = (profile_iop & kConstraintSet3Flag) != 0 ? kLevel1_b : kLevel1_1;
|
|||
|
|
break;
|
|||
|
|
case kLevel1:
|
|||
|
|
case kLevel1_2:
|
|||
|
|
case kLevel1_3:
|
|||
|
|
case kLevel2:
|
|||
|
|
case kLevel2_1:
|
|||
|
|
case kLevel2_2:
|
|||
|
|
case kLevel3:
|
|||
|
|
case kLevel3_1:
|
|||
|
|
case kLevel3_2:
|
|||
|
|
case kLevel4:
|
|||
|
|
case kLevel4_1:
|
|||
|
|
case kLevel4_2:
|
|||
|
|
case kLevel5:
|
|||
|
|
case kLevel5_1:
|
|||
|
|
case kLevel5_2:
|
|||
|
|
level = static_cast<Level>(level_idc);
|
|||
|
|
break;
|
|||
|
|
default:
|
|||
|
|
// Unrecognized level_idc.
|
|||
|
|
return absl::nullopt;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Parse profile_idc/profile_iop into a Profile enum.
|
|||
|
|
for (const ProfilePattern& pattern : kProfilePatterns) {
|
|||
|
|
if (profile_idc == pattern.profile_idc &&
|
|||
|
|
pattern.profile_iop.IsMatch(profile_iop)) {
|
|||
|
|
return ProfileLevelId(pattern.profile, level);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Unrecognized profile_idc/profile_iop combination.
|
|||
|
|
return absl::nullopt;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
absl::optional<Level> SupportedLevel(int max_frame_pixel_count, float max_fps) {
|
|||
|
|
static const int kPixelsPerMacroblock = 16 * 16;
|
|||
|
|
|
|||
|
|
for (int i = arraysize(kLevelConstraints) - 1; i >= 0; --i) {
|
|||
|
|
const LevelConstraint& level_constraint = kLevelConstraints[i];
|
|||
|
|
if (level_constraint.max_macroblock_frame_size * kPixelsPerMacroblock <=
|
|||
|
|
max_frame_pixel_count &&
|
|||
|
|
level_constraint.max_macroblocks_per_second <=
|
|||
|
|
max_fps * level_constraint.max_macroblock_frame_size) {
|
|||
|
|
return level_constraint.level;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// No level supported.
|
|||
|
|
return absl::nullopt;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
absl::optional<ProfileLevelId> ParseSdpProfileLevelId(
|
|||
|
|
const CodecParameterMap& params) {
|
|||
|
|
// TODO(magjed): The default should really be kProfileBaseline and kLevel1
|
|||
|
|
// according to the spec: https://tools.ietf.org/html/rfc6184#section-8.1. In
|
|||
|
|
// order to not break backwards compatibility with older versions of WebRTC
|
|||
|
|
// where external codecs don't have any parameters, use
|
|||
|
|
// kProfileConstrainedBaseline kLevel3_1 instead. This workaround will only be
|
|||
|
|
// done in an interim period to allow external clients to update their code.
|
|||
|
|
// http://crbug/webrtc/6337.
|
|||
|
|
static const ProfileLevelId kDefaultProfileLevelId(
|
|||
|
|
kProfileConstrainedBaseline, kLevel3_1);
|
|||
|
|
|
|||
|
|
const auto profile_level_id_it = params.find(kProfileLevelId);
|
|||
|
|
return (profile_level_id_it == params.end())
|
|||
|
|
? kDefaultProfileLevelId
|
|||
|
|
: ParseProfileLevelId(profile_level_id_it->second.c_str());
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
absl::optional<std::string> ProfileLevelIdToString(
|
|||
|
|
const ProfileLevelId& profile_level_id) {
|
|||
|
|
// Handle special case level == 1b.
|
|||
|
|
if (profile_level_id.level == kLevel1_b) {
|
|||
|
|
switch (profile_level_id.profile) {
|
|||
|
|
case kProfileConstrainedBaseline:
|
|||
|
|
return {"42f00b"};
|
|||
|
|
case kProfileBaseline:
|
|||
|
|
return {"42100b"};
|
|||
|
|
case kProfileMain:
|
|||
|
|
return {"4d100b"};
|
|||
|
|
// Level 1b is not allowed for other profiles.
|
|||
|
|
default:
|
|||
|
|
return absl::nullopt;
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
const char* profile_idc_iop_string;
|
|||
|
|
switch (profile_level_id.profile) {
|
|||
|
|
case kProfileConstrainedBaseline:
|
|||
|
|
profile_idc_iop_string = "42e0";
|
|||
|
|
break;
|
|||
|
|
case kProfileBaseline:
|
|||
|
|
profile_idc_iop_string = "4200";
|
|||
|
|
break;
|
|||
|
|
case kProfileMain:
|
|||
|
|
profile_idc_iop_string = "4d00";
|
|||
|
|
break;
|
|||
|
|
case kProfileConstrainedHigh:
|
|||
|
|
profile_idc_iop_string = "640c";
|
|||
|
|
break;
|
|||
|
|
case kProfileHigh:
|
|||
|
|
profile_idc_iop_string = "6400";
|
|||
|
|
break;
|
|||
|
|
// Unrecognized profile.
|
|||
|
|
default:
|
|||
|
|
return absl::nullopt;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
char str[7];
|
|||
|
|
snprintf(str, 7u, "%s%02x", profile_idc_iop_string, profile_level_id.level);
|
|||
|
|
return {str};
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Set level according to https://tools.ietf.org/html/rfc6184#section-8.2.2.
|
|||
|
|
void GenerateProfileLevelIdForAnswer(
|
|||
|
|
const CodecParameterMap& local_supported_params,
|
|||
|
|
const CodecParameterMap& remote_offered_params,
|
|||
|
|
CodecParameterMap* answer_params) {
|
|||
|
|
// If both local and remote haven't set profile-level-id, they are both using
|
|||
|
|
// the default profile. In this case, don't set profile-level-id in answer
|
|||
|
|
// either.
|
|||
|
|
if (!local_supported_params.count(kProfileLevelId) &&
|
|||
|
|
!remote_offered_params.count(kProfileLevelId)) {
|
|||
|
|
return;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Parse profile-level-ids.
|
|||
|
|
const absl::optional<ProfileLevelId> local_profile_level_id =
|
|||
|
|
ParseSdpProfileLevelId(local_supported_params);
|
|||
|
|
const absl::optional<ProfileLevelId> remote_profile_level_id =
|
|||
|
|
ParseSdpProfileLevelId(remote_offered_params);
|
|||
|
|
// The local and remote codec must have valid and equal H264 Profiles.
|
|||
|
|
RTC_DCHECK(local_profile_level_id);
|
|||
|
|
RTC_DCHECK(remote_profile_level_id);
|
|||
|
|
RTC_DCHECK_EQ(local_profile_level_id->profile,
|
|||
|
|
remote_profile_level_id->profile);
|
|||
|
|
|
|||
|
|
// Parse level information.
|
|||
|
|
const bool level_asymmetry_allowed =
|
|||
|
|
IsLevelAsymmetryAllowed(local_supported_params) &&
|
|||
|
|
IsLevelAsymmetryAllowed(remote_offered_params);
|
|||
|
|
const Level local_level = local_profile_level_id->level;
|
|||
|
|
const Level remote_level = remote_profile_level_id->level;
|
|||
|
|
const Level min_level = Min(local_level, remote_level);
|
|||
|
|
|
|||
|
|
// Determine answer level. When level asymmetry is not allowed, level upgrade
|
|||
|
|
// is not allowed, i.e., the level in the answer must be equal to or lower
|
|||
|
|
// than the level in the offer.
|
|||
|
|
const Level answer_level = level_asymmetry_allowed ? local_level : min_level;
|
|||
|
|
|
|||
|
|
// Set the resulting profile-level-id in the answer parameters.
|
|||
|
|
(*answer_params)[kProfileLevelId] = *ProfileLevelIdToString(
|
|||
|
|
ProfileLevelId(local_profile_level_id->profile, answer_level));
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
bool IsSameH264Profile(const CodecParameterMap& params1,
|
|||
|
|
const CodecParameterMap& params2) {
|
|||
|
|
const absl::optional<webrtc::H264::ProfileLevelId> profile_level_id =
|
|||
|
|
webrtc::H264::ParseSdpProfileLevelId(params1);
|
|||
|
|
const absl::optional<webrtc::H264::ProfileLevelId> other_profile_level_id =
|
|||
|
|
webrtc::H264::ParseSdpProfileLevelId(params2);
|
|||
|
|
// Compare H264 profiles, but not levels.
|
|||
|
|
return profile_level_id && other_profile_level_id &&
|
|||
|
|
profile_level_id->profile == other_profile_level_id->profile;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
} // namespace H264
|
|||
|
|
} // namespace webrtc
|