sdp_video_format_utils.cc | Explore in Territory

/*
 *  Copyright (c) 2019 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/sdp_video_format_utils.h"

#include <cstring>
#include <map>
#include <string>
#include <utility>

#include "api/video_codecs/h264_profile_level_id.h"
#ifdef RTC_ENABLE_H265
#include "api/video_codecs/h265_profile_tier_level.h"
#endif
#include "absl/algorithm/container.h"
#include "media/base/media_constants.h"
#include "rtc_base/checks.h"
#include "rtc_base/string_to_number.h"

namespace webrtc {
namespace {
const char kProfileLevelId[] = …;
const char kH264LevelAsymmetryAllowed[] = …;
// Max frame rate for VP8 and VP9 video.
const char kVPxFmtpMaxFrameRate[] = …;
// Max frame size for VP8 and VP9 video.
const char kVPxFmtpMaxFrameSize[] = …;
const int kVPxFmtpFrameSizeSubBlockPixels = …;
#ifdef RTC_ENABLE_H265
constexpr char kH265ProfileId[] = "profile-id";
constexpr char kH265TierFlag[] = "tier-flag";
constexpr char kH265LevelId[] = "level-id";
#endif

bool IsH264LevelAsymmetryAllowed(const CodecParameterMap& params) { … }

// Compare H264 levels and handle the level 1b case.
bool H264LevelIsLess(H264Level a, H264Level b) { … }

H264Level H264LevelMin(H264Level a, H264Level b) { … }

absl::optional<int> ParsePositiveNumberFromParams(
    const CodecParameterMap& params,
    const char* parameter_name) { … }

#ifdef RTC_ENABLE_H265
// Compares two H265Level and return the smaller.
H265Level H265LevelMin(H265Level a, H265Level b) {
  return a <= b ? a : b;
}

// Returns true if none of profile-id/tier-flag/level-id is specified
// explicitly in the param.
bool IsDefaultH265PTL(const CodecParameterMap& params) {
  return !params.count(kH265ProfileId) && !params.count(kH265TierFlag) &&
         !params.count(kH265LevelId);
}
#endif

}  // namespace

#ifdef RTC_ENABLE_H265
// Set level according to https://tools.ietf.org/html/rfc7798#section-7.1
void H265GenerateProfileTierLevelForAnswer(
    const CodecParameterMap& local_supported_params,
    const CodecParameterMap& remote_offered_params,
    CodecParameterMap* answer_params) {
  // If local and remote haven't set profile-id/tier-flag/level-id, they
  // are both using the default PTL In this case, don't set PTL in answer
  // either.
  if (IsDefaultH265PTL(local_supported_params) &&
      IsDefaultH265PTL(remote_offered_params)) {
    return;
  }

  // Parse profile-tier-level.
  const absl::optional<H265ProfileTierLevel> local_profile_tier_level =
      ParseSdpForH265ProfileTierLevel(local_supported_params);
  const absl::optional<H265ProfileTierLevel> remote_profile_tier_level =
      ParseSdpForH265ProfileTierLevel(remote_offered_params);
  // Profile and tier for local and remote codec must be valid and equal.
  RTC_DCHECK(local_profile_tier_level);
  RTC_DCHECK(remote_profile_tier_level);
  RTC_DCHECK_EQ(local_profile_tier_level->profile,
                remote_profile_tier_level->profile);
  RTC_DCHECK_EQ(local_profile_tier_level->tier,
                remote_profile_tier_level->tier);

  const H265Level answer_level = H265LevelMin(local_profile_tier_level->level,
                                              remote_profile_tier_level->level);

  // Level-id in answer is changable as long as the highest level indicated by
  // the answer is not higher than that indicated by the offer. See
  // https://tools.ietf.org/html/rfc7798#section-7.2.2, sub-clause 2.
  (*answer_params)[kH265LevelId] = H265LevelToString(answer_level);
}
#endif

// Set level according to https://tools.ietf.org/html/rfc6184#section-8.2.2.
void H264GenerateProfileLevelIdForAnswer(
    const CodecParameterMap& local_supported_params,
    const CodecParameterMap& remote_offered_params,
    CodecParameterMap* answer_params) { … }

absl::optional<int> ParseSdpForVPxMaxFrameRate(
    const CodecParameterMap& params) { … }

absl::optional<int> ParseSdpForVPxMaxFrameSize(
    const CodecParameterMap& params) { … }

bool SupportsPerLayerPictureLossIndication(const CodecParameterMap& params) { … }

}  // namespace webrtc
chromium/third_party/webrtc/media/base/sdp_video_format_utils.cc
