Cleanup static constants in modules/rtp_rtcp/

Change static const to static constexpr where applicable
In .cc files ensure static constants are in unnamed namespace
Remove obsolete declaration for class level constexpr values

Bug: None
Change-Id: I23759974b5042c8c9d9ec2816ee7df283a8872d4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/364483
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Emil Lundmark <lndmrk@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43171}

modules/rtp_rtcp/source/packet_loss_stats.cc

@@ -16,11 +16,14 @@
 
 #include "rtc_base/checks.h"
 
+namespace webrtc {
+namespace {
+
 // After this many packets are added, adding additional packets will cause the
 // oldest packets to be pruned from the buffer.
-static const int kBufferSize = 100;
+constexpr int kBufferSize = 100;
 
-namespace webrtc {
+}  // namespace
 
 PacketLossStats::PacketLossStats()
     : single_loss_historic_count_(0),

modules/rtp_rtcp/source/rtcp_packet.cc

@@ -15,7 +15,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr size_t RtcpPacket::kHeaderLength;
 
 rtc::Buffer RtcpPacket::Build() const {
   rtc::Buffer packet(BlockLength());

modules/rtp_rtcp/source/rtcp_packet/app.cc

@@ -21,8 +21,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t App::kPacketType;
-constexpr size_t App::kMaxDataSize;
 // Application-Defined packet (APP) (RFC 3550).
 //
 //     0                   1                   2                   3

modules/rtp_rtcp/source/rtcp_packet/bye.cc

@@ -23,7 +23,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Bye::kPacketType;
 // Bye packet (BYE) (RFC 3550).
 //
 //        0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

modules/rtp_rtcp/source/rtcp_packet/bye.h

@@ -46,7 +46,8 @@ class Bye : public RtcpPacket {
               PacketReadyCallback callback) const override;
 
  private:
-  static const int kMaxNumberOfCsrcs = 0x1f - 1;  // First item is sender SSRC.
+  static constexpr int kMaxNumberOfCsrcs =
+      0x1f - 1;  // First item is sender SSRC.
 
   std::vector<uint32_t> csrcs_;
   std::string reason_;

modules/rtp_rtcp/source/rtcp_packet/common_header.cc

@@ -15,7 +15,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr size_t CommonHeader::kHeaderSizeBytes;
 //    0                   1           1       2                   3
 //    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 //   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

modules/rtp_rtcp/source/rtcp_packet/dlrr.h

@@ -42,7 +42,7 @@ inline bool operator!=(const ReceiveTimeInfo& lhs, const ReceiveTimeInfo& rhs) {
 // DLRR Report Block: Delay since the Last Receiver Report (RFC 3611).
 class Dlrr {
  public:
-  static const uint8_t kBlockType = 5;
+  static constexpr uint8_t kBlockType = 5;
 
   Dlrr();
   Dlrr(const Dlrr& other);
@@ -70,8 +70,8 @@ class Dlrr {
   const std::vector<ReceiveTimeInfo>& sub_blocks() const { return sub_blocks_; }
 
  private:
-  static const size_t kBlockHeaderLength = 4;
+  static constexpr size_t kBlockHeaderLength = 4;
-  static const size_t kSubBlockLength = 12;
+  static constexpr size_t kSubBlockLength = 12;
 
   std::vector<ReceiveTimeInfo> sub_blocks_;
 };

modules/rtp_rtcp/source/rtcp_packet/extended_reports.cc

@@ -19,8 +19,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t ExtendedReports::kPacketType;
-constexpr size_t ExtendedReports::kMaxNumberOfDlrrItems;
 // From RFC 3611: RTP Control Protocol Extended Reports (RTCP XR).
 //
 // Format for XR packets:

modules/rtp_rtcp/source/rtcp_packet/fir.cc

@@ -17,7 +17,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Fir::kFeedbackMessageType;
 // RFC 4585: Feedback format.
 // Common packet format:
 //

modules/rtp_rtcp/source/rtcp_packet/nack.cc

@@ -21,8 +21,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Nack::kFeedbackMessageType;
-constexpr size_t Nack::kNackItemLength;
 // RFC 4585: Feedback format.
 //
 // Common packet format:

modules/rtp_rtcp/source/rtcp_packet/pli.cc

@@ -16,7 +16,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Pli::kFeedbackMessageType;
 // RFC 4585: Feedback format.
 //
 // Common packet format:

modules/rtp_rtcp/source/rtcp_packet/psfb.cc

@@ -14,9 +14,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Psfb::kPacketType;
-constexpr uint8_t Psfb::kAfbMessageType;
-constexpr size_t Psfb::kCommonFeedbackLength;
 // RFC 4585: Feedback format.
 //
 // Common packet format:

modules/rtp_rtcp/source/rtcp_packet/rapid_resync_request.cc

@@ -16,7 +16,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t RapidResyncRequest::kFeedbackMessageType;
 // RFC 4585: Feedback format.
 // Rapid Resynchronisation Request (draft-perkins-avt-rapid-rtp-sync-03).
 //

modules/rtp_rtcp/source/rtcp_packet/receiver_report.cc

@@ -19,8 +19,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t ReceiverReport::kPacketType;
-constexpr size_t ReceiverReport::kMaxNumberOfReportBlocks;
 // RTCP receiver report (RFC 3550).
 //
 //   0                   1                   2                   3

modules/rtp_rtcp/source/rtcp_packet/receiver_report.h

@@ -50,7 +50,7 @@ class ReceiverReport : public RtcpPacket {
               PacketReadyCallback callback) const override;
 
  private:
-  static const size_t kRrBaseLength = 4;
+  static constexpr size_t kRrBaseLength = 4;
 
   std::vector<ReportBlock> report_blocks_;
 };

modules/rtp_rtcp/source/rtcp_packet/report_block.h

@@ -22,7 +22,7 @@ namespace rtcp {
 // RFC 3550 section 6.4.1.
 class ReportBlock {
  public:
-  static const size_t kLength = 24;
+  static constexpr size_t kLength = 24;
 
   ReportBlock();
   ~ReportBlock() {}

modules/rtp_rtcp/source/rtcp_packet/rrtr.h

@@ -22,9 +22,9 @@ namespace rtcp {
 
 class Rrtr {
  public:
-  static const uint8_t kBlockType = 4;
+  static constexpr uint8_t kBlockType = 4;
-  static const uint16_t kBlockLength = 2;
+  static constexpr uint16_t kBlockLength = 2;
-  static const size_t kLength = 4 * (kBlockLength + 1);  // 12
+  static constexpr size_t kLength = 4 * (kBlockLength + 1);  // 12
 
   Rrtr() {}
   Rrtr(const Rrtr&) = default;

modules/rtp_rtcp/source/rtcp_packet/rtpfb.cc

@@ -14,7 +14,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Rtpfb::kPacketType;
 // RFC 4585, Section 6.1: Feedback format.
 //
 // Common packet format:

modules/rtp_rtcp/source/rtcp_packet/sdes.cc

@@ -22,8 +22,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Sdes::kPacketType;
-constexpr size_t Sdes::kMaxNumberOfChunks;
 // Source Description (SDES) (RFC 3550).
 //
 //         0                   1                   2                   3

modules/rtp_rtcp/source/rtcp_packet/sender_report.cc

@@ -19,9 +19,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t SenderReport::kPacketType;
-constexpr size_t SenderReport::kMaxNumberOfReportBlocks;
-constexpr size_t SenderReport::kSenderBaseLength;
 //    Sender report (SR) (RFC 3550).
 //     0                   1                   2                   3
 //     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

modules/rtp_rtcp/source/rtcp_packet/target_bitrate.cc

@@ -16,9 +16,11 @@
 
 namespace webrtc {
 namespace rtcp {
+namespace {
+
 constexpr size_t kTargetBitrateHeaderSizeBytes = 4;
-constexpr uint8_t TargetBitrate::kBlockType;
+
-const size_t TargetBitrate::kBitrateItemSizeBytes = 4;
+}  // namespace
 
 TargetBitrate::BitrateItem::BitrateItem()
     : spatial_layer(0), temporal_layer(0), target_bitrate_kbps(0) {}

modules/rtp_rtcp/source/rtcp_packet/target_bitrate.h

@@ -24,7 +24,7 @@ class TargetBitrate {
   // TODO(sprang): This block type is just a place holder. We need to get an
   //               id assigned by IANA.
   static constexpr uint8_t kBlockType = 42;
-  static const size_t kBitrateItemSizeBytes;
+  static constexpr size_t kBitrateItemSizeBytes = 4;
 
   struct BitrateItem {
     BitrateItem();

modules/rtp_rtcp/source/rtcp_packet/tmmb_item.h

@@ -21,7 +21,7 @@ namespace rtcp {
 // Used both by TMMBR and TMMBN rtcp packets.
 class TmmbItem {
  public:
-  static const size_t kLength = 8;
+  static constexpr size_t kLength = 8;
 
   TmmbItem() : ssrc_(0), bitrate_bps_(0), packet_overhead_(0) {}
   TmmbItem(uint32_t ssrc, uint64_t bitrate_bps, uint16_t overhead);

modules/rtp_rtcp/source/rtcp_packet/tmmbn.cc

@@ -16,7 +16,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Tmmbn::kFeedbackMessageType;
 // RFC 4585: Feedback format.
 // Common packet format:
 //

modules/rtp_rtcp/source/rtcp_packet/tmmbr.cc

@@ -16,7 +16,6 @@
 
 namespace webrtc {
 namespace rtcp {
-constexpr uint8_t Tmmbr::kFeedbackMessageType;
 // RFC 4585: Feedback format.
 // Common packet format:
 //

modules/rtp_rtcp/source/rtcp_packet/transport_feedback.cc

@@ -73,13 +73,6 @@ constexpr TimeDelta kTimeWrapPeriod = kBaseTimeTick * (1 << 24);
 //    |           recv delta          |  recv delta   | zero padding  |
 //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 }  // namespace
-constexpr uint8_t TransportFeedback::kFeedbackMessageType;
-constexpr size_t TransportFeedback::kMaxReportedPackets;
-
-constexpr size_t TransportFeedback::LastChunk::kMaxRunLengthCapacity;
-constexpr size_t TransportFeedback::LastChunk::kMaxOneBitCapacity;
-constexpr size_t TransportFeedback::LastChunk::kMaxTwoBitCapacity;
-constexpr size_t TransportFeedback::LastChunk::kMaxVectorCapacity;
 
 TransportFeedback::LastChunk::LastChunk() {
   Clear();

modules/rtp_rtcp/source/rtcp_receiver.cc

@@ -107,8 +107,6 @@ bool ResetTimestampIfExpired(const Timestamp now,
 
 }  // namespace
 
-constexpr size_t RTCPReceiver::RegisteredSsrcs::kMediaSsrcIndex;
-
 RTCPReceiver::RegisteredSsrcs::RegisteredSsrcs(
     bool disable_sequence_checker,
     const RtpRtcpInterface::Configuration& config)

modules/rtp_rtcp/source/rtcp_sender_unittest.cc

@@ -49,6 +49,9 @@
 #include "test/mock_transport.h"
 #include "test/rtcp_packet_parser.h"
 
+namespace webrtc {
+namespace {
+
 using ::testing::_;
 using ::testing::ElementsAre;
 using ::testing::Eq;
@@ -56,8 +59,6 @@ using ::testing::Invoke;
 using ::testing::Property;
 using ::testing::SizeIs;
 
-namespace webrtc {
-
 class RtcpPacketTypeCounterObserverImpl : public RtcpPacketTypeCounterObserver {
  public:
   RtcpPacketTypeCounterObserverImpl() : ssrc_(0) {}
@@ -87,12 +88,10 @@ class TestTransport : public Transport {
   test::RtcpPacketParser parser_;
 };
 
-namespace {
+constexpr uint32_t kSenderSsrc = 0x11111111;
-static const uint32_t kSenderSsrc = 0x11111111;
+constexpr uint32_t kRemoteSsrc = 0x22222222;
-static const uint32_t kRemoteSsrc = 0x22222222;
+constexpr uint32_t kStartRtpTimestamp = 0x34567;
-static const uint32_t kStartRtpTimestamp = 0x34567;
+constexpr uint32_t kRtpTimestamp = 0x45678;
-static const uint32_t kRtpTimestamp = 0x45678;
-}  // namespace
 
 class RtcpSenderTest : public ::testing::Test {
  protected:
@@ -856,4 +855,5 @@ TEST_F(RtcpSenderTest, SendsCombinedRtcpPacket) {
   EXPECT_EQ(parser()->app()->sender_ssrc(), kSenderSsrc);
 }
 
+}  // namespace
 }  // namespace webrtc

modules/rtp_rtcp/source/rtp_dependency_descriptor_extension.cc

@@ -22,9 +22,6 @@
 
 namespace webrtc {
 
-constexpr RTPExtensionType RtpDependencyDescriptorExtension::kId;
-constexpr std::bitset<32> RtpDependencyDescriptorExtension::kAllChainsAreActive;
-
 bool RtpDependencyDescriptorExtension::Parse(
     rtc::ArrayView<const uint8_t> data,
     const FrameDependencyStructure* structure,

modules/rtp_rtcp/source/rtp_fec_unittest.cc

@@ -173,7 +173,7 @@ bool RtpFecTest<ForwardErrorCorrectionType>::IsRecoveryComplete() {
 
 class FlexfecForwardErrorCorrection : public ForwardErrorCorrection {
  public:
-  static const uint32_t kFecSsrc = kFlexfecSsrc;
+  static constexpr uint32_t kFecSsrc = kFlexfecSsrc;
 
   FlexfecForwardErrorCorrection()
       : ForwardErrorCorrection(
@@ -192,7 +192,7 @@ class FlexfecForwardErrorCorrection : public ForwardErrorCorrection {
 
 class UlpfecForwardErrorCorrection : public ForwardErrorCorrection {
  public:
-  static const uint32_t kFecSsrc = kMediaSsrc;
+  static constexpr uint32_t kFecSsrc = kMediaSsrc;
 
   UlpfecForwardErrorCorrection()
       : ForwardErrorCorrection(

modules/rtp_rtcp/source/rtp_format_h264.cc

@@ -34,9 +34,9 @@
 namespace webrtc {
 namespace {
 
-static const size_t kNalHeaderSize = 1;
+constexpr size_t kNalHeaderSize = 1;
-static const size_t kFuAHeaderSize = 2;
+constexpr size_t kFuAHeaderSize = 2;
-static const size_t kLengthFieldSize = 2;
+constexpr size_t kLengthFieldSize = 2;
 
 }  // namespace
 

modules/rtp_rtcp/source/rtp_format_h264_unittest.cc

@@ -47,8 +47,8 @@ enum Nalu {
   kFuA = 28
 };
 
-static const size_t kNalHeaderSize = 1;
+constexpr size_t kNalHeaderSize = 1;
-static const size_t kFuAHeaderSize = 2;
+constexpr size_t kFuAHeaderSize = 2;
 
 // Creates Buffer that looks like nal unit of given size.
 rtc::Buffer GenerateNalUnit(size_t size) {

modules/rtp_rtcp/source/rtp_format_video_generic.cc

@@ -19,9 +19,12 @@
 #include "rtc_base/logging.h"
 
 namespace webrtc {
+namespace {
 
-static const size_t kGenericHeaderLength = 1;
+constexpr size_t kGenericHeaderLength = 1;
-static const size_t kExtendedHeaderLength = 2;
+constexpr size_t kExtendedHeaderLength = 2;
+
+}  // namespace
 
 RtpPacketizerGeneric::RtpPacketizerGeneric(
     rtc::ArrayView<const uint8_t> payload,

modules/rtp_rtcp/source/rtp_format_video_generic.h

@@ -23,11 +23,11 @@ class RtpPacketToSend;
 struct RTPVideoHeader;
 
 namespace RtpFormatVideoGeneric {
-static const uint8_t kKeyFrameBit = 0x01;
+inline constexpr uint8_t kKeyFrameBit = 0x01;
-static const uint8_t kFirstPacketBit = 0x02;
+inline constexpr uint8_t kFirstPacketBit = 0x02;
 // If this bit is set, there will be an extended header contained in this
 // packet. This was added later so old clients will not send this.
-static const uint8_t kExtendedHeaderBit = 0x04;
+inline constexpr uint8_t kExtendedHeaderBit = 0x04;
 }  // namespace RtpFormatVideoGeneric
 
 class RtpPacketizerGeneric : public RtpPacketizer {

modules/rtp_rtcp/source/rtp_generic_frame_descriptor.cc

@@ -16,10 +16,6 @@
 
 namespace webrtc {
 
-constexpr int RtpGenericFrameDescriptor::kMaxNumFrameDependencies;
-constexpr int RtpGenericFrameDescriptor::kMaxTemporalLayers;
-constexpr int RtpGenericFrameDescriptor::kMaxSpatialLayers;
-
 RtpGenericFrameDescriptor::RtpGenericFrameDescriptor() = default;
 RtpGenericFrameDescriptor::RtpGenericFrameDescriptor(
     const RtpGenericFrameDescriptor&) = default;

modules/rtp_rtcp/source/rtp_generic_frame_descriptor_extension.cc

@@ -56,7 +56,6 @@ constexpr uint8_t kFlageXtendedOffset = 0x02;
 //      +---------------+
 //      |      ...      |
 //      +-+-+-+-+-+-+-+-+
-constexpr RTPExtensionType RtpGenericFrameDescriptorExtension00::kId;
 
 bool RtpGenericFrameDescriptorExtension00::Parse(
     rtc::ArrayView<const uint8_t> data,

modules/rtp_rtcp/source/rtp_header_extension_map.cc

@@ -70,9 +70,6 @@ static_assert(arraysize(kExtensions) ==
 
 }  // namespace
 
-constexpr RTPExtensionType RtpHeaderExtensionMap::kInvalidType;
-constexpr int RtpHeaderExtensionMap::kInvalidId;
-
 RtpHeaderExtensionMap::RtpHeaderExtensionMap() : RtpHeaderExtensionMap(false) {}
 
 RtpHeaderExtensionMap::RtpHeaderExtensionMap(bool extmap_allow_mixed)

modules/rtp_rtcp/source/rtp_packet_history_unittest.cc

@@ -160,7 +160,7 @@ TEST_P(RtpPacketHistoryTest, GetRtpPacket) {
 }
 
 TEST_P(RtpPacketHistoryTest, MinResendTime) {
-  static const TimeDelta kMinRetransmitInterval = TimeDelta::Millis(100);
+  static constexpr TimeDelta kMinRetransmitInterval = TimeDelta::Millis(100);
 
   hist_.SetStorePacketsStatus(StorageMode::kStoreAndCull, 10);
   hist_.SetRtt(kMinRetransmitInterval);

modules/rtp_rtcp/source/rtp_video_layers_allocation_extension.cc

@@ -20,9 +20,6 @@
 #include "rtc_base/checks.h"
 
 namespace webrtc {
-
-constexpr RTPExtensionType RtpVideoLayersAllocationExtension::kId;
-
 namespace {
 
 constexpr int kMaxNumRtpStreams = 4;