From 1ccc5a55e1df129d4335e7bc5cdaa57b1ab9883c Mon Sep 17 00:00:00 2001
From: Danil Chapovalov <danilchap@webrtc.org>
Date: Tue, 20 Jul 2021 10:00:47 +0000
Subject: [PATCH] Delete helper to parse rtcp packet into rtp header

The only user of that function is only interested in the type of the
first rtcp message in the packet, which can be extracted in a simpler way

Bug: None
Change-Id: I96aeb8ed66099f94d506aa7d8d0d07378f6c952e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226543
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34515}
---
 modules/rtp_rtcp/source/rtp_utility.cc | 27 --------------------------
 modules/rtp_rtcp/source/rtp_utility.h  |  1 -
 test/rtp_file_reader.cc                | 26 ++++++++++++-------------
 3 files changed, 13 insertions(+), 41 deletions(-)

diff --git a/modules/rtp_rtcp/source/rtp_utility.cc b/modules/rtp_rtcp/source/rtp_utility.cc
index 9b68f0dead..d76e1981f6 100644
--- a/modules/rtp_rtcp/source/rtp_utility.cc
+++ b/modules/rtp_rtcp/source/rtp_utility.cc
@@ -130,33 +130,6 @@ bool RtpHeaderParser::RTCP() const {
   }
 }
 
-bool RtpHeaderParser::ParseRtcp(RTPHeader* header) const {
-  RTC_DCHECK(header);
-
-  const ptrdiff_t length = _ptrRTPDataEnd - _ptrRTPDataBegin;
-  if (length < kRtcpMinParseLength) {
-    return false;
-  }
-
-  const uint8_t V = _ptrRTPDataBegin[0] >> 6;
-  if (V != kRtcpExpectedVersion) {
-    return false;
-  }
-
-  const uint8_t PT = _ptrRTPDataBegin[1];
-  const size_t len = (_ptrRTPDataBegin[2] << 8) + _ptrRTPDataBegin[3];
-  const uint8_t* ptr = &_ptrRTPDataBegin[4];
-
-  uint32_t SSRC = ByteReader<uint32_t>::ReadBigEndian(ptr);
-  ptr += 4;
-
-  header->payloadType = PT;
-  header->ssrc = SSRC;
-  header->headerLength = 4 + (len << 2);
-
-  return true;
-}
-
 bool RtpHeaderParser::Parse(RTPHeader* header,
                             const RtpHeaderExtensionMap* ptrExtensionMap,
                             bool header_only) const {
diff --git a/modules/rtp_rtcp/source/rtp_utility.h b/modules/rtp_rtcp/source/rtp_utility.h
index cdfff4072f..20aac54855 100644
--- a/modules/rtp_rtcp/source/rtp_utility.h
+++ b/modules/rtp_rtcp/source/rtp_utility.h
@@ -37,7 +37,6 @@ class RtpHeaderParser {
 
   ABSL_DEPRECATED("Use IsRtpPacket or IsRtcpPacket")
   bool RTCP() const;
-  bool ParseRtcp(RTPHeader* header) const;
   bool Parse(RTPHeader* parsedPacket,
              const RtpHeaderExtensionMap* ptrExtensionMap = nullptr,
              bool header_only = false) const;
diff --git a/test/rtp_file_reader.cc b/test/rtp_file_reader.cc
index a09d5a66e4..203cbdfeed 100644
--- a/test/rtp_file_reader.cc
+++ b/test/rtp_file_reader.cc
@@ -18,7 +18,6 @@
 #include <vector>
 
 #include "modules/rtp_rtcp/source/rtp_util.h"
-#include "modules/rtp_rtcp/source/rtp_utility.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/format_macros.h"
@@ -295,7 +294,7 @@ class PcapReader : public RtpFileReaderImpl {
          mit != packets_by_ssrc_.end(); ++mit) {
       uint32_t ssrc = mit->first;
       const std::vector<uint32_t>& packet_indices = mit->second;
-      uint8_t pt = packets_[packet_indices[0]].rtp_header.payloadType;
+      int pt = packets_[packet_indices[0]].payload_type;
       printf("SSRC: %08x, %" RTC_PRIuS " packets, pt=%d\n", ssrc,
              packet_indices.size(), pt);
     }
@@ -358,7 +357,9 @@ class PcapReader : public RtpFileReaderImpl {
     uint32_t dest_ip;
     uint16_t source_port;
     uint16_t dest_port;
-    RTPHeader rtp_header;
+    // Payload type of the RTP packet,
+    // or RTCP packet type of the first RTCP packet in a compound RTCP packet.
+    int payload_type;
     int32_t pos_in_file;  // Byte offset of payload from start of file.
     uint32_t payload_length;
   };
@@ -434,17 +435,13 @@ class PcapReader : public RtpFileReaderImpl {
     }
     TRY_PCAP(Read(read_buffer_, marker.payload_length));
 
-    RtpUtility::RtpHeaderParser rtp_parser(read_buffer_, marker.payload_length);
-    if (IsRtcpPacket(rtc::MakeArrayView(read_buffer_, marker.payload_length))) {
-      rtp_parser.ParseRtcp(&marker.rtp_header);
+    rtc::ArrayView<const uint8_t> packet(read_buffer_, marker.payload_length);
+    if (IsRtcpPacket(packet)) {
+      marker.payload_type = packet[1];
       packets_.push_back(marker);
-    } else {
-      if (!rtp_parser.Parse(&marker.rtp_header, nullptr)) {
-        RTC_LOG(LS_INFO) << "Not recognized as RTP/RTCP";
-        return kResultSkip;
-      }
-
-      uint32_t ssrc = marker.rtp_header.ssrc;
+    } else if (IsRtpPacket(packet)) {
+      uint32_t ssrc = ParseRtpSsrc(packet);
+      marker.payload_type = ParseRtpPayloadType(packet);
       if (ssrc_filter.empty() || ssrc_filter.find(ssrc) != ssrc_filter.end()) {
         packets_by_ssrc_[ssrc].push_back(
             static_cast<uint32_t>(packets_.size()));
@@ -452,6 +449,9 @@ class PcapReader : public RtpFileReaderImpl {
       } else {
         return kResultSkip;
       }
+    } else {
+      RTC_LOG(LS_INFO) << "Not recognized as RTP/RTCP";
+      return kResultSkip;
     }
 
     return kResultSuccess;