Bug 1628630 - Add Support for RTX in WebRTC SDP CAPI;r=dminor

Differential Revision: https://phabricator.services.mozilla.com/D70330

--HG--
extra : moz-landing-system : lando

media/webrtc/signaling/src/sdp/RsdparsaSdpAttributeList.cpp

@@ -680,6 +680,9 @@ std::tuple<SdpRtpmapAttributeList::CodecType, FmtDefaults> strToCodecType(
   } else if (!nsCRT::strcasecmp(name.c_str(), "telephone-event")) {
     codec = SdpRtpmapAttributeList::kTelephoneEvent;
     defaults = {1};
+  } else if (!nsCRT::strcasecmp(name.c_str(), "rtx")) {
+    codec = SdpRtpmapAttributeList::kRtx;
+    defaults = {0};
   }
   return std::make_tuple(codec, defaults);
 }
@@ -777,11 +780,17 @@ void RsdparsaSdpAttributeList::LoadFmtp(RustAttributeList* attributeList) {
 
       fmtpParameters.reset(
           new SdpFmtpAttributeList::RedParameters(std::move(redParameters)));
+    } else if (codecName == "RTX") {
+      Maybe<uint32_t> rtx_time = Nothing();
+      if (rustFmtpParameters.rtx.has_rtx_time) {
+        rtx_time = Some(rustFmtpParameters.rtx.rtx_time);
+      }
+      fmtpParameters.reset(new SdpFmtpAttributeList::RtxParameters(
+          rustFmtpParameters.rtx.apt, rtx_time));
     } else {
       // The parameter set is unknown so skip it
       continue;
     }
-
     fmtpList->PushEntry(std::to_string(payloadType), std::move(fmtpParameters));
   }
   SetAttribute(fmtpList.release());

media/webrtc/signaling/src/sdp/RsdparsaSdpInc.h

@@ -7,6 +7,7 @@
 #define _RUSTSDPINC_H_
 
 #include "nsError.h"
+#include "mozilla/Maybe.h"
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -193,6 +194,12 @@ struct RustSdpAttributeImageAttr {
   RustSdpAttributeImageAttrSetList recv;
 };
 
+struct RustRtxFmtpParameters {
+  uint8_t apt;
+  bool has_rtx_time;
+  uint32_t rtx_time;
+};
+
 struct RustSdpAttributeFmtpParameters {
   // H264
   uint32_t packetization_mode;
@@ -218,6 +225,9 @@ struct RustSdpAttributeFmtpParameters {
   // telephone-event
   StringView dtmf_tones;
 
+  // RTX
+  RustRtxFmtpParameters rtx;
+
   // Red codecs
   U8Vec* encodings;
 

media/webrtc/signaling/src/sdp/SdpAttribute.cpp

@@ -1046,6 +1046,7 @@ static bool ShouldSerializeChannels(SdpRtpmapAttributeList::CodecType type) {
     case SdpRtpmapAttributeList::kRed:
     case SdpRtpmapAttributeList::kUlpfec:
     case SdpRtpmapAttributeList::kTelephoneEvent:
+    case SdpRtpmapAttributeList::kRtx:
       return false;
     case SdpRtpmapAttributeList::kOtherCodec:
       return true;

media/webrtc/signaling/src/sdp/SdpAttribute.h

@@ -1071,6 +1071,7 @@ class SdpRtpmapAttributeList : public SdpAttribute {
     kRed,
     kUlpfec,
     kTelephoneEvent,
+    kRtx,
     kOtherCodec
   };
 
@@ -1153,6 +1154,9 @@ inline std::ostream& operator<<(std::ostream& os,
     case SdpRtpmapAttributeList::kTelephoneEvent:
       os << "telephone-event";
       break;
+    case SdpRtpmapAttributeList::kRtx:
+      os << "rtx";
+      break;
     default:
       MOZ_ASSERT(false);
       os << "?";
@@ -1208,6 +1212,36 @@ class SdpFmtpAttributeList : public SdpAttribute {
     std::vector<uint8_t> encodings;
   };
 
+  class RtxParameters : public Parameters {
+   public:
+    uint8_t apt;
+    Maybe<uint32_t> rtx_time;
+
+    RtxParameters(const uint8_t aApt, const Maybe<uint32_t>& aRtxTime)
+        : Parameters(SdpRtpmapAttributeList::kRtx),
+          apt(aApt),
+          rtx_time(aRtxTime) {}
+
+    virtual ~RtxParameters() {}
+
+    virtual Parameters* Clone() const override {
+      return new RtxParameters(*this);
+    }
+
+    virtual void Serialize(std::ostream& os) const override {
+      os << "apt=" << apt;
+      rtx_time.apply([&](const auto& time) { os << ";rtx-time=" << time; });
+    }
+
+    virtual bool CompareEq(const Parameters& aOther) const override {
+      if (aOther.codec_type != codec_type) {
+        return false;
+      }
+      auto other = static_cast<const RtxParameters&>(aOther);
+      return other.apt == apt && other.rtx_time == rtx_time;
+    }
+  };
+
   class H264Parameters : public Parameters {
    public:
     static const uint32_t kDefaultProfileLevelId = 0x420010;

media/webrtc/signaling/src/sdp/rsdparsa_capi/src/attribute.rs

@@ -398,6 +398,14 @@ pub unsafe extern "C" fn sdp_get_rtpmaps(
     rtpmaps.copy_from_slice(attrs.as_slice());
 }
 
+#[repr(C)]
+#[derive(Clone, Copy)]
+pub struct RustRtxFmtpParameters {
+    pub apt: u8,
+    pub has_rtx_time: bool,
+    pub rtx_time: u32,
+}
+
 #[repr(C)]
 #[derive(Clone, Copy)]
 pub struct RustSdpAttributeFmtpParameters {
@@ -425,6 +433,9 @@ pub struct RustSdpAttributeFmtpParameters {
     // telephone-event
     pub dtmf_tones: StringView,
 
+    // RTX
+    pub rtx: RustRtxFmtpParameters,
+
     // Red
     pub encodings: *const Vec<u8>,
 
@@ -434,6 +445,20 @@ pub struct RustSdpAttributeFmtpParameters {
 
 impl<'a> From<&'a SdpAttributeFmtpParameters> for RustSdpAttributeFmtpParameters {
     fn from(other: &SdpAttributeFmtpParameters) -> Self {
+        let rtx = if let Some(rtx) = other.rtx {
+            RustRtxFmtpParameters {
+                apt: rtx.apt,
+                has_rtx_time: rtx.rtx_time.is_some(),
+                rtx_time: rtx.rtx_time.unwrap_or(0),
+            }
+        } else {
+            RustRtxFmtpParameters {
+                apt: 0,
+                has_rtx_time: false,
+                rtx_time: 0,
+            }
+        };
+
         RustSdpAttributeFmtpParameters {
             packetization_mode: other.packetization_mode,
             level_asymmetry_allowed: other.level_asymmetry_allowed,
@@ -450,6 +475,7 @@ impl<'a> From<&'a SdpAttributeFmtpParameters> for RustSdpAttributeFmtpParameters
             max_fr: other.max_fr,
             maxplaybackrate: other.maxplaybackrate,
             dtmf_tones: StringView::from(other.dtmf_tones.as_str()),
+            rtx,
             encodings: &other.encodings,
             unknown_tokens: &other.unknown_tokens,
         }