Make setCodecPreferences only look at receive codecs

which is what is noted in JSEP:
  https://www.rfc-editor.org/rfc/rfc8829.html#name-setcodecpreferences

Some W3C spec modifications are required since the W3C specification
currently takes into account send codecs as well.

Spec issue:
  w3c/webrtc-pc#2888
Spec PR:
 w3c/webrtc-pc#2926

setCodecPreferences continues to modify the codecs in an offer.

Also rename RtpSender::SetCodecPreferences to RtpSender::SetSendCodecs for consistent semantics.

BUG=webrtc:15396

Change-Id: I1e8fbe77cb2670575578a777ed1336567a1e4031
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/328780
Reviewed-by: Henrik Boström <[email protected]>
Commit-Queue: Philipp Hancke <[email protected]>
Reviewed-by: Harald Alvestrand <[email protected]>
Cr-Commit-Position: refs/heads/main@{#41719}

Author: fippo

media/base/media_engine.cc

@@ -67,11 +67,11 @@ std::vector<webrtc::RtpExtension> GetDefaultEnabledRtpHeaderExtensions(
 
 webrtc::RTCError CheckScalabilityModeValues(
     const webrtc::RtpParameters& rtp_parameters,
-    rtc::ArrayView<cricket::Codec> codec_preferences,
+    rtc::ArrayView<cricket::Codec> send_codecs,
     absl::optional<cricket::Codec> send_codec) {
   using webrtc::RTCErrorType;
 
-  if (codec_preferences.empty()) {
+  if (send_codecs.empty()) {
     // This is an audio sender or an extra check in the stack where the codec
     // list is not available and we can't check the scalability_mode values.
     return webrtc::RTCError::OK();
@@ -80,7 +80,7 @@ webrtc::RTCError CheckScalabilityModeValues(
   for (size_t i = 0; i < rtp_parameters.encodings.size(); ++i) {
     if (rtp_parameters.encodings[i].codec) {
       bool codecFound = false;
-      for (const cricket::VideoCodec& codec : codec_preferences) {
+      for (const cricket::Codec& codec : send_codecs) {
         if (codec.MatchesRtpCodec(*rtp_parameters.encodings[i].codec)) {
           codecFound = true;
           send_codec = codec;
@@ -97,7 +97,7 @@ webrtc::RTCError CheckScalabilityModeValues(
     if (rtp_parameters.encodings[i].scalability_mode) {
       if (!send_codec) {
         bool scalabilityModeFound = false;
-        for (const cricket::VideoCodec& codec : codec_preferences) {
+        for (const cricket::Codec& codec : send_codecs) {
           for (const auto& scalability_mode : codec.scalability_modes) {
             if (ScalabilityModeToString(scalability_mode) ==
                 *rtp_parameters.encodings[i].scalability_mode) {
@@ -139,7 +139,7 @@ webrtc::RTCError CheckScalabilityModeValues(
 
 webrtc::RTCError CheckRtpParametersValues(
     const webrtc::RtpParameters& rtp_parameters,
-    rtc::ArrayView<cricket::Codec> codec_preferences,
+    rtc::ArrayView<cricket::Codec> send_codecs,
     absl::optional<cricket::Codec> send_codec) {
   using webrtc::RTCErrorType;
 
@@ -196,8 +196,7 @@ webrtc::RTCError CheckRtpParametersValues(
     }
   }
 
-  return CheckScalabilityModeValues(rtp_parameters, codec_preferences,
-                                    send_codec);
+  return CheckScalabilityModeValues(rtp_parameters, send_codecs, send_codec);
 }
 
 webrtc::RTCError CheckRtpParametersInvalidModificationAndValues(
@@ -210,7 +209,7 @@ webrtc::RTCError CheckRtpParametersInvalidModificationAndValues(
 webrtc::RTCError CheckRtpParametersInvalidModificationAndValues(
     const webrtc::RtpParameters& old_rtp_parameters,
     const webrtc::RtpParameters& rtp_parameters,
-    rtc::ArrayView<cricket::Codec> codec_preferences,
+    rtc::ArrayView<cricket::Codec> send_codecs,
     absl::optional<cricket::Codec> send_codec) {
   using webrtc::RTCErrorType;
   if (rtp_parameters.encodings.size() != old_rtp_parameters.encodings.size()) {
@@ -246,8 +245,7 @@ webrtc::RTCError CheckRtpParametersInvalidModificationAndValues(
                          "Attempted to set RtpParameters with modified SSRC");
   }
 
-  return CheckRtpParametersValues(rtp_parameters, codec_preferences,
-                                  send_codec);
+  return CheckRtpParametersValues(rtp_parameters, send_codecs, send_codec);
 }
 
 CompositeMediaEngine::CompositeMediaEngine(

media/base/media_engine.h

@@ -42,22 +42,22 @@ namespace cricket {
 // least one video codec of the list. If the list is empty, no check is done.
 webrtc::RTCError CheckScalabilityModeValues(
     const webrtc::RtpParameters& new_parameters,
-    rtc::ArrayView<cricket::Codec> codec_preferences,
+    rtc::ArrayView<cricket::Codec> send_codecs,
     absl::optional<cricket::Codec> send_codec);
 
 // Checks the parameters have valid and supported values, and checks parameters
 // with CheckScalabilityModeValues().
 webrtc::RTCError CheckRtpParametersValues(
     const webrtc::RtpParameters& new_parameters,
-    rtc::ArrayView<cricket::Codec> codec_preferences,
+    rtc::ArrayView<cricket::Codec> send_codecs,
     absl::optional<cricket::Codec> send_codec);
 
 // Checks that the immutable values have not changed in new_parameters and
 // checks all parameters with CheckRtpParametersValues().
 webrtc::RTCError CheckRtpParametersInvalidModificationAndValues(
     const webrtc::RtpParameters& old_parameters,
     const webrtc::RtpParameters& new_parameters,
-    rtc::ArrayView<cricket::Codec> codec_preferences,
+    rtc::ArrayView<cricket::Codec> send_codecs,
     absl::optional<cricket::Codec> send_codec);
 
 // Checks that the immutable values have not changed in new_parameters and