Improve the audio codec factory documentation.

Bug: none
Change-Id: Iefddb49d515bde0c8c5b7fb0d5c8dc79399b03a0
Reviewed-on: https://webrtc-review.googlesource.com/c/113802
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25969}

2 files changed, 16 insertions, 10 deletions

diff --git a/api/audio_codecs/audio_decoder_factory.h b/api/audio_codecs/audio_decoder_factory.h
index 55e197a14a..3d80958338 100644
--- a/api/audio_codecs/audio_decoder_factory.h
+++ b/api/audio_codecs/audio_decoder_factory.h
@@ -29,11 +29,14 @@ class AudioDecoderFactory : public rtc::RefCountInterface {
 
   virtual bool IsSupportedDecoder(const SdpAudioFormat& format) = 0;
 
-  // Create a new decoder instance. The `codec_pair_id` argument is used to
-  // link encoders and decoders that talk to the same remote entity; if a
-  // MakeAudioEncoder() and a MakeAudioDecoder() call receive non-null IDs that
+  // Create a new decoder instance. The `codec_pair_id` argument is used to link
+  // encoders and decoders that talk to the same remote entity: if a
+  // AudioEncoderFactory::MakeAudioEncoder() and a
+  // AudioDecoderFactory::MakeAudioDecoder() call receive non-null IDs that
   // compare equal, the factory implementations may assume that the encoder and
-  // decoder form a pair.
+  // decoder form a pair. (The intended use case for this is to set up
+  // communication between the AudioEncoder and AudioDecoder instances, which is
+  // needed for some codecs with built-in bandwidth adaptation.)
   //
   // Note: Implementations need to be robust against combinations other than
   // one encoder, one decoder getting the same ID; such decoders must still
diff --git a/api/audio_codecs/audio_encoder_factory.h b/api/audio_codecs/audio_encoder_factory.h
index b290967c78..a5fd561b6c 100644
--- a/api/audio_codecs/audio_encoder_factory.h
+++ b/api/audio_codecs/audio_encoder_factory.h
@@ -34,12 +34,15 @@ class AudioEncoderFactory : public rtc::RefCountInterface {
   virtual absl::optional<AudioCodecInfo> QueryAudioEncoder(
       const SdpAudioFormat& format) = 0;
 
-  // Creates an AudioEncoder for the specified format. The encoder will tags
-  // its payloads with the specified payload type. The `codec_pair_id` argument
-  // is used to link encoders and decoders that talk to the same remote entity;
-  // if a MakeAudioEncoder() and a MakeAudioDecoder() call receive non-null IDs
-  // that compare equal, the factory implementations may assume that the
-  // encoder and decoder form a pair.
+  // Creates an AudioEncoder for the specified format. The encoder will tags its
+  // payloads with the specified payload type. The `codec_pair_id` argument is
+  // used to link encoders and decoders that talk to the same remote entity: if
+  // a AudioEncoderFactory::MakeAudioEncoder() and a
+  // AudioDecoderFactory::MakeAudioDecoder() call receive non-null IDs that
+  // compare equal, the factory implementations may assume that the encoder and
+  // decoder form a pair. (The intended use case for this is to set up
+  // communication between the AudioEncoder and AudioDecoder instances, which is
+  // needed for some codecs with built-in bandwidth adaptation.)
   //
   // Note: Implementations need to be robust against combinations other than
   // one encoder, one decoder getting the same ID; such encoders must still