H264 codec: Check profile-level-id when matching

webrtc/media/base/codec.h

 /*
  *  Copyright (c) 2004 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 63 matching lines @@
   Codec();
   Codec(const Codec& c);
   virtual ~Codec();
 
   // Indicates if this codec is compatible with the specified codec.
   bool Matches(const Codec& codec) const;
 
   // Find the parameter for |name| and write the value to |out|.
   bool GetParam(const std::string& name, std::string* out) const;
   bool GetParam(const std::string& name, int* out) const;
+  // Return the contained value for |name| if available, and |default_value|
+  // otherwise.
+  std::string GetParam(const std::string& name,
+                       const std::string& default_value) const;

[hta-webrtc, 2016/09/19 06:38:36]

Suggest not having this function. I've had this pair of functions for constraint
fetching, and decided it was a bad idea, since it required programmers to
remember two idioms instead of one.

Alternatively, name it GetParamOrDefault.

[magjed_webrtc, 2016/09/19 12:40:30]

Ok, I removed it from the public interface and made it a private helper function
in codec.cc. I hope that's ok since it's exactly the functionality I want and I
don't want to inline it four times.

The modern way of doing this would be to return an rtc::Optional<std::String>
(or std::Optional when that becomes available). Then we can write code like
GetParam(...).value_or(default_value).

 
   void SetParam(const std::string& name, const std::string& value);
   void SetParam(const std::string& name, int value);
 
   // It is safe to input a non-existent parameter.
   // Returns true if the parameter existed, false if it did not exist.
   bool RemoveParam(const std::string& name);
 
   bool HasFeedbackParam(const FeedbackParam& param) const;
   void AddFeedbackParam(const FeedbackParam& param);
@@ skipping 54 matching lines @@
              const std::string& name,
              int width,
              int height,
              int framerate);
   VideoCodec(int id, const std::string& name);
   // Creates an empty codec.
   VideoCodec();
   VideoCodec(const VideoCodec& c);
   virtual ~VideoCodec() = default;
 
+  // Indicates if this codec is compatible with the specified codec.
+  bool Matches(const VideoCodec& codec) const;
+
   std::string ToString() const;
 
   VideoCodec& operator=(const VideoCodec& c);
 
   bool operator==(const VideoCodec& c) const;
 
   bool operator!=(const VideoCodec& c) const {
     return !(*this == c);
   }
 
@@ skipping 41 matching lines @@
 }
 
 bool CodecNamesEq(const std::string& name1, const std::string& name2);
 bool HasNack(const Codec& codec);
 bool HasRemb(const Codec& codec);
 bool HasTransportCc(const Codec& codec);
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_BASE_CODEC_H_