Add proper lifetime of encoder-specific settings.

webrtc/config.h

Index: webrtc/config.h
diff --git a/webrtc/config.h b/webrtc/config.h
index 1550a9f8a13ac1b121c90b31a771eee56e12f1a6..f5eaa604a031410651952ff3118fad58c74cf8a3 100644
--- a/webrtc/config.h
+++ b/webrtc/config.h
@@ -17,6 +17,8 @@
 #include <vector>
 
 #include "webrtc/base/optional.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/common.h"
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
@@ -125,6 +127,51 @@ struct VideoStream {
 };
 
 struct VideoEncoderConfig {
+  // These are reference counted to permit copying VideoEncoderConfig and be
+  // kept alive until all encoder_specific_settings go out of scope.
+  // TODO(pbos): Consider removing the need for copying VideoEncoderConfig and
+  // use a rtc::Optional for encoder_specific_settings instead.
+  class EncoderSpecificSettings : public rtc::RefCountInterface {

[perkj_webrtc, 2016/09/14 09:51:31]

I really think this should be landed. But I think specifics_ must be copyable
and encoder_specific_settings should be stored in a std::unique_ptr<>. No need
for ref counting as far as I can see. Note that VideoEncoderConfig has a copy
method that needs to be updated. 

+   public:
+    virtual ~EncoderSpecificSettings() {}
+    // TODO(pbos): Remove FillEncoderSpecificSettings as soon as VideoCodec is
+    // not in use and encoder implementations ask for codec-specific structs
+    // directly.
+    void FillEncoderSpecificSettings(VideoCodec* codec_struct) const;
+
+    virtual void FillVideoCodecVp8(VideoCodecVP8* vp8_settings) const;
+    virtual void FillVideoCodecVp9(VideoCodecVP9* vp9_settings) const;
+    virtual void FillVideoCodecH264(VideoCodecH264* h264_settings) const;
+  };
+
+  class H264EncoderSpecificSettings : public EncoderSpecificSettings {
+   public:
+    explicit H264EncoderSpecificSettings(const VideoCodecH264& specifics);
+    virtual void FillVideoCodecH264(
+        VideoCodecH264* h264_settings) const override;
+
+   private:
+    VideoCodecH264 specifics_;
+  };
+
+  class Vp8EncoderSpecificSettings : public EncoderSpecificSettings {
+   public:
+    explicit Vp8EncoderSpecificSettings(const VideoCodecVP8& specifics);
+    virtual void FillVideoCodecVp8(VideoCodecVP8* vp8_settings) const override;
+
+   private:
+    VideoCodecVP8 specifics_;
+  };
+
+  class Vp9EncoderSpecificSettings : public EncoderSpecificSettings {
+   public:
+    explicit Vp9EncoderSpecificSettings(const VideoCodecVP9& specifics);
+    virtual void FillVideoCodecVp9(VideoCodecVP9* vp9_settings) const override;
+
+   private:
+    VideoCodecVP9 specifics_;
+  };
+
   enum class ContentType {
     kRealtimeVideo,
     kScreen,
@@ -137,7 +184,7 @@ struct VideoEncoderConfig {
   std::vector<VideoStream> streams;
   std::vector<SpatialLayer> spatial_layers;
   ContentType content_type;
-  void* encoder_specific_settings;
+  rtc::scoped_refptr<const EncoderSpecificSettings> encoder_specific_settings;
 
   // Padding will be used up to this bitrate regardless of the bitrate produced
   // by the encoder. Padding above what's actually produced by the encoder helps