Add proper lifetime of encoder-specific settings

webrtc/config.h

 /*
  *  Copyright (c) 2013 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.
  */
 
 // TODO(pbos): Move Config from common.h to here.
 
 #ifndef WEBRTC_CONFIG_H_
 #define WEBRTC_CONFIG_H_
 
 #include <string>
 #include <vector>
 
 #include "webrtc/base/optional.h"
+#include "webrtc/base/refcount.h"
+#include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
 
 namespace webrtc {
 
 // Settings for NACK, see RFC 4585 for details.
 struct NackConfig {
   NackConfig() : rtp_history_ms(0) {}
   std::string ToString() const;
   // Send side: the time RTP packets are stored for retransmissions.
@@ skipping 81 matching lines @@
   int max_qp;
 
   // Bitrate thresholds for enabling additional temporal layers. Since these are
   // thresholds in between layers, we have one additional layer. One threshold
   // gives two temporal layers, one below the threshold and one above, two give
   // three, and so on.
   // The VideoEncoder may redistribute bitrates over the temporal layers so a
   // bitrate threshold of 100k and an estimate of 105k does not imply that we
   // get 100k in one temporal layer and 5k in the other, just that the bitrate
   // in the first temporal layer should not exceed 100k.
-  // TODO(pbos): Apart from a special case for two-layer screencast these
+  // TODO(kthelgason): Apart from a special case for two-layer screencast these
   // thresholds are not propagated to the VideoEncoder. To be implemented.
   std::vector<int> temporal_layer_thresholds_bps;
 };
 
 struct VideoEncoderConfig {
  public:
+  // These are reference counted to permit copying VideoEncoderConfig and be
+  // kept alive until all encoder_specific_settings go out of scope.
+  // TODO(kthelgason): Consider removing the need for copying VideoEncoderConfig
+  // and use rtc::Optional for encoder_specific_settings instead.
+  class EncoderSpecificSettings : public rtc::RefCountInterface {
+   public:
+    virtual ~EncoderSpecificSettings() {}

[tommi, 2016/09/21 13:20:57]

for reference counted classes it's preferred to have the dtor private and friend
the refcounted type that's allowed to delete the instance.

[kthelgason, 2016/09/21 16:53:09]

Done.

+    // 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,
   };
 
   VideoEncoderConfig& operator=(VideoEncoderConfig&&) = default;
   VideoEncoderConfig& operator=(const VideoEncoderConfig&) = delete;
 
   // Mostly used by tests.  Avoid creating copies if you can.
   VideoEncoderConfig Copy() const { return VideoEncoderConfig(*this); }
 
   VideoEncoderConfig();
   VideoEncoderConfig(VideoEncoderConfig&&) = default;
   ~VideoEncoderConfig();
   std::string ToString() const;
 
   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
   // maintaining a higher bitrate estimate. Padding will however not be sent
   // unless the estimated bandwidth indicates that the link can handle it.
   int min_transmit_bitrate_bps;
   bool expect_encode_from_texture;
 
  private:
   // Access to the copy constructor is private to force use of the Copy()
   // method for those exceptional cases where we do use it.
   VideoEncoderConfig(const VideoEncoderConfig&) = default;
 };
 
 struct VideoDecoderH264Settings {
   std::string sprop_parameter_sets;
 };
 
 class DecoderSpecificSettings {
  public:
   virtual ~DecoderSpecificSettings() {}
   rtc::Optional<VideoDecoderH264Settings> h264_extra_settings;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_CONFIG_H_