RELAND: [Cast] Software encoder support for varying video frame sizes.

media/cast/sender/vp8_encoder.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_CAST_SENDER_CODECS_VP8_VP8_ENCODER_H_
 #define MEDIA_CAST_SENDER_CODECS_VP8_VP8_ENCODER_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/threading/thread_checker.h"
 #include "media/cast/cast_config.h"
 #include "media/cast/sender/software_video_encoder.h"
 #include "third_party/libvpx/source/libvpx/vpx/vpx_encoder.h"
+#include "ui/gfx/geometry/size.h"
 
 namespace media {
 class VideoFrame;
 }
 
 namespace media {
 namespace cast {
 
 class Vp8Encoder : public SoftwareVideoEncoder {
  public:
@@ skipping 25 matching lines @@
     kBufferSent,
     kBufferAcked
   };
 
   struct BufferState {
     uint32 frame_id;
     Vp8BufferState state;
   };
 
   bool is_initialized() const {
-    // Initialize() sets the timebase denominator value to non-zero if the
-    // encoder is successfully initialized, and it is zero otherwise.
+    // ConfigureForNewFrameSize() sets the timebase denominator value to
+    // non-zero if the encoder is successfully initialized, and it is zero
+    // otherwise.
     return config_.g_timebase.den != 0;
   }
 
+  // If the |encoder_| is live, attempt reconfiguration to allow it to encode
+  // frames at a new |frame_size|.  Otherwise, tear it down and re-create a new
+  // |encoder_| instance.
+  void ConfigureForNewFrameSize(const gfx::Size& frame_size);
+
   // Calculate which next Vp8 buffers to update with the next frame.
   Vp8Buffers GetNextBufferToUpdate();
 
   // Get encoder flags for our referenced encoder buffers.
   // Return which previous frame to reference.
   uint32 GetCodecReferenceFlags(vpx_codec_flags_t* flags);
 
   // Get encoder flags for our encoder buffers to update with next frame.
   void GetCodecUpdateFlags(Vp8Buffers buffer_to_update,
                            vpx_codec_flags_t* flags);
 
   const VideoSenderConfig cast_config_;
   const bool use_multiple_video_buffers_;
 
   // VP8 internal objects.  These are valid for use only while is_initialized()
   // returns true.
   vpx_codec_enc_cfg_t config_;
   vpx_codec_ctx_t encoder_;
 
-  // Wrapper for access to YUV data planes in a media::VideoFrame.
-  vpx_image_t* raw_image_;
-
   // Set to true to request the next frame emitted by Vp8Encoder be a key frame.
   bool key_frame_requested_;
 
+  // Saves the current bitrate setting, for when the |encoder_| is reconfigured
+  // for different frame sizes.
+  int bitrate_kbit_;
+
   // The |VideoFrame::timestamp()| of the last encoded frame.  This is used to
   // predict the duration of the next frame.
   base::TimeDelta last_frame_timestamp_;
 
   // The last encoded frame's ID.
   uint32 last_encoded_frame_id_;
 
   // Used to track which buffers are old enough to be re-used.
   uint32 last_acked_frame_id_;
 
   // Used by GetNextBufferToUpdate() to track how many consecutive times the
   // newest buffer had to be overwritten.
   int undroppable_frames_;
 
   // Tracks the lifecycle and dependency state of each of the three buffers.
   BufferState buffer_state_[kNumberOfVp8VideoBuffers];
 
   // This is bound to the thread where Initialize() is called.
   base::ThreadChecker thread_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(Vp8Encoder);
 };
 
 }  // namespace cast
 }  // namespace media
 
 #endif  // MEDIA_CAST_SENDER_CODECS_VP8_VP8_ENCODER_H_