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

media/cast/sender/video_encoder_impl.cc

 // 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.
 
 #include "media/cast/sender/video_encoder_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/logging.h"
@@ skipping 36 matching lines @@
   encoder->Encode(video_frame, reference_time, encoded_frame.get());
   environment->PostTask(
       CastEnvironment::MAIN,
       FROM_HERE,
       base::Bind(frame_encoded_callback, base::Passed(&encoded_frame)));
 }
 }  // namespace
 
 VideoEncoderImpl::VideoEncoderImpl(
     scoped_refptr<CastEnvironment> cast_environment,
-    const VideoSenderConfig& video_config)
+    const VideoSenderConfig& video_config,
+    const CastInitializationCallback& initialization_cb)
     : cast_environment_(cast_environment) {
   CHECK(cast_environment_->HasVideoThread());
   if (video_config.codec == CODEC_VIDEO_VP8) {
     encoder_.reset(new Vp8Encoder(video_config));
     cast_environment_->PostTask(CastEnvironment::VIDEO,
                                 FROM_HERE,
                                 base::Bind(&InitializeEncoderOnEncoderThread,
                                            cast_environment,
                                            encoder_.get()));
 #ifndef OFFICIAL_BUILD
   } else if (video_config.codec == CODEC_VIDEO_FAKE) {
     encoder_.reset(new FakeSoftwareVideoEncoder(video_config));
 #endif
   } else {
     DCHECK(false) << "Invalid config";  // Codec not supported.
   }
 
   dynamic_config_.key_frame_requested = false;
   dynamic_config_.latest_frame_id_to_reference = kStartFrameId;
   dynamic_config_.bit_rate = video_config.start_bitrate;
+
+  if (!initialization_cb.is_null()) {

[hubbe, 2015/01/31 00:55:51]

Why do we want to allow the initialization_cb to be null?

[miu, 2015/01/31 04:53:04]

For now, just to placate unit test code that doesn't want to provide a callback.
 I'm going to revisit these null checks in a soon-upcoming CL (when I plumb in
error reporting).

+    cast_environment_->PostTask(
+        CastEnvironment::MAIN,
+        FROM_HERE,
+        base::Bind(initialization_cb,
+                   encoder_.get() ? STATUS_VIDEO_INITIALIZED :
+                                    STATUS_UNSUPPORTED_VIDEO_CODEC));
+  }
 }
 
 VideoEncoderImpl::~VideoEncoderImpl() {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
   if (encoder_) {
     cast_environment_->PostTask(
         CastEnvironment::VIDEO,
         FROM_HERE,
         base::Bind(&base::DeletePointer<SoftwareVideoEncoder>,
                    encoder_.release()));
   }
 }
 
+bool VideoEncoderImpl::CanEncodeVariedFrameSizes() const {
+  // Both the VP8Encoder and FakeSoftwareVideoEncoder support calls to
+  // EncodeVideoFrame() with different frame sizes.
+  return true;
+}
+
 bool VideoEncoderImpl::EncodeVideoFrame(
     const scoped_refptr<media::VideoFrame>& video_frame,
     const base::TimeTicks& reference_time,
     const FrameEncodedCallback& frame_encoded_callback) {
   DCHECK(cast_environment_->CurrentlyOn(CastEnvironment::MAIN));
+  DCHECK(!video_frame->visible_rect().IsEmpty());
+  DCHECK(!frame_encoded_callback.is_null());
+
   cast_environment_->PostTask(CastEnvironment::VIDEO,
                               FROM_HERE,
                               base::Bind(&EncodeVideoFrameOnEncoderThread,
                                          cast_environment_,
                                          encoder_.get(),
                                          video_frame,
                                          reference_time,
                                          dynamic_config_,
                                          frame_encoded_callback));
 
@@ skipping 11 matching lines @@
   dynamic_config_.key_frame_requested = true;
 }
 
 // Inform the encoder to only reference frames older or equal to frame_id;
 void VideoEncoderImpl::LatestFrameIdToReference(uint32 frame_id) {
   dynamic_config_.latest_frame_id_to_reference = frame_id;
 }
 
 }  //  namespace cast
 }  //  namespace media