Extract bitrate allocation of spatial/temporal layers out of codec impl.

webrtc/modules/video_coding/video_coding_impl.cc

Index: webrtc/modules/video_coding/video_coding_impl.cc
diff --git a/webrtc/modules/video_coding/video_coding_impl.cc b/webrtc/modules/video_coding/video_coding_impl.cc
index 2f709b610c1453a6e8fc9415042189a9f03ddae2..f0c596c1e139bc740e0bf0275dfcb7a6650582aa 100644
--- a/webrtc/modules/video_coding/video_coding_impl.cc
+++ b/webrtc/modules/video_coding/video_coding_impl.cc
@@ -11,10 +11,14 @@
 #include "webrtc/modules/video_coding/video_coding_impl.h"
 
 #include <algorithm>
+#include <utility>
 
 #include "webrtc/common_types.h"
+#include "webrtc/common_video/include/video_bitrate_allocator.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/base/criticalsection.h"
+#include "webrtc/modules/video_coding/codecs/vp8/temporal_layers.h"
+#include "webrtc/modules/video_coding/include/video_codec_initializer.h"
 #include "webrtc/modules/video_coding/include/video_codec_interface.h"
 #include "webrtc/modules/video_coding/encoded_frame.h"
 #include "webrtc/modules/video_coding/jitter_buffer.h"
@@ -104,6 +108,16 @@ class VideoCodingModuleImpl : public VideoCodingModule {
   int32_t RegisterSendCodec(const VideoCodec* sendCodec,
                             uint32_t numberOfCores,
                             uint32_t maxPayloadSize) override {
+    if (sendCodec != nullptr && sendCodec->codecType == kVideoCodecVP8) {
+      VideoCodec vp8_codec = *sendCodec;
+      std::unique_ptr<TemporalLayersFactory> tl_factory(
+          new TemporalLayersFactory());
+      vp8_codec.VP8()->tl_factory = tl_factory.get();
+      rate_allocator_ = VideoCodecInitializer::GetBitrateAllocator(
+          vp8_codec, std::move(tl_factory));
+      return sender_.RegisterSendCodec(&vp8_codec, numberOfCores,
+                                       maxPayloadSize);

[stefan-webrtc, 2016/11/09 11:58:12]

I find it a bit difficult to understand lifetime of objects here. tl_factory
ownership is handed over to rate_allocator_, which lives up until
VideoCodingModuleImpl is destroyed? Or does it live only until RegisterSendCodec
is called again? Is it safe for vp8_codec to have a pointer to it? Maybe at
least worth commenting on.

[sprang_webrtc, 2016/11/09 12:26:18]

The TemporalLayersFactory is owned by the BitrateAllocator yes, and it must live
when InitEncode() is called on the codec implementation. Since this is done on a
task queue we can't really know when that is, so we let the instance live until
we destroy the video coding module or we register a new send codec.
I can add a comment.

[stefan-webrtc, 2016/11/09 12:40:26]

Does it make more sense to let the codec own the allocator? It seems to be the
only one really using it?

+    }
     return sender_.RegisterSendCodec(sendCodec, numberOfCores, maxPayloadSize);
   }
 
@@ -126,7 +140,8 @@ class VideoCodingModuleImpl : public VideoCodingModule {
   int32_t SetChannelParameters(uint32_t target_bitrate,  // bits/s.
                                uint8_t lossRate,
                                int64_t rtt) override {
-    return sender_.SetChannelParameters(target_bitrate, lossRate, rtt);
+    return sender_.SetChannelParameters(target_bitrate, lossRate, rtt,
+                                        rate_allocator_.get());
   }
 
   int32_t RegisterProtectionCallback(
@@ -256,6 +271,7 @@ class VideoCodingModuleImpl : public VideoCodingModule {
  private:
   EncodedImageCallbackWrapper post_encode_callback_;
   vcm::VideoSender sender_;
+  std::unique_ptr<VideoBitrateAllocator> rate_allocator_;
   vcm::VideoReceiver receiver_;
 };
 }  // namespace