commit 01611ed3ac4102dc209e50bd618dd7933e11f314
author Erik Språng <sprang@webrtc.org> Tue Mar 24 11:00:00 2020
committer Commit Bot <commit-bot@chromium.org> Tue Mar 24 12:29:05 2020
tree c40a9fdf3531d4526fc612143afaba3fa9c8eaef
parent 5b6a4d8908f87b22132ddee4ed2bd114b524ff03

Fix potential divide by zero in SimulcastEncoderAdapter

Bug: webrtc:11453
Change-Id: I4119955d7a3cdc4099b8f0ab013e5e33ec38715f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/171511
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30866}

media/engine/simulcast_encoder_adapter.cc

diff --git a/media/engine/simulcast_encoder_adapter.cc b/media/engine/simulcast_encoder_adapter.cc
index a5454eb..863ccc7 100644
--- a/media/engine/simulcast_encoder_adapter.cc
+++ b/media/engine/simulcast_encoder_adapter.cc
@@ -513,7 +513,8 @@
     }
 
     // Assign link allocation proportionally to spatial layer allocation.
-    if (parameters.bandwidth_allocation != DataRate::Zero()) {
+    if (!parameters.bandwidth_allocation.IsZero() &&
+        parameters.bitrate.get_sum_bps() > 0) {
       stream_parameters.bandwidth_allocation =
           DataRate::BitsPerSec((parameters.bandwidth_allocation.bps() *
                                 stream_parameters.bitrate.get_sum_bps()) /

media/engine/simulcast_encoder_adapter_unittest.cc

diff --git a/media/engine/simulcast_encoder_adapter_unittest.cc b/media/engine/simulcast_encoder_adapter_unittest.cc
index 14c1cd4..b467c49 100644
--- a/media/engine/simulcast_encoder_adapter_unittest.cc
+++ b/media/engine/simulcast_encoder_adapter_unittest.cc
@@ -1364,6 +1364,31 @@
   }
 }
 
+TEST_F(TestSimulcastEncoderAdapterFake, CanSetZeroBitrateWithHeadroom) {
+  SimulcastTestFixtureImpl::DefaultSettings(
+      &codec_, static_cast<const int*>(kTestTemporalLayerProfile),
+      kVideoCodecVP8);
+  codec_.numberOfSimulcastStreams = 3;
+
+  rate_allocator_.reset(new SimulcastRateAllocator(codec_));
+  EXPECT_EQ(0, adapter_->InitEncode(&codec_, kSettings));
+  adapter_->RegisterEncodeCompleteCallback(this);
+
+  // Set allocated bitrate to 0, but keep (network) bandwidth allocation.
+  VideoEncoder::RateControlParameters rate_params;
+  rate_params.framerate_fps = 30;
+  rate_params.bandwidth_allocation = DataRate::KilobitsPerSec(600);
+
+  adapter_->SetRates(rate_params);
+
+  std::vector<MockVideoEncoder*> encoders = helper_->factory()->encoders();
+
+  ASSERT_EQ(3u, encoders.size());
+  for (size_t i = 0; i < 3; ++i) {
+    EXPECT_EQ(0u, encoders[i]->last_set_rates().bitrate.get_sum_bps());
+  }
+}
+
 TEST_F(TestSimulcastEncoderAdapterFake, SupportsSimulcast) {
   SimulcastTestFixtureImpl::DefaultSettings(
       &codec_, static_cast<const int*>(kTestTemporalLayerProfile),