From dabe48bb4c8797d681b0463a61966c675f9bd2f9 Mon Sep 17 00:00:00 2001
From: Rasmus Brandt <brandtr@webrtc.org>
Date: Wed, 5 Aug 2020 11:32:38 +0200
Subject: [PATCH] Add WebRTC-VP8-GetEncoderInfoOverride field trial to libvpx.
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This trial allows the downstream users to quickly set the
requested resolution alignment.

Bug: webrtc:11832
Change-Id: I55b3213179021455740311247829b44926722efe
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/180884
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Commit-Queue: Rasmus Brandt <brandtr@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#31857}
---
 .../codecs/vp8/libvpx_vp8_encoder.cc          | 26 ++++++++++++++++---
 .../codecs/vp8/libvpx_vp8_encoder.h           |  3 +++
 .../codecs/vp8/test/vp8_impl_unittest.cc      | 13 ++++++++++
 3 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc b/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc
index 9b64d1654f..2f901ad811 100644
--- a/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc
+++ b/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.cc
@@ -44,12 +44,17 @@
 namespace webrtc {
 namespace {
 #if defined(WEBRTC_IOS)
-const char kVP8IosMaxNumberOfThreadFieldTrial[] =
+constexpr char kVP8IosMaxNumberOfThreadFieldTrial[] =
     "WebRTC-VP8IosMaxNumberOfThread";
-const char kVP8IosMaxNumberOfThreadFieldTrialParameter[] = "max_thread";
+constexpr char kVP8IosMaxNumberOfThreadFieldTrialParameter[] = "max_thread";
 #endif
 
-const char kVp8ForcePartitionResilience[] =
+constexpr char kVp8GetEncoderInfoOverrideFieldTrial[] =
+    "WebRTC-VP8-GetEncoderInfoOverride";
+constexpr char kVp8RequestedResolutionAlignmentFieldTrialParameter[] =
+    "requested_resolution_alignment";
+
+constexpr char kVp8ForcePartitionResilience[] =
     "WebRTC-VP8-ForcePartitionResilience";
 
 // QP is obtained from VP8-bitstream for HW, so the QP corresponds to the
@@ -222,6 +227,15 @@ void ApplyVp8EncoderConfigToVpxConfig(const Vp8EncoderConfig& encoder_config,
   }
 }
 
+absl::optional<int> GetRequestedResolutionAlignmentOverride() {
+  const std::string trial_string =
+      field_trial::FindFullName(kVp8GetEncoderInfoOverrideFieldTrial);
+  FieldTrialOptional<int> requested_resolution_alignment(
+      kVp8RequestedResolutionAlignmentFieldTrialParameter);
+  ParseFieldTrial({&requested_resolution_alignment}, trial_string);
+  return requested_resolution_alignment.GetOptional();
+}
+
 }  // namespace
 
 std::unique_ptr<VideoEncoder> VP8Encoder::Create() {
@@ -279,6 +293,8 @@ LibvpxVp8Encoder::LibvpxVp8Encoder(std::unique_ptr<LibvpxInterface> interface,
     : libvpx_(std::move(interface)),
       experimental_cpu_speed_config_arm_(CpuSpeedExperiment::GetConfigs()),
       rate_control_settings_(RateControlSettings::ParseFromFieldTrials()),
+      requested_resolution_alignment_override_(
+          GetRequestedResolutionAlignmentOverride()),
       frame_buffer_controller_factory_(
           std::move(settings.frame_buffer_controller_factory)),
       resolution_bitrate_limits_(std::move(settings.resolution_bitrate_limits)),
@@ -1233,6 +1249,10 @@ VideoEncoder::EncoderInfo LibvpxVp8Encoder::GetEncoderInfo() const {
   if (!resolution_bitrate_limits_.empty()) {
     info.resolution_bitrate_limits = resolution_bitrate_limits_;
   }
+  if (requested_resolution_alignment_override_) {
+    info.requested_resolution_alignment =
+        *requested_resolution_alignment_override_;
+  }
 
   const bool enable_scaling =
       num_active_streams_ == 1 &&
diff --git a/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.h b/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.h
index 8afcaae58f..f6cfd0ffe6 100644
--- a/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.h
+++ b/modules/video_coding/codecs/vp8/libvpx_vp8_encoder.h
@@ -99,6 +99,9 @@ class LibvpxVp8Encoder : public VideoEncoder {
       experimental_cpu_speed_config_arm_;
   const RateControlSettings rate_control_settings_;
 
+  // EncoderInfo::requested_resolution_alignment override from field trial.
+  const absl::optional<int> requested_resolution_alignment_override_;
+
   EncodedImageCallback* encoded_complete_callback_ = nullptr;
   VideoCodec codec_;
   bool inited_ = false;
diff --git a/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc b/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
index d3e4a1739e..342187b180 100644
--- a/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
+++ b/modules/video_coding/codecs/vp8/test/vp8_impl_unittest.cc
@@ -565,6 +565,19 @@ TEST(LibvpxVp8EncoderTest, GetEncoderInfoReturnsStaticInformation) {
   EXPECT_FALSE(info.has_internal_source);
   EXPECT_TRUE(info.supports_simulcast);
   EXPECT_EQ(info.implementation_name, "libvpx");
+  EXPECT_EQ(info.requested_resolution_alignment, 1);
+}
+
+TEST(LibvpxVp8EncoderTest, RequestedResolutionAlignmentFromFieldTrial) {
+  test::ScopedFieldTrials field_trials(
+      "WebRTC-VP8-GetEncoderInfoOverride/"
+      "requested_resolution_alignment:10/");
+
+  auto* const vpx = new NiceMock<MockLibvpxVp8Interface>();
+  LibvpxVp8Encoder encoder((std::unique_ptr<LibvpxInterface>(vpx)),
+                           VP8Encoder::Settings());
+
+  EXPECT_EQ(encoder.GetEncoderInfo().requested_resolution_alignment, 10);
 }
 
 TEST(LibvpxVp8EncoderTest,