Fix bug where min transmit bitrate wasn't working

webrtc/video/end_to_end_tests.cc

 /*
  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #include <algorithm>
 #include <list>
 #include <map>
 #include <memory>
 #include <sstream>
 #include <string>
 #include <vector>
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 #include "webrtc/base/checks.h"
 #include "webrtc/base/event.h"
 #include "webrtc/call.h"
 #include "webrtc/call/transport_adapter.h"
 #include "webrtc/common_video/include/frame_callback.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
 #include "webrtc/modules/rtp_rtcp/source/byte_io.h"
+#include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_utility.h"
 #include "webrtc/modules/video_coding/codecs/h264/include/h264.h"
 #include "webrtc/modules/video_coding/codecs/vp8/include/vp8.h"
 #include "webrtc/modules/video_coding/codecs/vp9/include/vp9.h"
 #include "webrtc/modules/video_coding/include/video_coding_defines.h"
 #include "webrtc/system_wrappers/include/metrics.h"
 #include "webrtc/system_wrappers/include/metrics_default.h"
 #include "webrtc/system_wrappers/include/sleep.h"
 #include "webrtc/test/call_test.h"
 #include "webrtc/test/direct_transport.h"
@@ skipping 2453 matching lines @@
 
    private:
     rtc::CriticalSection crit_;
     VideoSendStream* send_stream_;
     uint32_t bitrate_kbps_ GUARDED_BY(crit_);
   } test;
 
   RunBaseTest(&test);
 }
 
+class MinTransmitBitrateTest : public test::EndToEndTest,

[perkj_webrtc, 2016/07/04 07:24:49]

Why is this not a VideoSendStream test? What is the difference with EndToEnd
tests?

[perkj_webrtc, 2016/07/04 07:24:49]

How about testing padding instead?  There are tests that tests padding I think,
so why not change one of those tests to check that padding is sent if we start
with no padding and switch content type that needs padding? 

[sprang_webrtc, 2016/07/04 09:08:47]

I did that at first, it turned out to flake way too easily, so I abandoned it.

[sprang_webrtc, 2016/07/04 09:08:47]

I initially had planned to check received padding, but I ended up begin way too
flaky. Now it doesn't make sense anymore so have moved it to send stream test.

+                               public test::FakeEncoder {
+ public:
+  static const uint32_t kMinTransmitBitrateBps = 400000;
+  static const uint32_t kActualEncodeBitrateBps = 40000;
+  static const uint32_t kMinFramesToSend = 10;
+
+  explicit MinTransmitBitrateTest(bool run_init_phase_without_mtb)

[perkj_webrtc, 2016/07/04 07:24:49]

bool test_switch_content_type ? 

[sprang_webrtc, 2016/07/04 09:08:47]

Done.

+      : EndToEndTest(test::CallTest::kDefaultTimeoutMs),
+        FakeEncoder(Clock::GetRealTimeClock()),
+        call_(nullptr),
+        send_stream_(nullptr),
+        frames_sent_(0),
+        in_init_phase_(run_init_phase_without_mtb) {}
+
+  void OnVideoStreamsCreated(
+      VideoSendStream* send_stream,
+      const std::vector<VideoReceiveStream*>& receive_streams) override {
+    send_stream_ = send_stream;
+  }
+
+  void ModifyVideoConfigs(
+      VideoSendStream::Config* send_config,
+      std::vector<VideoReceiveStream::Config>* receive_configs,
+      VideoEncoderConfig* encoder_config) override {
+    send_config->encoder_settings.encoder = this;
+    RTC_DCHECK_EQ(1u, encoder_config->streams.size());
+    encoder_config->streams[0].target_bitrate_bps = kMinTransmitBitrateBps * 2;
+    encoder_config->streams[0].max_bitrate_bps = kMinTransmitBitrateBps * 4;
+    if (in_init_phase_) {
+      encoder_config->min_transmit_bitrate_bps = 0;
+      encoder_config->content_type =
+          VideoEncoderConfig::ContentType::kRealtimeVideo;
+    } else {
+      encoder_config->min_transmit_bitrate_bps = kMinTransmitBitrateBps;
+      encoder_config->content_type = VideoEncoderConfig::ContentType::kScreen;
+    }
+    encoder_config_ = *encoder_config;
+  }
+
+  int32_t SetRates(uint32_t new_target_bitrate, uint32_t framerate) override {
+    // Make sure not to trigger on any default zero bitrates.
+    if (new_target_bitrate == 0)
+      return 0;
+    rtc::CritScope lock(&crit_);
+    return FakeEncoder::SetRates(
+        std::min<uint32_t>(new_target_bitrate, kActualEncodeBitrateBps / 1000),
+        framerate);
+  }
+
+  int32_t Encode(const VideoFrame& input_image,
+                 const CodecSpecificInfo* codec_specific_info,
+                 const std::vector<FrameType>* frame_types) override {
+    int32_t res =
+        FakeEncoder::Encode(input_image, codec_specific_info, frame_types);
+    CheckDoneState();
+    return res;
+  }
+
+  void OnCallsCreated(Call* sender_call, Call* receiver_call) override {
+    call_ = sender_call;
+  }
+
+  void CheckDoneState() {
+    rtc::CritScope lock(&crit_);
+
+    if (in_init_phase_)
+      EXPECT_EQ(0, call_->GetStats().min_transmit_bitrate_bps);
+
+    // Wait until at least kMinFramesToSend frames have been encoded, so that
+    // we have reliable data.
+    if (++frames_sent_ < kMinFramesToSend)
+      return;
+
+    if (in_init_phase_) {
+      // We've sent kMinFramesToSend frames with default configuration, switch
+      // to enabling screen content and setting min transmit bitrate.
+      frames_sent_ = 0;
+      encoder_config_.min_transmit_bitrate_bps = kMinTransmitBitrateBps;
+      encoder_config_.content_type = VideoEncoderConfig::ContentType::kScreen;
+      send_stream_->ReconfigureVideoEncoder(encoder_config_);
+      in_init_phase_ = false;
+      return;
+    }
+
+    // Make sure the pacer has been configured with a min transmit bitrate.
+    if (call_->GetStats().min_transmit_bitrate_bps > 0)
+      observation_complete_.Set();
+  }
+
+  void PerformTest() override {
+    ASSERT_TRUE(Wait()) << "Timed out waiting for a valid padding bitrate.";
+  }
+
+ private:
+  rtc::CriticalSection crit_;
+  Call* call_;
+  VideoSendStream* send_stream_;
+  VideoEncoderConfig encoder_config_;
+  uint32_t frames_sent_ GUARDED_BY(crit_);
+  bool in_init_phase_;
+};
+
+TEST_F(EndToEndTest, RespectsMinTransmitBitrate) {
+  MinTransmitBitrateTest test(false);
+  RunBaseTest(&test);
+}
+
+TEST_F(EndToEndTest, RespectsMinTransmitBitrateAfterContentSwitch) {
+  MinTransmitBitrateTest test(true);
+  RunBaseTest(&test);
+}
+
 TEST_F(EndToEndTest, GetStats) {
   static const int kStartBitrateBps = 3000000;
   static const int kExpectedRenderDelayMs = 20;
 
   class ReceiveStreamRenderer : public rtc::VideoSinkInterface<VideoFrame> {
    public:
     ReceiveStreamRenderer() {}
 
    private:
     void OnFrame(const VideoFrame& video_frame) override {}
@@ skipping 1047 matching lines @@
    private:
     bool video_observed_;
     bool audio_observed_;
     SequenceNumberUnwrapper unwrapper_;
     std::set<int64_t> received_packet_ids_;
   } test;
 
   RunBaseTest(&test);
 }
 }  // namespace webrtc