From 4f3cc6efbe3c6959edb864561d2b70815708c49a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Erik=20Spr=C3=A5ng?= <sprang@webrtc.org>
Date: Tue, 6 Nov 2018 12:17:32 +0100
Subject: [PATCH] Make VideoSendStreamTest.NoPaddingWhenVideoIsMuted less flaky
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Make sure padding is sent by setting min transmit bitrate.
After camera has been restarted, stop camera again and make sure padding
is still produced. This avoids hoping for padding to be produced based
on assumptions of how padding allocation works with simulcast.

Bug: webrtc:9968
Change-Id: I7984abed4d04b35d3885f7edd62ca82f28bdcdb7
Reviewed-on: https://webrtc-review.googlesource.com/c/109564
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25520}
---
 video/video_send_stream_tests.cc | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/video/video_send_stream_tests.cc b/video/video_send_stream_tests.cc
index a7edaea6ab..590d58691f 100644
--- a/video/video_send_stream_tests.cc
+++ b/video/video_send_stream_tests.cc
@@ -1382,12 +1382,20 @@ TEST_P(VideoSendStreamTest, NoPaddingWhenVideoIsMuted) {
           header.headerLength + header.paddingLength == length;
 
       if (test_state_ == kBeforeStopCapture) {
+        // Packets are flowing, stop camera.
         capturer_->Stop();
         test_state_ = kWaitingForPadding;
       } else if (test_state_ == kWaitingForPadding && only_padding) {
+        // We're still getting padding, after stopping camera.
         test_state_ = kWaitingForNoPackets;
-      } else if (test_state_ == kWaitingForPaddingAfterCameraRestart &&
+      } else if (test_state_ == kWaitingForMediaAfterCameraRestart &&
+                 !only_padding) {
+        // Media packets are flowing again, stop camera a second time.
+        capturer_->Stop();
+        test_state_ = kWaitingForPaddingAfterCameraStopsAgain;
+      } else if (test_state_ == kWaitingForPaddingAfterCameraStopsAgain &&
                  only_padding) {
+        // Padding is still flowing, test ok.
         observation_complete_.Set();
       }
       return SEND_PACKET;
@@ -1400,13 +1408,20 @@ TEST_P(VideoSendStreamTest, NoPaddingWhenVideoIsMuted) {
           (last_packet_time_ms_ > 0 &&
            clock_->TimeInMilliseconds() - last_packet_time_ms_ >
                kNoPacketsThresholdMs)) {
+        // No packets seen for |kNoPacketsThresholdMs|, restart camera.
         capturer_->Start();
-        test_state_ = kWaitingForPaddingAfterCameraRestart;
+        test_state_ = kWaitingForMediaAfterCameraRestart;
       }
       return SEND_PACKET;
     }
 
-    size_t GetNumVideoStreams() const override { return 3; }
+    void ModifyVideoConfigs(
+        VideoSendStream::Config* send_config,
+        std::vector<VideoReceiveStream::Config>* receive_configs,
+        VideoEncoderConfig* encoder_config) override {
+      // Make sure padding is sent if encoder is not producing media.
+      encoder_config->min_transmit_bitrate_bps = 50000;
+    }
 
     void OnFrameGeneratorCapturerCreated(
         test::FrameGeneratorCapturer* frame_generator_capturer) override {
@@ -1423,7 +1438,8 @@ TEST_P(VideoSendStreamTest, NoPaddingWhenVideoIsMuted) {
       kBeforeStopCapture,
       kWaitingForPadding,
       kWaitingForNoPackets,
-      kWaitingForPaddingAfterCameraRestart
+      kWaitingForMediaAfterCameraRestart,
+      kWaitingForPaddingAfterCameraStopsAgain
     };
 
     TestState test_state_ = kBeforeStopCapture;