Add a new frame generator that cycles through randomly generated slides.

webrtc/video/screenshare_loopback.cc

 /*
  *  Copyright (c) 2015 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.
  */
 
@@ skipping 200 matching lines @@
     "E.g. running with --force_fieldtrials=WebRTC-FooFeature/Enable/"
     " will assign the group Enable to field trial WebRTC-FooFeature. Multiple "
     "trials are separated by \"/\"");
 
 // Screenshare-specific flags.
 DEFINE_int(min_transmit_bitrate, 400, "Min transmit bitrate incl. padding.");
 int MinTransmitBitrateKbps() {
   return FLAG_min_transmit_bitrate;
 }
 
+DEFINE_bool(generate_slides,
+           false,
+           "Whether to use randomly generated slides or read them from files.");
+bool GenerateSlides() {
+  return static_cast<int>(FLAG_generate_slides);
+}
+
 DEFINE_int(slide_change_interval,
            10,
            "Interval (in seconds) between simulated slide changes.");
 int SlideChangeInterval() {
   return static_cast<int>(FLAG_slide_change_interval);
 }
 
 DEFINE_int(
     scroll_duration,
     0,
@@ skipping 40 matching lines @@
                   flags::TargetBitrateKbps() * 1000,
                   flags::MaxBitrateKbps() * 1000,
                   false,
                   flags::Codec(),
                   flags::NumTemporalLayers(),
                   flags::SelectedTL(),
                   flags::MinTransmitBitrateKbps() * 1000,
                   false,  // ULPFEC disabled.
                   false,  // FlexFEC disabled.
                   ""};
-  params.screenshare = {true, flags::SlideChangeInterval(),
+  params.screenshare = {true, flags::GenerateSlides(),
+                        flags::SlideChangeInterval(),
                         flags::ScrollDuration(), flags::Slides()};
   params.analyzer = {"screenshare", 0.0, 0.0, flags::DurationSecs(),
       flags::OutputFilename(), flags::GraphTitle()};
   params.pipe = pipe_config;
   params.logging = {flags::FLAG_logs, flags::RtcEventLogName(),
                     flags::RtpDumpName(), flags::EncodedFramePath()};
 
   if (flags::NumStreams() > 1 && flags::Stream0().empty() &&
       flags::Stream1().empty()) {
     params.ss.infer_streams = true;
@@ skipping 27 matching lines @@
   }
 
   // InitFieldTrialsFromString needs a reference to an std::string instance,
   // with a scope that outlives the test.
   std::string field_trials = webrtc::flags::FLAG_force_fieldtrials;
   webrtc::test::InitFieldTrialsFromString(field_trials);
 
   webrtc::test::RunTest(webrtc::Loopback);
   return 0;
 }