Revert of Periodically update codec bit/frame rate settings.

webrtc/test/fake_encoder.cc

Index: webrtc/test/fake_encoder.cc
diff --git a/webrtc/test/fake_encoder.cc b/webrtc/test/fake_encoder.cc
index 962cd657a11df2a01c6191ce1e547fb5add45f36..fce12c61a804c8af841435b001779374b912066c 100644
--- a/webrtc/test/fake_encoder.cc
+++ b/webrtc/test/fake_encoder.cc
@@ -24,15 +24,11 @@
 namespace webrtc {
 namespace test {
 
-const int kKeyframeSizeFactor = 10;
-
 FakeEncoder::FakeEncoder(Clock* clock)
     : clock_(clock),
       callback_(nullptr),
-      configured_input_framerate_(-1),
       max_target_bitrate_kbps_(-1),
-      pending_keyframe_(true),
-      debt_bytes_(0) {
+      last_encode_time_ms_(0) {
   // Generate some arbitrary not-all-zero data
   for (size_t i = 0; i < sizeof(encoded_buffer_); ++i) {
     encoded_buffer_[i] = static_cast<uint8_t>(i);
@@ -51,8 +47,6 @@
   rtc::CritScope cs(&crit_sect_);
   config_ = *config;
   target_bitrate_.SetBitrate(0, 0, config_.startBitrate * 1000);
-  configured_input_framerate_ = config_.maxFramerate;
-  pending_keyframe_ = true;
   return 0;
 }
 
@@ -65,10 +59,9 @@
   EncodedImageCallback* callback;
   uint32_t target_bitrate_sum_kbps;
   int max_target_bitrate_kbps;
+  int64_t last_encode_time_ms;
   size_t num_encoded_bytes;
-  int framerate;
   VideoCodecMode mode;
-  bool keyframe;
   {
     rtc::CritScope cs(&crit_sect_);
     max_framerate = config_.maxFramerate;
@@ -79,33 +72,42 @@
     callback = callback_;
     target_bitrate_sum_kbps = target_bitrate_.get_sum_kbps();
     max_target_bitrate_kbps = max_target_bitrate_kbps_;
+    last_encode_time_ms = last_encode_time_ms_;
     num_encoded_bytes = sizeof(encoded_buffer_);
     mode = config_.mode;
-    if (configured_input_framerate_ > 0) {
-      framerate = configured_input_framerate_;
-    } else {
-      framerate = max_framerate;
-    }
-    keyframe = pending_keyframe_;
-    pending_keyframe_ = false;
-  }
-
-  for (FrameType frame_type : *frame_types) {
-    if (frame_type == kVideoFrameKey) {
-      keyframe = true;
-      break;
-    }
-  }
-
+  }
+
+  int64_t time_now_ms = clock_->TimeInMilliseconds();
+  const bool first_encode = (last_encode_time_ms == 0);
   RTC_DCHECK_GT(max_framerate, 0);
-
-  size_t bitrate = target_bitrate_sum_kbps;
-  bitrate =
-      std::max(bitrate, static_cast<size_t>(simulcast_streams[0].minBitrate));
-  if (max_target_bitrate_kbps > 0)
-    bitrate = std::min(bitrate, static_cast<size_t>(max_target_bitrate_kbps));
-
-  size_t bits_available = target_bitrate_sum_kbps * 1000 / framerate;
+  int64_t time_since_last_encode_ms = 1000 / max_framerate;
+  if (!first_encode) {
+    // For all frames but the first we can estimate the display time by looking
+    // at the display time of the previous frame.
+    time_since_last_encode_ms = time_now_ms - last_encode_time_ms;
+  }
+  if (time_since_last_encode_ms > 3 * 1000 / max_framerate) {
+    // Rudimentary check to make sure we don't widely overshoot bitrate target
+    // when resuming encoding after a suspension.
+    time_since_last_encode_ms = 3 * 1000 / max_framerate;
+  }
+
+  size_t bits_available =
+      static_cast<size_t>(target_bitrate_sum_kbps * time_since_last_encode_ms);
+  size_t min_bits = static_cast<size_t>(simulcast_streams[0].minBitrate *
+                                        time_since_last_encode_ms);
+
+  if (bits_available < min_bits)
+    bits_available = min_bits;
+  size_t max_bits =
+      static_cast<size_t>(max_target_bitrate_kbps * time_since_last_encode_ms);
+  if (max_bits > 0 && max_bits < bits_available)
+    bits_available = max_bits;
+
+  {
+    rtc::CritScope cs(&crit_sect_);
+    last_encode_time_ms_ = time_now_ms;
+  }
 
   RTC_DCHECK_GT(num_simulcast_streams, 0);
   for (unsigned char i = 0; i < num_simulcast_streams; ++i) {
@@ -114,27 +116,18 @@
     specifics.codecType = kVideoCodecGeneric;
     specifics.codecSpecific.generic.simulcast_idx = i;
     size_t min_stream_bits = static_cast<size_t>(
-        (simulcast_streams[i].minBitrate * 1000) / framerate);
+        simulcast_streams[i].minBitrate * time_since_last_encode_ms);
     size_t max_stream_bits = static_cast<size_t>(
-        (simulcast_streams[i].maxBitrate * 1000) / framerate);
+        simulcast_streams[i].maxBitrate * time_since_last_encode_ms);
     size_t stream_bits = (bits_available > max_stream_bits) ? max_stream_bits :
         bits_available;
     size_t stream_bytes = (stream_bits + 7) / 8;
-    if (keyframe) {
+    if (first_encode) {
       // The first frame is a key frame and should be larger.
-      // Store the overshoot bytes and distribute them over the coming frames,
-      // so that we on average meet the bitrate target.
-      debt_bytes_ += (kKeyframeSizeFactor - 1) * stream_bytes;
-      stream_bytes *= kKeyframeSizeFactor;
-    } else {
-      if (debt_bytes_ > 0) {
-        // Pay at most half of the frame size for old debts.
-        size_t payment_size = std::min(stream_bytes / 2, debt_bytes_);
-        debt_bytes_ -= payment_size;
-        stream_bytes -= payment_size;
-      }
+      // TODO(holmer): The FakeEncoder should store the bits_available between
+      // encodes so that it can compensate for oversized frames.
+      stream_bytes *= 10;
     }
-
     if (stream_bytes > num_encoded_bytes)
       stream_bytes = num_encoded_bytes;
 
@@ -182,18 +175,12 @@
                                        uint32_t framerate) {
   rtc::CritScope cs(&crit_sect_);
   target_bitrate_ = rate_allocation;
-  configured_input_framerate_ = framerate;
   return 0;
 }
 
 const char* FakeEncoder::kImplementationName = "fake_encoder";
 const char* FakeEncoder::ImplementationName() const {
   return kImplementationName;
-}
-
-int FakeEncoder::GetConfiguredInputFramerate() const {
-  rtc::CritScope cs(&crit_sect_);
-  return configured_input_framerate_;
 }
 
 FakeH264Encoder::FakeH264Encoder(Clock* clock)