vea_unittest: Calculate per-frame encode latency

content/common/gpu/media/video_encode_accelerator_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <algorithm>
+
 #include "base/at_exit.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/files/memory_mapped_file.h"
 #include "base/memory/scoped_vector.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/process/process_handle.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
@@ skipping 546 matching lines @@
             unsigned int keyframe_period,
             bool force_bitrate,
             bool test_perf,
             bool mid_stream_bitrate_switch,
             bool mid_stream_framerate_switch,
             bool run_at_fps);
   ~VEAClient() override;
   void CreateEncoder();
   void DestroyEncoder();
 
-  // Return the number of encoded frames per second.
+  // Returns the number of encoded frames per second.
   double frames_per_second();
 
+  // Returns the median encode delay for all the encoded frames.
+  base::TimeDelta median_encode_latency();
+
   // VideoDecodeAccelerator::Client implementation.
   void RequireBitstreamBuffers(unsigned int input_count,
                                const gfx::Size& input_coded_size,
                                size_t output_buffer_size) override;
   void BitstreamBufferReady(int32 bitstream_buffer_id,
                             size_t payload_size,
                             bool key_frame) override;
   void NotifyError(VideoEncodeAccelerator::Error error) override;
 
  private:
@@ skipping 31 matching lines @@
   // Test codec performance, failing the test if we are currently running
   // the performance test.
   void VerifyPerf();
 
   // Write IVF file header to test_stream_->out_filename.
   void WriteIvfFileHeader();
 
   // Write an IVF frame header to test_stream_->out_filename.
   void WriteIvfFrameHeader(int frame_index, size_t frame_size);
 
-  // Prepare and return a frame wrapping the data at |position| bytes in
-  // the input stream, ready to be sent to encoder.
-  scoped_refptr<media::VideoFrame> PrepareInputFrame(off_t position);
+  // Prepare and return a frame wrapping the data at |position| bytes in the
+  // input stream, ready to be sent to encoder. Returns a pair of video frame
+  // and the input frame id.
+  std::pair<scoped_refptr<media::VideoFrame>, int32> PrepareInputFrame(
+      off_t position);
 
   // Update the parameters according to |mid_stream_bitrate_switch| and
   // |mid_stream_framerate_switch|.
   void UpdateTestStreamData(bool mid_stream_bitrate_switch,
                             bool mid_stream_framerate_switch);
 
   // Callback function of the |input_timer_|.
   void OnInputTimer();
 
   ClientState state_;
   scoped_ptr<VideoEncodeAccelerator> encoder_;
 
   TestStream* test_stream_;
 
   // Used to notify another thread about the state. VEAClient does not own this.
   ClientStateNotification<ClientState>* note_;
 
-  // Ids assigned to VideoFrames (start at 1 for easy comparison with
-  // num_encoded_frames_).

[Justin Chuang, 2015/04/30 10:36:56]

The original comments is wrong. So remove it. (It actually starts at 0)

+  // Ids assigned to VideoFrames.
   std::set<int32> inputs_at_client_;
   int32 next_input_id_;
 
+  typedef std::map<int32, base::TimeTicks> IdToTicks;
+  // A map from input frame id to the encode start time of the frame.
+  IdToTicks encode_start_time_per_frame_;
+  // The encode latencies of all encoded frames.
+  std::vector<base::TimeDelta> encode_latencies_;
+
   // Ids for output BitstreamBuffers.
   typedef std::map<int32, base::SharedMemory*> IdToSHM;
   ScopedVector<base::SharedMemory> output_shms_;
   IdToSHM output_buffers_at_client_;
   int32 next_output_buffer_id_;
 
   // Current offset into input stream.
   off_t pos_in_input_stream_;
   gfx::Size input_coded_size_;
   // Requested by encoder.
@@ skipping 248 matching lines @@
   }
   if (requested_subsequent_framerate_ == 0)
     requested_subsequent_framerate_ = 1;
 }
 
 double VEAClient::frames_per_second() {
   base::TimeDelta duration = last_frame_ready_time_ - encode_start_time_;
   return num_encoded_frames_ / duration.InSecondsF();
 }
 
+base::TimeDelta VEAClient::median_encode_latency() {
+  if (encode_latencies_.size() == 0)
+    return base::TimeDelta();
+  std::sort(encode_latencies_.begin(), encode_latencies_.end());
+  int index = encode_latencies_.size() / 2;
+  if (encode_latencies_.size() % 2 != 0)
+    return encode_latencies_[index];
+  return (encode_latencies_[index] + encode_latencies_[index - 1]) / 2;
+}
+
 void VEAClient::RequireBitstreamBuffers(unsigned int input_count,
                                         const gfx::Size& input_coded_size,
                                         size_t output_size) {
   DCHECK(thread_checker_.CalledOnValidThread());
   ASSERT_EQ(state_, CS_INITIALIZED);
   SetState(CS_ENCODING);
 
   CreateAlignedInputStreamFile(input_coded_size, test_stream_);
 
   num_frames_to_encode_ = test_stream_->num_frames;
@@ skipping 103 matching lines @@
 }
 
 void VEAClient::InputNoLongerNeededCallback(int32 input_id) {
   std::set<int32>::iterator it = inputs_at_client_.find(input_id);
   ASSERT_NE(it, inputs_at_client_.end());
   inputs_at_client_.erase(it);
   if (!run_at_fps_)
     FeedEncoderWithOneInput();
 }
 
-scoped_refptr<media::VideoFrame> VEAClient::PrepareInputFrame(off_t position) {
+std::pair<scoped_refptr<media::VideoFrame>, int32> VEAClient::PrepareInputFrame(
+    off_t position) {
   CHECK_LE(position + test_stream_->aligned_buffer_size,
            test_stream_->mapped_aligned_in_file.length());
 
   uint8* frame_data_y = const_cast<uint8*>(
       test_stream_->mapped_aligned_in_file.data() + position);
   uint8* frame_data_u = frame_data_y + test_stream_->aligned_plane_size[0];
   uint8* frame_data_v = frame_data_u + test_stream_->aligned_plane_size[1];
 
   CHECK_GT(current_framerate_, 0U);
   scoped_refptr<media::VideoFrame> frame =
@@ skipping 10 matching lines @@
           frame_data_v,
           base::TimeDelta().FromMilliseconds(
               next_input_id_ * base::Time::kMillisecondsPerSecond /
               current_framerate_),
           media::BindToCurrentLoop(
               base::Bind(&VEAClient::InputNoLongerNeededCallback,
                          base::Unretained(this),
                          next_input_id_)));
 
   CHECK(inputs_at_client_.insert(next_input_id_).second);
-  ++next_input_id_;
 
-  return frame;
+  return std::make_pair(frame, next_input_id_++);
 }
 
 void VEAClient::OnInputTimer() {
   if (!has_encoder() || state_ != CS_ENCODING)
     input_timer_.reset();
   else if (inputs_at_client_.size() <
            num_required_input_buffers_ + kNumExtraInputFrames)
     FeedEncoderWithOneInput();
   else
     DVLOG(1) << "Dropping input frame";
@@ skipping 13 matching lines @@
     // we require for bitrate tests.
     pos_in_input_stream_ = 0;
   }
 
   bool force_keyframe = false;
   if (keyframe_period_ && next_input_id_ % keyframe_period_ == 0) {
     force_keyframe = true;
     ++num_keyframes_requested_;
   }
 
-  scoped_refptr<media::VideoFrame> video_frame =
-      PrepareInputFrame(pos_in_input_stream_);
+  auto ret = PrepareInputFrame(pos_in_input_stream_);
   pos_in_input_stream_ += test_stream_->aligned_buffer_size;
 
-  encoder_->Encode(video_frame, force_keyframe);
+  CHECK(encode_start_time_per_frame_.insert(
+      std::make_pair(ret.second, base::TimeTicks::Now())).second);
+  encoder_->Encode(ret.first, force_keyframe);
 }
 
 void VEAClient::FeedEncoderWithOutput(base::SharedMemory* shm) {
   if (!has_encoder())
     return;
 
   if (state_ != CS_ENCODING)
     return;
 
   base::SharedMemoryHandle dup_handle;
   CHECK(shm->ShareToProcess(base::GetCurrentProcessHandle(), &dup_handle));
 
   media::BitstreamBuffer bitstream_buffer(
       next_output_buffer_id_++, dup_handle, output_buffer_size_);
   CHECK(output_buffers_at_client_.insert(std::make_pair(bitstream_buffer.id(),
                                                         shm)).second);
   encoder_->UseOutputBitstreamBuffer(bitstream_buffer);
 }
 
 bool VEAClient::HandleEncodedFrame(bool keyframe) {
   // This would be a bug in the test, which should not ignore false
   // return value from this method.
   CHECK_LE(num_encoded_frames_, num_frames_to_encode_);
 
+  last_frame_ready_time_ = base::TimeTicks::Now();
+
+  // Record encode latency of this frame.
+  IdToTicks::iterator it =
+      encode_start_time_per_frame_.find(num_encoded_frames_);
+  CHECK_NE(it, encode_start_time_per_frame_.end());
+  encode_latencies_.push_back(last_frame_ready_time_ - it->second);
+  encode_start_time_per_frame_.erase(it);
+
   ++num_encoded_frames_;
   ++num_frames_since_last_check_;
 
-  last_frame_ready_time_ = base::TimeTicks::Now();
-
   // Because the keyframe behavior requirements are loose, we give
   // the encoder more freedom here. It could either deliver a keyframe
   // immediately after we requested it, which could be for a frame number
   // before the one we requested it for (if the keyframe request
   // is asynchronous, i.e. not bound to any concrete frame, and because
   // the pipeline can be deeper than one frame), at that frame, or after.
   // So the only constraints we put here is that we get a keyframe not
   // earlier than we requested one (in time), and not later than
   // kMaxKeyframeDelay frames after the frame, for which we requested
   // it, comes back encoded.
@@ skipping 30 matching lines @@
   return true;
 }
 
 void VEAClient::VerifyPerf() {
   double measured_fps = frames_per_second();
   LOG(INFO) << "Measured encoder FPS: " << measured_fps;
   g_env->LogToFile("Measured encoder FPS",
                    base::StringPrintf("%.3f", measured_fps));
   if (test_perf_)
     EXPECT_GE(measured_fps, kMinPerfFPS);
+
+  base::TimeDelta median_latency = median_encode_latency();
+  LOG(INFO) << "Median encode latency: " << median_latency.InMicroseconds()
+            << " us";
+  g_env->LogToFile(
+      "Median encode latency",
+      base::StringPrintf("%" PRId64 " us", median_latency.InMicroseconds()));
 }
 
 void VEAClient::VerifyStreamProperties() {
   CHECK_GT(num_frames_since_last_check_, 0UL);
   CHECK_GT(encoded_stream_size_since_last_check_, 0UL);
   unsigned int bitrate = encoded_stream_size_since_last_check_ * 8 *
                          current_framerate_ / num_frames_since_last_check_;
   DVLOG(1) << "Current chunk's bitrate: " << bitrate
            << " (expected: " << current_requested_bitrate_
            << " @ " << current_framerate_ << " FPS,"
@@ skipping 239 matching lines @@
   }
 
   content::g_env =
       reinterpret_cast<content::VideoEncodeAcceleratorTestEnvironment*>(
           testing::AddGlobalTestEnvironment(
               new content::VideoEncodeAcceleratorTestEnvironment(
                   test_stream_data.Pass(), log_path, run_at_fps)));
 
   return RUN_ALL_TESTS();
 }