Added tool for reference less video analysis

webrtc/tools/frame_analyzer/reference_less_video_analysis_lib.h

+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#ifndef WEBRTC_TOOLS_FRAME_ANALYZER_REFERENCE_LESS_VIDEO_ANALYSIS_LIB_H_
+#define WEBRTC_TOOLS_FRAME_ANALYZER_REFERENCE_LESS_VIDEO_ANALYSIS_LIB_H_
+
+#include <string>
+#include <vector>
+

[mandermo, 2017/02/07 14:57:50]

Using _ in function names is different from the other files in
webrtc/tools/frame_analyzer where CamelCase is used.

[kjellander_webrtc, 2017/02/08 09:11:31]

You're right, the style guide says CamelCase:
https://google.github.io/styleguide/cppguide.html#Function_Names
Charu, can you address in a follow-up CL?

+// Parse the file header to extract height, width and fps
+// for a given video file.
+void get_height_width_fps(int *height, int *width, int *fps,
+                          const std::string& video_file);
+
+// Returns true if the frame is frozen based on psnr and ssim freezing
+// threshold values.
+bool frozen_frame(std::vector<double> psnr_per_frame,
+                     std::vector<double> ssim_per_frame, size_t frame);
+
+// Returns the vector of identical cluster of frames that are frozen
+// and appears continuously.
+std::vector<int> find_frame_clusters(const std::vector<double>& psnr_per_frame,
+                                     const std::vector<double>& ssim_per_frame);
+
+// Prints various freezing metrics like identical frames,
+// total unique frames etc.
+void print_freezing_metrics(const std::vector<double>& psnr_per_frame,
+                            const std::vector<double>& ssim_per_frame);
+
+// Compute the metrics like freezing score based on PSNR and SSIM values for a
+// given video file.
+void compute_metrics(const std::string& video_file_name,
+                     std::vector<double>* psnr_per_frame,
+                     std::vector<double>* ssim_per_frame);
+
+// Checks the file extension and return true if it is y4m.
+bool check_file_extension(const std::string& video_file_name);
+
+// Compute freezing score metrics and prints the metrics
+// for a list of video files.
+int run_analysis(const std::string& video_file);

[mandermo, 2017/02/07 14:57:51]

Maybe it could be worth putting the functions in this header in a namespace.
Especially int run_analysis(const std::string&) is quite a general name and
could clash in the future if it is in the global namespace.

[kjellander_webrtc, 2017/02/08 09:11:32]

Yes, please use the webrtc::test namespace.

+
+#endif  // WEBRTC_TOOLS_FRAME_ANALYZER_REFERENCE_LESS_VIDEO_ANALYSIS_LIB_H_