Add -loop=N option to test ffmpeg ogv decoding on loop.

media/bench/bench.cc

 // Copyright (c) 2009 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.
 
 // Standalone benchmarking application based on FFmpeg.  This tool is used to
 // measure decoding performance between different FFmpeg compile and run-time
 // options.  We also use this tool to measure performance regressions when
 // testing newer builds of FFmpeg from trunk.
 
 #include "build/build_config.h"
@@ skipping 24 matching lines @@
 namespace switches {
 const wchar_t kStream[]                 = L"stream";
 const wchar_t kVideoThreads[]           = L"video-threads";
 const wchar_t kVerbose[]                = L"verbose";
 const wchar_t kFast2[]                  = L"fast2";
 const wchar_t kSkip[]                   = L"skip";
 const wchar_t kFlush[]                  = L"flush";
 const wchar_t kDjb2[]                   = L"djb2";
 const wchar_t kMd5[]                    = L"md5";
 const wchar_t kFrames[]                 = L"frames";
+const wchar_t kLoop[]                   = L"loop";
 
 }  // namespace switches
 
 namespace {
 // DJB2 hash
 unsigned int DJB2Hash(const uint8* s,
                       size_t len, unsigned int hash) {
   if (len > 0) {
     do {
       hash = hash * 33 + *s++;
@@ skipping 42 matching lines @@
   if (filenames.empty()) {
     std::cerr << "Usage: media_bench [OPTIONS] FILE [DUMPFILE]\n"
               << "  --stream=[audio|video]          "
               << "Benchmark either the audio or video stream\n"
               << "  --video-threads=N               "
               << "Decode video using N threads\n"
               << "  --verbose=N                     "
               << "Set FFmpeg log verbosity (-8 to 48)\n"
               << "  --frames=N                      "
               << "Decode N frames\n"
+              << "  --loop=N                        "
+              << "Loop N times\n"
               << "  --fast2                         "
               << "Enable fast2 flag\n"
               << "  --flush                         "
               << "Flush last frame\n"
               << "  --djb2                          "
               << "Hash decoded buffers (DJB2)\n"
               << "  --md5                           "
               << "Hash decoded buffers (MD5)\n"
               << "  --skip=[1|2|3]                  "
               << "1=loop nonref, 2=loop, 3= frame nonref\n" << std::endl;
@@ skipping 46 matching lines @@
   }
 
   // Determine number of frames to decode (optional).
   int max_frames = 0;
   std::wstring frames_opt(cmd_line->GetSwitchValue(switches::kFrames));
   if (!frames_opt.empty() &&
       !StringToInt(WideToUTF16Hack(frames_opt), &max_frames)) {
     max_frames = 0;
   }
 
+  // Determine number of times to loop (optional).
+  int max_loops = 0;
+  std::wstring loop_opt(cmd_line->GetSwitchValue(switches::kLoop));
+  if (!loop_opt.empty() &&
+      !StringToInt(WideToUTF16Hack(loop_opt), &max_loops)) {
+    max_loops = 0;
+  }
+
   bool fast2 = false;
   if (cmd_line->HasSwitch(switches::kFast2)) {
     fast2 = true;
   }
 
   bool flush = false;
   if (cmd_line->HasSwitch(switches::kFlush)) {
     flush = true;
   }
 
@@ skipping 151 matching lines @@
   std::vector<double> decode_times;
   decode_times.reserve(4096);
   // Parse through the entire stream until we hit EOF.
   base::TimeTicks start = base::TimeTicks::HighResNow();
   int frames = 0;
   int read_result = 0;
   do {
     read_result = av_read_frame(format_context, &packet);
 
     if (read_result < 0) {
+      if (max_loops) {
+        --max_loops;
+      }
+      if (max_loops > 0) {
+        av_seek_frame(format_context, -1, 0, AVSEEK_FLAG_BACKWARD);
+        read_result = 0;
+        continue;
+      }
       if (flush) {
         packet.stream_index = target_stream;
         packet.size = 0;
       } else {
         break;
       }
     }
 
     // Only decode packets from our target stream.
     if (packet.stream_index == target_stream) {
@@ skipping 105 matching lines @@
       }
     }
     // Free our packet.
     av_free_packet(&packet);
 
     if (max_frames && (frames >= max_frames))
       break;
   } while (read_result >= 0);
   base::TimeDelta total = base::TimeTicks::HighResNow() - start;
   LeaveTimingSection();
+
   if (output)
     file_util::CloseFile(output);
 
   // Calculate the sum of times.  Note that some of these may be zero.
   double sum = 0;
   for (size_t i = 0; i < decode_times.size(); ++i) {
     sum += decode_times[i];
   }
 
   // Print our results.
@@ skipping 40 matching lines @@
   }
 #if defined(OS_WIN)
   } __except(EXCEPTION_EXECUTE_HANDLER) {
     *log_out << "  Exception:" << std::setw(11) << GetExceptionCode()
              << " " << in_path << std::endl;
     return 1;
   }
 #endif
   return 0;
 }