Revert of Bug in ExtractFrame API (extracts frames incorrectly) (patchset #9 id:130001 of https://codereview.webrtc.org/2529923002/ )

Reason for revert:
Breaking some trybots due to memory error.

Original issue's description:
> Fixed bug in ExtractFrameFromY4mFile API which was not extracting the frames correctly.
>
> Issue: This API was calculating the file_header and frame_header offset only for the first frame which is not the right logic. We need to skip the file and frame header every time we extract a new frame.
>
> Also added a unit test case which compares the extracted frame with the frame stored in text file.
>
> BUG=webrtc:6761
>
> NOPRESUBMIT=true
> NOTRY=true
>
> Committed: https://crrev.com/b7636b4656d7f8c368963f2256dc2ef7b7ba89c8
> Cr-Commit-Position: refs/heads/master@{#15260}

TBR=phoglund@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6761

Review-Url: https://codereview.webrtc.org/2535783002
Cr-Commit-Position: refs/heads/master@{#15262}

resources/reference_less_video_test_file.y4m.sha1

@@ -1 +0,0 @@
-5a1620516daf59870158a66230d7bafd9fe9afa1

resources/video_quality_analysis_frame.txt.sha1

@@ -1 +0,0 @@
-4d1ac894f1743af8059e8d8ae2465f6eaa1790b0

webrtc/tools/BUILD.gn

@@ -234,11 +234,7 @@ if (rtc_include_tests) {
     ]
   }
 
-  tools_unittests_resources = [
-    "//resources/foreman_cif.yuv",
-    "//resources/reference_less_video_test_file.y4m",
-    "//resources/video_quality_analysis_frame.txt",
-  ]
+  tools_unittests_resources = [ "//resources/foreman_cif.yuv" ]
 
   if (is_ios) {
     bundle_data("tools_unittests_bundle_data") {

webrtc/tools/frame_analyzer/video_quality_analysis.cc

@@ -13,6 +13,7 @@
 #include <assert.h>
 #include <stdio.h>
 #include <stdlib.h>
+
 #include <string>
 
 #define STATS_LINE_LENGTH 32
@@ -125,8 +126,8 @@ bool ExtractFrameFromY4mFile(const char* y4m_file_name,
                              int frame_number,
                              uint8_t* result_frame) {
   int frame_size = GetI420FrameSize(width, height);
-  int inital_offset = frame_number * (frame_size + Y4M_FRAME_HEADER_SIZE);
-  int frame_offset = 0;
+  int frame_offset = frame_number * frame_size;
+  bool errors = false;
 
   FILE* input_file = fopen(y4m_file_name, "rb");
   if (input_file == NULL) {
@@ -137,11 +138,13 @@ bool ExtractFrameFromY4mFile(const char* y4m_file_name,
 
   // YUV4MPEG2, a.k.a. Y4M File format has a file header and a frame header. The
   // file header has the aspect: "YUV4MPEG2 C420 W640 H360 Ip F30:1 A1:1".
+  // Skip the header if this is the first frame of the file.
+  if (frame_number == 0) {
     char frame_header[Y4M_FILE_HEADER_MAX_SIZE];
     size_t bytes_read =
         fread(frame_header, 1, Y4M_FILE_HEADER_MAX_SIZE, input_file);
     if (bytes_read != static_cast<size_t>(frame_size) && ferror(input_file)) {
-    fprintf(stdout, "Error while reading frame from file %s\n",
+      fprintf(stdout, "Error while reading first frame from file %s\n",
           y4m_file_name);
       fclose(input_file);
       return false;
@@ -155,25 +158,21 @@ bool ExtractFrameFromY4mFile(const char* y4m_file_name,
       return false;
     }
     frame_offset = static_cast<int>(found);
+  }
 
   // Change stream pointer to new offset, skipping the frame header as well.
-  fseek(input_file, inital_offset + frame_offset + Y4M_FRAME_HEADER_SIZE,
-        SEEK_SET);
+  fseek(input_file, frame_offset + Y4M_FRAME_HEADER_SIZE, SEEK_SET);
 
-  bytes_read = fread(result_frame, 1, frame_size, input_file);
-  if (feof(input_file)) {
-    fclose(input_file);
-    return false;
-  }
-  if (bytes_read != static_cast<size_t>(frame_size) && ferror(input_file)) {
+  size_t bytes_read = fread(result_frame, 1, frame_size, input_file);
+  if (bytes_read != static_cast<size_t>(frame_size) &&
+      ferror(input_file)) {
     fprintf(stdout, "Error while reading frame no %d from file %s\n",
             frame_number, y4m_file_name);
-    fclose(input_file);
-    return false;
+    errors = true;
   }
 
   fclose(input_file);
-  return true;
+  return !errors;
 }
 
 double CalculateMetrics(VideoAnalysisMetricsType video_metrics_type,

webrtc/tools/frame_analyzer/video_quality_analysis_unittest.cc

@@ -11,7 +11,6 @@
 // This test doesn't actually verify the output since it's just printed
 // to stdout by void functions, but it's still useful as it executes the code.
 
-#include <stdio.h>
 #include <fstream>
 #include <string>
 
@@ -39,31 +38,6 @@ class VideoQualityAnalysisTest : public ::testing::Test {
 };
 FILE* VideoQualityAnalysisTest::logfile_ = NULL;
 
-TEST_F(VideoQualityAnalysisTest, MatchExtractedY4mFrame) {
-  std::string video_file =
-         webrtc::test::ResourcePath("reference_less_video_test_file", "y4m");
-
-  std::string extracted_frame_from_video_file =
-         webrtc::test::ResourcePath("video_quality_analysis_frame", "txt");
-
-  int frame_height = 720, frame_width = 1280;
-  int frame_number = 2;
-  int size = GetI420FrameSize(frame_width, frame_height);
-  uint8_t* result_frame = new uint8_t[size];
-  uint8_t* expected_frame = new uint8_t[size];
-
-  FILE* input_file = fopen(extracted_frame_from_video_file.c_str(), "rb");
-  fread(expected_frame, 1, size, input_file);
-
-  ExtractFrameFromY4mFile(video_file.c_str(),
-                          frame_width, frame_height,
-                          frame_number, result_frame);
-
-  EXPECT_EQ(*expected_frame, *result_frame);
-  delete[] result_frame;
-  delete[] expected_frame;
-}
-
 TEST_F(VideoQualityAnalysisTest, PrintAnalysisResultsEmpty) {
   ResultsContainer result;
   PrintAnalysisResults(logfile_, "Empty", &result);