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/*
* Copyright 2025 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.
*/
#include "video/corruption_detection/evaluation/utils.h"
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <string>
#include "absl/strings/string_view.h"
#include "api/array_view.h"
#include "rtc_base/checks.h"
#include "rtc_base/strings/string_builder.h"
#include "rtc_base/system/file_wrapper.h"
#include "test/testsupport/file_utils.h"
namespace webrtc {
namespace {
constexpr char kFrameHeader[] = "FRAME\n";
// Reading 30 bytes from the Y4M header should be enough to get the resolution
// and framerate. The header starts with: `YUV4MPEG2 W<WIDTH> H<HEIGTH>
// Fn<NUMERATOR>:Fd<DENOMINATOR>`.
constexpr int kHeaderBytesToRead = 30;
} // namespace
TempY4mFileCreator::TempY4mFileCreator(int width, int height, int framerate)
: width_(width),
height_(height),
framerate_(framerate),
frame_size_(width * height * 3 / 2),
y4m_filepath_(test::TempFilename(test::OutputPath(), "temp_video")) {
// A file with the given name path should just have been created.
RTC_CHECK_EQ(test::GetFileSize(y4m_filepath_), 0);
}
TempY4mFileCreator::~TempY4mFileCreator() {
RTC_CHECK(test::RemoveFile(y4m_filepath_.c_str()));
}
void TempY4mFileCreator::CreateTempY4mFile(
ArrayView<const uint8_t> file_content) {
RTC_CHECK_EQ(file_content.size() % frame_size_, 0)
<< "Content size is not a multiple of frame size. Probably some data is "
"missing.";
FileWrapper video_file = FileWrapper::OpenWriteOnly(y4m_filepath_);
RTC_CHECK(video_file.is_open());
WriteFileHeader(video_file);
// Write frame content.
int frame_number = file_content.size() / frame_size_;
for (int frame_index = 0; frame_index < frame_number; ++frame_index) {
RTC_CHECK(video_file.Write(kFrameHeader, sizeof(kFrameHeader) - 1));
RTC_CHECK_LT(frame_size_ * frame_index, file_content.size());
RTC_CHECK(video_file.Write(file_content.data() + frame_size_ * frame_index,
frame_size_));
}
RTC_CHECK(video_file.Flush());
}
void TempY4mFileCreator::WriteFileHeader(FileWrapper& video_file) const {
StringBuilder frame_header;
frame_header << "YUV4MPEG2 W" << width_ << " H" << height_ << " F"
<< framerate_ << ":1 C420\n";
RTC_CHECK(video_file.Write(frame_header.str().c_str(), frame_header.size()));
}
Y4mMetadata ReadMetadataFromY4mHeader(absl::string_view clip_path) {
FILE* file = fopen(std::string(clip_path).c_str(), "r");
RTC_CHECK(file) << "Could not open " << clip_path;
char header[kHeaderBytesToRead];
RTC_CHECK(fgets(header, sizeof(header), file) != nullptr)
<< "File " << clip_path << " is too small";
fclose(file);
int fps_numerator;
int fps_denominator;
int width;
int height;
RTC_CHECK_EQ(sscanf(header, "YUV4MPEG2 W%u H%u F%i:%i", &width, &height,
&fps_numerator, &fps_denominator),
4);
RTC_CHECK_NE(fps_denominator, 0);
return {.width = width,
.height = height,
.framerate = fps_numerator / fps_denominator};
}
} // namespace webrtc