webrtc/modules/video_processing/test/video_processing_unittest.cc - src - Git at Google

 /*
  *  Copyright (c) 2012 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 "webrtc/modules/video_processing/test/video_processing_unittest.h"

 #include <gflags/gflags.h>

 #include <memory>
 #include <string>

 #include "webrtc/base/keep_ref_until_done.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
 #include "webrtc/test/testsupport/fileutils.h"

 namespace webrtc {

 namespace {

 // Define command line flag 'gen_files' (default value: false).
 DEFINE_bool(gen_files, false, "Output files for visual inspection.");

 }  // namespace

 static void PreprocessFrameAndVerify(const VideoFrame& source,
                                      int target_width,
                                      int target_height,
                                      VideoProcessing* vpm,
                                      const VideoFrame* out_frame);
 rtc::scoped_refptr<VideoFrameBuffer> CropBuffer(
     const rtc::scoped_refptr<VideoFrameBuffer>& source_buffer,
     int source_width,
     int source_height,
     int offset_x,
     int offset_y,
     int cropped_width,
     int cropped_height);
 // The |source_data| is cropped and scaled to |target_width| x |target_height|,
 // and then scaled back to the expected cropped size. |expected_psnr| is used to
 // verify basic quality, and is set to be ~0.1/0.05dB lower than actual PSNR
 // verified under the same conditions.
 static void TestSize(
     const VideoFrame& source_frame,
     const rtc::scoped_refptr<VideoFrameBuffer>& cropped_source_buffer,
     int target_width,
     int target_height,
     double expected_psnr,
     VideoProcessing* vpm);
 static void WriteProcessedFrameForVisualInspection(const VideoFrame& source,
                                                    const VideoFrame& processed);

 VideoProcessingTest::VideoProcessingTest()
     : vp_(NULL),
       source_file_(NULL),
       width_(352),
       half_width_((width_ + 1) / 2),
       height_(288),
       size_y_(width_ * height_),
       size_uv_(half_width_ * ((height_ + 1) / 2)),
       frame_length_(CalcBufferSize(kI420, width_, height_)) {}

 void VideoProcessingTest::SetUp() {
   vp_ = VideoProcessing::Create();
   ASSERT_TRUE(vp_ != NULL);

   const std::string video_file =
       webrtc::test::ResourcePath("foreman_cif", "yuv");
   source_file_ = fopen(video_file.c_str(), "rb");
   ASSERT_TRUE(source_file_ != NULL)
       << "Cannot read source file: " + video_file + "\n";
 }

 void VideoProcessingTest::TearDown() {
   if (source_file_ != NULL) {
     ASSERT_EQ(0, fclose(source_file_));
   }
   source_file_ = NULL;
   delete vp_;
   vp_ = NULL;
 }

 #if defined(WEBRTC_IOS)
 TEST_F(VideoProcessingTest, DISABLED_PreprocessorLogic) {
 #else
 TEST_F(VideoProcessingTest, PreprocessorLogic) {
 #endif
   // Disable temporal sampling (frame dropping).
   vp_->EnableTemporalDecimation(false);
   int resolution = 100;
   EXPECT_EQ(VPM_OK, vp_->SetTargetResolution(resolution, resolution, 15));
   EXPECT_EQ(VPM_OK, vp_->SetTargetResolution(resolution, resolution, 30));
   // Disable spatial sampling.
   vp_->SetInputFrameResampleMode(kNoRescaling);
   EXPECT_EQ(VPM_OK, vp_->SetTargetResolution(resolution, resolution, 30));
   VideoFrame* out_frame = NULL;
   // Set rescaling => output frame != NULL.
   vp_->SetInputFrameResampleMode(kFastRescaling);

   rtc::scoped_refptr<webrtc::I420Buffer> buffer =
       I420Buffer::Create(width_, height_, width_, half_width_, half_width_);

   // Clear video frame so DrMemory/Valgrind will allow reads of the buffer.
   buffer->InitializeData();
   VideoFrame video_frame(buffer, 0, 0, webrtc::kVideoRotation_0);

   PreprocessFrameAndVerify(video_frame, resolution, resolution, vp_, out_frame);
   // No rescaling=> output frame = NULL.
   vp_->SetInputFrameResampleMode(kNoRescaling);
   EXPECT_TRUE(vp_->PreprocessFrame(video_frame) != nullptr);
 }

 #if defined(WEBRTC_IOS)
 TEST_F(VideoProcessingTest, DISABLED_Resampler) {
 #else
 TEST_F(VideoProcessingTest, Resampler) {
 #endif
   enum { NumRuns = 1 };

   int64_t min_runtime = 0;
   int64_t total_runtime = 0;

   rewind(source_file_);
   ASSERT_TRUE(source_file_ != NULL) << "Cannot read input file \n";

   // no temporal decimation
   vp_->EnableTemporalDecimation(false);

   // Reading test frame
   rtc::scoped_refptr<webrtc::I420Buffer> buffer =
       I420Buffer::Create(width_, height_, width_, half_width_, half_width_);

   ASSERT_EQ(static_cast<size_t>(size_y_),
             fread(buffer->MutableDataY(), 1, size_y_, source_file_));
   ASSERT_EQ(static_cast<size_t>(size_uv_),
             fread(buffer->MutableDataU(), 1, size_uv_, source_file_));
   ASSERT_EQ(static_cast<size_t>(size_uv_),
             fread(buffer->MutableDataV(), 1, size_uv_, source_file_));

   for (uint32_t run_idx = 0; run_idx < NumRuns; run_idx++) {
     // Initiate test timer.
     const int64_t time_start = rtc::TimeNanos();

     // Init the sourceFrame with a timestamp.
     int64_t time_start_ms = time_start / rtc::kNumNanosecsPerMillisec;
     VideoFrame video_frame(buffer, time_start_ms * 90, time_start_ms,
                            webrtc::kVideoRotation_0);

     // Test scaling to different sizes: source is of |width|/|height| = 352/288.
     // Pure scaling:
     TestSize(video_frame, buffer, width_ / 4, height_ / 4, 25.2, vp_);
     TestSize(video_frame, buffer, width_ / 2, height_ / 2, 28.1, vp_);
     // No resampling:
     TestSize(video_frame, buffer, width_, height_, -1, vp_);
     TestSize(video_frame, buffer, 2 * width_, 2 * height_, 32.2, vp_);

     // Scaling and cropping. The cropped source frame is the largest center
     // aligned region that can be used from the source while preserving aspect
     // ratio.
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 56, 352, 176),
              100, 50, 24.0, vp_);
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 30, 352, 225),
              400, 256, 31.3, vp_);
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 68, 0, 216, 288),
              480, 640, 32.15, vp_);
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 12, 352, 264),
              960, 720, 32.2, vp_);
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 44, 352, 198),
              1280, 720, 32.15, vp_);

     // Upsampling to odd size.
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 26, 352, 233),
              501, 333, 32.05, vp_);
     // Downsample to odd size.
     TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 34, 352, 219),
              281, 175, 29.3, vp_);

     // Stop timer.
     const int64_t runtime =
         (rtc::TimeNanos() - time_start) / rtc::kNumNanosecsPerMicrosec;
     if (runtime < min_runtime || run_idx == 0) {
       min_runtime = runtime;
     }
     total_runtime += runtime;
   }

   printf("\nAverage run time = %d us / frame\n",
          static_cast<int>(total_runtime));
   printf("Min run time = %d us / frame\n\n", static_cast<int>(min_runtime));
 }

 void PreprocessFrameAndVerify(const VideoFrame& source,
                               int target_width,
                               int target_height,
                               VideoProcessing* vpm,
                               const VideoFrame* out_frame) {
   ASSERT_EQ(VPM_OK, vpm->SetTargetResolution(target_width, target_height, 30));
   out_frame = vpm->PreprocessFrame(source);
   EXPECT_TRUE(out_frame != nullptr);

   // If no resizing is needed, expect the original frame.
   if (target_width == source.width() && target_height == source.height()) {
     EXPECT_EQ(&source, out_frame);
     return;
   }

   // Verify the resampled frame.
   EXPECT_TRUE(out_frame != NULL);
   EXPECT_EQ(source.render_time_ms(), (out_frame)->render_time_ms());
   EXPECT_EQ(source.timestamp(), (out_frame)->timestamp());
   EXPECT_EQ(target_width, (out_frame)->width());
   EXPECT_EQ(target_height, (out_frame)->height());
 }

 rtc::scoped_refptr<VideoFrameBuffer> CropBuffer(
     const rtc::scoped_refptr<VideoFrameBuffer>& source_buffer,
     int source_width,
     int source_height,
     int offset_x,
     int offset_y,
     int cropped_width,
     int cropped_height) {
   // Force even.
   offset_x &= 1;
   offset_y &= 1;

   size_t y_start = offset_x + offset_y * source_buffer->StrideY();
   size_t u_start = (offset_x / 2) + (offset_y / 2) * source_buffer->StrideU();
   size_t v_start = (offset_x / 2) + (offset_y / 2) * source_buffer->StrideU();

   return rtc::scoped_refptr<VideoFrameBuffer>(
       new rtc::RefCountedObject<WrappedI420Buffer>(
           cropped_width, cropped_height, source_buffer->DataY() + y_start,
           source_buffer->StrideY(), source_buffer->DataU() + u_start,
           source_buffer->StrideU(), source_buffer->DataV() + v_start,
           source_buffer->StrideV(), rtc::KeepRefUntilDone(source_buffer)));
 }

 void TestSize(const VideoFrame& source_frame,
               const rtc::scoped_refptr<VideoFrameBuffer>& cropped_source_buffer,
               int target_width,
               int target_height,
               double expected_psnr,
               VideoProcessing* vpm) {
   // Resample source_frame to out_frame.
   VideoFrame* out_frame = NULL;
   vpm->SetInputFrameResampleMode(kBox);
   PreprocessFrameAndVerify(source_frame, target_width, target_height, vpm,
                            out_frame);
   if (out_frame == NULL)
     return;
   WriteProcessedFrameForVisualInspection(source_frame, *out_frame);

   // Scale |resampled_source_frame| back to the source scale.
   VideoFrame resampled_source_frame;
   resampled_source_frame.CopyFrame(*out_frame);
   PreprocessFrameAndVerify(resampled_source_frame,
                            cropped_source_buffer->width(),
                            cropped_source_buffer->height(), vpm, out_frame);
   WriteProcessedFrameForVisualInspection(resampled_source_frame, *out_frame);

   // Compute PSNR against the cropped source frame and check expectation.
   double psnr =
       I420PSNR(*cropped_source_buffer, *out_frame->video_frame_buffer());
   EXPECT_GT(psnr, expected_psnr);
   printf(
       "PSNR: %f. PSNR is between source of size %d %d, and a modified "
       "source which is scaled down/up to: %d %d, and back to source size \n",
       psnr, source_frame.width(), source_frame.height(), target_width,
       target_height);
 }

 void WriteProcessedFrameForVisualInspection(const VideoFrame& source,
                                             const VideoFrame& processed) {
   // Skip if writing to files is not enabled.
   if (!FLAGS_gen_files)
     return;
   // Write the processed frame to file for visual inspection.
   std::ostringstream filename;
   filename << webrtc::test::OutputPath() << "Resampler_from_" << source.width()
            << "x" << source.height() << "_to_" << processed.width() << "x"
            << processed.height() << "_30Hz_P420.yuv";
   std::cout << "Watch " << filename.str() << " and verify that it is okay."
             << std::endl;
   FILE* stand_alone_file = fopen(filename.str().c_str(), "wb");
   if (PrintVideoFrame(processed, stand_alone_file) < 0)
     std::cerr << "Failed to write: " << filename.str() << std::endl;
   if (stand_alone_file)
     fclose(stand_alone_file);
 }

 }  // namespace webrtc
	/*
	* Copyright (c) 2012 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 "webrtc/modules/video_processing/test/video_processing_unittest.h"

	#include <gflags/gflags.h>

	#include <memory>
	#include <string>

	#include "webrtc/base/keep_ref_until_done.h"
	#include "webrtc/base/timeutils.h"
	#include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
	#include "webrtc/test/testsupport/fileutils.h"

	namespace webrtc {

	namespace {

	// Define command line flag 'gen_files' (default value: false).
	DEFINE_bool(gen_files, false, "Output files for visual inspection.");

	} // namespace

	static void PreprocessFrameAndVerify(const VideoFrame& source,
	int target_width,
	int target_height,
	VideoProcessing* vpm,
	const VideoFrame* out_frame);
	rtc::scoped_refptr<VideoFrameBuffer> CropBuffer(
	const rtc::scoped_refptr<VideoFrameBuffer>& source_buffer,
	int source_width,
	int source_height,
	int offset_x,
	int offset_y,
	int cropped_width,
	int cropped_height);
	// The \|source_data\| is cropped and scaled to \|target_width\| x \|target_height\|,
	// and then scaled back to the expected cropped size. \|expected_psnr\| is used to
	// verify basic quality, and is set to be ~0.1/0.05dB lower than actual PSNR
	// verified under the same conditions.
	static void TestSize(
	const VideoFrame& source_frame,
	const rtc::scoped_refptr<VideoFrameBuffer>& cropped_source_buffer,
	int target_width,
	int target_height,
	double expected_psnr,
	VideoProcessing* vpm);
	static void WriteProcessedFrameForVisualInspection(const VideoFrame& source,
	const VideoFrame& processed);

	VideoProcessingTest::VideoProcessingTest()
	: vp_(NULL),
	source_file_(NULL),
	width_(352),
	half_width_((width_ + 1) / 2),
	height_(288),
	size_y_(width_ * height_),
	size_uv_(half_width_ * ((height_ + 1) / 2)),
	frame_length_(CalcBufferSize(kI420, width_, height_)) {}

	void VideoProcessingTest::SetUp() {
	vp_ = VideoProcessing::Create();
	ASSERT_TRUE(vp_ != NULL);

	const std::string video_file =
	webrtc::test::ResourcePath("foreman_cif", "yuv");
	source_file_ = fopen(video_file.c_str(), "rb");
	ASSERT_TRUE(source_file_ != NULL)
	<< "Cannot read source file: " + video_file + "\n";
	}

	void VideoProcessingTest::TearDown() {
	if (source_file_ != NULL) {
	ASSERT_EQ(0, fclose(source_file_));
	}
	source_file_ = NULL;
	delete vp_;
	vp_ = NULL;
	}

	#if defined(WEBRTC_IOS)
	TEST_F(VideoProcessingTest, DISABLED_PreprocessorLogic) {
	#else
	TEST_F(VideoProcessingTest, PreprocessorLogic) {
	#endif
	// Disable temporal sampling (frame dropping).
	vp_->EnableTemporalDecimation(false);
	int resolution = 100;
	EXPECT_EQ(VPM_OK, vp_->SetTargetResolution(resolution, resolution, 15));
	EXPECT_EQ(VPM_OK, vp_->SetTargetResolution(resolution, resolution, 30));
	// Disable spatial sampling.
	vp_->SetInputFrameResampleMode(kNoRescaling);
	EXPECT_EQ(VPM_OK, vp_->SetTargetResolution(resolution, resolution, 30));
	VideoFrame* out_frame = NULL;
	// Set rescaling => output frame != NULL.
	vp_->SetInputFrameResampleMode(kFastRescaling);

	rtc::scoped_refptr<webrtc::I420Buffer> buffer =
	I420Buffer::Create(width_, height_, width_, half_width_, half_width_);

	// Clear video frame so DrMemory/Valgrind will allow reads of the buffer.
	buffer->InitializeData();
	VideoFrame video_frame(buffer, 0, 0, webrtc::kVideoRotation_0);

	PreprocessFrameAndVerify(video_frame, resolution, resolution, vp_, out_frame);
	// No rescaling=> output frame = NULL.
	vp_->SetInputFrameResampleMode(kNoRescaling);
	EXPECT_TRUE(vp_->PreprocessFrame(video_frame) != nullptr);
	}

	#if defined(WEBRTC_IOS)
	TEST_F(VideoProcessingTest, DISABLED_Resampler) {
	#else
	TEST_F(VideoProcessingTest, Resampler) {
	#endif
	enum { NumRuns = 1 };

	int64_t min_runtime = 0;
	int64_t total_runtime = 0;

	rewind(source_file_);
	ASSERT_TRUE(source_file_ != NULL) << "Cannot read input file \n";

	// no temporal decimation
	vp_->EnableTemporalDecimation(false);

	// Reading test frame
	rtc::scoped_refptr<webrtc::I420Buffer> buffer =
	I420Buffer::Create(width_, height_, width_, half_width_, half_width_);

	ASSERT_EQ(static_cast<size_t>(size_y_),
	fread(buffer->MutableDataY(), 1, size_y_, source_file_));
	ASSERT_EQ(static_cast<size_t>(size_uv_),
	fread(buffer->MutableDataU(), 1, size_uv_, source_file_));
	ASSERT_EQ(static_cast<size_t>(size_uv_),
	fread(buffer->MutableDataV(), 1, size_uv_, source_file_));

	for (uint32_t run_idx = 0; run_idx < NumRuns; run_idx++) {
	// Initiate test timer.
	const int64_t time_start = rtc::TimeNanos();

	// Init the sourceFrame with a timestamp.
	int64_t time_start_ms = time_start / rtc::kNumNanosecsPerMillisec;
	VideoFrame video_frame(buffer, time_start_ms * 90, time_start_ms,
	webrtc::kVideoRotation_0);

	// Test scaling to different sizes: source is of \|width\|/\|height\| = 352/288.
	// Pure scaling:
	TestSize(video_frame, buffer, width_ / 4, height_ / 4, 25.2, vp_);
	TestSize(video_frame, buffer, width_ / 2, height_ / 2, 28.1, vp_);
	// No resampling:
	TestSize(video_frame, buffer, width_, height_, -1, vp_);
	TestSize(video_frame, buffer, 2 * width_, 2 * height_, 32.2, vp_);

	// Scaling and cropping. The cropped source frame is the largest center
	// aligned region that can be used from the source while preserving aspect
	// ratio.
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 56, 352, 176),
	100, 50, 24.0, vp_);
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 30, 352, 225),
	400, 256, 31.3, vp_);
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 68, 0, 216, 288),
	480, 640, 32.15, vp_);
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 12, 352, 264),
	960, 720, 32.2, vp_);
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 44, 352, 198),
	1280, 720, 32.15, vp_);

	// Upsampling to odd size.
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 26, 352, 233),
	501, 333, 32.05, vp_);
	// Downsample to odd size.
	TestSize(video_frame, CropBuffer(buffer, width_, height_, 0, 34, 352, 219),
	281, 175, 29.3, vp_);

	// Stop timer.
	const int64_t runtime =
	(rtc::TimeNanos() - time_start) / rtc::kNumNanosecsPerMicrosec;
	if (runtime < min_runtime \|\| run_idx == 0) {
	min_runtime = runtime;
	}
	total_runtime += runtime;
	}

	printf("\nAverage run time = %d us / frame\n",
	static_cast<int>(total_runtime));
	printf("Min run time = %d us / frame\n\n", static_cast<int>(min_runtime));
	}

	void PreprocessFrameAndVerify(const VideoFrame& source,
	int target_width,
	int target_height,
	VideoProcessing* vpm,
	const VideoFrame* out_frame) {
	ASSERT_EQ(VPM_OK, vpm->SetTargetResolution(target_width, target_height, 30));
	out_frame = vpm->PreprocessFrame(source);
	EXPECT_TRUE(out_frame != nullptr);

	// If no resizing is needed, expect the original frame.
	if (target_width == source.width() && target_height == source.height()) {
	EXPECT_EQ(&source, out_frame);
	return;
	}

	// Verify the resampled frame.
	EXPECT_TRUE(out_frame != NULL);
	EXPECT_EQ(source.render_time_ms(), (out_frame)->render_time_ms());
	EXPECT_EQ(source.timestamp(), (out_frame)->timestamp());
	EXPECT_EQ(target_width, (out_frame)->width());
	EXPECT_EQ(target_height, (out_frame)->height());
	}

	rtc::scoped_refptr<VideoFrameBuffer> CropBuffer(
	const rtc::scoped_refptr<VideoFrameBuffer>& source_buffer,
	int source_width,
	int source_height,
	int offset_x,
	int offset_y,
	int cropped_width,
	int cropped_height) {
	// Force even.
	offset_x &= 1;
	offset_y &= 1;

	size_t y_start = offset_x + offset_y * source_buffer->StrideY();
	size_t u_start = (offset_x / 2) + (offset_y / 2) * source_buffer->StrideU();
	size_t v_start = (offset_x / 2) + (offset_y / 2) * source_buffer->StrideU();

	return rtc::scoped_refptr<VideoFrameBuffer>(
	new rtc::RefCountedObject<WrappedI420Buffer>(
	cropped_width, cropped_height, source_buffer->DataY() + y_start,
	source_buffer->StrideY(), source_buffer->DataU() + u_start,
	source_buffer->StrideU(), source_buffer->DataV() + v_start,
	source_buffer->StrideV(), rtc::KeepRefUntilDone(source_buffer)));
	}

	void TestSize(const VideoFrame& source_frame,
	const rtc::scoped_refptr<VideoFrameBuffer>& cropped_source_buffer,
	int target_width,
	int target_height,
	double expected_psnr,
	VideoProcessing* vpm) {
	// Resample source_frame to out_frame.
	VideoFrame* out_frame = NULL;
	vpm->SetInputFrameResampleMode(kBox);
	PreprocessFrameAndVerify(source_frame, target_width, target_height, vpm,
	out_frame);
	if (out_frame == NULL)
	return;
	WriteProcessedFrameForVisualInspection(source_frame, *out_frame);

	// Scale \|resampled_source_frame\| back to the source scale.
	VideoFrame resampled_source_frame;
	resampled_source_frame.CopyFrame(*out_frame);
	PreprocessFrameAndVerify(resampled_source_frame,
	cropped_source_buffer->width(),
	cropped_source_buffer->height(), vpm, out_frame);
	WriteProcessedFrameForVisualInspection(resampled_source_frame, *out_frame);

	// Compute PSNR against the cropped source frame and check expectation.
	double psnr =
	I420PSNR(cropped_source_buffer, out_frame->video_frame_buffer());
	EXPECT_GT(psnr, expected_psnr);
	printf(
	"PSNR: %f. PSNR is between source of size %d %d, and a modified "
	"source which is scaled down/up to: %d %d, and back to source size \n",
	psnr, source_frame.width(), source_frame.height(), target_width,
	target_height);
	}

	void WriteProcessedFrameForVisualInspection(const VideoFrame& source,
	const VideoFrame& processed) {
	// Skip if writing to files is not enabled.
	if (!FLAGS_gen_files)
	return;
	// Write the processed frame to file for visual inspection.
	std::ostringstream filename;
	filename << webrtc::test::OutputPath() << "Resampler_from_" << source.width()
	<< "x" << source.height() << "_to_" << processed.width() << "x"
	<< processed.height() << "_30Hz_P420.yuv";
	std::cout << "Watch " << filename.str() << " and verify that it is okay."
	<< std::endl;
	FILE* stand_alone_file = fopen(filename.str().c_str(), "wb");
	if (PrintVideoFrame(processed, stand_alone_file) < 0)
	std::cerr << "Failed to write: " << filename.str() << std::endl;
	if (stand_alone_file)
	fclose(stand_alone_file);
	}

	} // namespace webrtc