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96 lines
3.5 KiB
C++
96 lines
3.5 KiB
C++
/**
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* @file
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* @brief Example application showing how to attach VideoCacheThread to an FFmpegReader
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* @author Jonathan Thomas <jonathan@openshot.org>
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*
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* @ref License
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*/
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// Copyright (c) 2008-2025 OpenShot Studios, LLC
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//
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// SPDX-License-Identifier: LGPL-3.0-or-later
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#include <chrono>
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#include <iostream>
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#include <memory>
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#include "Frame.h"
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#include "FFmpegReader.h"
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#include "FFmpegWriter.h"
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#include "Timeline.h"
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#include "Qt/VideoCacheThread.h" // <— your new header
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using namespace openshot;
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int main(int argc, char* argv[]) {
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// 1) Open the FFmpegReader as usual
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const char* input_path = "/home/jonathan/Downloads/openshot-testing/sintel_trailer-720p.mp4";
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FFmpegReader reader(input_path);
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reader.Open();
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const int64_t total_frames = reader.info.video_length;
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std::cout << "Total frames: " << total_frames << "\n";
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Timeline timeline(reader.info.width, reader.info.height, reader.info.fps, reader.info.sample_rate, reader.info.channels, reader.info.channel_layout);
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Clip c1(&reader);
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timeline.AddClip(&c1);
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timeline.Open();
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timeline.DisplayInfo();
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// 2) Construct a VideoCacheThread around 'reader' and start its background loop
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// (VideoCacheThread inherits juce::Thread)
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std::shared_ptr<VideoCacheThread> cache = std::make_shared<VideoCacheThread>();
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cache->Reader(&timeline); // attaches the FFmpegReader and internally calls Play()
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cache->StartThread(); // juce::Thread method, begins run()
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// 3) Set up the writer exactly as before
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FFmpegWriter writer("/home/jonathan/Downloads/performance‐cachetest.mp4");
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writer.SetAudioOptions("aac", 48000, 192000);
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writer.SetVideoOptions("libx264", 1280, 720, Fraction(30, 1), 5000000);
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writer.Open();
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// 4) Forward pass: for each frame 1…N, tell the cache thread to seek to that frame,
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// then immediately call cache->GetFrame(frame), which will block only if that frame
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// hasn’t been decoded into the cache yet.
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auto t0 = std::chrono::high_resolution_clock::now();
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cache->setSpeed(1);
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for (int64_t f = 1; f <= total_frames; ++f) {
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float pct = (float(f) / total_frames) * 100.0f;
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std::cout << "Forward: requesting frame " << f << " (" << pct << "%)\n";
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cache->Seek(f); // signal “I need frame f now (and please prefetch f+1, f+2, …)”
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std::shared_ptr<Frame> framePtr = timeline.GetFrame(f);
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writer.WriteFrame(framePtr);
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}
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auto t1 = std::chrono::high_resolution_clock::now();
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auto forward_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t1 - t0).count();
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// 5) Backward pass: same idea in reverse
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auto t2 = std::chrono::high_resolution_clock::now();
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cache->setSpeed(-1);
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for (int64_t f = total_frames; f >= 1; --f) {
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float pct = (float(total_frames - f + 1) / total_frames) * 100.0f;
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std::cout << "Backward: requesting frame " << f << " (" << pct << "%)\n";
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cache->Seek(f);
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std::shared_ptr<Frame> framePtr = timeline.GetFrame(f);
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writer.WriteFrame(framePtr);
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}
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auto t3 = std::chrono::high_resolution_clock::now();
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auto backward_ms = std::chrono::duration_cast<std::chrono::milliseconds>(t3 - t2).count();
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std::cout << "\nForward pass elapsed: " << forward_ms << " ms\n";
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std::cout << "Backward pass elapsed: " << backward_ms << " ms\n";
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// 6) Shut down the cache thread, close everything
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cache->StopThread(10000); // politely tells run() to exit, waits up to 10s
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reader.Close();
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writer.Close();
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timeline.Close();
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return 0;
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}
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