Method GetFrame

src/CacheDisk.cpp:157–224

Get a frame from the cache (or NULL shared_ptr if no frame is found)

// Get a frame from the cache (or NULL shared_ptr if no frame is found)
std::shared_ptr<Frame> CacheDisk::GetFrame(int64_t frame_number)
{
	// Create a scoped lock, to protect the cache from multiple threads
	const std::lock_guard<std::recursive_mutex> lock(*cacheMutex);

	// Does frame exists in cache?
	if (frames.count(frame_number)) {
		// Does frame exist on disk
		QString frame_path(path.path() + "/" + QString("%1.").arg(frame_number) + QString(image_format.c_str()).toLower());
		if (path.exists(frame_path)) {

			// Load image file
			auto image = std::make_shared<QImage>();
			image->load(frame_path);

			// Set pixel formatimage->
			image = std::make_shared<QImage>(image->convertToFormat(QImage::Format_RGBA8888_Premultiplied));

			// Create frame object
			auto frame = std::make_shared<Frame>();
			frame->number = frame_number;
			frame->AddImage(image);

			// Get audio data (if found)
			QString audio_path(path.path() + "/" + QString("%1").arg(frame_number) + ".audio");
			QFile audio_file(audio_path);
			if (audio_file.exists()) {
				// Open audio file
				QTextStream in(&audio_file);
				if (audio_file.open(QIODevice::ReadOnly)) {
					int sample_rate = in.readLine().toInt();
					int channels = in.readLine().toInt();
					int sample_count = in.readLine().toInt();
					int channel_layout = in.readLine().toInt();

					// Set basic audio properties
					frame->ResizeAudio(channels, sample_count, sample_rate, (ChannelLayout) channel_layout);

					// Loop through audio samples and add to frame
					int current_channel = 0;
					int current_sample = 0;
					float *channel_samples = new float[sample_count];
					while (!in.atEnd()) {
						// Add sample to channel array
						channel_samples[current_sample] = in.readLine().toFloat();
						current_sample++;

						if (current_sample == sample_count) {
							// Add audio to frame
							frame->AddAudio(true, current_channel, 0, channel_samples, sample_count, 1.0);

							// Increment channel, and reset sample position
							current_channel++;
							current_sample = 0;
						}

					}
				}