Method ExtractSamples

src/AudioWaveformer.cpp:51–82

Extract audio samples from any ReaderBase class

// Extract audio samples from any ReaderBase class
AudioWaveformData AudioWaveformer::ExtractSamples(int channel, int num_per_second, bool normalize) {
	// Legacy entry point: resolve a source reader (unwrap Clip/FrameMapper), then extract audio-only.
	AudioWaveformData data;
	if (!reader) {
		return data;
	}

	ReaderBase* source = ResolveWaveformReader();

	Fraction source_fps = ResolveSourceFPS(source);

	AudioWaveformData base = ExtractSamplesFromReader(source, channel, num_per_second, false);

	// If this is a Clip, apply its keyframes using project fps (timeline if available, else reader fps)
	if (auto clip = dynamic_cast<Clip*>(reader)) {
		Timeline* timeline = dynamic_cast<Timeline*>(clip->ParentTimeline());
		Fraction project_fps = timeline ? timeline->info.fps : clip->Reader()->info.fps;
		return ApplyKeyframes(base, &clip->time, &clip->volume, project_fps, source_fps, source->info.channels, num_per_second, channel, normalize);
	}

	// No keyframes to apply
	if (normalize) {
		float max_sample = 0.0f;
		for (auto v : base.max_samples) {
			max_sample = std::max(max_sample, std::abs(v));
		}
		if (max_sample > 0.0f) {
			base.scale(static_cast<int>(base.max_samples.size()), 1.0f / max_sample);
		}
	}
	return base;
}

AudioWaveformData AudioWaveformer::ExtractSamples(const std::string& path, int channel, int num_per_second, bool normalize) {
	FFmpegReader temp_reader(path);