Aegisub/aegisub/src/audio_provider_pcm.h

// Copyright (c) 2007-2008, Niels Martin Hansen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
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//     this list of conditions and the following disclaimer.
//   * Redistributions in binary form must reproduce the above copyright notice,
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// Aegisub Project http://www.aegisub.org/

/// @file audio_provider_pcm.h
/// @see audio_provider_pcm.cpp
/// @ingroup audio_input
///

#include <vector>

#ifdef _WIN32
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#endif

#include "include/aegisub/audio_provider.h"

#include <libaegisub/scoped_ptr.h>

class PCMAudioProvider : public AudioProvider {
	mutable void *current_mapping = nullptr;

#ifdef _WIN32
	mutable int64_t mapping_start = 0;
	mutable size_t mapping_length = 0;

	agi::scoped_holder<HANDLE, BOOL (__stdcall *)(HANDLE)> file_handle;
	agi::scoped_holder<HANDLE, BOOL (__stdcall *)(HANDLE)> file_mapping;
#else
	mutable off_t mapping_start = 0;
	mutable size_t mapping_length = 0;

	agi::scoped_holder<int, int(*)(int)> file_handle;
#endif

protected:
	PCMAudioProvider(agi::fs::path const& filename); // Create base object and open the file mapping
	virtual ~PCMAudioProvider(); // Closes the file mapping
	char * EnsureRangeAccessible(int64_t range_start, int64_t range_length) const; // Ensure that the given range of bytes are accessible in the file mapping and return a pointer to the first byte of the requested range

	/// Size of the opened file
	int64_t file_size = 0;

	struct IndexPoint {
		int64_t start_byte;
		int64_t start_sample;
		int64_t num_samples;
	};

	typedef std::vector<IndexPoint> IndexVector;

	IndexVector index_points;

	void FillBuffer(void *buf, int64_t start, int64_t count) const override;
};

// Construct the right PCM audio provider (if any) for the file
std::unique_ptr<AudioProvider> CreatePCMAudioProvider(agi::fs::path const& filename);