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OpenTTD/src/soundloader_wav.cpp

102 lines
3.4 KiB
C++

/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @file soundloader_wav.cpp Loading of wav sounds. */
#include "stdafx.h"
#include "core/bitmath_func.hpp"
#include "core/math_func.hpp"
#include "random_access_file_type.h"
#include "sound_type.h"
#include "soundloader_type.h"
#include "safeguards.h"
/** Wav file (RIFF/WAVE) sound loader. */
class SoundLoader_Wav : public SoundLoader {
public:
SoundLoader_Wav() : SoundLoader("wav", "Wav sound loader", 0) {}
static constexpr uint16_t DEFAULT_SAMPLE_RATE = 11025;
bool Load(SoundEntry &sound, bool new_format, std::vector<uint8_t> &data) override
{
RandomAccessFile &file = *sound.file;
/* Check RIFF/WAVE header. */
if (file.ReadDword() != std::byteswap<uint32_t>('RIFF')) return false;
file.ReadDword(); // Skip data size
if (file.ReadDword() != std::byteswap<uint32_t>('WAVE')) return false;
/* Read riff tags */
for (;;) {
uint32_t tag = file.ReadDword();
uint32_t size = file.ReadDword();
if (tag == std::byteswap<uint32_t>('fmt ')) {
uint16_t format = file.ReadWord();
if (format != 1) return false; // File must be uncompressed PCM
sound.channels = file.ReadWord();
if (sound.channels != 1) return false; // File must be mono.
sound.rate = file.ReadDword();
if (!new_format) sound.rate = DEFAULT_SAMPLE_RATE; // All old samples should be played at 11025 Hz.
file.ReadDword(); // avg bytes per second
file.ReadWord(); // alignment
sound.bits_per_sample = file.ReadWord();
if (sound.bits_per_sample != 8 && sound.bits_per_sample != 16) return false; // File must be 8 or 16 BPS.
/* We've read 16 bytes of this chunk, we can skip anything extra. */
size -= 16;
} else if (tag == std::byteswap<uint32_t>('data')) {
uint align = sound.channels * sound.bits_per_sample / 8;
if (Align(size, align) != size) return false; // Ensure length is aligned correctly for channels and BPS.
if (size == 0) return true; // No need to continue.
/* Allocate an extra sample to ensure the runtime resampler doesn't go out of bounds. */
data.reserve(size + align);
data.resize(size);
file.ReadBlock(std::data(data), size);
switch (sound.bits_per_sample) {
case 8:
/* Convert 8-bit samples from unsigned to signed. */
for (auto &sample : data) {
sample = sample - 128;
}
break;
case 16:
/* 16-bit samples in wav files are little endian, and may need to be converted to native endian. */
if constexpr (std::endian::native != std::endian::little) {
for (auto it = std::begin(data); it != std::end(data); /* nothing */) {
std::swap(*it++, *it++);
}
}
break;
default: NOT_REACHED();
}
return true;
}
/* Skip rest of chunk. */
if (size > 0) file.SkipBytes(size);
}
return false;
}
};
static SoundLoader_Wav s_sound_loader_wav;