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/*
* Copyright (c) 2020, William McPherson <willmcpherson2@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibAudio/WavWriter.h>
#include <LibCore/DeprecatedFile.h>
namespace Audio {
WavWriter::WavWriter(StringView path, int sample_rate, u16 num_channels, u16 bits_per_sample)
: m_sample_rate(sample_rate)
, m_num_channels(num_channels)
, m_bits_per_sample(bits_per_sample)
{
set_file(path);
}
WavWriter::WavWriter(int sample_rate, u16 num_channels, u16 bits_per_sample)
: m_sample_rate(sample_rate)
, m_num_channels(num_channels)
, m_bits_per_sample(bits_per_sample)
{
}
WavWriter::~WavWriter()
{
if (!m_finalized)
finalize();
}
void WavWriter::set_file(StringView path)
{
m_file = Core::DeprecatedFile::construct(path);
if (!m_file->open(Core::OpenMode::ReadWrite)) {
m_error_string = DeprecatedString::formatted("Can't open file: {}", m_file->error_string());
return;
}
m_file->seek(44);
m_finalized = false;
}
void WavWriter::write_samples(Span<Sample> samples)
{
m_data_sz += samples.size() * sizeof(Sample);
for (auto const& sample : samples) {
// FIXME: This only really works for 16-bit samples.
u16 left = static_cast<i16>(sample.left * static_cast<float>(1 << m_bits_per_sample));
u16 right = static_cast<i16>(sample.right * static_cast<float>(1 << m_bits_per_sample));
// FIXME: This ignores endianness.
m_file->write(bit_cast<u8 const*>(&left), sizeof(u16));
m_file->write(bit_cast<u8 const*>(&right), sizeof(u16));
}
}
void WavWriter::finalize()
{
VERIFY(!m_finalized);
m_finalized = true;
if (m_file) {
m_file->seek(0);
write_header();
m_file->close();
}
m_data_sz = 0;
}
void WavWriter::write_header()
{
// "RIFF"
static u32 riff = 0x46464952;
m_file->write(reinterpret_cast<u8*>(&riff), sizeof(riff));
// Size of data + (size of header - previous field - this field)
u32 sz = m_data_sz + (44 - 4 - 4);
m_file->write(reinterpret_cast<u8*>(&sz), sizeof(sz));
// "WAVE"
static u32 wave = 0x45564157;
m_file->write(reinterpret_cast<u8*>(&wave), sizeof(wave));
// "fmt "
static u32 fmt_id = 0x20746D66;
m_file->write(reinterpret_cast<u8*>(&fmt_id), sizeof(fmt_id));
// Size of the next 6 fields
static u32 fmt_size = 16;
m_file->write(reinterpret_cast<u8*>(&fmt_size), sizeof(fmt_size));
// 1 for PCM
static u16 audio_format = 1;
m_file->write(reinterpret_cast<u8*>(&audio_format), sizeof(audio_format));
m_file->write(reinterpret_cast<u8*>(&m_num_channels), sizeof(m_num_channels));
m_file->write(reinterpret_cast<u8*>(&m_sample_rate), sizeof(m_sample_rate));
u32 byte_rate = m_sample_rate * m_num_channels * (m_bits_per_sample / 8);
m_file->write(reinterpret_cast<u8*>(&byte_rate), sizeof(byte_rate));
u16 block_align = m_num_channels * (m_bits_per_sample / 8);
m_file->write(reinterpret_cast<u8*>(&block_align), sizeof(block_align));
m_file->write(reinterpret_cast<u8*>(&m_bits_per_sample), sizeof(m_bits_per_sample));
// "data"
static u32 chunk_id = 0x61746164;
m_file->write(reinterpret_cast<u8*>(&chunk_id), sizeof(chunk_id));
m_file->write(reinterpret_cast<u8*>(&m_data_sz), sizeof(m_data_sz));
}
}
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