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/*
* Copyright (c) 2020, William McPherson <willmcpherson2@gmail.com>
* Copyright (c) 2023, Cameron Youell <cameronyouell@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibAudio/WavWriter.h>
namespace Audio {
ErrorOr<NonnullOwnPtr<WavWriter>> WavWriter::create_from_file(StringView path, int sample_rate, u16 num_channels, u16 bits_per_sample)
{
auto wav_writer = TRY(adopt_nonnull_own_or_enomem(new (nothrow) WavWriter(sample_rate, num_channels, bits_per_sample)));
TRY(wav_writer->set_file(path));
return wav_writer;
}
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();
}
ErrorOr<void> WavWriter::set_file(StringView path)
{
m_file = TRY(Core::File::open(path, Core::File::OpenMode::ReadWrite));
TRY(m_file->seek(44, SeekMode::SetPosition));
m_finalized = false;
return {};
}
ErrorOr<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.
TRY(m_file->write_value(left));
TRY(m_file->write_value(right));
}
return {};
}
void WavWriter::finalize()
{
VERIFY(!m_finalized);
m_finalized = true;
if (m_file && m_file->is_open()) {
auto result = [&]() -> ErrorOr<void> {
TRY(m_file->seek(0, SeekMode::SetPosition));
return TRY(write_header());
}();
if (result.is_error())
dbgln("Failed to finalize WavWriter: {}", result.error());
m_file->close();
}
m_data_sz = 0;
}
ErrorOr<void> WavWriter::write_header()
{
// "RIFF"
static u32 riff = 0x46464952;
TRY(m_file->write_value(riff));
// Size of data + (size of header - previous field - this field)
u32 sz = m_data_sz + (44 - 4 - 4);
TRY(m_file->write_value(sz));
// "WAVE"
static u32 wave = 0x45564157;
TRY(m_file->write_value(wave));
// "fmt "
static u32 fmt_id = 0x20746D66;
TRY(m_file->write_value(fmt_id));
// Size of the next 6 fields
static u32 fmt_size = 16;
TRY(m_file->write_value(fmt_size));
// 1 for PCM
static u16 audio_format = 1;
TRY(m_file->write_value(audio_format));
TRY(m_file->write_value(m_num_channels));
TRY(m_file->write_value(m_sample_rate));
u32 byte_rate = m_sample_rate * m_num_channels * (m_bits_per_sample / 8);
TRY(m_file->write_value(byte_rate));
u16 block_align = m_num_channels * (m_bits_per_sample / 8);
TRY(m_file->write_value(block_align));
TRY(m_file->write_value(m_bits_per_sample));
// "data"
static u32 chunk_id = 0x61746164;
TRY(m_file->write_value(chunk_id));
TRY(m_file->write_value(m_data_sz));
return {};
}
}
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