Duckstation/src/common/wav_writer.cpp

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2020-03-15 12:03:22 +00:00
#include "wav_writer.h"
#include "file_system.h"
#include "log.h"
Log_SetChannel(WAVWriter);
#pragma pack(push, 1)
struct WAV_HEADER
{
u32 chunk_id; // RIFF
u32 chunk_size;
u32 format; // WAVE
struct FormatChunk
{
u32 chunk_id; // "fmt "
u32 chunk_size;
u16 audio_format; // pcm = 1
u16 num_channels;
u32 sample_rate;
u32 byte_rate;
u16 block_align;
u16 bits_per_sample;
} fmt_chunk;
struct DataChunkHeader
{
u32 chunk_id; // "data "
u32 chunk_size;
} data_chunk_header;
};
#pragma pack(pop)
namespace Common {
WAVWriter::WAVWriter() = default;
WAVWriter::~WAVWriter()
{
if (IsOpen())
Close();
}
bool WAVWriter::Open(const char* filename, u32 sample_rate, u32 num_channels)
{
if (IsOpen())
Close();
m_file = FileSystem::OpenCFile(filename, "wb");
if (!m_file)
return false;
m_sample_rate = sample_rate;
m_num_channels = num_channels;
if (!WriteHeader())
{
Log_ErrorPrintf("Failed to write header to file");
m_sample_rate = 0;
m_num_channels = 0;
std::fclose(m_file);
m_file = nullptr;
return false;
}
return true;
}
void WAVWriter::Close()
{
if (!IsOpen())
return;
if (std::fseek(m_file, 0, SEEK_SET) != 0 || !WriteHeader())
Log_ErrorPrintf("Failed to re-write header on file, file may be unplayable");
std::fclose(m_file);
m_file = nullptr;
m_sample_rate = 0;
m_num_channels = 0;
m_num_frames = 0;
}
void WAVWriter::WriteFrames(const s16* samples, u32 num_frames)
{
const u32 num_frames_written =
static_cast<u32>(std::fwrite(samples, sizeof(s16) * m_num_channels, num_frames, m_file));
if (num_frames_written != num_frames)
Log_ErrorPrintf("Only wrote %u of %u frames to output file", num_frames_written);
m_num_frames += num_frames_written;
}
bool WAVWriter::WriteHeader()
{
const u32 data_size = sizeof(SampleType) * m_num_channels * m_num_frames;
WAV_HEADER header = {};
header.chunk_id = 0x46464952; // 0x52494646
header.chunk_size = sizeof(WAV_HEADER) - 8 + data_size;
header.format = 0x45564157; // 0x57415645
header.fmt_chunk.chunk_id = 0x20746d66; // 0x666d7420
header.fmt_chunk.chunk_size = sizeof(header.fmt_chunk) - 8;
header.fmt_chunk.audio_format = 1;
header.fmt_chunk.num_channels = static_cast<u16>(m_num_channels);
header.fmt_chunk.sample_rate = m_sample_rate;
header.fmt_chunk.byte_rate = m_sample_rate * m_num_channels * sizeof(SampleType);
header.fmt_chunk.block_align = static_cast<u16>(m_num_channels * sizeof(SampleType));
header.fmt_chunk.bits_per_sample = 16;
header.data_chunk_header.chunk_id = 0x61746164; // 0x64617461
header.data_chunk_header.chunk_size = data_size;
return (std::fwrite(&header, sizeof(header), 1, m_file) == 1);
}
} // namespace Common