mirror of
https://github.com/eried/portapack-mayhem.git
synced 2024-12-30 09:46:32 -05:00
103 lines
3.8 KiB
C++
103 lines
3.8 KiB
C++
/*
|
|
* Copyright (C) 2023 Mark Thompson
|
|
*
|
|
* This file is part of PortaPack.
|
|
*
|
|
* This program 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; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program 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 this program; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, Inc., 51 Franklin Street,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#include "io_convert.hpp"
|
|
#include "complex.hpp"
|
|
|
|
namespace fs = std::filesystem;
|
|
static const fs::path c8_ext = u".C8";
|
|
|
|
namespace file_convert {
|
|
|
|
// Convert buffer contents from c16 to c8.
|
|
// Same buffer used for input & output; input size is bytes; output size is bytes/2.
|
|
void c16_to_c8(const void* buffer, File::Size bytes) {
|
|
complex16_t* src = (complex16_t*)buffer;
|
|
complex8_t* dest = (complex8_t*)buffer;
|
|
|
|
// Shift isn't used here because it would amplify noise at center freq since it's a signed number
|
|
// i.e. ((-1 >> 8) << 8) = -256, whereas (-1 / 256) * 256 = 0
|
|
for (File::Size i = 0; i < bytes / sizeof(complex16_t); i++) {
|
|
auto re_out = src[i].real() / 256;
|
|
auto im_out = src[i].imag() / 256;
|
|
dest[i] = {(int8_t)re_out, (int8_t)im_out};
|
|
}
|
|
}
|
|
|
|
// Convert c8 buffer to c16 buffer.
|
|
// Same buffer used for input & output; input size is bytes; output size is 2*bytes.
|
|
void c8_to_c16(const void* buffer, File::Size bytes) {
|
|
complex8_t* src = (complex8_t*)buffer;
|
|
complex16_t* dest = (complex16_t*)buffer;
|
|
uint32_t i = bytes / sizeof(complex8_t);
|
|
|
|
if (i != 0) {
|
|
do {
|
|
i--;
|
|
auto re_out = (int16_t)src[i].real() * 256; // C8 to C16 conversion;
|
|
auto im_out = (int16_t)src[i].imag() * 256; // Can't shift signed numbers left, so using multiply
|
|
dest[i] = {(int16_t)re_out, (int16_t)im_out};
|
|
} while (i != 0);
|
|
}
|
|
}
|
|
|
|
} /* namespace file_convert */
|
|
|
|
// Automatically enables C8/C16 conversion based on file extension
|
|
Optional<File::Error> FileConvertReader::open(const std::filesystem::path& filename) {
|
|
convert_c8_to_c16 = path_iequal(filename.extension(), c8_ext);
|
|
return file_.open(filename);
|
|
}
|
|
|
|
// If C8 conversion enabled, half the number of bytes are read from the file & expanded to fill the whole buffer.
|
|
File::Result<File::Size> FileConvertReader::read(void* const buffer, const File::Size bytes) {
|
|
auto read_result = file_.read(buffer, convert_c8_to_c16 ? bytes / 2 : bytes);
|
|
if (read_result.is_ok()) {
|
|
if (convert_c8_to_c16) {
|
|
file_convert::c8_to_c16(buffer, read_result.value());
|
|
read_result = read_result.value() * 2;
|
|
}
|
|
bytes_read_ += read_result.value();
|
|
}
|
|
return read_result;
|
|
}
|
|
|
|
// Automatically enables C8/C16 conversion based on file extension
|
|
Optional<File::Error> FileConvertWriter::create(const std::filesystem::path& filename) {
|
|
convert_c16_to_c8 = path_iequal(filename.extension(), c8_ext);
|
|
return file_.create(filename);
|
|
}
|
|
|
|
// If C8 conversion is enabled, half the number of bytes are written to the file.
|
|
File::Result<File::Size> FileConvertWriter::write(const void* const buffer, const File::Size bytes) {
|
|
if (convert_c16_to_c8) {
|
|
file_convert::c16_to_c8(buffer, bytes);
|
|
}
|
|
auto write_result = file_.write(buffer, convert_c16_to_c8 ? bytes / 2 : bytes);
|
|
if (write_result.is_ok()) {
|
|
if (convert_c16_to_c8) {
|
|
write_result = write_result.value() * 2;
|
|
}
|
|
bytes_written_ += write_result.value();
|
|
}
|
|
return write_result;
|
|
}
|