Fork of Tangara with customizations
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tangara-fw/src/codecs/wav.cpp

258 lines
8.1 KiB

/*
* Copyright 2023 Daniel <ailuruxx@gmail.com>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#include "wav.hpp"
#include <stdint.h>
#include <sys/_stdint.h>
#include <algorithm>
#include <cstdlib>
#include <string>
#include "debug.hpp"
#include "esp_log.h"
#include "sample.hpp"
namespace codecs {
[[maybe_unused]] static const char kTag[] = "wav";
static inline auto bytes_to_u16(cpp::span<std::byte const, 2> bytes)
-> uint16_t {
return (uint16_t)bytes[0] | (uint16_t)bytes[1] << 8;
}
static inline auto bytes_to_u32(cpp::span<std::byte const, 4> bytes)
-> uint32_t {
return (uint32_t)bytes[0] | (uint32_t)bytes[1] << 8 |
(uint32_t)bytes[2] << 16 | (uint32_t)bytes[3] << 24;
}
static inline auto bytes_to_str(cpp::span<std::byte const> bytes)
-> std::string {
return std::string(reinterpret_cast<const char*>(bytes.data()),
bytes.size_bytes());
}
static int16_t convert_f32_to_16_bit(cpp::span<const std::byte> bytes) {
uint64_t val = 0;
val = (uint8_t)bytes[3];
val = (val << 8) | (uint8_t)bytes[2];
val = (val << 8) | (uint8_t)bytes[1];
val = (val << 8) | (uint8_t)bytes[0];
// Isolate the sign and remove from the value
uint64_t sign = val >> 31;
val -= (sign << 31);
// Isolate the exponent and remove from the value
uint64_t exp = (val >> 23);
val -= (exp << 23);
// Remove old bias and add new bias
exp = exp - 127 + 1023;
// Reconstruct the bits in the correct order and convert to double
uint64_t dval = (sign << 63) + (exp << 52) + (val << 29);
double* fval = reinterpret_cast<double*>(&dval);
return sample::FromDouble(*fval);
}
static int16_t convert_to_16_bit(cpp::span<const std::byte> bytes) {
int depth = bytes.size();
int32_t val = 0;
// If 8-bit Assume Unsigned
if (depth == 1) {
return sample::FromUnsigned((uint8_t)bytes[0], 8);
}
// Otherwise, build the signed int of the right depth
switch (depth) {
case 4:
val = (uint8_t)bytes[3];
case 3:
val = (val << 8) | (uint8_t)bytes[2];
case 2:
val = (val << 8) | (uint8_t)bytes[1];
case 1:
val = (val << 8) | (uint8_t)bytes[0];
}
// Convert to sample
int16_t result = sample::FromSigned(val, depth * 8);
return result;
}
WavDecoder::WavDecoder() : input_(), buffer_() {}
WavDecoder::~WavDecoder() {}
auto WavDecoder::OpenStream(std::shared_ptr<IStream> input,uint32_t offset)
-> cpp::result<OutputFormat, Error> {
input_ = input;
std::array<std::byte, 255> buf{std::byte{0}};
auto size = input->Read(buf);
if (size < 44) {
return cpp::fail(Error::kOutOfInput);
}
// - check the first 4 bytes = 'RIFF'
// - next 4 bytes = file size
// - check next 4 bytes = 'WAVE'
// - index of 'fmt\0' (i) marks start of fmt data
// - i + 4 = size of fmt header (16, 18 or 40)
// - i + 8 = format (should be 0x01 for pcm, 0xfffe for
// wave_format_exstensible)
// - i + 10 = num channels
// - i + 12 = sample rate
// - i + 16 = byte rate (sample rate * channels * bits per sample / 8)
// - i + 20 = sample size (bits per sample * channels / 8)
// - i + 22 = bits per sample (2 bytes)
// - end of this part, next header we care about is 'data'
// - and then the next 4 bytes = 32 bit int = size of data
auto buffer_span = cpp::span{buf};
std::string riff = bytes_to_str(buffer_span.subspan(0, 4));
if (riff != "RIFF") {
ESP_LOGW(kTag, "file is not RIFF");
return cpp::fail(Error::kMalformedData);
}
uint32_t file_size = bytes_to_u32(buffer_span.subspan(4, 4)) + 8;
std::string fmt_header = bytes_to_str(buffer_span.subspan(12, 4));
ESP_LOGI(kTag, "fmt header found? %s",
(fmt_header.starts_with("fmt")) ? "yes" : "no");
if (!fmt_header.starts_with("fmt")) {
ESP_LOGW(kTag, "Could not find format chunk");
return cpp::fail(Error::kMalformedData);
}
// Size of the fmt header, should be 16, 18 or 40
uint32_t fmt_header_size = bytes_to_u32(buffer_span.subspan(16, 4));
wave_format_ = bytes_to_u16(buffer_span.subspan(20, 2));
if (wave_format_ == kWaveFormatPCM) {
ESP_LOGD(kTag, "wave format: PCM");
} else if (wave_format_ == kWaveFormatExtensible) {
ESP_LOGD(kTag, "wave format: extensible");
} else if (wave_format_ == kWaveFormatIEEEFloat) {
ESP_LOGD(kTag, "wave format: IEEE Float");
} else {
ESP_LOGW(kTag, "WAVE format not supported");
return cpp::fail(Error::kUnsupportedFormat);
}
num_channels_ = bytes_to_u16(buffer_span.subspan(22, 2));
uint32_t samples_per_second = bytes_to_u32(buffer_span.subspan(24, 4));
uint32_t avg_bytes_per_second = bytes_to_u32(buffer_span.subspan(28, 4));
uint16_t block_align = bytes_to_u16(buffer_span.subspan(32, 2));
bytes_per_sample_ = block_align / num_channels_;
uint16_t bits_per_sample = bytes_to_u16(buffer_span.subspan(34, 2));
// find the start of the data chunk
std::array<std::byte, 4> data_tag = {std::byte{0x64}, std::byte{0x61},
std::byte{0x74}, std::byte{0x61}};
auto data_loc = std::ranges::search(buffer_span, data_tag);
if (data_loc.begin() == buffer_span.end()) {
ESP_LOGW(kTag, "Could not find data chunk!");
return cpp::fail(Error::kMalformedData);
}
int data_chunk_index = std::distance(buffer_span.begin(), data_loc.begin());
uint32_t data_chunk_size =
bytes_to_u32(buffer_span.subspan(data_chunk_index + 4, 4));
// calculate number of samples
int number_of_samples = data_chunk_size / bytes_per_sample_;
// extension to the fmt chunk size (0 or 22)
uint16_t extension_size = 0;
if (wave_format_ == kWaveFormatExtensible) {
extension_size = bytes_to_u16(buffer_span.subspan(36, 2));
}
// Parse extension if applicable
if (extension_size == 22) {
// Valid bits per sample
uint16_t valid_bits_per_sample = bytes_to_u16(buffer_span.subspan(38, 2));
uint32_t speaker_mask = bytes_to_u32(buffer_span.subspan(40, 4));
// Parse subformat
subformat_ = bytes_to_u16(buffer_span.subspan(44, 2));
if (!(subformat_ == kWaveFormatPCM ||
subformat_ == kWaveFormatIEEEFloat)) {
ESP_LOGW(kTag, "WAVE extensible subformat_ not supported");
return cpp::fail(Error::kUnsupportedFormat);
}
}
// 64 bit float is not implemented yet, make sure we're not letting it through
if (GetFormat() == kWaveFormatIEEEFloat && bytes_per_sample_ == 8) {
ESP_LOGW(kTag, "WAVE 64-Bit Float not supported");
return cpp::fail(Error::kUnsupportedFormat);
}
int64_t data_offset = offset * samples_per_second * bytes_per_sample_;
// Seek track to start of data
input->SeekTo(data_chunk_index + 8 + data_offset, IStream::SeekFrom::kStartOfStream);
output_format_ = {.num_channels = (uint8_t)num_channels_,
.sample_rate_hz = samples_per_second,
.total_samples = number_of_samples};
return output_format_;
}
auto WavDecoder::DecodeTo(cpp::span<sample::Sample> output)
-> cpp::result<OutputInfo, Error> {
bool is_eof = buffer_.Refill(input_.get());
size_t samples_written = 0;
buffer_.ConsumeBytes([&](cpp::span<std::byte> buf) -> size_t {
size_t bytes_read = buf.size_bytes();
size_t frames_read =
bytes_read / bytes_per_sample_ / output_format_.num_channels;
samples_written =
std::min<size_t>(frames_read,
output.size() / output_format_.num_channels) *
output_format_.num_channels;
// For each sample that we're going to write
for (size_t i = 0; i < samples_written; i++) {
auto data = buf.subspan(i * bytes_per_sample_, bytes_per_sample_);
if (GetFormat() == kWaveFormatPCM) {
// PCM
output[i] = convert_to_16_bit(data);
} else if (GetFormat() == kWaveFormatIEEEFloat) {
// 32-Bit Float
if (bytes_per_sample_ == 4) {
output[i] = convert_f32_to_16_bit(data);
}
}
}
return samples_written * bytes_per_sample_;
});
return OutputInfo{.samples_written = samples_written,
.is_stream_finished = samples_written == 0 && is_eof};
}
auto codecs::WavDecoder::GetFormat() const -> uint16_t {
if (wave_format_ == kWaveFormatExtensible) {
return subformat_;
}
return wave_format_;
}
} // namespace codecs