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/*
* Copyright 2023 jacqueline <me@jacqueline.id.au>
*
* SPDX-License-Identifier: GPL-3.0-only
*/
#include "i2s_audio_output.hpp"
#include <stdint.h>
#include <algorithm>
#include <cstddef>
#include <memory>
#include <variant>
#include "digital_pot.hpp"
#include "esp_err.h"
#include "freertos/portmacro.h"
#include "audio_element.hpp"
#include "freertos/projdefs.h"
#include "gpio_expander.hpp"
#include "i2s_dac.hpp"
#include "result.hpp"
#include "stream_info.hpp"
static const char* kTag = "I2SOUT";
namespace audio {
I2SAudioOutput::I2SAudioOutput(drivers::GpioExpander* expander,
std::weak_ptr<drivers::I2SDac> dac,
std::weak_ptr<drivers::DigitalPot> pots)
: expander_(expander),
dac_(dac.lock()),
pots_(pots.lock()),
current_config_(),
left_difference_(0),
attenuation_(pots_->GetMaxAttenuation()) {
SetVolume(25); // For testing
dac_->SetSource(buffer());
}
I2SAudioOutput::~I2SAudioOutput() {
dac_->Stop();
dac_->SetSource(nullptr);
}
auto I2SAudioOutput::SetInUse(bool in_use) -> void {
if (in_use) {
dac_->Start();
} else {
dac_->Stop();
}
pots_->SetZeroCrossDetect(in_use);
}
auto I2SAudioOutput::SetVolumeImbalance(int_fast8_t balance) -> void {
int_fast8_t new_difference = balance - left_difference_;
left_difference_ = balance;
if (attenuation_ + new_difference <= pots_->GetMinAttenuation()) {
// Volume is currently very high, so shift the left channel down.
pots_->SetRelative(drivers::DigitalPot::Channel::kLeft, -new_difference);
} else if (attenuation_ - new_difference >= pots_->GetMaxAttenuation()) {
// Volume is currently very low, so shift the left channel up.
pots_->SetRelative(drivers::DigitalPot::Channel::kLeft, new_difference);
} else {
ESP_LOGE(kTag, "volume imbalance higher than attenuation range");
}
}
auto I2SAudioOutput::SetVolume(uint_fast8_t percent) -> void {
percent = 100 - percent;
int_fast8_t target_attenuation =
static_cast<int_fast8_t>(static_cast<float>(GetAdjustedMaxAttenuation()) /
100.0f * static_cast<float>(percent));
target_attenuation -= pots_->GetMinAttenuation();
int_fast8_t difference = target_attenuation - attenuation_;
pots_->SetRelative(difference);
attenuation_ = target_attenuation;
ESP_LOGI(kTag, "adjusting attenuation by %idB to %idB", difference,
attenuation_);
}
auto I2SAudioOutput::GetVolume() -> uint_fast8_t {
// Convert to percentage.
uint_fast8_t percent = static_cast<uint_fast8_t>(
static_cast<float>(attenuation_) /
static_cast<float>(GetAdjustedMaxAttenuation()) * 100.0f);
// Invert to get from attenuation to volume.
return 100 - percent;
}
auto I2SAudioOutput::GetAdjustedMaxAttenuation() -> int_fast8_t {
// Clip to account for imbalance.
int_fast8_t adjusted_max =
pots_->GetMaxAttenuation() - std::abs(left_difference_);
// Shift to be zero minimum.
adjusted_max -= pots_->GetMinAttenuation();
return adjusted_max;
}
auto I2SAudioOutput::AdjustVolumeUp() -> void {
if (attenuation_ + left_difference_ <= pots_->GetMinAttenuation()) {
return;
}
attenuation_--;
pots_->SetRelative(-1);
}
auto I2SAudioOutput::AdjustVolumeDown() -> void {
if (attenuation_ - left_difference_ >= pots_->GetMaxAttenuation()) {
return;
}
attenuation_++;
pots_->SetRelative(1);
}
auto I2SAudioOutput::Configure(const StreamInfo::Format& format) -> bool {
if (!std::holds_alternative<StreamInfo::Pcm>(format)) {
ESP_LOGI(kTag, "ignoring non-pcm stream (%d)", format.index());
return false;
}
StreamInfo::Pcm pcm = std::get<StreamInfo::Pcm>(format);
if (current_config_ && pcm == *current_config_) {
ESP_LOGI(kTag, "ignoring unchanged format");
return true;
}
ESP_LOGI(kTag, "incoming audio stream: %u ch %u bpp @ %lu Hz", pcm.channels,
pcm.bits_per_sample, pcm.sample_rate);
drivers::I2SDac::Channels ch;
switch (pcm.channels) {
case 1:
ch = drivers::I2SDac::CHANNELS_MONO;
break;
case 2:
ch = drivers::I2SDac::CHANNELS_STEREO;
break;
default:
ESP_LOGE(kTag, "dropping stream with out of bounds channels");
return false;
}
drivers::I2SDac::BitsPerSample bps;
switch (pcm.bits_per_sample) {
case 16:
bps = drivers::I2SDac::BPS_16;
break;
case 24:
bps = drivers::I2SDac::BPS_24;
break;
case 32:
bps = drivers::I2SDac::BPS_32;
break;
default:
ESP_LOGE(kTag, "dropping stream with unknown bps");
return false;
}
drivers::I2SDac::SampleRate sample_rate;
switch (pcm.sample_rate) {
case 44100:
sample_rate = drivers::I2SDac::SAMPLE_RATE_44_1;
break;
case 48000:
sample_rate = drivers::I2SDac::SAMPLE_RATE_48;
break;
default:
ESP_LOGE(kTag, "dropping stream with unknown rate");
return false;
}
dac_->Reconfigure(ch, bps, sample_rate);
current_config_ = pcm;
return true;
}
auto I2SAudioOutput::Send(const cpp::span<std::byte>& data) -> void {
dac_->WriteData(data);
}
} // namespace audio
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