ESP8266Audio/src/AudioOutputSPDIF.h

77 lines
2.5 KiB
C++

/*
AudioOutputSPDIF
S/PDIF output via I2S
Needs transceiver from CMOS level to either optical or coaxial interface
See: https://www.epanorama.net/documents/audio/spdif.html
Original idea and sources:
Forum thread discussing implementation
https://forum.pjrc.com/threads/28639-S-pdif
Teensy Audio Library
https://github.com/PaulStoffregen/Audio/blob/master/output_spdif2.cpp
Adapted for ESP8266Audio
Copyright (C) 2020 Ivan Kostoski
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 3 of the License, 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. If not, see <http://www.gnu.org/licenses/>.
*/
#if defined(ESP32) || defined(ESP8266)
#pragma once
#include "AudioOutput.h"
#if defined(ESP32)
#define SPDIF_OUT_PIN_DEFAULT 27
#define DMA_BUF_COUNT_DEFAULT 8
#define DMA_BUF_SIZE_DEFAULT 256
#elif defined(ESP8266)
#define SPDIF_OUT_PIN_DEFAULT 3
#define DMA_BUF_COUNT_DEFAULT 32
#define DMA_BUF_SIZE_DEFAULT 64
#endif
class AudioOutputSPDIF : public AudioOutput
{
public:
AudioOutputSPDIF(int dout_pin=SPDIF_OUT_PIN_DEFAULT, int port=0, int dma_buf_count = DMA_BUF_COUNT_DEFAULT);
virtual ~AudioOutputSPDIF() override;
bool SetPinout(int bclkPin, int wclkPin, int doutPin);
virtual bool SetRate(int hz) override;
virtual bool SetBitsPerSample(int bits) override;
virtual bool SetChannels(int channels) override;
virtual bool begin() override;
virtual bool ConsumeSample(int16_t sample[2]) override;
virtual bool stop() override;
bool SetOutputModeMono(bool mono); // Force mono output no matter the input
const uint32_t VUCP_PREAMBLE_B = 0xCCE80000; // 11001100 11101000
const uint32_t VUCP_PREAMBLE_M = 0xCCE20000; // 11001100 11100010
const uint32_t VUCP_PREAMBLE_W = 0xCCE40000; // 11001100 11100100
protected:
virtual inline int AdjustI2SRate(int hz) { return rate_multiplier * hz; }
uint8_t portNo;
bool mono;
bool i2sOn;
uint8_t frame_num;
uint8_t rate_multiplier;
};
#endif // _AUDIOOUTPUTSPDIF_H