codec_audio.h

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// SPDX-License-Identifier: AGPL-3.0-or-later
 
#ifndef __CODEC_AUDIO_H
#define __CODEC_AUDIO_H
 
#include <cstdint>
#include <mutex>
 
extern "C" {
#include <libavcodec/avcodec.h>
}
 
class cSoftHdAudio;
 
enum PassthroughMask {
    CODEC_AC3  = (1 << 2), 
    CODEC_EAC3 = (1 << 3), 
    CODEC_DTS  = (1 << 4), 
};
 
enum IEC61937Type {
    IEC61937_NULL   = 0x00, 
    IEC61937_AC3    = 0x01, 
    IEC61937_EAC3   = 0x15, 
    IEC61937_DTS1   = 0x0B, 
    IEC61937_DTS2   = 0x0C, 
    IEC61937_DTS3   = 0x0D, 
    IEC61937_DTSHD  = 0x11, 
    IEC61937_TRUEHD = 0x16, 
};
 
enum IEC61937Preamble {
    IEC61937_PREAMBLE1  = 0xF872,
    IEC61937_PREAMBLE2  = 0x4E1F,
    DTS_PREAMBLE_16BE_1 = 0x7FFE,
    DTS_PREAMBLE_16BE_2 = 0x8001,
};
 
enum CodecFrameSizes {
    DTS1_FRAME_SIZE   = 512,
    DTS2_FRAME_SIZE   = 1024,
    DTS3_FRAME_SIZE   = 2048,
    AC3_FRAME_SIZE    = 1536,
    EAC3_FRAME_SIZE   = 6144,
    MAX_FRAME_SIZE    = EAC3_FRAME_SIZE,
 
    TRUEHD_FRAME_SIZE = 15360, 
};
 
class cAudioDecoder {
public:
    cAudioDecoder(cSoftHdAudio *);
    ~cAudioDecoder(void);
    void Open(AVCodecID, AVCodecParameters * = nullptr, AVRational = { .num = 1, .den = 90000 });
    void Close(void);
    void Decode(const AVPacket *);
    void FlushBuffers(void);
    void SetPassthroughMask(int);
    AVCodecID GetCodecId() const { return m_codecId; };
 
private:
    cSoftHdAudio *m_pAudio;                     
    AVCodecContext *m_pAudioCtx = nullptr;      
    AVCodecID m_codecId = AV_CODEC_ID_NONE;     
    AVFrame *m_pFrame;                          
    int64_t m_lastPts = AV_NOPTS_VALUE;         
    int m_passthroughMask;                      
    int m_currentPassthroughMask;               
    int m_currentSampleRate;                    
    int m_currentNumChannels;                   
    int m_currentHwSampleRate;                  
    int m_currentHwNumChannels;                 
    uint16_t m_spdifOutput[(MAX_FRAME_SIZE * 4 + 16) / 2]; 
    int m_spdifIndex;                           
    int m_spdifRepeatCount;                     
    std::mutex m_mutex;                         
 
    int DecodePassthrough(const AVPacket *, AVFrame *);
    int UpdateFormat(void);
    void ResetSpdif(void);
};
 
#endif