dtmfgenerator.h

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/*
 *  Copyright (C) 2004-2025 Savoir-faire Linux Inc.
 *
 *  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 <https://www.gnu.org/licenses/>.
 */
#pragma once
 
#include <stdexcept>
#include <string>
#include <vector>
#include "noncopyable.h"
#include "tone.h"
 
#define NUM_TONES 16
 
/*
 * @file dtmfgenerator.h
 * @brief DMTF Generator Exception
 */
 
namespace jami {
 
class DTMFException : public std::runtime_error
{
public:
    DTMFException(const std::string& str)
        : std::runtime_error(str) {};
};
 
/*
 * @file dtmfgenerator.h
 * @brief DTMF Tone Generator
 */
class DTMFGenerator
{
private:
    struct DTMFTone
    {
        unsigned char code; 
        unsigned lower;          
        unsigned higher;         
    };
 
    struct DTMFState
    {
        unsigned int offset; 
        AVFrame* sample; 
    };
 
    DTMFState state;
 
    static const DTMFTone tones_[NUM_TONES];
 
    std::array<libjami::FrameBuffer, NUM_TONES> toneBuffers_;
 
    unsigned sampleRate_;
 
    Tone tone_;
 
public:
    DTMFGenerator(unsigned int sampleRate, AVSampleFormat sampleFormat);
 
    ~DTMFGenerator();
 
    NON_COPYABLE(DTMFGenerator);
 
    /*
     * Get n samples of the signal of code code
     * @param frame  the output AVFrame to fill
     * @param code   dtmf code to get sound
     */
    void getSamples(AVFrame* frame, unsigned char code);
 
    /*
     * Get next n samples (continues where previous call to
     * genSample or genNextSamples stopped
     * @param buffer a AudioSample vector
     */
    void getNextSamples(AVFrame* frame);
 
private:
    libjami::FrameBuffer fillToneBuffer(int index);
};
 
} // namespace jami