audio_stream_resampled.h

/*************************************************************************/
/*  audio_stream_resampled.h                                             */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2016 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#ifndef AUDIO_STREAM_RESAMPLED_H
#define AUDIO_STREAM_RESAMPLED_H

#include "scene/resources/audio_stream.h"

#if 0

class AudioStreamResampled : public AudioStream {
    OBJ_TYPE(AudioStreamResampled,AudioStream);

    uint32_t rb_bits;
    uint32_t rb_len;
    uint32_t rb_mask;
    uint32_t read_buff_len;
    uint32_t channels;
    uint32_t mix_rate;

    volatile int rb_read_pos;
    volatile int rb_write_pos;

    int32_t offset; //contains the fractional remainder of the resampler
    enum {
        MIX_FRAC_BITS=13,
        MIX_FRAC_LEN=(1<<MIX_FRAC_BITS),
        MIX_FRAC_MASK=MIX_FRAC_LEN-1,
    };

    int16_t *read_buf;
    int16_t *rb;


    template<int C>
    uint32_t _resample(int32_t *p_dest,int p_todo,int32_t p_increment);


protected:

    _FORCE_INLINE_ int get_total() const {

        return rb_len;
    }

    _FORCE_INLINE_ int get_todo() const { //return amount of frames to mix

        int todo;
        int read_pos_cache=rb_read_pos;

        if (read_pos_cache==rb_write_pos) {
            todo=rb_len-1;
        } else if (read_pos_cache>rb_write_pos) {

            todo=read_pos_cache-rb_write_pos-1;
        } else {

            todo=(rb_len-rb_write_pos)+read_pos_cache-1;
        }

        return todo;
    }

    //Stream virtual funcs
    virtual int get_channel_count() const;
    virtual bool mix(int32_t *p_dest, int p_frames);

    _FORCE_INLINE_ void _flush() {
        rb_read_pos=0;
        rb_write_pos=0;
    }

    _FORCE_INLINE_ int16_t *get_write_buffer() { return read_buf; }
    _FORCE_INLINE_ void write(uint32_t p_frames) {

        ERR_FAIL_COND(p_frames >= rb_len);

        switch(channels) {
            case 1: {

                for(uint32_t i=0;i<p_frames;i++) {

                    rb[ rb_write_pos ] = read_buf[i];
                    rb_write_pos=(rb_write_pos+1)&rb_mask;
                }
            } break;
            case 2: {

                for(uint32_t i=0;i<p_frames;i++) {

                    rb[ (rb_write_pos<<1)+0 ] = read_buf[(i<<1)+0];
                    rb[ (rb_write_pos<<1)+1 ] = read_buf[(i<<1)+1];
                    rb_write_pos=(rb_write_pos+1)&rb_mask;
                }
            } break;
            case 4: {

                for(uint32_t i=0;i<p_frames;i++) {

                    rb[ (rb_write_pos<<2)+0 ] = read_buf[(i<<2)+0];
                    rb[ (rb_write_pos<<2)+1 ] = read_buf[(i<<2)+1];
                    rb[ (rb_write_pos<<2)+2 ] = read_buf[(i<<2)+2];
                    rb[ (rb_write_pos<<2)+3 ] = read_buf[(i<<2)+3];
                    rb_write_pos=(rb_write_pos+1)&rb_mask;
                }
            } break;
            case 6: {

                for(uint32_t i=0;i<p_frames;i++) {

                    rb[ (rb_write_pos*6)+0 ] = read_buf[(i*6)+0];
                    rb[ (rb_write_pos*6)+1 ] = read_buf[(i*6)+1];
                    rb[ (rb_write_pos*6)+2 ] = read_buf[(i*6)+2];
                    rb[ (rb_write_pos*6)+3 ] = read_buf[(i*6)+3];
                    rb[ (rb_write_pos*6)+4 ] = read_buf[(i*6)+4];
                    rb[ (rb_write_pos*6)+5 ] = read_buf[(i*6)+5];
                    rb_write_pos=(rb_write_pos+1)&rb_mask;
                }
            } break;


        }

    }

    virtual bool _can_mix() const =0;

    _FORCE_INLINE_ bool _is_ready() const{
        return rb!=NULL;
    }

    Error _setup(int p_channels,int p_mix_rate,int p_minbuff_needed=-1);
    void _clear();

public:
    AudioStreamResampled();
    ~AudioStreamResampled();
};
#endif
#endif // AUDIO_STREAM_RESAMPLED_H