audioseq-coder/pcm.cpp at main · thirv/audioseq-coder · GitHub

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#include "pcm.hpp"
using namespace std;


pcm_header get_header(unsigned int frame_size, ifstream &f)
{
        pcm_header head;
        head.bytes.resize(44); //wav-related magic number
        f.read(reinterpret_cast<char*>(&head.bytes[0]), head.bytes.size());
        head.nro_ch = head.bytes[23] << 8 | head.bytes[22];
        head.fs = head.bytes[27] << 24 | head.bytes[26] << 16 |
                  head.bytes[25] << 8 | head.bytes[24];
        head.nro_bytes = (head.bytes[7] << 24 | head.bytes[6] << 16 |
                          head.bytes[5] << 8 | head.bytes[4]) - 36;
        auto tmp = head.nro_bytes / (2.0 * head.nro_ch * frame_size); // 16 bit only?
        head.nro_fr = (unsigned int) ceil(tmp);
        head.last_size = ((unsigned int) tmp - (head.nro_fr - 1)) * frame_size;
        return head;
}


vector<uint8_t> header_bytes(unsigned int nro_ch, unsigned int fs, unsigned int nro_frames, unsigned int frame_size)
{
        // so far for 16 bit linear quant
        unsigned int nro_bytes = 2 * nro_ch * nro_frames * frame_size;
        vector<uint8_t> bytes = {'R','I','F','F','\0','\0','\0','\0','W','A','V','E','f','m','t',' ',
                                 '\x10','\0','\0','\0','\x01','\0','\x01','\0','\0','\0','\0','\0', // size of wave bytes?
                                 '\0','\0','\0','\0','\0','\0','\x10','\0','d','a','t','a','\0','\0','\0','\0'};
        unsigned int tmp = nro_bytes + 36;
        bytes[4] = tmp & 0xFF;
        bytes[5] = tmp >> 8 & 0xFF;
        bytes[6] = tmp >> 16 & 0xFF;
        bytes[7] = tmp >> 24 & 0xFF;
        bytes[22] = nro_ch & 0xFF;
        bytes[23] = nro_ch >> 8 & 0xFF;
        bytes[24] = fs & 0xFF;
        bytes[25] = fs >> 8 & 0xFF;
        bytes[26] = fs >> 16 & 0xFF;
        bytes[27] = fs >> 24 & 0xFF;
        tmp = 2 * nro_ch * fs;
        bytes[28] = tmp & 0xFF;
        bytes[29] = tmp >> 8 & 0xFF;
        bytes[30] = tmp >> 16 & 0xFF;
        bytes[31] = tmp >> 24 & 0xFF;
        tmp = 2 * nro_ch;
        bytes[32] = tmp & 0xFF;
        bytes[33] = tmp>> 8 & 0xFF;
        bytes[40] = nro_bytes & 0xFF;
        bytes[41] = nro_bytes >> 8 & 0xFF;
        bytes[42] = nro_bytes >> 16 & 0xFF;
        bytes[43] = nro_bytes >> 24 & 0xFF;
        return bytes;
}


vector<vector<float>> get_pcm(unsigned int nro_ch, unsigned int frame_size, ifstream &f)
{
        vector<uint8_t> bytes(2*nro_ch*frame_size); // for 16 bit wav
        f.read(reinterpret_cast<char*>(&bytes[0]), bytes.size());
        vector<vector<float>> pcm(nro_ch, vector<float> (frame_size));
        for (unsigned int i=0; i<nro_ch; i++) {
                for (unsigned int j=0; j<frame_size; j++) {
                    auto ind = 2 * (j * nro_ch + i);
                    auto tmp = (int) (bytes[ind+1] << 8 | bytes[ind]);
                    if(tmp>32767)
                        t   mp = tmp - 65536;
                    pcm[i][j] = tmp / 32767.0f;
                }
        }
        return pcm;
}


void put_pcm(const vector<vector<float>> &pcm, unsigned int nro_ch, unsigned int frame_size, ofstream &f)
{
        if(frame_size==0)
                return;
        vector<uint8_t> bytes(2*nro_ch*frame_size); // for 16 bit wav;

        for (unsigned int i=0; i<nro_ch; i++) {
                for (unsigned int j=0; j<frame_size; j++) {
                        auto tmp = (int) round(pcm[i][j]*32767.0f);
                        if (tmp<0)
                                tmp = tmp + 65536;
                        auto ind = 2 * (j * nro_ch + i);
                        bytes[ind] = (uint8_t) (tmp & 0xFF);
                        bytes[ind+1] = (uint8_t) (tmp >> 8);
                }
        }
        f.write(reinterpret_cast<char*>(&bytes[0]), bytes.size());
}