hvirtual/libmpeg3/audio/synthesizers.c

Go to the documentation of this file.

#include "mpeg3private.h"
#include "mpeg3protos.h"
#include "tables.h"

#define WRITE_SAMPLE(samples, sum) \
{ \
        (*samples) = (sum); \
}

int mpeg3audio_synth_stereo(mpeg3_layer_t *audio, 
        float *bandPtr, 
        int channel, 
        float *out, 
        int *pnt)
{
        float *samples = out + *pnt;
    register float sum;
        float *b0, (*buf)[0x110];
        int bo1;

        if(!channel)
        {
        audio->bo--;
        audio->bo &= 0xf;
        buf = audio->synth_stereo_buffs[0];
        }
        else 
        {
        buf = audio->synth_stereo_buffs[1];
        }

        if(audio->bo & 0x1)
        {
        b0 = buf[0];
        bo1 = audio->bo;
        mpeg3audio_dct64(buf[1] + ((audio->bo + 1) & 0xf), buf[0] + audio->bo, bandPtr);
        }
        else 
        {
        b0 = buf[1];
        bo1 = audio->bo + 1;
        mpeg3audio_dct64(buf[0] + audio->bo, buf[1] + audio->bo + 1, bandPtr);
        }

/*printf("%f %f %f\n", buf[0][0], buf[1][0], bandPtr[0]); */

        {
        int j;
        float *window = mpeg3_decwin + 16 - bo1;

        for(j = 16; j; j--, b0 += 0x10, window += 0x20, samples++)
        {
                sum  = window[0x0] * b0[0x0];
                sum -= window[0x1] * b0[0x1];
                sum += window[0x2] * b0[0x2];
                sum -= window[0x3] * b0[0x3];
                sum += window[0x4] * b0[0x4];
                sum -= window[0x5] * b0[0x5];
                sum += window[0x6] * b0[0x6];
                sum -= window[0x7] * b0[0x7];
                sum += window[0x8] * b0[0x8];
                sum -= window[0x9] * b0[0x9];
                sum += window[0xA] * b0[0xA];
                sum -= window[0xB] * b0[0xB];
                sum += window[0xC] * b0[0xC];
                sum -= window[0xD] * b0[0xD];
                sum += window[0xE] * b0[0xE];
                sum -= window[0xF] * b0[0xF];

                WRITE_SAMPLE(samples, sum);
        }

        sum  = window[0x0] * b0[0x0];
        sum += window[0x2] * b0[0x2];
        sum += window[0x4] * b0[0x4];
        sum += window[0x6] * b0[0x6];
        sum += window[0x8] * b0[0x8];
        sum += window[0xA] * b0[0xA];
        sum += window[0xC] * b0[0xC];
        sum += window[0xE] * b0[0xE];
        WRITE_SAMPLE(samples, sum);
        b0 -= 0x10;
                window -= 0x20;
                samples++;
        window += bo1 << 1;

        for(j = 15; j; j--, b0 -= 0x10, window -= 0x20, samples++)
        {
                sum = -window[-0x1] * b0[0x0];
                sum -= window[-0x2] * b0[0x1];
                sum -= window[-0x3] * b0[0x2];
                sum -= window[-0x4] * b0[0x3];
                sum -= window[-0x5] * b0[0x4];
                sum -= window[-0x6] * b0[0x5];
                sum -= window[-0x7] * b0[0x6];
                sum -= window[-0x8] * b0[0x7];
                sum -= window[-0x9] * b0[0x8];
                sum -= window[-0xA] * b0[0x9];
                sum -= window[-0xB] * b0[0xA];
                sum -= window[-0xC] * b0[0xB];
                sum -= window[-0xD] * b0[0xC];
                sum -= window[-0xE] * b0[0xD];
                sum -= window[-0xF] * b0[0xE];
                sum -= window[-0x0] * b0[0xF];

                WRITE_SAMPLE(samples, sum);
        }
        }
        *pnt += 32;

        return 0;
}



/* Call this after every seek to reset the buffers */
int mpeg3audio_reset_synths(mpeg3_layer_t *audio)
{
        int i, j, k;
        for(i = 0; i < 2; i++)
        {
                for(j = 0; j < 2; j++)
                {
                        for(k = 0; k < 0x110; k++)
                        {
                                audio->synth_stereo_buffs[i][j][k] = 0;
                        }
                }
        }
        for(i = 0; i < 64; i++)
        {
                audio->synth_mono_buff[i] = 0;
                audio->layer2_scfsi_buf[i] = 0;
        }
        for(i = 0; i < 2; i++)
        {
                for(j = 0; j < 2; j++)
                {
                        for(k = 0; k < SBLIMIT * SSLIMIT; k++)
                        {
                                audio->mp3_block[i][j][k] = 0;
                        }
                }
        }
        audio->mp3_blc[0] = 0;
        audio->mp3_blc[1] = 0;
        return 0;
}

---