mpv/liba52/resample.c

126 lines
2.9 KiB
C

// this code come from a52dec/libao/audio_out_oss.c
// FIXME FIXME FIXME
// a52_resample_init should find the requested converter (from type flags ->
// given number of channels) and set up some function pointers...
// a52_resample() should do the conversion.
#include <inttypes.h>
#include "a52.h"
static inline int16_t convert (int32_t i)
{
if (i > 0x43c07fff)
return 32767;
else if (i < 0x43bf8000)
return -32768;
else
return i - 0x43c00000;
}
static int chans=2;
static int flags=0;
void a52_resample_init(int _flags,int _chans){
chans=_chans;
flags=_flags;
}
int a52_resample(float * _f, int16_t * s16)
{
int i;
int32_t * f = (int32_t *) _f;
switch (flags) {
case A52_MONO:
for (i = 0; i < 256; i++) {
s16[5*i] = s16[5*i+1] = s16[5*i+2] = s16[5*i+3] = 0;
s16[5*i+4] = convert (f[i]);
}
break;
case A52_CHANNEL:
case A52_STEREO:
case A52_DOLBY:
for (i = 0; i < 256; i++) {
s16[2*i] = convert (f[i]);
s16[2*i+1] = convert (f[i+256]);
}
break;
case A52_3F:
for (i = 0; i < 256; i++) {
s16[5*i] = convert (f[i]);
s16[5*i+1] = convert (f[i+512]);
s16[5*i+2] = s16[5*i+3] = 0;
s16[5*i+4] = convert (f[i+256]);
}
break;
case A52_2F2R:
for (i = 0; i < 256; i++) {
s16[4*i] = convert (f[i]);
s16[4*i+1] = convert (f[i+256]);
s16[4*i+2] = convert (f[i+512]);
s16[4*i+3] = convert (f[i+768]);
}
break;
case A52_3F2R:
for (i = 0; i < 256; i++) {
s16[5*i] = convert (f[i]);
s16[5*i+1] = convert (f[i+512]);
s16[5*i+2] = convert (f[i+768]);
s16[5*i+3] = convert (f[i+1024]);
s16[5*i+4] = convert (f[i+256]);
}
break;
case A52_MONO | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = s16[6*i+1] = s16[6*i+2] = s16[6*i+3] = 0;
s16[6*i+4] = convert (f[i+256]);
s16[6*i+5] = convert (f[i]);
}
break;
case A52_CHANNEL | A52_LFE:
case A52_STEREO | A52_LFE:
case A52_DOLBY | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+512]);
s16[6*i+2] = s16[6*i+3] = s16[6*i+4] = 0;
s16[6*i+5] = convert (f[i]);
}
break;
case A52_3F | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+768]);
s16[6*i+2] = s16[6*i+3] = 0;
s16[6*i+4] = convert (f[i+512]);
s16[6*i+5] = convert (f[i]);
}
break;
case A52_2F2R | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+512]);
s16[6*i+2] = convert (f[i+768]);
s16[6*i+3] = convert (f[i+1024]);
s16[6*i+4] = 0;
s16[6*i+5] = convert (f[i]);
}
break;
case A52_3F2R | A52_LFE:
for (i = 0; i < 256; i++) {
s16[6*i] = convert (f[i+256]);
s16[6*i+1] = convert (f[i+768]);
s16[6*i+2] = convert (f[i+1024]);
s16[6*i+3] = convert (f[i+1280]);
s16[6*i+4] = convert (f[i+512]);
s16[6*i+5] = convert (f[i]);
}
break;
}
return chans*256;
}