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lowercasing filenames, part2

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git-svn-id: file:///home/notaz/opt/svn/PicoDrive@575 be3aeb3a-fb24-0410-a615-afba39da0efa
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notaz 2008-08-28 12:36:04 +00:00
parent efcba75f8a
commit d158df697d
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114
Pico/pico/xpcm.c Normal file
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/*
* The following ADPCM algorithm was stolen from MAME aica driver.
* I'm quite sure it's not the right one, but it's the
* best sounding of the ones that I tried.
*/
#include "../pico_int.h"
#define ADPCMSHIFT 8
#define ADFIX(f) (int) ((double)f * (double)(1<<ADPCMSHIFT))
/* limitter */
#define Limit(val, max, min) { \
if ( val > max ) val = max; \
else if ( val < min ) val = min; \
}
static const int TableQuant[8] =
{
ADFIX(0.8984375),
ADFIX(0.8984375),
ADFIX(0.8984375),
ADFIX(0.8984375),
ADFIX(1.19921875),
ADFIX(1.59765625),
ADFIX(2.0),
ADFIX(2.3984375)
};
// changed using trial and error..
//static const int quant_mul[16] = { 1, 3, 5, 7, 9, 11, 13, 15, -1, -3, -5, -7, -9, -11, -13, -15 };
static const int quant_mul[16] = { 1, 3, 5, 7, 9, 11, 13, -1, -1, -3, -5, -7, -9, -11, -13, -15 };
static int sample = 0, quant = 0, sgn = 0;
static int stepsamples = (44100<<10)/16000;
PICO_INTERNAL void PicoPicoPCMReset(void)
{
sample = sgn = 0;
quant = 0x7f;
memset(PicoPicohw.xpcm_buffer, 0, sizeof(PicoPicohw.xpcm_buffer));
}
PICO_INTERNAL void PicoPicoPCMRerate(int xpcm_rate)
{
stepsamples = (PsndRate<<10)/xpcm_rate;
}
#define XSHIFT 6
#define do_sample() \
{ \
int delta = quant * quant_mul[srcval] >> XSHIFT; \
sample += delta - (delta >> 2); /* 3/4 */ \
quant = (quant * TableQuant[srcval&7]) >> ADPCMSHIFT; \
Limit(quant, 0x6000, 0x7f); \
Limit(sample, 32767*3/4, -32768*3/4); \
}
PICO_INTERNAL void PicoPicoPCMUpdate(short *buffer, int length, int stereo)
{
unsigned char *src = PicoPicohw.xpcm_buffer;
unsigned char *lim = PicoPicohw.xpcm_ptr;
int srcval, needsamples = 0;
if (src == lim) goto end;
for (; length > 0 && src < lim; src++)
{
srcval = *src >> 4;
do_sample();
for (needsamples += stepsamples; needsamples > (1<<10) && length > 0; needsamples -= (1<<10), length--) {
*buffer++ += sample;
if (stereo) { buffer[0] = buffer[-1]; buffer++; }
}
srcval = *src & 0xf;
do_sample();
for (needsamples += stepsamples; needsamples > (1<<10) && length > 0; needsamples -= (1<<10), length--) {
*buffer++ += sample;
if (stereo) { buffer[0] = buffer[-1]; buffer++; }
}
// lame normalization stuff, needed due to wrong adpcm algo
sgn += (sample < 0) ? -1 : 1;
if (sgn < -16 || sgn > 16) sample -= sample >> 5;
}
if (src < lim) {
int di = lim - src;
memmove(PicoPicohw.xpcm_buffer, src, di);
PicoPicohw.xpcm_ptr = PicoPicohw.xpcm_buffer + di;
elprintf(EL_PICOHW, "xpcm update: over %i", di);
// adjust fifo
PicoPicohw.fifo_bytes = di;
return;
}
elprintf(EL_PICOHW, "xpcm update: under %i", length);
PicoPicohw.xpcm_ptr = PicoPicohw.xpcm_buffer;
end:
if (stereo)
// still must expand SN76496 to stereo
for (; length > 0; buffer+=2, length--)
buffer[1] = buffer[0];
sample = sgn = 0;
quant = 0x7f;
}