rockbox/apps/plugins/rockboy/rbsound.c
Brandon Low 413da2a3d9 Rework PCM buffer
* Linked list instead of static array buffer pointers
* Variable sized chunks
* Improved mix handling
* Reduction in duplicated code
* Reduced IRAM usage w/o sacrificing performance
* Converted to almost entirely unsigned math
* Add pause function to reduce pcm_* exposure to playback.

This WILL break playback on the iPod until linuxstb makes a followup commit.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@8612 a1c6a512-1295-4272-9138-f99709370657
2006-02-07 20:38:55 +00:00

143 lines
2.7 KiB
C

#include "rockmacros.h"
#include "defs.h"
#include "pcm.h"
#include "rc.h"
//#define ONEBUF // Note: I think the single buffer implementation is more responsive with sound(less lag)
// but it creates more choppyness overall to the sound. 2 buffer's don't seem to make
// a difference, but 4 buffers is definately noticable
struct pcm pcm IBSS_ATTR;
bool sound = 1;
#ifdef ONEBUF
#define N_BUFS 1
#else
#define N_BUFS 4
#endif
#define BUF_SIZE 1024
rcvar_t pcm_exports[] =
{
RCV_END
};
#if CONFIG_CODEC == SWCODEC && !defined(SIMULATOR)
#ifndef ONEBUF
static short curbuf,gmcurbuf;
#else
bool doneplay=0;
#endif
static unsigned char *buf=0;
static unsigned short *gmbuf;
static bool newly_started;
void get_more(unsigned char** start, size_t* size)
{
#ifdef ONEBUF
doneplay=1;
*start = (unsigned char*)(gmbuf);
#else
*start = (unsigned char*)(&gmbuf[pcm.len*curbuf]);
#endif
*size = BUF_SIZE*sizeof(short);
}
void pcm_init(void)
{
if(!sound) return;
newly_started = true;
pcm.hz = 11025;
pcm.stereo = 1;
pcm.len = BUF_SIZE;
if(!buf){
buf = my_malloc(pcm.len * N_BUFS);
gmbuf = my_malloc(pcm.len * N_BUFS*sizeof (short));
pcm.buf = buf;
pcm.pos = 0;
#ifndef ONEBUF
curbuf = gmcurbuf= 0;
#endif
memset(gmbuf, 0, pcm.len * N_BUFS *sizeof(short));
memset(buf, 0, pcm.len * N_BUFS);
}
rb->pcm_play_stop();
rb->pcm_set_frequency(11025); // 44100 22050 11025
}
void pcm_close(void)
{
memset(&pcm, 0, sizeof pcm);
newly_started = true;
rb->pcm_play_stop();
rb->pcm_set_frequency(44100);
}
int pcm_submit(void)
{
register int i;
if (!sound) {
pcm.pos = 0;
return 0;
}
if (pcm.pos < pcm.len) return 1;
#ifndef ONEBUF
curbuf = (curbuf + 1) % N_BUFS;
pcm.buf = buf + pcm.len * curbuf;
#endif
pcm.pos = 0;
// gotta convert the 8 bit buffer to 16
for(i=0; i<pcm.len;i++)
#ifdef ONEBUF
gmbuf[i] = (pcm.buf[i]<<8)-0x8000;
#else
gmbuf[i+pcm.len*curbuf] = (pcm.buf[i]<<8)-0x8000;
#endif
if(newly_started)
{
rb->pcm_play_data(&get_more,NULL,0);
newly_started = false;
}
// this while loop and done play are in place to make sure the sound timing is correct(although it's not)
#ifdef ONEBUF
while(doneplay==0) rb->yield();
doneplay=0;
#endif
return 1;
}
#else
static byte buf1_unal[(BUF_SIZE / sizeof(short)) + 2]; // to make sure 4 byte aligned
void pcm_init(void)
{
pcm.hz = 11025;
pcm.stereo = 1;
pcm.buf = buf1_unal;
pcm.len = (BUF_SIZE / sizeof(short));
pcm.pos = 0;
}
void pcm_close(void)
{
memset(&pcm, 0, sizeof pcm);
}
int pcm_submit(void)
{
pcm.pos =0;
return 0;
}
#endif