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//
// BeOS code for amp-0.7.4, (C) 1997 Andy Lo A Foe
//
#include <MediaKit.h>
#include <KernelKit.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "transform.h"
#include "audioIO.h"
#include "audio.h"
// Define the streambuf size here. streambuf is used
// as a simple fit buffer.
#define STREAMBUF_SIZE (32*1152)
long bytes_in_streambuf;
// streambuf definition and base indicator
BSubscriber *the_sub;
BDACStream *the_stream;
sem_id ok_to_read;
sem_id ok_to_write;
char streambuf[STREAMBUF_SIZE];
char *readbase;
static int au_vol = 100;
// Define our own printout function since we are
// first writing in the streambuf (not needed, I think,
// but I don't know if the DACStream accepts a buffer
// size of 1152. Try it...
void printout(void)
{
if (A_WRITE_TO_FILE) {
#ifndef NO_BYTE_SWAPPING
int i,j;
short *ptr;
if (nch==2) {
ptr=(short*)stereo_samples;
i=j=32 * 18 * 2;
} else {
ptr=(short*)mono_samples;
i=j=32 * 18;
}
for (;i>=0;--i)
ptr[i] = ptr[i] << 8 | ptr[i] >> 8;
#endif
if (nch==2)
fwrite(stereo_samples,1,sizeof stereo_samples,out_file);
else
fwrite(mono_samples,1,sizeof mono_samples,out_file);
}
if (A_AUDIO_PLAY) {
static char au_buf[STREAMBUF_SIZE];
static int au_ptr =0, avail = 0;
static int num_smp;
static char *readbase = &au_buf[0];
// Write amount of samples to copy somewhere
num_smp = (nch == 2 ? sizeof stereo_samples : sizeof mono_samples);
// Copy samples in the fit buffer
memcpy(au_buf+au_ptr,(nch == 2 ? (char *)stereo_samples : (char *)mono_samples),
num_smp);
// Increase fit buffer pointer and available sample count
au_ptr+=num_smp;
avail+=num_smp;
if (avail >= 4096) { // Are there enough smps to feed the stream?
audioWrite((char*)readbase,4096); // Feed it!
readbase+=4096; // Increase readbase
avail-=4096; // Decrease avail smps count
if (au_ptr == STREAMBUF_SIZE) { // At end of fit buffer?
au_ptr=0; // Reset all pointers
readbase=&au_buf[0];
}
}
}
}
// Fake Buffer functions, just to keep the sources clean,
// buffer.c should not be included in the link process...
int AUDIO_BUFFER_SIZE;
int
audioBufferOpen(int frequency, int stereo, int volume)
{
audioOpen(frequency, stereo, volume);
}
inline void
audioBufferWrite(char *buf,int bytes)
{
audioWrite(buf, bytes);
}
void
audioBufferClose()
{
audioClose();
}
int audioRead(char *buffer, int count)
{
//printf("acquiring ok_to_read (%d bytes)\n", count);
if (acquire_sem(ok_to_read)==B_NO_ERROR) {
for (register int i=0; i < count;i++) {
*(buffer++)+=*(readbase++);
}
bytes_in_streambuf-=count;
if (bytes_in_streambuf <= 0) {
release_sem(ok_to_write);
bytes_in_streambuf = 0;
} else {
release_sem(ok_to_read);
}
}
return (0);
}
bool stream_func(void *arg, char *buf, size_t count, void *header)
{
audioRead(buf, count);
return TRUE;
}
void audioOpen() {
readbase = &streambuf[0];
bytes_in_streambuf = 0;
the_sub = new BSubscriber("amp DAC writer");
the_stream = new BDACStream();
the_sub->Subscribe(the_stream);
the_stream->SetSamplingRate(frequency);
// Create semaphores
ok_to_read = create_sem(0, "read sem");
ok_to_write = create_sem(1, "write sem");
}
void audioInit(int sampleSize,int frequency, int stereo)
{
// Initialize the streambuf
bytes_in_streambuf = 0;
memset(&streambuf, 0, STREAMBUF_SIZE);
// Enter the stream
the_sub->EnterStream(NULL, TRUE, NULL, stream_func, NULL, TRUE);
}
void audioSetVolume(int volume)
{
if (volume > 128) // This allows for a modest volume boost
volume = 128;
au_vol = volume;
}
void audioClose()
{
the_sub->ExitStream(TRUE);
the_sub->Unsubscribe();
delete_sem(ok_to_read);
delete_sem(ok_to_write);
delete the_sub;
delete the_stream;
}
// audioWrite is called from the player thread
int audioWrite(char *buffer, int count)
{
//printf("acquiring ok_to_write (%d bytes)\n", count);
if(acquire_sem(ok_to_write)==B_NO_ERROR)
{
memcpy(&streambuf, buffer, count);
if (au_vol != 100) { // Handle volume scaling here
short *b=(short *)&streambuf;
for (int i=0; i < count/2; i++) {
int v=((int)b[i]*au_vol)/100;
b[i]=(v>32767) ? 32767 : ((v<-32768) ? -32768 : v);
}
}
bytes_in_streambuf = count;
readbase = &streambuf[0];
release_sem(ok_to_read);
}
return 0;
}
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