valter/dosbox-staging
1
0
Fork 0
Code Releases Activity

New mixer routine to handle speeding up emulator causing faster output

Browse source 
Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@2482
This commit is contained in:
Sjoerd van der Berg 2006-02-11 09:37:16 +00:00
parent f6efa75ba5
commit 0e3603396e
1 changed files with 53 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

79
src/hardware/mixer.cpp
View file

@ -16,7 +16,7 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* $Id: mixer.cpp,v 1.37 2006-02-09 11:47:49 qbix79 Exp $ */
/* $Id: mixer.cpp,v 1.38 2006-02-11 09:37:16 harekiet Exp $ */
/*
Remove the sdl code from here and have it handeld in the sdlmain.
@ -80,13 +80,13 @@ struct MIXER_Channel {
static struct {
Bit32s work[MIXER_BUFSIZE][2];
Bitu pos,done;
Bitu needed,min_needed;
Bitu needed, min_needed, max_needed;
Bit32u tick_add,tick_remain;
float mastervol[2];
MixerChannel * channels;
bool nosound;
Bit32u freq;
Bit32u blocksize;
Bit32u tick_add,tick_remain;
} mixer;
Bit8u MixTemp[MIXER_BUFSIZE];
@ -292,8 +292,6 @@ static void MIXER_MixData(Bitu needed) {
readpos=(readpos+1)&MIXER_BUFMASK;
}
CAPTURE_AddWave( mixer.freq, added, (Bit16s*)convert );
//Reset the the tick_add for constant speed
mixer.tick_add=((mixer.freq) << MIXER_SHIFT)/1000;
}
mixer.done=needed;
}
@ -329,34 +327,62 @@ static void MIXER_Mix_NoSound(void) {
static void MIXER_CallBack(void * userdata, Uint8 *stream, int len) {
Bitu need=(Bitu)len/MIXER_SSIZE;
if (need>mixer.done) {
//LOG_MSG("%d Buffer underrun %d done and %d needed",count++,mixer.done,need);
return;
}//else LOG_MSG("%d Buffer regular run %d done and %d needed",count++,mixer.done,need);
Bit16s * output=(Bit16s *)stream;
Bitu reduce;
Bitu pos, index, index_add;
Bits sample;
/* Enough room in the buffer ? */
if (mixer.done < need) {
// LOG_MSG("Full underrun need %d, have %d, min %d", need, mixer.done, mixer.min_needed);
reduce = mixer.done;
index_add = (reduce << MIXER_SHIFT) / need;
} else if (mixer.done < mixer.max_needed) {
Bitu left = mixer.done - need;
if (left < mixer.min_needed) {
left = (mixer.min_needed - left);
left = 1 + (2*left) / mixer.min_needed;
// left = 1;
// left = 1 + (left / 128);
// LOG_MSG("needed underrun need %d, have %d, min %d, left %d", need, mixer.done, mixer.min_needed, left);
reduce = need - left;
index_add = (reduce << MIXER_SHIFT) / need;
} else {
reduce = need;
index_add = (1 << MIXER_SHIFT);
}
} else {
/* There is way too much data in the buffer */
if (mixer.done > MIXER_BUFSIZE)
index_add = MIXER_BUFSIZE - mixer.min_needed;
else
index_add = mixer.done - mixer.min_needed;
index_add = (index_add << MIXER_SHIFT) / need;
reduce = mixer.done - mixer.min_needed;
}
/* Reduce done count in all channels */
for (MixerChannel * chan=mixer.channels;chan;chan=chan->next) {
if (chan->done>need) chan->done-=need;
if (chan->done>need) chan->done-=reduce;
else chan->done=0;
}
mixer.done-=need;
mixer.needed-=need;
if (mixer.done > mixer.min_needed) {
Bitu diff=mixer.done-mixer.min_needed;
mixer.tick_add = ((mixer.freq-(diff/5)) << MIXER_SHIFT)/1000;
} else {
Bitu diff = ((mixer.min_needed>mixer.needed)?mixer.min_needed:mixer.needed) - mixer.done;
mixer.tick_add = ((mixer.freq+(diff*3)) << MIXER_SHIFT)/1000;
}
Bit16s * output=(Bit16s *)stream;
Bits sample;
mixer.done -= reduce;
mixer.needed -= reduce;
pos = mixer.pos;
mixer.pos = (mixer.pos + reduce) & MIXER_BUFMASK;
index = 0;
while (need--) {
sample=mixer.work[mixer.pos][0]>>MIXER_VOLSHIFT;
Bitu i = (pos + (index >> MIXER_SHIFT )) & MIXER_BUFMASK;
index += index_add;
sample=mixer.work[i][0]>>MIXER_VOLSHIFT;
*output++=MIXER_CLIP(sample);
mixer.work[mixer.pos][0]=0;
sample=mixer.work[mixer.pos][1]>>MIXER_VOLSHIFT;
sample=mixer.work[i][1]>>MIXER_VOLSHIFT;
*output++=MIXER_CLIP(sample);
mixer.work[mixer.pos][1]=0;
mixer.pos=(mixer.pos+1)&MIXER_BUFMASK;
}
/* Clean the used buffer */
while (reduce--) {
pos &= MIXER_BUFMASK;
mixer.work[pos][0]=0;
mixer.work[pos][1]=0;
pos++;
}
}
@ -505,6 +531,7 @@ void MIXER_Init(Section* sec) {
mixer.min_needed=section->Get_int("prebuffer");
if (mixer.min_needed>100) mixer.min_needed=100;
mixer.min_needed=(mixer.freq*mixer.min_needed)/1000;
mixer.max_needed=mixer.blocksize * 2 + mixer.min_needed;
mixer.needed=mixer.min_needed+1;
PROGRAMS_MakeFile("MIXER.COM",MIXER_ProgramStart);
}