From: notaz <notasas@gmail.com>
Date: Tue, 6 Feb 2007 22:25:53 +0000 (+0000)
Subject: sound code rewrite for lower sample rates (except mp3s)
X-Git-Tag: v1.85~759
X-Git-Url: https://notaz.gp2x.de/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a93adeb29f01f5867ff36606cd73a382b6ee0e3;p=picodrive.git

sound code rewrite for lower sample rates (except mp3s)

git-svn-id: file:///home/notaz/opt/svn/PicoDrive@30 be3aeb3a-fb24-0410-a615-afba39da0efa
---

diff --git a/Pico/Pico.c b/Pico/Pico.c
index 004a247e..3cee0c27 100644
--- a/Pico/Pico.c
+++ b/Pico/Pico.c
@@ -18,7 +18,7 @@ int PicoSkipFrame=0; // skip rendering frame?
 int PicoRegionOverride = 0; // override the region detection 0: Auto, 1: Japan NTSC, 2: Japan PAL, 4: US, 8: Europe
 int PicoAutoRgnOrder = 0;
 int emustatus = 0;
-void (*PicoWriteSound)(void) = 0; // called once per frame at the best time to send sound buffer (PsndOut) to hardware
+void (*PicoWriteSound)(int len) = 0; // called once per frame at the best time to send sound buffer (PsndOut) to hardware
 
 struct PicoSRAM SRam;
 int z80startCycle = 0, z80stopCycle = 0; // in 68k cycles
@@ -315,21 +315,22 @@ static int CheckIdle(void)
 // to be called on 224 or line_sample scanlines only
 static __inline void getSamples(int y)
 {
+  static int curr_pos = 0;
+
   if(y == 224) {
     //dprintf("sta%i: %i [%i]", (emustatus & 2), emustatus, y);
     if(emustatus & 2)
-        sound_render(PsndLen/2, PsndLen-PsndLen/2);
-    else sound_render(0, PsndLen);
+         curr_pos += sound_render(curr_pos, PsndLen-PsndLen/2);
+    else curr_pos  = sound_render(0, PsndLen);
     if (emustatus&1) emustatus|=2; else emustatus&=~2;
-    if (PicoWriteSound) PicoWriteSound();
+    if (PicoWriteSound) PicoWriteSound(curr_pos);
     // clear sound buffer
     sound_clear();
-    //memset(PsndOut, 0, (PicoOpt & 8) ? (PsndLen<<2) : (PsndLen<<1));
   }
   else if(emustatus & 3) {
     emustatus|= 2;
     emustatus&=~1;
-    sound_render(0, PsndLen/2);
+    curr_pos = sound_render(0, PsndLen/2);
   }
 }
 
@@ -538,10 +539,10 @@ static int PicoFrameSimple(void)
 
   // here we render sound if ym2612 is disabled
   if(!(PicoOpt&1) && PsndOut) {
-    sound_render(0, PsndLen);
-    if(PicoWriteSound) PicoWriteSound();
+    int len = sound_render(0, PsndLen);
+    if(PicoWriteSound) PicoWriteSound(len);
     // clear sound buffer
-    memset(PsndOut, 0, (PicoOpt & 8) ? (PsndLen<<2) : (PsndLen<<1));
+    sound_clear();
   }
 
   // render screen
diff --git a/Pico/Pico.h b/Pico/Pico.h
index ef2db109..7e7633cc 100644
--- a/Pico/Pico.h
+++ b/Pico/Pico.h
@@ -42,7 +42,7 @@ int PicoReset(int hard);
 int PicoFrame(void);
 extern int PicoPad[2]; // Joypads, format is MXYZ SACB RLDU
 extern int (*PicoCram)(int cram); // Callback to convert colour ram 0000bbb0 ggg0rrr0
-extern void (*PicoWriteSound)(void); // called once per frame at the best time to send sound buffer (PsndOut) to hardware
+extern void (*PicoWriteSound)(int len); // called once per frame at the best time to send sound buffer (PsndOut) to hardware
 
 int PicoFrameMCD(void);
 
@@ -89,7 +89,7 @@ extern void (*PicoPrepareCram)();    // prepares PicoCramHigh for renderer to us
 extern int PsndRate,PsndLen;
 extern short *PsndOut;
 void sound_reset();
-void sound_rerate();
+void sound_rerate(int preserve_state);
 void z80_pack(unsigned char *data);
 void z80_unpack(unsigned char *data);
 void z80_reset();
diff --git a/Pico/PicoInt.h b/Pico/PicoInt.h
index c7b72a21..b17277f2 100644
--- a/Pico/PicoInt.h
+++ b/Pico/PicoInt.h
@@ -277,6 +277,10 @@ int SekInitS68k(void);
 int SekResetS68k(void);
 int SekInterruptS68k(int irq);
 
+// sound/sound.c
+extern int PsndLen_exc_cnt;
+extern int PsndLen_exc_add;
+
 // VideoPort.c
 void PicoVideoWrite(unsigned int a,unsigned short d);
 unsigned int PicoVideoRead(unsigned int a);
diff --git a/Pico/cd/Pico.c b/Pico/cd/Pico.c
index d643cb7f..dfdbf5e8 100644
--- a/Pico/cd/Pico.c
+++ b/Pico/cd/Pico.c
@@ -131,27 +131,6 @@ static __inline void update_chips(void)
 		gfx_cd_update();
 }
 
-// to be called on 224 or line_sample scanlines only
-static __inline void getSamples(int y)
-{
-  if(y == 224) {
-    //dprintf("sta%i: %i [%i]", (emustatus & 2), emustatus, y);
-    if(emustatus & 2)
-        sound_render(PsndLen/2, PsndLen-PsndLen/2);
-    else sound_render(0, PsndLen);
-    if (emustatus&1) emustatus|=2; else emustatus&=~2;
-    if (PicoWriteSound) PicoWriteSound();
-    // clear sound buffer
-    sound_clear();
-    //memset(PsndOut, 0, (PicoOpt & 8) ? (PsndLen<<2) : (PsndLen<<1));
-  }
-  else if(emustatus & 3) {
-    emustatus|= 2;
-    emustatus&=~1;
-    sound_render(0, PsndLen/2);
-  }
-}
-
 
 static int PicoFrameHintsMCD(void)
 {
@@ -240,10 +219,12 @@ static int PicoFrameHintsMCD(void)
       sound_timers_and_dac(y);
 
     // get samples from sound chips
-    if(y == 32 && PsndOut)
-      emustatus &= ~1;
-    else if((y == 224 || y == line_sample) && PsndOut)
-      getSamples(y);
+    if (y == 224 && PsndOut) {
+      int len = sound_render(0, PsndLen);
+      if (PicoWriteSound) PicoWriteSound(len);
+      // clear sound buffer
+      sound_clear();
+    }
 
     // Run scanline:
       //dprintf("m68k starting exec @ %06x", SekPc);
diff --git a/Pico/sound/mix.s b/Pico/sound/mix.s
index ab0853e1..d34a2735 100644
--- a/Pico/sound/mix.s
+++ b/Pico/sound/mix.s
@@ -206,10 +206,10 @@ m16_32_s2_no_unal2:
 @ limit
 @ reg=int_sample, lr=1, r3=tmp, kills flags
 .macro Limit reg
-    add     r3, lr, \reg, asr #16
+    add     r3, lr, \reg, asr #15
     bics    r3, r3, #1			@ in non-overflow conditions r3 is 0 or 1
     movne   \reg, #0x8000
-    submi   \reg, \reg, #1
+    subpl   \reg, \reg, #1
 .endm
 
 
@@ -223,11 +223,11 @@ m16_32_s2_no_unal2:
 @    mov     r3, #0x8000
 @    subpl   r3, r3, #1
 
-    add     r3, lr, \reg, asr #16
+    add     r3, lr, \reg, asr #15
     bics    r3, r3, #1			@ in non-overflow conditions r3 is 0 or 1
     moveq   \reg, \reg, lsl #16
     movne   \reg, #0x80000000
-    submi   \reg, \reg, #0x00010000
+    subpl   \reg, \reg, #0x00010000
 .endm
 
 
@@ -292,7 +292,7 @@ mix_32_to_16_mono:
     @ check if dest is word aligned
     tst     r0, #2
     beq     m32_16_mo_no_unalw
-    ldrsh   r5, [r0], #2
+    ldrsh   r5, [r0]
     ldr     r4, [r1], #4
     sub     r2, r2, #1
     add     r4, r4, r5
@@ -339,7 +339,7 @@ m32_16_mo_end:
 m32_16_mo_no_unal2:
     tst     r2, #1
     ldmeqfd sp!, {r4-r8,pc}
-    ldrsh   r5, [r0], #2
+    ldrsh   r5, [r0]
     ldr     r4, [r1], #4
     add     r4, r4, r5
     Limit   r4
diff --git a/Pico/sound/sound.c b/Pico/sound/sound.c
index 6ea966bb..18cc46ea 100644
--- a/Pico/sound/sound.c
+++ b/Pico/sound/sound.c
@@ -38,6 +38,8 @@ unsigned short dac_info[312]; // pppppppp ppppllll, p - pos in buff, l - length
 // for Pico
 int PsndRate=0;
 int PsndLen=0; // number of mono samples, multiply by 2 for stereo
+int PsndLen_exc_add=0; // this is for non-integer sample counts per line, eg. 22050/60
+int PsndLen_exc_cnt=0;
 short *PsndOut=NULL; // PCM data buffer
 
 // from ym2612.c
@@ -55,7 +57,7 @@ static void dac_recalculate()
 
   if(PsndLen <= lines) {
     // shrinking algo
-    dac_cnt = 0;//lines - PsndLen;
+    dac_cnt = -PsndLen;
     len=1; pos=0;
     dac_info[225] = 1;
 
@@ -72,7 +74,7 @@ static void dac_recalculate()
     }
   } else {
     // stretching
-    dac_cnt = PsndLen/2;
+    dac_cnt = PsndLen;
     pos=0;
     for(i = 225; i != 224; i++) {
       if (i >= lines) i = 0;
@@ -92,12 +94,16 @@ static void dac_recalculate()
     }
     // last sample
     for(len = 0, i = pos; i < PsndLen; i++) len++;
+    if (PsndLen_exc_add) len++;
     dac_info[224] = (pos<<4)|len;
   }
-//  dprintf("rate is %i, len %i", PsndRate, PsndLen);
-//  for(i=0; i < lines; i++)
-//    dprintf("%03i : %03i : %i", i, dac_info[i]>>4, dac_info[i]&0xf);
-//exit(8);
+  //for(i=len=0; i < lines; i++) {
+  //  printf("%03i : %03i : %i\n", i, dac_info[i]>>4, dac_info[i]&0xf);
+  //  len+=dac_info[i]&0xf;
+  //}
+  //printf("rate is %i, len %f\n", PsndRate, (double)PsndRate/(Pico.m.pal ? 50.0 : 60.0));
+  //printf("len total: %i, last pos: %i\n", len, pos);
+  //exit(8);
 }
 
 
@@ -106,53 +112,58 @@ void sound_reset()
   extern int z80stopCycle;
   void *ym2612_regs;
 
-  // init even if we are not going to use them, just in case we ever enable it
-  YM2612Init(Pico.m.pal ? OSC_PAL/7 : OSC_NTSC/7, PsndRate);
   // also clear the internal registers+addr line
   ym2612_regs = YM2612GetRegs();
   memset(ym2612_regs, 0, 0x200+4);
-
-  SN76496_init(Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15, PsndRate);
-
-  // calculate PsndLen
-  PsndLen=PsndRate/(Pico.m.pal ? 50 : 60);
-
-  // recalculate dac info
-  dac_recalculate();
   z80stopCycle = 0;
+
+  sound_rerate(0);
 }
 
 
 // to be called after changing sound rate or chips
-void sound_rerate()
+void sound_rerate(int preserve_state)
 {
   unsigned int state[28];
+  int target_fps = Pico.m.pal ? 50 : 60;
 
-  // not all rates are supported in MCD mode due to mp3 decoder
+  // not all rates are supported in MCD mode due to mp3 decoder limitations
   if (PicoMCD & 1) {
     if (PsndRate != 11025 && PsndRate != 22050 && PsndRate != 44100) PsndRate = 22050;
-    if (!(PicoOpt & 8)) PicoOpt |= 8;
+    PicoOpt |= 8; // force stereo
   }
 
-  if ((PicoMCD & 1) && Pico_mcd->m.audio_track) Pico_mcd->m.audio_offset = mp3_get_offset();
+  if (preserve_state) {
+    if ((PicoMCD & 1) && Pico_mcd->m.audio_track)
+      Pico_mcd->m.audio_offset = mp3_get_offset();
+  }
   YM2612Init(Pico.m.pal ? OSC_PAL/7 : OSC_NTSC/7, PsndRate);
-  // feed it back it's own registers, just like after loading state
-  YM2612PicoStateLoad();
-  if ((PicoMCD & 1) && Pico_mcd->m.audio_track)
-    mp3_start_play(Pico_mcd->TOC.Tracks[Pico_mcd->m.audio_track].F, Pico_mcd->m.audio_offset);
+  if (preserve_state) {
+    // feed it back it's own registers, just like after loading state
+    YM2612PicoStateLoad();
+    if ((PicoMCD & 1) && Pico_mcd->m.audio_track)
+      mp3_start_play(Pico_mcd->TOC.Tracks[Pico_mcd->m.audio_track].F, Pico_mcd->m.audio_offset);
+  }
 
-  memcpy(state, sn76496_regs, 28*4); // remember old state
+  if (preserve_state) memcpy(state, sn76496_regs, 28*4); // remember old state
   SN76496_init(Pico.m.pal ? OSC_PAL/15 : OSC_NTSC/15, PsndRate);
-  memcpy(sn76496_regs, state, 28*4); // restore old state
+  if (preserve_state) memcpy(sn76496_regs, state, 28*4); // restore old state
 
   // calculate PsndLen
-  PsndLen=PsndRate/(Pico.m.pal ? 50 : 60);
+  PsndLen=PsndRate / target_fps;
+  PsndLen_exc_add=((PsndRate - PsndLen*target_fps)<<16) / target_fps;
+  PsndLen_exc_cnt=0;
 
   // recalculate dac info
   dac_recalculate();
 
   if (PicoMCD & 1)
     pcm_set_rate(PsndRate);
+
+  // clear all buffers
+  memset32(PsndBuffer, 0, sizeof(PsndBuffer)/4);
+  if (PsndOut)
+    sound_clear();
 }
 
 
@@ -181,22 +192,16 @@ void sound_timers_and_dac(int raster)
       d[0] = dout;
       if (len > 1) {
         d[2] = dout;
-        if (len > 2) {
+        if (len > 2)
           d[4] = dout;
-          if (len > 3)
-            d[6] = dout;
-        }
       }
     } else {
       short *d = PsndOut + pos;
       d[0] = dout;
       if (len > 1) {
         d[1] = dout;
-        if (len > 2) {
+        if (len > 2)
           d[2] = dout;
-          if (len > 3)
-            d[3] = dout;
-        }
       }
     }
   }
@@ -213,9 +218,10 @@ void sound_timers_and_dac(int raster)
 
 void sound_clear(void)
 {
-  if (PicoOpt & 8) memset32((int *) PsndOut, 0, PsndLen);
-  else memset(PsndOut, 0, PsndLen<<1);
-//  memset(PsndBuffer, 0, (PicoOpt & 8) ? (PsndLen<<3) : (PsndLen<<2));
+  int len = PsndLen;
+  if (PsndLen_exc_add) len++;
+  if (PicoOpt & 8) memset32((int *) PsndOut, 0, len); // clear both channels at once
+  else memset(PsndOut, 0, len<<1);
 }
 
 
@@ -227,6 +233,15 @@ int sound_render(int offset, int length)
   int do_pcm = (PicoMCD&1) && (PicoOpt&0x400) && (Pico_mcd->pcm.control & 0x80) && Pico_mcd->pcm.enabled;
   offset <<= stereo;
 
+  if (offset == 0) { // should happen once per frame
+    // compensate for float part of PsndLen
+    PsndLen_exc_cnt += PsndLen_exc_add;
+    if (PsndLen_exc_cnt >= 0x10000) {
+      PsndLen_exc_cnt -= 0x10000;
+      length++;
+    }
+  }
+
   // PSG
   if (PicoOpt & 2)
     SN76496Update(PsndOut+offset, length, stereo);
@@ -235,10 +250,11 @@ int sound_render(int offset, int length)
   if (PicoOpt & 1)
     YM2612UpdateOne(buf32, length, stereo, 1);
 
+  // CD: PCM sound
   if (do_pcm)
     pcm_update(buf32, length, stereo);
 
-  // CDDA audio
+  // CD: CDDA audio
 //  if ((PicoMCD & 1) && (PicoOpt & 0x800))
 //    mp3_update(PsndBuffer+offset, length, stereo);
 
@@ -247,7 +263,7 @@ int sound_render(int offset, int length)
        mix_32_to_16l_stereo(PsndOut+offset, buf32, length);
   else mix_32_to_16_mono   (PsndOut+offset, buf32, length);
 
-  return 0;
+  return length;
 }
 
 
diff --git a/platform/gp2x/940ctl_ym2612.c b/platform/gp2x/940ctl_ym2612.c
index 1a8160d3..29fd8bf5 100644
--- a/platform/gp2x/940ctl_ym2612.c
+++ b/platform/gp2x/940ctl_ym2612.c
@@ -537,6 +537,12 @@ int YM2612UpdateOne_940(int *buffer, int length, int stereo, int is_buf_empty)
 	}
 	writebuff_ptr = 0;
 
+	/* predict sample counter for next frame */
+	if (PsndLen_exc_add) {
+		if (PsndLen_exc_cnt + PsndLen_exc_add >= 0x10000) length = PsndLen + 1;
+		else length = PsndLen;
+	}
+
 	/* give 940 ym job */
 	shared_ctl->writebuffsel ^= 1;
 	shared_ctl->length = length;
diff --git a/platform/gp2x/code940/940.c b/platform/gp2x/code940/940.c
index 3f7130aa..18d282cb 100644
--- a/platform/gp2x/code940/940.c
+++ b/platform/gp2x/code940/940.c
@@ -4,7 +4,6 @@ static _940_data_t *shared_data = (_940_data_t *)   0x00100000;
 static _940_ctl_t  *shared_ctl  = (_940_ctl_t *)    0x00200000;
 static unsigned char *mp3_data  = (unsigned char *) 0x01000000;
 YM2612 *ym2612_940;
-int *mix_buffer;
 
 // from init.s
 void wait_irq(void);
@@ -59,8 +58,8 @@ static void mp3_decode(void)
 
 void Main940(int startvector, int pc_at_irq)
 {
+	int mix_buffer = shared_data->mix_buffer;
 	ym2612_940 = &shared_data->ym2612;
-	mix_buffer = shared_data->mix_buffer;
 
 	// debug
 	shared_ctl->vstarts[startvector]++;
diff --git a/platform/gp2x/emu.c b/platform/gp2x/emu.c
index bbb78b2d..871d05fd 100644
--- a/platform/gp2x/emu.c
+++ b/platform/gp2x/emu.c
@@ -48,6 +48,7 @@ unsigned char *rom_data = NULL;
 
 extern int crashed_940;
 
+static short sndBuffer[2*44100/50];
 static char noticeMsg[64];					// notice msg to draw
 static struct timeval noticeMsgTime = { 0, 0 };	// when started showing
 static int reset_timing, osd_fps_x;
@@ -927,24 +928,10 @@ static void updateKeys(void)
 	prevEvents = (allActions[0] | allActions[1]) >> 16;
 }
 
-static int snd_excess_add = 0, snd_excess_cnt = 0; // hack
 
-static void updateSound(void)
+static void updateSound(int len)
 {
-	int len = (PicoOpt&8)?PsndLen*2:PsndLen;
-
-	snd_excess_cnt += snd_excess_add;
-	if (snd_excess_cnt >= 0x10000) {
-		snd_excess_cnt -= 0x10000;
-		if (PicoOpt&8) {
-			PsndOut[len]   = PsndOut[len-2];
-			PsndOut[len+1] = PsndOut[len-1];
-			len+=2;
-		} else {
-			PsndOut[len]   = PsndOut[len-1];
-			len++;
-		}
-	}
+	if (PicoOpt&8) len<<=1;
 
 	gp2x_sound_write(PsndOut, len<<1);
 }
@@ -1024,22 +1011,23 @@ void emu_Loop(void)
 
 	// prepare sound stuff
 	if(currentConfig.EmuOpt & 4) {
+		int snd_excess_add;
 		if(PsndRate != PsndRate_old || (PicoOpt&0x20b) != (PicoOpt_old&0x20b) || Pico.m.pal != pal_old || crashed_940) {
 			/* if 940 is turned off, we need it to be put back to sleep */
 			if (!(PicoOpt&0x200) && ((PicoOpt^PicoOpt_old)&0x200)) {
 				Reset940(1, 2);
 				Pause940(1);
 			}
-			sound_rerate();
+			sound_rerate(1);
 		}
 		//excess_samples = PsndRate - PsndLen*target_fps;
-		snd_excess_cnt = 0;
 		snd_excess_add = ((PsndRate - PsndLen*target_fps)<<16) / target_fps;
 		printf("starting audio: %i len: %i (ex: %04x) stereo: %i, pal: %i\n", PsndRate, PsndLen, snd_excess_add, (PicoOpt&8)>>3, Pico.m.pal);
 		gp2x_start_sound(PsndRate, 16, (PicoOpt&8)>>3);
 		gp2x_sound_volume(currentConfig.volume, currentConfig.volume);
 		PicoWriteSound = updateSound;
-		PsndOut = calloc((PicoOpt&8) ? (PsndLen*4+4) : (PsndLen*2+2), 1);
+		memset(sndBuffer, 0, sizeof(sndBuffer));
+		PsndOut = sndBuffer;
 		PsndRate_old = PsndRate;
 		PsndLen_real = PsndLen;
 		PicoOpt_old  = PicoOpt;
@@ -1239,11 +1227,6 @@ if (Pico.m.frame_count == 31563) {
 		emu_SaveLoadGame(0, 1);
 		SRam.changed = 0;
 	}
-
-	if (PsndOut != 0) {
-		free(PsndOut);
-		PsndOut = 0;
-	}
 }