Mix sound sources in 32-bit buffer, then clip to 16-bit for output. Fixes overflow in some situations, eg MegaRace on SB16.

src/sound.c

@@ -78,7 +78,7 @@ void sound_card_init()
 
 static struct
 {
-        void (*get_buffer)(int16_t *buffer, int len, void *p);
+        void (*get_buffer)(int32_t *buffer, int len, void *p);
         void *priv;
 } sound_handlers[8];
 
@@ -157,20 +157,20 @@ static void sound_cd_thread(void *param)
         }
 }
 
-static uint16_t *outbuffer;
+static int32_t *outbuffer;
 
 void sound_init()
 {
         initalmain(0,NULL);
         inital();
 
-        outbuffer = malloc(SOUNDBUFLEN * 2 * sizeof(int16_t));
+        outbuffer = malloc(SOUNDBUFLEN * 2 * sizeof(int32_t));
         
         sound_cd_event = thread_create_event();
         sound_cd_thread_h = thread_create(sound_cd_thread, NULL);
 }
 
-void sound_add_handler(void (*get_buffer)(int16_t *buffer, int len, void *p), void *p)
+void sound_add_handler(void (*get_buffer)(int32_t *buffer, int len, void *p), void *p)
 {
         sound_handlers[sound_handlers_num].get_buffer = get_buffer;
         sound_handlers[sound_handlers_num].priv = p;
@@ -185,14 +185,26 @@ void sound_poll(void *priv)
         if (sound_pos_global == SOUNDBUFLEN)
         {
                 int c;
+/*                int16_t buf16[SOUNDBUFLEN * 2 ];*/
 
-                memset(outbuffer, 0, SOUNDBUFLEN * 2 * sizeof(int16_t));
+                memset(outbuffer, 0, SOUNDBUFLEN * 2 * sizeof(int32_t));
 
                 for (c = 0; c < sound_handlers_num; c++)
                         sound_handlers[c].get_buffer(outbuffer, SOUNDBUFLEN, sound_handlers[c].priv);
 
-/*        if (!soundf) soundf=fopen("sound.pcm","wb");
+
-        fwrite(outbuffer,(SOUNDBUFLEN)*2*2,1,soundf);*/
+/*                for (c=0;c<SOUNDBUFLEN*2;c++)
+                {
+                        if (outbuffer[c] < -32768)
+                                buf16[c] = -32768;
+                        else if (outbuffer[c] > 32767)
+                                buf16[c] = 32767;
+                        else
+                                buf16[c] = outbuffer[c];
+                }
+
+        if (!soundf) soundf=fopen("sound.pcm","wb");
+        fwrite(buf16,(SOUNDBUFLEN)*2*2,1,soundf);*/
         
                 if (soundon) givealbuffer(outbuffer);
         

src/sound.h

@@ -1,6 +1,6 @@
 #include "timer.h"
 
-void sound_add_handler(void (*get_buffer)(int16_t *buffer, int len, void *p), void *p);
+void sound_add_handler(void (*get_buffer)(int32_t *buffer, int len, void *p), void *p);
 
 extern int sbtype;
 

src/sound_adlib.c

@@ -11,7 +11,7 @@ typedef struct adlib_t
         opl_t   opl;
 } adlib_t;
 
-static void adlib_get_buffer(int16_t *buffer, int len, void *p)
+static void adlib_get_buffer(int32_t *buffer, int len, void *p)
 {
         adlib_t *adlib = (adlib_t *)p;
         int c;
@@ -19,7 +19,7 @@ static void adlib_get_buffer(int16_t *buffer, int len, void *p)
         opl2_update2(&adlib->opl);
         
         for (c = 0; c < len * 2; c++)
-                buffer[c] += adlib->opl.buffer[c];
+                buffer[c] += (int32_t)adlib->opl.buffer[c];
 
         adlib->opl.pos = 0;
 }

src/sound_adlibgold.c

@@ -651,7 +651,7 @@ void adgold_timer_poll(void *p)
         }
 }
 
-static void adgold_get_buffer(int16_t *buffer, int len, void *p)
+static void adgold_get_buffer(int32_t *buffer, int len, void *p)
 {
         adgold_t *adgold = (adgold_t *)p;
         int16_t adgold_buffer[len*2];

src/sound_cms.c

@@ -84,7 +84,7 @@ void cms_update(cms_t *cms)
         }
 }
 
-void cms_get_buffer(int16_t *buffer, int len, void *p)
+void cms_get_buffer(int32_t *buffer, int len, void *p)
 {
         cms_t *cms = (cms_t *)p;
         

src/sound_gus.c

@@ -1047,7 +1047,7 @@ void gus_poll_wave(void *p)
                 pollgusirqs(gus);
 }
 
-static void gus_get_buffer(int16_t *buffer, int len, void *p)
+static void gus_get_buffer(int32_t *buffer, int len, void *p)
 {
         gus_t *gus = (gus_t *)p;
         int c;
@@ -1056,7 +1056,7 @@ static void gus_get_buffer(int16_t *buffer, int len, void *p)
         
         for (c = 0; c < len * 2; c++)
         {
-                buffer[c] += gus->buffer[c & 1][c >> 1];
+                buffer[c] += (int32_t)gus->buffer[c & 1][c >> 1];
         }
 
         gus->pos = 0;

src/sound_pas16.c

@@ -706,7 +706,7 @@ static void pas16_update(pas16_t *pas16)
         }
 }
 
-void pas16_get_buffer(int16_t *buffer, int len, void *p)
+void pas16_get_buffer(int32_t *buffer, int len, void *p)
 {
         pas16_t *pas16 = (pas16_t *)p;
         int c;

src/sound_ps1.c

@@ -126,7 +126,7 @@ static void ps1_audio_callback(void *p)
         ps1->timer_count += ps1->timer_latch * TIMER_USEC;
 }
 
-static void ps1_audio_get_buffer(int16_t *buffer, int len, void *p)
+static void ps1_audio_get_buffer(int32_t *buffer, int len, void *p)
 {
         ps1_audio_t *ps1 = (ps1_audio_t *)p;
         int c;

src/sound_pssj.c

@@ -167,7 +167,7 @@ static void pssj_callback(void *p)
         pssj->timer_count += (int)(TIMER_USEC * (1000000.0 / 3579545.0) * (double)(pssj->freq ? pssj->freq : 0x400));
 }
 
-static void pssj_get_buffer(int16_t *buffer, int len, void *p)
+static void pssj_get_buffer(int32_t *buffer, int len, void *p)
 {
         pssj_t *pssj = (pssj_t *)p;
         int c;

src/sound_sb.c

@@ -11,12 +11,12 @@
 
 typedef struct sb_mixer_t
 {
-        unsigned int master_l, master_r;
+        int master_l, master_r;
-        unsigned int voice_l,  voice_r;
+        int voice_l,  voice_r;
-        unsigned int fm_l,     fm_r;
+        int fm_l,     fm_r;
-        unsigned int cd_l,     cd_r;
+        int cd_l,     cd_r;
-        unsigned int bass_l,   bass_r;
+        int bass_l,   bass_r;
-        unsigned int treble_l, treble_r;
+        int treble_l, treble_r;
         int filter;
 
         int index;
@@ -41,7 +41,7 @@ static int sb_att[]=
         39036,46395,55140,65535
 };
 
-static void sb_get_buffer_opl2(int16_t *buffer, int len, void *p)
+static void sb_get_buffer_opl2(int32_t *buffer, int len, void *p)
 {
         sb_t *sb = (sb_t *)p;
         sb_mixer_t *mixer = &sb->mixer;
@@ -52,7 +52,7 @@ static void sb_get_buffer_opl2(int16_t *buffer, int len, void *p)
         sb_dsp_update(&sb->dsp);
         for (c = 0; c < len * 2; c += 2)
         {
-                int16_t out_l, out_r;
+                int32_t out_l, out_r;
                 
                 out_l = ((sb->opl.buffer[c]     * mixer->fm_l) >> 16);
                 out_r = ((sb->opl.buffer[c + 1] * mixer->fm_r) >> 16);
@@ -92,7 +92,7 @@ static void sb_get_buffer_opl2(int16_t *buffer, int len, void *p)
         sb->dsp.pos = 0;
 }
 
-static void sb_get_buffer_opl3(int16_t *buffer, int len, void *p)
+static void sb_get_buffer_opl3(int32_t *buffer, int len, void *p)
 {
         sb_t *sb = (sb_t *)p;
         sb_mixer_t *mixer = &sb->mixer;
@@ -104,7 +104,7 @@ static void sb_get_buffer_opl3(int16_t *buffer, int len, void *p)
         for (c = 0; c < len * 2; c += 2)
         {
                 int c_emu8k = (((c/2) * 44100) / 48000)*2;
-                int16_t out_l, out_r;
+                int32_t out_l, out_r;
                 
                 out_l = ((sb->opl.buffer[c]     * mixer->fm_l) >> 16);
                 out_r = ((sb->opl.buffer[c + 1] * mixer->fm_r) >> 16);
@@ -145,7 +145,7 @@ static void sb_get_buffer_opl3(int16_t *buffer, int len, void *p)
         sb->emu8k.pos = 0;
 }
 
-static void sb_get_buffer_emu8k(int16_t *buffer, int len, void *p)
+static void sb_get_buffer_emu8k(int32_t *buffer, int len, void *p)
 {
         sb_t *sb = (sb_t *)p;
         sb_mixer_t *mixer = &sb->mixer;
@@ -158,10 +158,10 @@ static void sb_get_buffer_emu8k(int16_t *buffer, int len, void *p)
         for (c = 0; c < len * 2; c += 2)
         {
                 int c_emu8k = (((c/2) * 44100) / 48000)*2;
-                int16_t out_l, out_r;
+                int32_t out_l, out_r;
                 
-                out_l = ((sb->opl.buffer[c]     * mixer->fm_l) >> 16);
+                out_l = (((int32_t)sb->opl.buffer[c]     * (int32_t)mixer->fm_l) >> 16);
-                out_r = ((sb->opl.buffer[c + 1] * mixer->fm_r) >> 16);
+                out_r = (((int32_t)sb->opl.buffer[c + 1] * (int32_t)mixer->fm_r) >> 16);
 
                 out_l += ((sb->emu8k.buffer[c_emu8k]     * mixer->fm_l) >> 16);
                 out_r += ((sb->emu8k.buffer[c_emu8k + 1] * mixer->fm_l) >> 16);

src/sound_sn76489.c

@@ -60,7 +60,7 @@ void sn76489_update(sn76489_t *sn76489)
         }
 }
 
-void sn76489_get_buffer(int16_t *buffer, int len, void *p)
+void sn76489_get_buffer(int32_t *buffer, int len, void *p)
 {
         sn76489_t *sn76489 = (sn76489_t *)p;
         

src/sound_speaker.c

@@ -37,7 +37,7 @@ void speaker_update()
         }
 }
 
-static void speaker_get_buffer(int16_t *buffer, int len, void *p)
+static void speaker_get_buffer(int32_t *buffer, int len, void *p)
 {
         int c;
 

src/sound_ssi2001.c

@@ -22,7 +22,7 @@ static void ssi2001_update(ssi2001_t *ssi2001)
         ssi2001->pos = sound_pos_global;
 }
 
-static void ssi2001_get_buffer(int16_t *buffer, int len, void *p)
+static void ssi2001_get_buffer(int32_t *buffer, int len, void *p)
 {
         ssi2001_t *ssi2001 = (ssi2001_t *)p;
         int c;

src/sound_wss.c

@@ -57,7 +57,7 @@ void wss_write(uint16_t addr, uint8_t val, void *p)
         ad1848_setirq(&wss->ad1848, wss_irq[(val >> 3) & 7]);
 }
 
-static void wss_get_buffer(int16_t *buffer, int len, void *p)
+static void wss_get_buffer(int32_t *buffer, int len, void *p)
 {
         wss_t *wss = (wss_t *)p;
         

src/soundopenal.c

@@ -141,9 +141,10 @@ void inital()
 #endif
 }
 
-void givealbuffer(int16_t *buf)
+void givealbuffer(int32_t *buf)
 {
 #ifdef USE_OPENAL
+        int16_t buf16[BUFLEN*2];
         int processed;
         int state;
         
@@ -172,14 +173,24 @@ void givealbuffer(int16_t *buf)
 
         if (processed>=1)
         {
+                int c;
                 ALuint buffer;
 
                 alSourceUnqueueBuffers(source[0], 1, &buffer);
 //                printf("U ");
                 check();
 
+                for (c=0;c<BUFLEN*2;c++)
+                {
+                        if (buf[c] < -32768)
+                                buf16[c] = -32768;
+                        else if (buf[c] > 32767)
+                                buf16[c] = 32767;
+                        else
+                                buf16[c] = buf[c];
+                }
 //                for (c=0;c<BUFLEN*2;c++) buf[c]^=0x8000;
-                alBufferData(buffer, AL_FORMAT_STEREO16, buf, BUFLEN*2*2, FREQ);
+                alBufferData(buffer, AL_FORMAT_STEREO16, buf16, BUFLEN*2*2, FREQ);
 //                printf("B ");
                check();