From 67c020eeafd6d3db7f9d2c314a77990177a1c4ff Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Mon, 25 Mar 2024 23:26:10 +0200
Subject: [PATCH] spu: don't leave garbage in capture buffers

---
 plugins/dfsound/externals.h |  1 +
 plugins/dfsound/freeze.c    |  1 +
 plugins/dfsound/spu.c       |  2 ++
 plugins/dfsound/xa.c        | 10 +++++++++-
 4 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/plugins/dfsound/externals.h b/plugins/dfsound/externals.h
index ac0960f6..8e479c53 100644
--- a/plugins/dfsound/externals.h
+++ b/plugins/dfsound/externals.h
@@ -214,6 +214,7 @@ typedef struct
  int             iLeftXAVol;
  int             iRightXAVol;
 
+ int             cdClearSamples;       // extra samples to clear the capture buffers
  struct {                              // channel volume in the cd controller
   unsigned char  ll, lr, rl, rr;       // see cdr.Attenuator* in cdrom.c
  } cdv;                                // applied on spu side for easier emulation
diff --git a/plugins/dfsound/freeze.c b/plugins/dfsound/freeze.c
index bddf0ada..36b89959 100644
--- a/plugins/dfsound/freeze.c
+++ b/plugins/dfsound/freeze.c
@@ -338,6 +338,7 @@ long CALLBACK SPUfreeze(unsigned int ulFreezeMode, SPUFreeze_t * pF,
 
  spu.XAPlay = spu.XAFeed = spu.XAStart;
  spu.CDDAPlay = spu.CDDAFeed = spu.CDDAStart;
+ spu.cdClearSamples = 512;
  if (pFO && pFO->xa_left && pF->xaS.nsamples) {        // start xa again
   FeedXA(&pF->xaS);
   spu.XAPlay = spu.XAFeed - pFO->xa_left;
diff --git a/plugins/dfsound/spu.c b/plugins/dfsound/spu.c
index 022a1e3d..ed5b4b5c 100644
--- a/plugins/dfsound/spu.c
+++ b/plugins/dfsound/spu.c
@@ -1389,6 +1389,7 @@ void CALLBACK SPUplayADPCMchannel(xa_decode_t *xap, unsigned int cycle, int is_s
 
  FeedXA(xap);                          // call main XA feeder
  spu.xapGlobal = xap;                  // store info for save states
+ spu.cdClearSamples = 512;
 }
 
 // CDDA AUDIO
@@ -1401,6 +1402,7 @@ int CALLBACK SPUplayCDDAchannel(short *pcm, int nbytes, unsigned int cycle, int
   do_samples(cycle, 1);                // catch up to prevent source underflows later
 
  FeedCDDA((unsigned char *)pcm, nbytes);
+ spu.cdClearSamples = 512;
  return 0;
 }
 
diff --git a/plugins/dfsound/xa.c b/plugins/dfsound/xa.c
index 6b5433fb..380d1388 100644
--- a/plugins/dfsound/xa.c
+++ b/plugins/dfsound/xa.c
@@ -152,8 +152,16 @@ INLINE void MixCD(int *SSumLR, int *RVB, int ns_to, int decode_pos)
    }
   spu.XALastVal = v;
  }
- else
+ else if (spu.cdClearSamples > 0)
+ {
+  for(ns = 0; ns < ns_to; ns++)
+   {
+    spu.spuMem[cursor] = spu.spuMem[cursor + 0x400/2] = 0;
+    cursor = (cursor + 1) & 0x1ff;
+   }
+  spu.cdClearSamples -= ns_to;
   spu.XALastVal = 0;
+ }
 }
 
 ////////////////////////////////////////////////////////////////////////
-- 
2.39.2