From: Dimitris Panokostas <midwan@gmail.com>
Date: Tue, 9 Jun 2026 21:30:41 +0000 (+0200)
Subject: Fix UAESND stream volume handling
X-Git-Url: https://git.unchartedbackwaters.co.uk/w/?a=commitdiff_plain;h=8986ee69833bd44217cfd437936a9c1d8d36b234;p=francis%2Fwinuae.git

Fix UAESND stream volume handling

- Apply writes to the current sample set volume register immediately.
  The stream volume was only loaded when a sample set was (re)loaded,
  so volume changes during playback (e.g. AHI volume fades on a
  looping sound) were silently ignored, even though current-set
  register writes are documented to take effect on the next sample
  period.
- Scale samples by the set volume and board channel volume
  multiplicatively. The previous averaging formula had a 0.5 gain
  floor, so volume 0 still played at half loudness.
- Initialize the board channel volumes for all stream channels, not
  just the first two.
---

diff --git a/sndboard.cpp b/sndboard.cpp
index ba7de950..edf553ea 100644
--- a/sndboard.cpp
+++ b/sndboard.cpp
@@ -562,6 +562,11 @@ static bool uaesnd_directload(struct uaesndboard_data *data, struct uaesndboard_
 	if (reg < 0 || reg == 20) {
 		s->replen = get_long_host(s->io + 20);
 	}
+	if (reg < 0 || reg == 24 || reg == 26) {
+		// repeat count + volume share a long word; reload volume so
+		// current-set volume writes take effect while playing
+		s->volume = get_word_host(s->io + 26);
+	}
 	return uaesnd_validate(data, s);
 }
 
@@ -686,7 +691,9 @@ static bool audio_state_sndboard_uae(int streamid, void *params)
 				if (sign)
 					sample -= 0x8000;
 				uae_s16 samples = (uae_s16)sample;
-				s->sample[i] = samples * ((s->volume + 1) / 2 + (data->volume[i] + 1) / 2) / 32768;
+				// scale by set volume and board channel volume multiplicatively
+				// so volume 0 is silent (the old averaged formula had a 0.5 gain floor)
+				s->sample[i] = samples * s->volume / 32768 * data->volume[i] / 32768;
 			}
 			if (len < 0)
 				addr -= s->framesize;
@@ -1213,8 +1220,9 @@ bool uaesndboard_init (struct autoconfig_info *aci, int z)
 	if (!ert)
 		return false;
 	data->streammask = 0;
-	data->volume[0] = 32768;
-	data->volume[1] = 32768;
+	for (int i = 0; i < MAX_UAE_CHANNELS; i++) {
+		data->volume[i] = 32768;
+	}
 	put_long_host(data->info + 0, (UAEMAJOR << 16) | (UAEMINOR << 8) | (UAESUBREV));
 	put_long_host(data->info + 4, (1 << 16) | (0));
 	put_long_host(data->info + 8, currprefs.sound_freq);