From 71644ff3e64d00dd6e5a6efdff9d579e7a839662 Mon Sep 17 00:00:00 2001
From: Matiq <kokagishi@proton.me>
Date: Sat, 22 Aug 2026 10:59:26 +0300
Subject: [PATCH] =?UTF-8?q?fix(render48k):=20chunk-scan=20WAV=20loader=20?=
 =?UTF-8?q?=E2=80=94=20hdr[40]=20is=20not=20data=20size=20when=20bext/junk?=
 =?UTF-8?q?=20present?=
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---
 dsp/render48k.cpp | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/dsp/render48k.cpp b/dsp/render48k.cpp
index 0351525..559a7c0 100644
--- a/dsp/render48k.cpp
+++ b/dsp/render48k.cpp
@@ -26,7 +26,21 @@ static bool load_wav(const char* path, std::vector<float>& out, int& sr) {
     sr = *(int*)(hdr + 24);
     int ch = *(short*)(hdr + 22);
     int bits = *(short*)(hdr + 34);
-    int data = *(int*)(hdr + 40);
+    // scan chunks to find data chunk size (hdr[40] may be bext/junk size)
+    int data = 0;
+    int64_t pos = 12;
+    fseek(f, 12, SEEK_SET);
+    while (pos < 32 * 1024 * 1024) {
+        char cid[4]; int csize;
+        if (fread(cid, 1, 4, f) < 4 || fread(&csize, 4, 1, f) < 1) break;
+        pos += 8;
+        if (memcmp(cid, "data", 4) == 0) { data = csize; break; }
+        pos += csize;
+        int skip = csize;
+        if (csize % 2) skip++;  // odd chunk size padded
+        fseek(f, skip, SEEK_CUR);
+    }
+    if (!data) { fclose(f); return false; }
     int n = data / (ch * (bits / 8));
     g_in_ch = ch;
     out.resize(n);