From 9466df90e089bb0248b92d4b0319d9ef48b9664f Mon Sep 17 00:00:00 2001
From: SnapOtter <snapotter.hq@gmail.com>
Date: Mon, 11 May 2026 18:13:29 +0800
Subject: [PATCH] fix: extract first frame from multi-image FITS files

ImageMagick outputs numbered files (fits-out-0.png, fits-out-1.png)
for multi-image FITS, but decodeFits expected a single output file.
Added [0] selector to extract only the first frame, matching the
pattern used by DDS and PSD decoders.
---
 apps/api/src/lib/format-decoders.ts | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/apps/api/src/lib/format-decoders.ts b/apps/api/src/lib/format-decoders.ts
index c5031d58..dd2ea6f5 100644
--- a/apps/api/src/lib/format-decoders.ts
+++ b/apps/api/src/lib/format-decoders.ts
@@ -438,7 +438,13 @@ async function decodeFits(buffer: Buffer): Promise<Buffer> {
     await writeFile(inputPath, buffer);
     await execFileAsync(
       cmd,
-      magickArgs(cmd, [inputPath, "-normalize", "-colorspace", "sRGB", `png:${outputPath}`]),
+      magickArgs(cmd, [
+        `${inputPath}[0]`,
+        "-normalize",
+        "-colorspace",
+        "sRGB",
+        `png:${outputPath}`,
+      ]),
       { timeout: 120_000 },
     );
     return await readFile(outputPath);