diff --git a/gltf/basisenc.cpp b/gltf/basisenc.cpp
index c1080949..c415d2c5 100644
--- a/gltf/basisenc.cpp
+++ b/gltf/basisenc.cpp
@@ -26,15 +26,15 @@ struct BasisSettings
 };
 
 static const BasisSettings kBasisSettings[10] = {
-    {1, 1, 0, 1.5f},
-    {1, 6, 0, 1.f},
-    {1, 20, 1, 1.0f},
-    {1, 50, 1, 0.75f},
-    {1, 90, 1, 0.5f},
-    {1, 128, 1, 0.4f},
-    {1, 160, 1, 0.34f},
-    {1, 192, 1, 0.29f}, // default
-    {1, 224, 2, 0.26f},
+    {1, 1, 0, 4.f},
+    {1, 32, 0, 3.f},
+    {1, 64, 1, 2.f},
+    {1, 96, 1, 1.5f},
+    {1, 128, 1, 1.f}, // quality arguments aligned with basisu defaults
+    {1, 150, 1, 0.8f},
+    {1, 170, 1, 0.6f},
+    {1, 192, 1, 0.4f}, // gltfpack defaults
+    {1, 224, 2, 0.2f},
     {1, 255, 2, 0.f},
 };
 
diff --git a/tools/bitmask.py b/tools/bitmask.py
old mode 100755
new mode 100644
diff --git a/tools/gltfbasis.py b/tools/gltfbasis.py
new file mode 100644
index 00000000..9fc88166
--- /dev/null
+++ b/tools/gltfbasis.py
@@ -0,0 +1,77 @@
+#!/usr/bin/python3
+
+import argparse
+import concurrent.futures
+import matplotlib.pyplot as plt
+import os
+import os.path
+import re
+import subprocess
+
+argp = argparse.ArgumentParser()
+argp.add_argument('--basisu', type=str, required=True)
+argp.add_argument('--graph', type=str, default="basisu.png")
+argp.add_argument('--etcbase', action='store_true')
+argp.add_argument('files', type=str, nargs='+')
+args = argp.parse_args()
+
+def compress(path, flags):
+    temp_path = "/dev/null" if os.name == "posix" else "NUL"
+    output = subprocess.check_output([args.basisu, "-file", path, "-output_file", temp_path, "-stats", "-ktx2"] + flags)
+    for line in output.splitlines():
+        if m := re.match(r".*source image.*?(\d+)x(\d+)", line.decode()):
+            pixels = int(m.group(1)) * int(m.group(2))
+        elif m := re.match(r".*Compression succeeded.*size (\d+) bytes", line.decode()):
+            bytes = int(m.group(1))
+        elif m := re.match(r"\.basis RGB Avg:.*RMS: (\d+\.\d+) PSNR: (\d+\.\d+)", line.decode()):
+            rms = float(m.group(1))
+            psnr = float(m.group(2))
+
+    return {'path': path, 'bpp': bytes * 8 / pixels, 'rms': rms, 'psnr': psnr}
+
+def stats(path):
+    with concurrent.futures.ThreadPoolExecutor(16) as executor:
+        futures = []
+        for i in range(0, 26):
+            rdo_l = i / 5
+            flags = ["-uastc", "-uastc_level", "1", "-uastc_rdo_l", str(rdo_l), "-uastc_rdo_d", "1024"]
+            futures.append((executor.submit(compress, path, flags), rdo_l))
+        concurrent.futures.wait([f for (f, r) in futures])
+        results = []
+        bppbase = 0
+        for future, rdo_l in futures:
+            res = future.result()
+            if rdo_l == 0:
+                bppbase = res['bpp']
+            res['rdo_l'] = rdo_l
+            res['ratio'] = res['bpp'] / bppbase
+            results.append(res)
+        return results
+
+fields = ['bpp', 'rms', 'psnr', 'ratio']
+fig, axs = plt.subplots(1, len(fields) + 1, layout='constrained')
+fig.set_figwidth(5 * (len(fields) + 1))
+lines = []
+
+for path in args.files:
+    print('Processing', path)
+    results = stats(path)
+    etcbase = compress(path, ["-q", "192"]) if args.etcbase else None
+
+    for idx, field in enumerate(fields):
+        line, = axs[idx].plot([r['rdo_l'] for r in results], [r[field] for r in results])
+        if etcbase and field in etcbase:
+            axs[idx].axhline(etcbase[field], color=line.get_color(), linestyle='dotted')
+        if idx == 0:
+            lines.append(line)
+
+    axs[len(fields)].scatter([r['ratio'] for r in results], [r['psnr'] for r in results], color=line.get_color())
+
+for idx, field in enumerate(fields):
+    axs[idx].set_title(field)
+
+axs[len(fields)].set_title('psnr vs ratio')
+
+fig.legend(lines, [os.path.basename(path) for path in args.files], loc='outside right upper')
+
+plt.savefig(args.graph)