Use the correct stream bitrate for strict min/max rates

src/encode.moon

@@ -341,9 +341,10 @@ encode = (region, startTime, endTime) ->
 
 			if options.strict_filesize_constraint
 				type = format.videoCodec != "" and "ovc" or "oac"
+				strict_bitrate = format.videoCodec != "" and video_bitrate or audio_bitrate
 				append(command, {
-					"--#{type}opts-add=minrate=#{bitrate}k",
-					"--#{type}opts-add=maxrate=#{bitrate}k",
+					"--#{type}opts-add=minrate=#{strict_bitrate}k",
+					"--#{type}opts-add=maxrate=#{strict_bitrate}k",
 				})
 		else
 			type = format.videoCodec != "" and "ovc" or "oac"

tests/testcases/test_strict_filesize.py

@@ -0,0 +1,33 @@
+from .base_test_case import BaseTestCase
+
+
+class TestStrictFilesize(BaseTestCase):
+    def checkEncode(self, output_format):
+        if output_format == "mp3":
+            source = self.tempdir / "tone.wav"
+            self.runTool("ffmpeg", "-v", "error", "-f", "lavfi", "-i",
+                         "sine=frequency=440:duration=2", str(source))
+            target, end, expected, stream, extension = 32, 2, 128, "oac", "mp3"
+        else:
+            source = self.createVideo()
+            target, end, expected, stream, extension = 100, 1, 800, "ovc", "mp4"
+        self.openTestVideoFile(source)
+        self.encodeClip(0, end, options={
+            "output_format": output_format, "target_filesize": target,
+            "strict_filesize_constraint": True, "twopass": False,
+            "output_template": "strict",
+        })
+        output = self.tempdir / ("strict." + extension)
+        self.assertGreater(output.stat().st_size, 100)
+        self.assertTrue(self.probeVideo(output)["streams"])
+        self.waitUntil(lambda: "Command line:" in self.getLog(), "encoder command log")
+        command = next(line for line in self.getLog().splitlines() if "Command line:" in line)
+        for option in ("b", "minrate", "maxrate"):
+            self.assertIn(f"--{stream}opts-add={option}={expected}k", command)
+        self.assertNotIn("nilk", command)
+
+    def test_video_strict_bitrate(self):
+        self.checkEncode("avc")
+
+    def test_audio_only_strict_bitrate(self):
+        self.checkEncode("mp3")