Add a testcase

This patch introduces a new WPT verifying that `VideoDecoder` can decode
data without providing an image size during `configure()` step. Although
the issue was initially observed with the VP8 decoder
(FFmpegVideoDecoder via libvpx), the test applies to all supported
codecs, ensuring robust behavior across different decoder
implementations.

Differential Revision: https://phabricator.services.mozilla.com/D232914

bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1928120
gecko-commit: a5f9a1eab5a88273e0a30b3610530bca0c94850e
gecko-reviewers: media-playback-reviewers, alwu

webcodecs/video-decoder-no-size-in-configure.https.any.js

@@ -0,0 +1,77 @@
+// META: global=window,dedicatedworker
+// META: script=/webcodecs/video-encoder-utils.js
+// META: variant=?av1
+// META: variant=?vp8
+// META: variant=?vp9_p0
+// META: variant=?h264_avc
+// META: variant=?h264_annexb
+
+var CODEC = null;
+promise_setup(async () => {
+  CODEC = {
+    '?av1': { codec: 'av01.0.04M.08' },
+    '?vp8': { codec: 'vp8' },
+    '?vp9_p0': { codec: 'vp09.00.10.08' },
+    '?h264_avc': { codec: 'avc1.42001E', avc: { format: 'avc' } },
+    '?h264_annexb': { codec: 'avc1.42001E', avc: { format: 'annexb' } },
+  }[location.search];
+});
+
+promise_test(async t => {
+  let encoderConfig = {
+    ...CODEC,
+    width: 320,
+    height: 240,
+  };
+
+  const encoderSupport = await VideoEncoder.isConfigSupported(encoderConfig);
+  assert_implements_optional(encoderSupport.supported,  `${encoderConfig.codec} encoder is unsupported`);
+
+  let encodedResult;
+  const encoder = new VideoEncoder({
+    output: (chunk, metadata) => {
+      encodedResult = { chunk, metadata };
+    },
+    error: e => {
+      t.unreached_func('Unexpected encoding error: ' + e);
+    },
+  });
+
+  encoderConfig.framerate = 30;
+  encoderConfig.bitrate = 3000000;
+  encoder.configure(encoderConfig);
+
+  let frame = createFrame(encoderConfig.width, encoderConfig.height, 0);
+  encoder.encode(frame);
+  frame.close();
+
+  await encoder.flush();
+  encoder.close();
+
+  let decoderConfig = encodedResult.metadata.decoderConfig;
+  delete decoderConfig.codedWidth;
+  delete decoderConfig.codedHeight;
+  delete decoderConfig.displayAspectWidth;
+  delete decoderConfig.displayAspectHeight;
+
+  const decoderSupport = await VideoDecoder.isConfigSupported(decoderConfig);
+  assert_implements_optional(decoderSupport.supported,  `${decoderConfig.codec} decoder is unsupported`);
+
+  let decodedResult;
+  const decoder = new VideoDecoder({
+    output: frame => {
+      decodedResult = frame;
+    },
+    error: e => {
+      t.unreached_func('Unexpected decoding error: ' + e);
+    },
+  });
+
+
+  decoder.configure(decoderConfig);
+  decoder.decode(encodedResult.chunk);
+  await decoder.flush();
+
+  assert_equals(decodedResult.codedWidth, encoderConfig.width, 'decoded frame width');
+  assert_equals(decodedResult.codedHeight, encoderConfig.height, 'decoded frame height');
+}, 'Test configure() without setting width and height');