diff --git a/dist/bundles/mediabunny.cjs b/dist/bundles/mediabunny.cjs
index 1a91660f1f0d24296002c852b44ddfe22ca47143..3e27051639e6d9a44bc6fc616d6719b38ef83ddc 100644
--- a/dist/bundles/mediabunny.cjs
+++ b/dist/bundles/mediabunny.cjs
@@ -2191,10 +2191,11 @@ var Mediabunny = (() => {
       const picWidthInMbsMinus1 = readExpGolomb(bitstream);
       const picHeightInMapUnitsMinus1 = readExpGolomb(bitstream);
       const codedWidth = 16 * (picWidthInMbsMinus1 + 1);
-      const codedHeight = 16 * (picHeightInMapUnitsMinus1 + 1);
+      // Patched (4k-video-upscaler, formats design §1): H.264 §7.4.2.1.1 FrameHeightInMbs = (2 − frame_mbs_only_flag) × PicHeightInMapUnits.
+      const frameMbsOnlyFlag = bitstream.readBits(1);
+      const codedHeight = 16 * (2 - frameMbsOnlyFlag) * (picHeightInMapUnitsMinus1 + 1);
       let displayWidth = codedWidth;
       let displayHeight = codedHeight;
-      const frameMbsOnlyFlag = bitstream.readBits(1);
       if (!frameMbsOnlyFlag) {
         bitstream.skipBits(1);
       }
diff --git a/dist/bundles/mediabunny.mjs b/dist/bundles/mediabunny.mjs
index 12b1c71b5d0e954c06ba36709c05eb4a7a31be61..14b0a7e7871c5fcd2dca13222d11ed1c2bd958a4 100644
--- a/dist/bundles/mediabunny.mjs
+++ b/dist/bundles/mediabunny.mjs
@@ -2034,10 +2034,11 @@ var parseAvcSps = (sps) => {
     const picWidthInMbsMinus1 = readExpGolomb(bitstream);
     const picHeightInMapUnitsMinus1 = readExpGolomb(bitstream);
     const codedWidth = 16 * (picWidthInMbsMinus1 + 1);
-    const codedHeight = 16 * (picHeightInMapUnitsMinus1 + 1);
+    // Patched (4k-video-upscaler, formats design §1): H.264 §7.4.2.1.1 FrameHeightInMbs = (2 − frame_mbs_only_flag) × PicHeightInMapUnits.
+    const frameMbsOnlyFlag = bitstream.readBits(1);
+    const codedHeight = 16 * (2 - frameMbsOnlyFlag) * (picHeightInMapUnitsMinus1 + 1);
     let displayWidth = codedWidth;
     let displayHeight = codedHeight;
-    const frameMbsOnlyFlag = bitstream.readBits(1);
     if (!frameMbsOnlyFlag) {
       bitstream.skipBits(1);
     }
diff --git a/dist/bundles/mediabunny.node.cjs b/dist/bundles/mediabunny.node.cjs
index 47a99909074645a807acbe24f50959efff7a1cc7..728d3bae62a9f468227f5e85a81a7198dbabb9ef 100644
--- a/dist/bundles/mediabunny.node.cjs
+++ b/dist/bundles/mediabunny.node.cjs
@@ -2188,10 +2188,11 @@ var Mediabunny = (() => {
       const picWidthInMbsMinus1 = readExpGolomb(bitstream);
       const picHeightInMapUnitsMinus1 = readExpGolomb(bitstream);
       const codedWidth = 16 * (picWidthInMbsMinus1 + 1);
-      const codedHeight = 16 * (picHeightInMapUnitsMinus1 + 1);
+      // Patched (4k-video-upscaler, formats design §1): H.264 §7.4.2.1.1 FrameHeightInMbs = (2 − frame_mbs_only_flag) × PicHeightInMapUnits.
+      const frameMbsOnlyFlag = bitstream.readBits(1);
+      const codedHeight = 16 * (2 - frameMbsOnlyFlag) * (picHeightInMapUnitsMinus1 + 1);
       let displayWidth = codedWidth;
       let displayHeight = codedHeight;
-      const frameMbsOnlyFlag = bitstream.readBits(1);
       if (!frameMbsOnlyFlag) {
         bitstream.skipBits(1);
       }
diff --git a/dist/modules/src/codec-data.js b/dist/modules/src/codec-data.js
index 88f9e0013df04b1d82679f2ec86818803aa93186..aeb90ac8ca13a27566efab0fe5f05a471f631648 100644
--- a/dist/modules/src/codec-data.js
+++ b/dist/modules/src/codec-data.js
@@ -479,10 +479,11 @@ export const parseAvcSps = (sps) => {
         const picWidthInMbsMinus1 = readExpGolomb(bitstream);
         const picHeightInMapUnitsMinus1 = readExpGolomb(bitstream);
         const codedWidth = 16 * (picWidthInMbsMinus1 + 1);
-        const codedHeight = 16 * (picHeightInMapUnitsMinus1 + 1);
+        // Patched (4k-video-upscaler, formats design §1): H.264 §7.4.2.1.1 FrameHeightInMbs = (2 − frame_mbs_only_flag) × PicHeightInMapUnits.
+        const frameMbsOnlyFlag = bitstream.readBits(1);
+        const codedHeight = 16 * (2 - frameMbsOnlyFlag) * (picHeightInMapUnitsMinus1 + 1);
         let displayWidth = codedWidth;
         let displayHeight = codedHeight;
-        const frameMbsOnlyFlag = bitstream.readBits(1);
         if (!frameMbsOnlyFlag) {
             bitstream.skipBits(1); // mb_adaptive_frame_field_flag
         }
diff --git a/src/codec-data.ts b/src/codec-data.ts
index 25eab4ef23f5da245849f7f4a79c782ae30a4f9f..6a383deb2e5924f6112243a4df73dc62e0e9c87b 100644
--- a/src/codec-data.ts
+++ b/src/codec-data.ts
@@ -637,11 +637,11 @@ export const parseAvcSps = (sps: Uint8Array): AvcSpsInfo | null => {
 		const picWidthInMbsMinus1 = readExpGolomb(bitstream);
 		const picHeightInMapUnitsMinus1 = readExpGolomb(bitstream);
 		const codedWidth = 16 * (picWidthInMbsMinus1 + 1);
-		const codedHeight = 16 * (picHeightInMapUnitsMinus1 + 1);
+		// Patched (4k-video-upscaler, formats design §1): H.264 §7.4.2.1.1 FrameHeightInMbs = (2 − frame_mbs_only_flag) × PicHeightInMapUnits.
+		const frameMbsOnlyFlag = bitstream.readBits(1);
+		const codedHeight = 16 * (2 - frameMbsOnlyFlag) * (picHeightInMapUnitsMinus1 + 1);
 		let displayWidth = codedWidth;
 		let displayHeight = codedHeight;
-
-		const frameMbsOnlyFlag = bitstream.readBits(1);
 		if (!frameMbsOnlyFlag) {
 			bitstream.skipBits(1); // mb_adaptive_frame_field_flag
 		}